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PAMS Application Programming Interface
Because the BEA MessageQ application programming interface (API) is portable, the API is documented once for all supported platforms. This chapter describes all BEA MessageQ callable services in alphabetical order using a standard description -format.
BEA MessageQ API Description Format
The beginning of each description contains the entry-point name and a brief description of the function performed. Table 8-1 describes the sections in the description of each callable service.
In the section entitled . . . |
You will find . . . |
---|---|
Syntax |
The syntax for using the callable service with the entry-point name and argument list. Square brackets ([ ]) indicate optional arguments to the service. |
Arguments |
The data type, passing mechanism, C language prototype, and access for each argument. |
Argument Definitions |
Detailed information on how to specify each argument. |
Description |
More detailed information on how to use the callable service. |
Return Values |
The return codes with the platforms on which they are supported. |
See Also |
A list of related callable services. |
Example |
A sample program illustrating the use of the callable service. These sample programs are available in the examples directory of the BEA MessageQ media kit. |
BEA MessageQ API arguments use data types defined by the C programming language and some data types defined by BEA MessageQ software. Data types such as short, -unsigned short, and char are data types defined by the C programming language. BEA MessageQ data types such as q_address and the PSB and show_buffer structures are defined in the p_entry.h include file.
BEA MessageQ supports data type definitions for signed and -unsigned longwords. The int32 data type defined by BEA MessageQ is a 32-bit signed integer. The int32 data type replaces the use of the integer data type long, the size of which is operating system dependent. The int32 data type definition guarantees a consistent definition across all platforms and was added to accommodate next generation 64-bit architectures such as Compaq's Alpha AXP systems. The uint32 data type designates a 32-bit unsigned integer and replaces the use of unsigned long.
Note: The int32 and uint32 data type definitions are not available on BEA MessageQ Version 2.0 platforms. BEA MessageQ Version 2.0 software uses the standard signed longword and unsigned longword data types defined by the C programming language.
pams_attach_q
Connects an application program to the BEA MessageQ message queuing bus by attaching it to a message queue. An application must successfully execute this function before it can send and receive messages. When an application uses this function to attach to a queue, it becomes the owner of the queue. Only one application program can attach to a primary queue and read messages from it. When an application attaches to a permanent primary queue defined with secondary queue attachments, the secondary queues are also attached by this function.
Syntax
int32 pams_attach_q ( attach_mode, q_attached, [q_type], [q_name],
[q_name_len], [name_space_list], [name_space_list_len], [timeout],
[nullarg_2], [nullarg_3] )
Arguments
Argument |
Data Type |
Mechanism |
Prototype |
Access |
---|---|---|---|---|
attach_mode |
int32 |
reference |
int32 * |
passed |
q_attached |
q_address |
reference |
q_address * |
returned |
[q_type] |
int32 |
reference |
int32 * |
passed |
[q_name] |
char |
reference |
char * |
passed |
[q_name_len] |
int32 |
reference |
int32 * |
passed |
[name_space_list] |
int32 array |
reference |
int32 array * |
passed |
[name_space_list_len] |
int32 |
reference |
int32 * |
passed |
[timeout] |
int32 |
reference |
int32 * |
passed |
[nullarg_2] |
char |
reference |
char * |
passed |
[nullarg_3] |
char |
reference |
char * |
passed |
Supplies the mode for attaching the application to a message queue. The three predefined constants for this argument are:
When attach_mode is PSYM_ATTACH_BY_NAME, the application attaches to the queue identified by the specified queue or alias name. BEA MessageQ finds the queue by implicitly performing a pams_locate_q call for the specified q_name. The procedure that BEA MessageQ uses is determined by the name_space_list argument.
Receives the queue address from BEA MessageQ when an application has successfully attached to a message queue.
Supplies the queue type for the attachment. The two predefined constants for this argument are:
Supplies the name or number of the permanent queue to attach to the application if the attach_mode argument specifies attachment by queue name or queue number. Queue names are alphanumeric strings with no embedded spaces and allow the following special characters: underscore (_), hyphen (-), and dollar sign ($).
References to queue names are case sensitive and must match the queue name entered in the group initialization file. Some example queue names are: QUEUE_1, high-priority, and My$Queue.
The q_name argument has the following dependencies with the attach_mode argument:
Supplies the number of characters in the q_name argument. The maximum string length on UNIX, Windows NT, and OpenVMS servers is 255 characters. For all other BEA MessageQ environments, the maximum string length is 31.
Supplies a list of name tables to search when the attach_mode argument PSYM_ATTACH_BY_NAME is specified.
If the name_space_list is specified, then the name_space_list_len argument must also be specified. If this argument is unspecified, then PSEL_TBL_GRP is the default.
Possible values in a name_space_list argument are as follows:
Location It Represents |
Symbolic Value |
---|---|
Process cache |
PSEL_TBL_PROC |
Group/group cache |
PSEL_TBL_GRP |
Global name space |
PSEL_TBL_BUS ( or PSEL_TBL_BUS_MEDIUM or PSEL_TBL_BUS_LOW) |
The name_space_list argument identifies the scope of the name as follows:
The name_space_list argument also controls the cache access as follows.
To lookup all caches in the global name space before looking in the master database, specify PSEL_TBL_BUS_LOW instead of PSEL_TBL_BUS.
To lookup only the slower but more up-to-date caches in the global name space before looking in the master database, specify PSEL_TBL_BUS_MEDIUM instead of PSEL_TBL_BUS.
For more information on dynamic binding of queue addresses, see the Using Naming topic.
Supplies the number of entries in the name_space_list argument. If the name_space_list_len argument is zero, BEA MessageQ uses PSEL_TBL_GRP as the default in the name_space_list argument.
The number of PAMS time units (1/10 second intervals) to allow for the attach to complete. If a zero is specified, the group's ATTACH_TMO property is used. If the ATTACH_TMO property is also zero, 600 is used.
Reserved for BEA MessageQ internal use as a placeholder argument. This argument must be supplied as a null pointer.
Reserved for BEA MessageQ internal use as a placeholder argument. This argument must be supplied as a null pointer.
Description
Before an application can use the pams_attach_q function, the BEA MessageQ message queuing bus must be configured. A BEA MessageQ message queuing bus is a collection of one or more BEA MessageQ message queuing groups. A message queuing group is a collection of message queues that reside on a system, share global memory sections and files, and are served by the same server processes. A BEA MessageQ message queue is an area of memory or disk where messages are stored and retrieved. See the installation and configuration guide for the platform you are using to learn how to configure the BEA MessageQ environment.
To receive BEA MessageQ messages, an application must attach to at least one message queue. The pams_attach_q function enables an application to attach in the following ways:
Applications can specify an attachment as primary or secondary. All applications must have a primary queue. In addition, applications can attach to one or more secondary queues. Primary queues can be configured in the group definition as the owners of secondary queues. When an application attaches to a primary queue that is the owner of secondary queues, the application is automatically attached to the secondary queues at the same time it is attached to the primary queue.
In addition, an application can attach to a multireader queue. A multireader queue can be read by many applications and is configured as part of the group definition.
Return Values
Return Code |
Platform |
Description |
---|---|---|
PAMS__BADARGLIST |
OpenVMS |
Wrong number of call arguments has been passed to this function. |
PAMS__BADDECLARE |
All |
Queue has already been attached to this application. |
PAMS__BADNAME |
All |
Invalid name string was specified. |
PAMS__BADPARAM |
All |
Invalid argument in the argument list. |
PAMS__BADPROCNUM |
All |
Queue number out of range. |
PAMS__BADQTYPE |
All |
Invalid queue type. |
PAMS__BADTMPPROC |
OpenVMS |
Invalid temporary queue number. |
PAMS__DECLARED |
All |
The queue number is already attached to another application or process. |
PAMS__DUPLQNAME |
OpenVMS |
Duplicate queue name. |
PAMS__NETERROR |
Clients |
Network error resulted in a communications link abort. |
PAMS__NOACCESS |
All |
No access to the resource. The address of the specified name is either 0 or it is in another group. |
PAMS__NOACL |
All |
The queue access control file could not be found. |
PAMS__NOOBJECT |
All |
No such queue name. For a global queue reference, this error can be caused by a bad default pathname in the group configuration file. |
PAMS__NOQUOTA |
OpenVMS |
Insufficient receive message or byte quota to attach. |
PAMS__NOTBOUND |
All |
The queue name is not bound to an address. |
PAMS__NOTMRQ |
OpenVMS |
Attempting to attach to Multi-reader Queue and queue type is not an MRQ. |
PAMS__NOTPRIMARYQ |
All |
Queue name or number is not a primary queue. |
PAMS__NOTSECONDARYQ |
All |
Queue name or number is not a secondary queue. |
PAMS__PAMSDOWN |
All |
The specified BEA MessageQ group is not running. |
PAMS__PREVCALLBUSY |
Clients |
The previous call to CLS has not been completed. |
PAMS__PNUMNOEXIST |
OpenVMS |
Target queue name or number does not exist. |
PAMS__RESRCFAIL |
All |
Failed to allocate resources. |
PAMS__SUCCESS |
All |
Successful completion of an action. |
PAMS__TIMEOUT |
All |
The timeout period specified has expired. |
Dynamically associates a queue address to a queue reference at run-time. This enables a server application to dynamically sign up to service a queue alias at run-time. Thus, an end user can access a service without having to be aware that its normal host computer is down and that the service is being provided from another host computer.
Syntax
int32 pams_bind_q (q_addr, q_alias, q_alias_len, [name_space_list],
[name_space_list_len], [timeout], [nullarg_1]);
Arguments
Argument |
Data Type |
Mechanism |
Prototype |
Access |
---|---|---|---|---|
q_addr |
q_address |
reference |
q_address * |
passed |
q_alias |
char |
reference |
char * |
passed |
q_alias_len |
int32 |
reference |
int32 * |
passed |
[name_space_list] |
int32 array |
reference |
int32 array * |
passed |
[name_space_list_len] |
int32 |
reference |
int32 * |
passed |
[timeout] |
int32 |
reference |
int32 * |
passed |
[nullarg_1] |
char |
reference |
char * |
passed |
The value specified to this argument controls whether the queue address is bound or unbound:
Identifies a global queue reference or a local queue reference. The procedure that BEA MessageQ uses to find this alias is controlled by the name_space_list argument, which is described below.
Specifies the number of characters in q_alias.
If specified, identifies a one-entry list containing either PSEL_TBL_BUS or PSEL_TBL_GRP.
To identify a local queue reference, an application must have a name space list of PSEL_TBL_GRP and pass its name in the q_alias argument. To identify a global queue reference, an application must have a name space list of PSEL_TBL_BUS and specify its pathname, either explicitly or implicitly:
For more information on dynamic binding of queue addresses, see the Using Naming topic.
Specifies the number of entries in name_space_list argument. The number of entries is either 0 or 1. If the number of entries is 0 (indicating that the name_space_list is omitted), PSEL_TBL_GRP is assumed.
Specifies the number of PAMS time units (1/10 second intervals) to allow for the bind to complete. If 0 is specified, the group's ATTACH_TMO property is used. If the ATTACH_TMO property is also 0, 600 is used.
Reserved for BEA MessageQ internal use as a placeholder argument. This argument must be supplied as a null pointer.
Description
Before an application can call pams_bind_q, it must be attached to the specified queue address. Listing 8-1 shows an attach before the bind call and is typical usage of the two functions together:
Listing 8-1 Example of Using pams_bind_q
int32 mode = PSYM_ATTACH_BY_NUMBER;
int32 q_type = PSYM_ATTACH_PQ;
int32 len=1;
int32 status;
q_address qid;
status = pams_attach_q(&mode,&qid,&q_type,"2",&len,0,0,0,0,0);
if (status == PAMS__SUCCESS {
int32 ns=PSEL_TBL_BUS;
int32 ns_len=1;
len = strlen("Q2");
status = pams_bind_q(&qid,"Q2",&len,&ns,&ns_len,0,0);
}
Return Values
Return Code |
Platform |
Description |
---|---|---|
PAMS__BADARGLIST |
All |
Invalid number of call arguments. |
PAMS__BADNAME |
All |
Name contains bad characters. |
PAMS__BADPARAM |
All |
The name space list is invalid. |
PAMS__BOUND |
All |
Returned if a non-zero value for q_addr is passed and the specified q_alias is already assigned to a queue address. |
PAMS__DUPLQNAME |
All |
Duplicate queue name. |
PAMS__FAIL |
All |
Operation failed. |
PAMS__NOACCESS |
All |
No access to the resource. The address of the specified name is either 0 or it is in another group. |
PAMS__NOOBJECT |
All |
For a global reference, this error can be caused by a bad default pathname in the group configuration file. |
PAMS__NOTBOUND |
All |
The queue name is not bound to an address. |
PAMS__NOTDCL |
All |
Not attached to BEA MessageQ. |
PAMS__PAMSDOWN |
All |
The specified BEA MessageQ group is not running. |
PAMS__SUCCESS |
All |
Indicates successful completion. |
PAMS__TIMEOUT |
All |
The timeout period specified has expired. In this situation, BEA MessageQ internally unbinds the specified queue alias. Subsequent pams_bind_q calls to the same name will return the PAMS__UNBINDING error until the internal unbind succeeds. |
PAMS__UNBINDING |
All |
The bind cannot be done because BEA MessageQ is still in the process of has unbinding the old binding. |
The pams_bind_q example illustrates how to bind a queue reference to a queue address at runtime. The complete code example called x_bind.c is contained in the examples directory.
pams_cancel_get
Cancels all pending pams_get_msga requests that match the value specified in the sel_filter argument. When a pending pams_get_msga request is canceled, the PAMS Status Block (PSB) delivery status is set to PAMS__CANCEL and the specified action routine is queued. The pams_cancel_get function waits until completion to allow for proper synchronization between the pams_cancel_get function and the request for pams_get_msga functions. Any outstanding pams_get_msga function requests are canceled by the pams_exit function or at image exit.
Syntax
int32 pams_cancel_get ( sel_filter )
Arguments
Argument |
Data Type |
Mechanism |
Prototype |
Access |
---|---|---|---|---|
sel_filter |
int32 |
reference |
int32 * |
passed |
Supplies the criteria that enables the application to selectively cancel outstanding pams_get_msga requests. For a description of the sel_filter argument, see the pams_get_msg function. For a description of how to create a complex selection filter, see the pams_set_select function.
Return Values
Return Code |
Platform |
Description |
---|---|---|
PAMS__BADARGLIST |
OpenVMS |
Argument list is invalid. |
PAMS__SUCCESS |
OpenVMS |
Indicates successful completion. |
SS$_EXQUOTA |
OpenVMS |
Process has exceeded its asynchronous system trap (AST) quota. |
Releases the selection array and index handle associated with a previously generated selection mask. An index_handle and associated selection mask are created using the pams_set_select function. When the selection mask is used in the OpenVMS environment with asynchronous read requests, this function also cancels any pending pams_get_msga requests that use the referenced index_handle.
Syntax
int32 pams_cancel_select ( index_handle )
Arguments
Argument |
Data Type |
Mechanism |
Prototype |
Access |
---|---|---|---|---|
index_handle |
int32 |
reference |
int32 * |
passed |
Supplies the index handle of the selection mask to cancel. The index_handle is returned by the pams_set_select function.
Return Values
Return Code |
Platform |
Description |
---|---|---|
PAMS__BADARGLIST |
OpenVMS |
Invalid number of call arguments. |
PAMS__BADPARAM |
UNIX |
The value of the selection index is null. |
PAMS__BADSELIDX |
All |
Invalid or undefined selective receive index. |
PAMS__NETERROR |
Clients |
Network error resulted in a communications link abort. |
PAMS__NOTDCL |
All |
Process has not been attached to BEA MessageQ. |
PAMS__PAMSDOWN |
UNIX |
The specified BEA MessageQ group is not running. |
PAMS__PREVCALLBUSY |
Clients |
Previous call to CLS has not been completed. |
PAMS__SUCCESS |
All |
Indicates successful completion. |
Deletes the BEA MessageQ timer identified by the timer_id argument that is passed to this function. All expired timers with the selected identification code that are waiting in the message queue are purged and are not delivered.
Syntax
int32 pams_cancel_timer ( timer_id )
Arguments
Argument |
Data Type |
Mechanism |
Prototype |
Access |
---|---|---|---|---|
timer_id |
int32 |
reference |
int32 * |
passed |
Supplies the timer ID of the timer to cancel. The timer_id is returned by the pams_set_timer function.
Return Values
Return Code |
Platform |
Description |
---|---|---|
PAMS__BADARGLIST |
OpenVMS |
Invalid number of arguments. |
PAMS__BADPARAM |
All |
The timer_id argument was specified as null. |
PAMS__INVALIDNUM |
All |
The application has supplied an invalid value for the timer_id. |
PAMS__NETERROR |
Clients |
Network error resulted in a communications link abort. |
PAMS__NOTDCL |
All |
The application has not attached to a queue. |
PAMS__PAMSDOWN |
UNIX |
The specified BEA MessageQ group is not running. |
PAMS__PREVCALLBUSY |
Clients |
Previous call to CLS has not been completed. |
PAMS__RESRCFAIL |
All |
Insufficient resources to complete the operation. |
PAMS__SUCCESS |
All |
Indicates successful completion. |
Closes the MRS journal file associated with the jrn_handle argument. The two types of journal files are dead letter journal (DLJ) and postconfirmation journal (PCJ). See Using Recoverable Messaging for a description of how to use the BEA MessageQ message recovery system.
Syntax
int32 pams_close_jrn ( jrn_handle )
Arguments
Argument |
Data Type |
Mechanism |
Prototype |
Access |
---|---|---|---|---|
jrn_handle |
int32 |
reference |
int32 * |
passed |
Supplies the journal handle of the message recovery journal file to close. The jrn_handle is returned by the pams_open_jrn function.
Return Values
Return Code |
Platform |
Description |
---|---|---|
PAMS__BADARGLIST |
OpenVMS |
Invalid number of arguments. |
PAMS__INVJH |
OpenVMS |
The application has supplied an invalid journal handle. |
PAMS__SUCCESS |
OpenVMS |
Indicates successful completion. |
Confirms receipt of a message that requires explicit confirmation. This can be a recoverable message sent to a queue that is configured for explicit confirmation or a message sent using the ACK delivery mode which must be explicitly confirmed upon receipt. Applications should examine the PSB status field of each message received to determine if the message requires explicit confirmation.
When a recoverable message is received, the application must call the pams_confirm_msg function in order to delete it from the message recovery journal disk storage. If receipt of a recoverable message is not confirmed, the message continues to be stored by the recovery system and will be redelivered if the application detaches and then reattaches to the queue.
BEA MessageQ can confirm receipt of a recoverable message automatically when the next consecutive message in the recovery journal is delivered. This feature is called implicit confirmation.
All queues must be configured for implicit or explicit confirmation. For complete information on how to configure message queues, see the installation and configuration guide for your system.
Successfully delivered recoverable messages can be recorded in the postconfirmation journal (PCJ). The pams_confirm_msg function uses the force_j argument to write messages to the PCJ file if the system is not currently configured to store them. Note that successfully delivered recoverable messages cannot be written to the PCJ file unless they are explicitly confirmed using the pams_confirm_msg function.
Syntax
int32 pams_confirm_msg ( msg_seq_num, confirmation_status,
force_j )
Arguments
Argument |
Data Type |
Mechanism |
Prototype |
Access |
---|---|---|---|---|
msg_seq_num |
uint32 array |
reference |
uint32 array * |
passed |
confirmation_status |
int32 |
reference |
int32 * |
passed |
force_j |
char |
reference |
char * |
passed |
Argument Definitions
Supplies the message sequence number of the recoverable message being confirmed. The message sequence number is generated by the BEA MessageQ message recovery system for each recoverable message. This value is passed to the receiver program in the PSB of the pams_get_msg function when it reads each recoverable message.
Supplies the confirmation status value stored with the message in the postconfirmation journal (PCJ) file. The value is set by the calling application. See the Using Recoverable Messaging topic for more information on using the PCJ file.
Supplies the journaling action for this message. Following are the predefined constants for this argument:
Symbol |
Description |
---|---|
PDEL_DEFAULT_JRN |
Enables writing the message to the PCJ file if the journaling is configured in the group initialization file. |
PDEL_FORCE_JRN |
Enables writing to the PCJ only if journaling is configured. It is not possible to write messages to the PCJ on UNIX and Windows NT systems if a path was not defined for the PCJ in the group configuration information. |
PDEL_NO_JRN |
Disables journaling regardless of whether journaling is configured. |
The PSB status codes associated with recoverable message delivery are
PAMS__CONFIRMREQ and PAMS__POSSDUPL. The PAMS__CONFIRMREQ PSB status code indicates that it is the first time the application received the recoverable message. The PAMS__POSSDUPL status code indicates that the message was retrieved from the recovery journal and may have been sent previously. This status code allows the application to take extra precautions to handle duplicate messages if necessary.
The PSB also contains a sequence number that uniquely identifies the message. The pams_confirm_msg function requires this sequence number. If one of these status codes is present and the pams_confirm_msg function is not called, the message will continue to be stored by the message recovery system and will be delivered again if the application exits and then reattaches.
Return Values
Return Code |
Platform |
Description |
---|---|---|
PAMS__BADARGLIST |
OpenVMS |
Invalid number of arguments. |
PAMS__BADPARAM |
All |
Bad argument value. |
PAMS__BADSEQ |
All |
Journal sequence number is not known to the Message Recovery Services (MRS). |
PAMS__DQF_DEVICE_FAIL |
OpenVMS |
I/O error writing to the destination queue file for the target queue. |
PAMS__NETERROR |
Clients |
Network error resulted in a communications link abort. |
PAMS__NOMRS |
All |
MRS is not available. |
PAMS__NOTDCL |
All |
Process is not attached to BEA MessageQ. |
PAMS__NOTJRN |
All |
Message is not written to the PCJ file. |
PAMS__NOTSUPPORTED |
OpenVMS |
Attached to the dead letter queue. |
PAMS__PAMSDOWN |
UNIX |
The specified BEA MessageQ group is not running. |
PAMS__PREVCALLBUSY |
Clients |
Previous call to CLS has not been completed. |
PAMS__RESRCFAIL |
OpenVMS |
BEA MessageQ resources exhausted. |
PAMS__SUCCESS |
All |
Indicates successful completion. |
Confirm Receipt of Recoverable Messages
This example demonstrates using recoverable messaging. It attaches to queue_1, puts some recoverable messages to queue_2, exits, attaches to queue_2, gets the messages, prints them out, then exits.
The queues named "queue_1" and "queue_2" are defined in your initialization file. On OpenVMS systems, you must set up a DQF for queue_2. The complete code example called x_recovr.c is contained in the examples directory.
pams_detach_q
Detaches a selected message queue or all of the application's message queues from the message queuing bus. When an application detaches from its primary queue, this function automatically detaches all secondary queue attachments defined for the primary queue. When the last message queue has been detached, the application is automatically detached from the BEA MessageQ message queuing bus.
Syntax
int32 pams_detach_q ( q, detach_opt_list, detach_opt_len,
msgs_flushed )
Arguments
Argument |
Data Type |
Mechanism |
Prototype |
Access |
---|---|---|---|---|
q |
q_address |
reference |
q_address * |
passed |
detach_opt_list |
int32 array |
reference |
int32 * |
passed |
detach_opt_len |
int32 |
reference |
int32 * |
passed |
msg_flushed |
int32 |
reference |
int32 * |
returned |
Argument Definitions
Supplies the queue address of the queue to be detached. This function can be used to detach primary, secondary, and multireader queues.
Supplies an array of int32 values used to control how the queue is detached. The predefined constants for this argument are:
Supplies the number of int32 values in the detach_opt_list array. The maximum number of int32 longwords is 32,767.
Receives the number of messages that were flushed from the queue. Message count statistics are enabled on all systems by default; therefore, it is not necessary to enable statistics on UNIX and Windows NT systems in order to properly return this value.
Description
If you are using implicit confirmation with recoverable messaging, you must ensure that the last message is confirmed before:
If you do not ensure that the last message was confirmed before detaching or exiting, the message will be redelivered when the queue is reattached. The easiest method to ensure confirmation is to save the PSB delivery status of the last message received, check it for the required confirmation status, and then exit after the message has been confirmed.
Return Values
Return Code |
Platform |
Description |
---|---|---|
PAMS__BADARGLIST |
OpenVMS |
Invalid number of arguments. |
PAMS__BADPARAM |
All |
Invalid detach_opt_list. |
PAMS__DETACHED |
All |
Process has detached from BEA MessageQ. |
PAMS__NETERROR |
Clients |
Network error resulted in a communications link abort. |
PAMS__NOTDCL |
All |
Not attached to BEA MessageQ. |
PAMS__PREVCALLBUSY |
Clients |
Previous call to CLS has not been completed. |
PAMS__PNUMNOEXIST |
All |
Invalid queue address or queue not owned by process. |
PAMS__SUCCESS |
All |
Queue successfully detached. |
Terminates all attachments between the application and the BEA MessageQ message queuing bus. All pending messages in temporary queues and permanent queues which are not permanently active multi-reader queues are discarded. Only the messages pending in permanently active multi-reader queues are retained. To retain messages in permanently active queues, call pams_detach_q with option PSYM_NOFLUSH_Q before calling pams_exit.
Syntax
int32 pams_exit (void)
Arguments
None.
Description
If you are using implicit confirmation with recoverable messaging, you must ensure that the last message is confirmed before:
If you do not ensure that the last message was confirmed before detaching or exiting, the message will be redelivered when the queue is reattached. The easiest method to ensure confirmation is to save the PSB delivery status of the last message received, check it for the required confirmation status, and then exit after the message has been confirmed.
Return Values
Return Code |
Platform |
Description |
---|---|---|
PAMS__NETERROR |
OpenVMS Client |
Network error resulted in a communications link abort. |
PAMS__NOTDCL |
OpenVMS |
Not attached to BEA MessageQ. |
PAMS__PREVCALLBUSY |
OpenVMSClient |
Previous call to CLS has not been completed. |
PAMS__PNUMNOEXIST |
OpenVMS |
Invalid queue address or queue not owned by process. |
PAMS__SUCCESS |
All |
Indicates successful completion. |
Exit the Message Queuing Bus
This example shows how to use the pams_exit function. The complete code example called x_exit.c is contained in the examples directory.
pams_get_msg
Retrieves the next available message from a selected queue and moves it to the location specified in the msg_area argument. When no selection filter is specified, the function returns the next available message in first-in/first-out (FIFO) order based on message priority to the buffer specified in the msg_area argument. Priority ranges from 0 (lowest priority) to 99 (highest priority). For example, priority 1 messages are always placed before priority 0 messages. Messages are placed in first-in/first out order by message priority. If a selection filter is specified, then only messages that meet the selection criteria are retrieved. If no messages are available or meet the selection criteria, then the return status is PAMS__NOMOREMSG.
Applications should check the PSB status field of each message to determine if the message was sent with a recoverable delivery mode. If an application receives a recoverable message, it must call the pams_confirm_msg function to delete it from the message recovery journal disk storage. If receipt of a recoverable message is not confirmed, the message continues to be stored by the recovery system and will be redelivered if the application detaches and then reattaches to the queue.
The receiver program determines whether each message is a FML32 buffer or large message by reading the msg_area_len argument. See the Sending and Receiving BEA MessageQ Messages topic for more information on working with FML32 buffers and large messages.
Syntax
int32 pams_get_msg ( msg_area, priority, source, class, type,
msg_area_len, len_data, [sel_filter], [psb],
[show_buffer], [show_buffer_len], [large_area_len],
[large_size], [nullarg_3] )
Arguments
Argument |
Data Type |
Mechanism |
Prototype |
Access |
---|---|---|---|---|
msg_area |
char |
reference |
char * |
returned |
priority |
char |
reference |
char * |
passed |
source |
q_address |
reference |
q_address * |
returned |
class |
short |
reference |
short * |
returned |
type |
short |
reference |
short * |
returned |
msg_area_len |
short |
reference |
short * |
passed |
len_data |
short |
reference |
short* |
returned |
[sel_filter] |
int32 |
reference |
int32 * |
passed |
[psb] |
struct psb |
reference |
struct psb * |
returned |
[show_buffer] |
struct show_buffer |
reference |
struct |
returned |
[show_buffer_len] |
int32 |
reference |
int32 * |
passed |
[large_area_len] |
int32 |
reference |
int32 * |
passed/ |
[large_size] |
int32 |
reference |
int32 * |
returned |
[nullarg_3] |
char |
reference |
char* |
passed |
For static buffer-style messaging, receives the address of a memory region where BEA MessageQ writes the contents of the retrieved message. For FML-style messaging or when using double pointers, receives a pointer to the address of the message being retrieved.
Supplies the priority level for selective message reception. Priority ranges from 0 (lowest priority) to 99 (highest priority). If the priority is set to 0, the pams_get_msqw function gets messages of any priority. If the priority is set to any value from 1 to 99, the pams_get_msqw function gets only messages of that priority.
Receives a data structure containing the group ID and queue number of the sender program's primary queue in the following format:
Receives the class code of the retrieved message. The class is specified in the pams_put_msg function. BEA MessageQ supports the use of symbolic names for class argument values. Symbolic class names should begin with MSG_CLAS_. For information on defining class symbols, see the p_typecl.h include file. On UNIX and Windows NT systems, the p_typecl.h include file cannot be edited. You must create an include file to define type and class symbols for use by your application.
Class symbols reserved by BEA MessageQ are as follows:
Reserved Class |
Symbol Value |
---|---|
MSG_CLAS_MRS |
28 |
MSG_CLAS_PAMS |
29 |
MSG_CLAS_ETHERNET |
100 |
MSG_CLAS_UCB |
102 |
MSG_CLAS_TUXEDO |
31001 |
MSG_CLAS_TUXEDO_TPSUCCESS |
31002 |
MSG_CLAS_TUXEDO_TPFAIL |
31003 |
MSG_CLAS_XXX |
30000 through 32767 (except 31001-31003) |
Receives the type code of the retrieved message. The type is specified in the pams_put_msg function. BEA MessageQ supports the use of symbolic names for type argument values. Symbolic type names begin with MSG_TYPE_. For specific information on defining type symbols, see the p_typecl.h include file.
BEA MessageQ has reserved the symbol value range -1 through -5000. A zero value for this argument indicates that no processing by message type is expected.
For static buffer-style messaging with messages of up to 32767 bytes, this argument receives the number of bytes retrieved from the message queue and stored in the area specified by the msg_area argument. This field also receives the PSYM_MSG_BUFFER_PTR symbol for double buffer and FML-style messages and PSYM_MSG_LARGE for buffer-style messages larger than 32767 bytes.
Supplies the criterion to enable the application to selectively retrieve messages. The argument contains one of the following selection criteria:
The sel_filter argument is composed of two words as follows:
Enables applications to read messages from the queue based on the order in which they arrived. The default selection, PSEL_DEFAULT, reads the next pending message from the message queue. Messages are stored by priority and then in FIFO order. To specify this explicitly, both words in the sel_filter argument should be set to 0.
Allows the application to retrieve messages based upon a queue type or combination of queue types. This selection criteria is used to retrieve the first pending message that matches the criteria on the first queue it encounters. FIFO ordering is maintained within each queue. The predefined constants for this argument are as follows:
Select Mode |
Select Variable |
Mode Description |
---|---|---|
PSEL_PQ |
0 |
Enables the application to read from the primary queue (PQ) only. The select variable must equal 0. |
PSEL_AQ |
Alternate queue number |
Enables an application to read from an alternate queue (AQ) only. The queue type can be a secondary queue (SQ). |
PSEL_PQ_AQ |
Alternate queue number |
Attempts to selectively retrieve from a primary queue and then from an alternate queue. |
PSEL_AQ_PQ |
Alternate queue number |
Attempts to selectively retrieve from an alternate queue and then from a primary queue. |
PSEL_TQ_PQ |
Alternate queue number |
Attempts to selectively retrieve messages from a timer queue (TQ), and then from a primary queue. |
PSEL_TQ_PQ_AQ |
Alternate queue number |
Attempts to selectively retrieve messages from a timer queue (TQ), then from a primary queue, and finally from an alternate queue. |
PSEL_UCB |
0 |
Retrieves messages only from the user callback queues (UCB). |
Selection by Message Attribute
Enables the application to select messages based on the message type, class, or priority. The predefined constants for this argument are as follows:
Select Mode |
Select Variable |
Mode Description |
---|---|---|
PSEL_PQ_TYPE |
Type |
Selects the first pending message from the primary queue that matches the type value in the select variable word. |
PSEL_PQ_CLASS |
Class |
Selects the first pending message from the primary queue that matches the class value in the select variable word. |
PSEL_PQ_PRI |
PSEL_PRI_ANY |
Selects the first pending message with a priority equal to an integer between 0 and 99 inclusive (or equal to the select variable value) from within the primary queue. Specifying the direct integer value is the preferred method of selected messages by priority. Using PSEL_PRI_ANY enables the reading of any pending messages of all priorities. Setting PSEL_PRI_P0 enables the application to retrieve pending messages of priority 0 only. Setting PSEL_PRI_P1 enables the strict retrieval of pending messages with a priority of 1. |
Provides for the selection of pending messages from primary and secondary queues, by source group ID, queue number, or both. The format for selection by source -follows:
Some examples of possible sel_filter arguments and their actions are as follows:
sel_filter Argument |
Action |
---|---|
Zero or not specified |
No filtering of any messages. All messages can be retrieved. |
Source q_address |
Only those messages that have a matching q_address are retrieved. |
Selection mask created with pams_set_select |
Only messages that exactly match the specified selection mask are retrieved. |
Allows the application to formulate complex rules for the order in which the message queues are searched. The pams_set_select function allows the application to create custom selection masks that can be used in the low-order word of the sel_filter argument. The format for compound selection follows:
Receives a PAMS Status Block containing the final completion status. The psb argument is used when sending or receiving recoverable messages. The PSB structure stores the status information from the message recovery system and may be checked after sending or receiving a message. The structure of the PSB is as follows:
Low Byte |
High Byte |
Contents |
Description |
---|---|---|---|
0 |
1 |
Type |
PSB type |
2 |
3 |
Call Dependent |
Currently not used. |
4 |
7 |
PSB Delivery Status |
The completion status of the function. For recoverable messages, this field contains PAMS__CONFIRMREQ or PAMS__POSSDUPL. For nonrecoverable messages, it may also contain a value of PAMS__SUCCESS. |
8 |
15 |
Message Sequence Number |
A unique number assigned to a message when it is sent and follows the message to the destination PSB. This number is input to pams_confirm_msg to release a recoverable message. |
16 |
19 |
PSB UMA Status |
This field is not used for the pams_get_msg function. |
20 |
23 |
Function Return Status |
This field is not used for the pams_get_msg function. |
24 |
31 |
Not Used |
Not used. |
Receives additional information which BEA MessageQ extracts from the message header. The structure of the show_buffer argument is as follows:
Longword |
Contents |
Description |
---|---|---|
0 |
Version |
The version of the show_buffer structure. Valid values are as follows: |
1 |
Transfer Status |
The status code associated with the transfer of show_buffer information into the application's buffer. Valid symbols are as follows: PAMS__SUCCESS-All available information has been transferred. PAMS__BUFFEROVF-Information was lost due to receiver buffer overflow. 0-No message returned. There is no information to transfer. |
2 |
Transfer Size |
The number of bytes transferred to the application buffer. |
3 |
Flags |
A bit array showing the status of fields in the show_buffer. A set bit indicates a valid field, while a cleared bit indicates indeterminable data or the end of the allocated show_buffer memory. The symbols for the flags field are as follows: PSYM_SHOW_VERSION |
4 |
Not Used |
Fills out the Control Section to its maximum 24 bytes. |
5 |
Not Used |
Fills out the Control Section to its maximum 24 bytes. |
6 |
Not Used |
Fills out the Control Section to its maximum 24 bytes. |
7 |
Not Used |
Fills out the Control Section to its maximum 24 bytes. |
8 |
Not Used |
Fills out the Control Section to its maximum 24 bytes. |
9 |
Not Used |
Fills out the Control Section to its maximum 24 bytes. |
10 |
Target |
The q_address of the latest message target. |
11 |
Original Target |
The q_address of the original message target. |
12 |
Source |
The q_address of the latest message source. |
13 |
Original Source |
The q_address of the original message. |
14 |
Delivery Mode |
The delivery mode that was used to queue the message. This is not necessarily the delivery mode used to generate the message. |
15 |
Priority |
The priority used to queue the message. |
16 |
Endian |
The byte ordering or encoding schemes of 2- and 4-byte integers. The possible settings are as follows: PSYM_UNKNOWN |
17 |
Correlation ID |
The 32 byte correlation ID associated with the message. |
Supplies the length in bytes of the buffer defined in the show_buffer argument. The minimum length is 40 bytes. If the buffer is too small to contain all of the information, then the return code PAMS_BUFFEROVF will be in the show_buffer transfer status.
Specifies the size of the message area to receive messages larger than 32K. Also specifies the length of the message buffer when using double buffers (as indicated by PSYM_MSG_BUFFER_POINTER). This argument also stores the length of double buffers and FML32 buffers after reallocation.
Returns the actual size of the large message, double buffer message, or FML32 message written to the message buffer.
Reserved for BEA MessageQ internal use as a placeholder argument. This argument must be supplied as a null pointer.
Return Values
Return Code |
Platform |
Description |
---|---|---|
PAMS__AREATOSMALL |
All |
Received message is larger than the user's message area. |
PAMS__BADARGLIST |
All |
Wrong number of call arguments have been passed to this function. |
PAMS__BADHANDLE |
All |
Invalid message handle. |
PAMS__BADPARAM |
All |
Bad argument value. |
PAMS__BADPRIORITY |
All |
Invalid priority value used for receive. |
PAMS__BADSELIDX |
All |
Invalid or undefined selective receive index. |
PAMS__BUFFEROVF |
UNIX |
The size of the show_buffer specified is too small. |
PAMS__EXHAUSTBLKS |
OpenVMS |
No more message blocks available. |
PAMS__FMLERROR |
All |
Problem detected with internal format of FML message; this can be an error in processing or data corruption. |
PAMS__INSQUEFAIL |
All |
Failed to properly queue a message buffer. |
PAMS__MSGTOSMALL |
All |
The msg_area_len argument must be positive or zero. |
PAMS__MSGUNDEL |
All |
Message returned is undeliverable. |
PAMS__NEED_BUFFER_PTR |
UNIX |
FML32 buffer received but msg_area_len argument not set to PSYM_MSG_BUFFER_PTR. |
PAMS__NETERROR |
Clients |
Network error resulted in a communications link abort. |
PAMS__NOACCESS |
All |
No access to resource. |
PAMS__NOACL |
All |
Queue access control file could not be found. |
PAMS__NOMEMORY |
OpenVMS |
Insuffucient memory resources to reallocate buffer pointer. |
PAMS__NOMOREMSG |
All |
No messages available. |
PAMS__NOMRQRESRC |
All |
Insufficient multireader queue resources to allow access. |
PAMS__NOTDCL |
All |
Process has not been attached to BEA MessageQ. |
PAMS__NOTSUPPORTED |
UNIX |
The supplied delivery mode is not -supported. |
PAMS__PAMSDOWN |
UNIX |
The specified BEA MessageQ group is not running. |
PAMS__PREVCALLBUSY |
Clients |
Previous call to CLS has not been completed. |
PAMS__QUECORRUPT |
OpenVMS |
Message buffer queue corrupt. |
PAMS__REMQUEFAIL |
All |
Failed to properly read from a message buffer. |
PAMS__STALE |
All |
Resource is no longer valid and must be freed by the user. |
PAMS__STOPPED |
All |
The requested queue has been stopped. |
PAMS__SUCCESS |
All |
Indicates successful completion. |
PSB Delivery Status |
Platform |
Description |
---|---|---|
PAMS__CONFIRMREQ |
All |
Confirmation required for this message. |
PAMS__PAMSDOWN |
UNIX |
The specified BEA MessageQ group is not running. |
PAMS__POSSDUPL |
All |
Message is a possible duplicate. |
PAMS__SUCCESS |
All |
Indicates successful completion. |
Read a Message
This example uses the pams_get_msg function to retrieve all the messages currently in the queue and sends them to a print function. The complete code example called x_get.c is contained in the examples directory.
pams_get_msga
The pams_get_msga function is only available on OpenVMS systems.
Requests asynchronous notification of a message arrival. The pams_get_msga function triggers an asynchronous system trap (AST) routine when a message arrives in that queue. Notification to the application occurs by triggering an AST, by setting an event flag, or both.
When no selection filter is specified, the function returns the next available message in first-in/first-out (FIFO) order based on message priority to the user-supplied msg_area argument. Priority ranges from 0 (lowest priority) to 99 (highest priority). For example, priority 1 messages are always placed before priority 0 messages. Messages are placed in first-in/first out order by message priority. If a selection filter is specified, then only messages that meet the selection criteria are retrieved, and the AST or event flag is triggered only when a matching message arrives.
If a queue has been sent a recoverable message, the receiver program can confirm receipt of the message using the pams_confirm_msg function. The pams_confirm_msg function enables the successfully delivered message to be deleted from the message recovery system. See the Using Recoverable Messaging topic for a description of the BEA MessageQ recovery system.
See the Sending and Receiving BEA MessageQ Messages topic for more information on working with FML32 buffers and large messages.
Syntax
int32 pams_get_msga ( msg_area, priority, source, class, type,
msg_area_len, len_data, [sel_filter], [psb],
[show_buffer], [show_buffer_len],
[large_area_len], [large_size], [actrtn],
[actparm], [flag_id], [nullarg_3] )
Arguments
Argument |
Data Type |
Mechanism |
Prototype |
Access |
---|---|---|---|---|
msg_area |
char |
reference |
char * |
returned |
priority |
char |
reference |
char * |
passed |
source |
q_address |
reference |
q_address * |
returned |
class |
short |
reference |
short * |
returned |
type |
short |
reference |
short * |
returned |
msg_area_len |
short |
reference |
short * |
passed |
len_data |
short |
reference |
short * |
returned |
[sel_filter] |
int32 |
reference |
int32 * |
passed |
[psb] |
struct psb |
reference |
struct psb * |
returned |
[show_buffer] |
struct |
reference |
struct |
returned |
[show_buffer_len] |
int32 |
reference |
int32 * |
passed |
[large_area_len] |
int32 |
reference |
int32 * |
passed/ |
[large_size |
int32 |
reference |
int32 * |
returned |
[actrtn] |
int32 |
value |
int32 * |
passed |
[actparm] |
int32 |
reference |
int32 * |
passed |
[flag_id] |
int32 |
reference |
int32 * |
passed |
[nullarg_3] |
char |
reference |
char * |
passed |
For static buffer-style messaging, receives the address of a memory region where BEA MessageQ writes the contents of the retrieved message. For FML-style messaging or when using double pointers, receives a pointer to the address of the message being retrieved. When using double buffer pointers with pams_get_msga, the new buffer size is returned in large_size. (This differs from pams_get_msg[w}, where the new buffer size is returned in large_area_len.)
Supplies the priority level for selective message reception. Priority ranges from 0 (lowest priority) to 99 (highest priority)..
Receives a data structure containing the group ID and queue number of the sender program's primary queue in the following format:
Receives the class code of the retrieved message. The class is specified in the pams_put_msg function. BEA MessageQ supports the use of symbolic names for class argument values. Symbolic class names should begin with MSG_CLAS_. For information on defining class symbols, see the p_typecl.h include file.
Class symbols reserved by BEA MessageQ are as follows:
Reserved Class |
Symbol Value |
---|---|
MSG_CLAS_MRS |
28 |
MSG_CLAS_PAMS |
29 |
MSG_CLAS_ETHERNET |
100 |
MSG_CLAS_UCB |
102 |
MSG_CLAS_TUXEDO |
31001 |
MSG_CLAS_TUXEDO_TPSUCCESS |
31002 |
MSG_CLAS_TUXEDO_TPFAIL |
31003 |
MSG_CLAS_XXX |
30000 through 32767 (except 31001-31003) |
Receives the type code of the retrieved message. The type is specified in the pams_put_msg function. BEA MessageQ supports the use of symbolic names for type argument values. Symbolic type names begin with MSG_TYPE_. For specific information on defining type symbols, see the p_typecl.h include file.
BEA MessageQ has reserved the symbol value range -1 through -5000. A zero value for this argument indicates that no processing by message type is expected.
For static buffer-style messaging with messages of up to 32767 bytes, this argument receives the number of bytes retrieved from the message queue and stored in the area specified by the msg_area argument. This field also receives the PSYM_MSG_BUFFER_PTR symbol for FML-style messages and PSYM_MSG_LARGE for buffer-style messages larger than 32767 bytes.
Supplies the criteria enabling the application to selectively retrieve messages. The argument contains one of the following selection criteria:
The sel_filter argument is composed of two words as follows:
Enables applications to read messages from the queue based on the order in which they arrived. The default selection, PSEL_DEFAULT, reads the next pending message from the message queue. Messages are stored by priority and then in FIFO order. To specify this explicitly, both words in the sel_filter argument should be set to 0.
Selection by Message Queue
Allows the application to retrieve messages based upon a queue type or combination of queue types. This selection criteria is used to retrieve the first pending message that matches the criteria on the first queue it encounters. FIFO ordering is maintained within each queue.
The predefined constants for this argument are as follows:
Select Mode |
Select Variable |
Mode Description |
---|---|---|
PSEL_PQ |
0 |
Enables the application to read from the primary queue (PQ) only. The select variable must equal 0. |
PSEL_AQ |
Alternate queue number |
Enables an application to read from an alternate queue (AQ) only. The queue type can be a secondary queue (SQ). |
PSEL_PQ_AQ |
Alternate queue number |
Attempts to selectively retrieve from a primary queue and then from an alternate queue. |
PSEL_AQ_PQ |
Alternate queue number |
Attempts to selectively retrieve from an alternate queue and then from a primary queue. |
PSEL_TQ_PQ |
Alternate queue number |
Attempts to selectively retrieve messages from a timer queue (TQ), and then from a primary queue. |
PSEL_TQ_PQ_AQ |
Alternate queue number |
Attempts to selectively retrieve messages from a timer queue (TQ), then from a primary queue, and finally from an alternate queue. |
PSEL_UCB |
0 |
Retrieves messages only from the user callback queues (UCB). |
Selection by Message Attribute
Enables the application to select messages based on the message type, class, or priority. The predefined constants for this argument are as follows:
Select Mode |
Select Variable |
Mode Description |
---|---|---|
PSEL_PQ_TYPE |
Type |
Selects the first pending message from the primary queue that matches the type value in the select variable word. |
PSEL_PQ_CLASS |
Class |
Selects the first pending message from the primary queue that matches the class value in the select variable word. |
PSEL_PQ_PRI |
PSEL_PRI_ANY |
Selects the first pending message with a priority equal to an integer between 0 and 99 inclusive (or equal to the select variable value) from within the primary queue. Specifying the direct integer value is the preferred method of selected messages by priority. Using PSEL_PRI_ANY enables the reading of any pending messages of all priorities. Setting PSEL_PRI_P0 enables the application to retrieve pending messages of priority 0 only. Setting PSEL_PRI_P1 enables the strict retrieval of pending messages with a priority of 1. |
Provides for the selection of pending messages from primary and secondary queues, by source group ID, queue number, or both. The format for selection by source follows:
Some examples of possible sel_filter arguments and their actions are as follows:
sel_filter Argument |
Action |
---|---|
Zero or not specified |
No filtering of any messages. All messages can be retrieved. |
Source q_address |
Only those messages that have a matching q_address are retrieved. |
Selection mask created with pams_set_select |
Only messages that exactly match the specified selection mask are retrieved. |
Allows the application to formulate complex rules for the order in which the message queues are searched. The pams_set_select function allows the application to create custom selection masks that can be used in the low-order word of the sel_filter argument. The format for compound selection follows.
Receives a PAMS Status Block containing the final completion status. The psb argument is used when sending or receiving recoverable messages. The PSB structure stores the status information from the message recovery system and may be checked after sending or receiving a message. The structure of the PSB is as follows:
Low Byte |
High Byte |
Contents |
Description |
---|---|---|---|
0 |
1 |
Type |
PSB type |
2 |
3 |
Call Dependent |
Currently not used. |
4 |
7 |
PSB Delivery Status |
The completion status of the function. For recoverable messages, this field contains PAMS__CONFIRMREQ or PAMS__POSSDUPL. For nonrecoverable messages, it may also contain a value of PAMS__SUCCESS. |
8 |
15 |
Message Sequence Number |
A unique number assigned to a message when it is sent and follows the message to the destination PSB. This number is input to pams_confirm_msg to release a recoverable message. |
16 |
19 |
PSB UMA Status |
This field is not used with the pams_get_msga function. |
20 |
23 |
Function Return Status |
This field is not used with the pams_get_msga function. |
24 |
31 |
Not Used |
Not used. |
Note: This function utilizes the AST services of OpenVMS; therefore, the application must check the status information returned in the PSB.
Receives additional information which BEA MessageQ extracts from the message header. The structure of the show_buffer argument is as follows:
Longword |
Contents |
Description |
---|---|---|
0 |
Version |
The version of the show_buffer structure. Valid values are as follows: 10 = Version 1.0 |
1 |
Transfer Status |
The status code associated with the transfer of show_buffer information into the application's buffer. Valid symbols are as follows: PAMS__SUCCESS-All available information has been transferred. PAMS__BUFFEROVF-Information was lost due to receiver buffer overflow. 0-No message returned. There is no information to transfer. |
2 |
Transfer Size |
The number of bytes transferred to the application buffer. |
3 |
Flags |
A bit array showing the status of fields in the show_buffer. A set bit indicates a valid field, while a cleared bit indicates indeterminable data or the end of the allocated show_buffer memory. The symbols for the flags field are as follows: PSYM_SHOW_VERSION |
4 |
Not Used |
Fills out the Control Section to its maximum 40 bytes. |
5 |
Not Used |
Fills out the Control Section to its maximum 40 bytes. |
6 |
Not Used |
Fills out the Control Section to its maximum 40 bytes. |
7 |
Not Used |
Fills out the Control Section to its maximum 40 bytes. |
8 |
Not Used |
Fills out the Control Section to its maximum 40 bytes. |
9 |
Not Used |
Fills out the Control Section to its maximum 40 bytes. |
10 |
Target |
The q_address of the latest message target. |
11 |
Original Target |
The q_address of the original message target. |
12 |
Source |
The q_address of the latest message source. |
13 |
Original Source |
The q_address of the original message. |
14 |
Delivery Mode |
The delivery mode that was used to queue the message. This is not necessarily the delivery mode used to generate the message. |
15 |
Priority |
The priority used to queue the message. |
16 |
Endian |
The byte ordering or encoding schemes of 2- and 4-byte integers. The possible settings are as follows: PSYM_UNKNOWN |
17 |
Correlation ID |
The 32 byte correlation ID associated with the message. |
Supplies the length in bytes of the buffer defined in the show_buffer argument. The minimum length is 40 bytes. If the buffer is too small to contain all of the information, then the return code PAMS__BUFFEROVF will be in the show_buffer transfer status.
Specifies the size of the message area to receive messages larger than 32K. Also specifies the length of the message buffer when using double buffers (as indicated by PSYM_MSG_BUFFER_POINTER).
Returns the actual size of the large message, double buffer message, or FML32 message written to the message buffer. When using double buffer pointers with pams_get_msga, the new buffer size is returned in large_size. (This differs from pams_get_msg[w}, where the new buffer size is returned in large_area_len.)
Supplies the address of an int32 value that is the entry point to an action routine. This action routine is executed when the pams_get_msga function completes.
Supplies an int32 value that is passed to the action routine specified in the actrtn argument when it is invoked.
Supplies the int32 value for the flag number to be set when the pams_get_msga function completes. When the pams_get_msga function executes, it clears this flag. If this argument value is not supplied, no flag is used.
Reserved for BEA MessageQ internal use as a placeholder argument. This argument must be supplied as a null pointer.
Description
Because the pams_get_msga function executes asynchronously, it obtains several argument values only after the message arrives. These argument values are the message buffer, source, class, type of the message, and a PAMS Status Block (PSB) status code containing the delivery status, UMA status, and the sequence number of the message. These values are not set until the message arrival triggers the AST routine or sets the event flag.
The pams_get_msga function specifies an AST parameter which is passed by value to the AST routine when the parameter is called. This parameter is used to provide a context for the information contained in the message and can be used to identify the specific processing required for the message. Following are some suggestions and rules for programming with ASTs:
Return Code |
Platform |
Description |
---|---|---|
PAMS__BADARGLIST |
OpenVMS |
Wrong number of call arguments have been passed to this function. |
PAMS__BADPARAM |
OpenVMS |
Bad argument value. |
PAMS__BADPRIORITY |
OpenVMS |
Invalid priority value used for receive. |
PAMS__BADSELIDX |
OpenVMS |
Invalid or undefined selective receive index. |
PAMS__BADHANDLE |
OpenVMS |
Invalid message handle. |
PAMS__MSGTOSMALL |
OpenVMS |
The msg_area_len argument must be positive or zero. |
PAMS__NOACCESS |
OpenVMS |
No access to the queue. |
PAMS__NOACL |
OpenVMS |
No access to resource. The ACL check failed. |
PAMS__NOMEMORY |
OpenVMS |
Insuffucient memory resources to reallocate buffer pointer. |
PAMS__NOTDCL |
OpenVMS |
The application has not been attached to BEA MessageQ. |
PAMS__NOTSUPPORTED |
OpenVMS |
Feature not supported or available. |
PAMS__RESRCFAIL |
OpenVMS |
Failed to allocate a resource. |
PAMS__STALE |
OpenVMS |
Resource is no longer valid and must be freed by the user. |
PAMS__STOPPED |
OpenVMS |
The requested queue has been stopped. |
PAMS__SUCCESS |
OpenVMS |
Indicates successful completion. |
PSB Delivery Status |
Platform |
Description |
---|---|---|
PAMS__CONFIRMREQ |
OpenVMS |
Confirmation required for this message. |
PAMS__POSSDUPL |
OpenVMS |
Message is a possible duplicate. |
PAMS__SUCCESS |
OpenVMS |
Indicates successful completion. |
Retrieves the next available message from a specified queue and moves it to the location specified in the msg_area argument. This function waits until a message arrives in the queue or a user-specified timeout period has elapsed.
When no selection filter is specified, the function returns the next available message in first-in/first-out (FIFO) order based on message priority to the user-supplied msg_area argument. Priority ranges from 0 (lowest priority) to 99 (highest priority). If the priority is set to 0, the pams_get_msqw function gets messages of any priority. If the priority is set to any value from 1 to 99, the pams_get_msqw function gets only messages of that priority. Messages are placed in first-in/first-out order by message priority. If a selection filter is specified, then only messages that meet the selection criteria are retrieved. If no message arrives, or no available message meets the selection criteria before the timeout period expires, then the return status is PAMS__TIMEOUT.
If a queue has been sent a recoverable message, the receiver program can confirm receipt of the message using the pams_confirm_msg function. The pams_confirm_msg function enables the successfully delivered message to be deleted from the message recovery system. See the Using Recoverable Messaging topic for a description of the BEA MessageQ recovery system.
See the Sending and Receiving BEA MessageQ Messages topic for more information on working with FML32 buffers and large messages.
Syntax
int32 pams_get_msgw ( msg_area, priority, source, class, type,
msg_area_len, len_data, timeout, [sel_filter],
[psb], [show_buffer], [show_buffer_len],
[large_area_len], [large_size],[nullarg_3] )
Argument
Argument |
Data Type |
Mechanism |
Prototype |
Access |
---|---|---|---|---|
msg_area |
char |
reference |
char * |
returned |
priority |
char |
reference |
char * |
passed |
source |
q_address |
reference |
q_address * |
returned |
class |
short |
reference |
short * |
returned |
type |
short |
reference |
short * |
returned |
msg_area_len |
short |
reference |
short * |
passed |
len_data |
short |
reference |
short * |
returned |
timeout |
int32 |
reference |
int32 * |
passed |
[sel_filter] |
int32 |
reference |
int32 * |
passed |
[psb] |
struct psb |
reference |
struct psb * |
returned |
[show_buffer] |
struct show_buffer |
reference |
struct |
returned |
[show_buffer_len] |
int32 |
reference |
int32 * |
passed |
[large_area_len] |
int32 |
reference |
int32 * |
passed/ |
[large_size] |
int32 |
reference |
int32 * |
returned |
[nullarg_3] |
char |
reference |
char * |
passed |
For buffer-style messaging, receives the address of a memory region where BEA MessageQ writes the contents of the retrieved message. For FML-style messaging or when using double ponters, receives a pointer to the address of the message being retrieved.
Supplies the priority level for selective message reception. Priority ranges from 0 (lowest priority) to 99 (highest priority). If the priority is set to 0, the pams_get_msqw function gets messages of any priority. If the priority is set to any value from 1 to 99, the pams_get_msqw function gets only messages of that priority.
Receives a structure identifying the group ID and queue number of the sender program's primary queue in the following format:
Receives the class code of the retrieved message. The class is specified in the arguments of the pams_put_msg function. BEA MessageQ supports the use of symbolic names for class argument values. Symbolic class names should begin with MSG_CLAS_. For information on defining class symbols, see the p_typecl.h include file. On UNIX and Windows NT systems, the p_typecl.h include file cannot be edited. You must create an include file to define type and class symbols for use by your -application.
Class symbols reserved by BEA MessageQ are as follows:
Reserved Class |
Symbol Value |
---|---|
MSG_CLAS_MRS |
28 |
MSG_CLAS_PAMS |
29 |
MSG_CLAS_ETHERNET |
100 |
MSG_CLAS_UCB |
102 |
MSG_CLAS_TUXEDO |
31001 |
MSG_CLAS_TUXEDO_TPSUCCESS |
31002 |
MSG_CLAS_TUXEDO_TPFAIL |
31003 |
MSG_CLAS_XXX |
30000 through 32767 (except 31001-31003) |
Receives the type code of the retrieved message. The type is specified in the arguments of the pams_put_msg function. BEA MessageQ supports the use of symbolic names for type argument values. Symbolic type names begin with MSG_TYPE_. For specific information on defining type symbols, see the p_typecl.h include file.
BEA MessageQ has reserved the symbol value range -1 through -5000. A zero value for this argument indicates that no processing by message type is expected.
For static buffer-style messaging with messages of up to 32767 bytes, this argument receives the number of bytes retrieved from the message queue and stored in the area specified by the msg_area argument. This field also receives the PSYM_MSG_BUFFER_PTR symbol for double buffer and FML-style messages and PSYM_MSG_LARGE for buffer-style messages larger than 32767 bytes.
Supplies the maximum amount of time the pams_get_msg function waits for a message to arrive before returning control to the application. The timeout value is entered in tenths (0.1) of a second. A value of 100 indicates a timeout of 10 seconds. If the timeout occurs before a message arrives, the status code of PAMS__TIMEOUT is -returned.
If an unlimited timeout period is required, set this argument to 0. On UNIX and Windows NT systems, a value of zero for this argument causes this function to block indefinitely or until it receives a message. On OpenVMS systems, this function waits for approximately 5 days or until it receives a message.
Supplies the criteria for the application to selectively retrieve messages. The argument contains one of the following selection criteria:
The sel_filter argument is composed of two words as follows:
Enables applications to read messages from the queue based on the order in which they arrived. The default selection, PSEL_DEFAULT, reads the next pending message from the message queue. Messages are stored by priority and then in FIFO order. To specify this explicitly, both words in the sel_filter argument should be set to 0.
Allows the application to retrieve messages based upon a queue type or combination of queue types. This selection criteria is used to retrieve the first pending message that matches the criteria on the first queue it encounters. FIFO ordering is maintained within each queue. The predefined constants for this argument are as follows:
Select Mode |
Select Variable |
Mode Description |
---|---|---|
PSEL_PQ |
0 |
Enables the application to read from the primary queue (PQ) only. The select variable must equal 0. |
PSEL_AQ |
Alternate queue number |
Enables an application to read from an alternate queue (AQ) only. The queue type can be a secondary queue (SQ). |
PSEL_PQ_AQ |
Alternate queue number |
Attempts to selectively retrieve from a primary queue and then from an alternate queue. |
PSEL_AQ_PQ |
Alternate queue number |
Attempts to selectively retrieve from an alternate queue and then from a primary queue. |
PSEL_TQ_PQ |
Alternate queue number |
Attempts to selectively retrieve messages from a timer queue (TQ), and then from a primary queue. |
PSEL_TQ_PQ_AQ |
Alternate queue number |
Attempts to selectively retrieve messages from a timer queue (TQ), then from a primary queue, and finally from an alternate queue. |
PSEL_UCB |
0 |
Retrieves messages only from the user callback queues (UCB). |
Enables the application to select messages based on the message type, class, or priority. The predefined constants for this argument are as follows:
Select Mode |
Select Variable |
Mode Description |
---|---|---|
PSEL_PQ_TYPE |
Type |
Selects the first pending message from the primary queue that matches the type value in the select variable word. |
PSEL_PQ_CLASS |
Class |
Selects the first pending message from the primary queue that matches the class value in the select variable word. |
PSEL_PQ_PRI |
PSEL_PRI_ANY |
Selects the first pending message with a priority equal to an integer between 0 and 99 inclusive (or equal to the select variable value) from within the primary queue. Specifying the direct integer value is the preferred method of selected messages by priority. Using PSEL_PRI_ANY enables the reading of any pending messages of all priorities. Setting PSEL_PRI_P0 enables the application to retrieve pending messages of priority 0 only. Setting PSEL_PRI_P1 enables the strict retrieval of pending messages with a priority of 1. |
Provides for the selection of pending messages from primary and secondary queues, by source group ID, queue number, or both. The format for selection by source -follows:
Some examples of possible sel_filter arguments and their actions are as follows:
sel_filter Argument |
Action |
---|---|
Zero or not specified |
No filtering of any messages. All messages can be -retrieved. |
Source q_address |
Only those messages that have a matching q_address are retrieved. |
Selection mask created with pams_set_select |
Only messages that exactly match the specified selection mask are retrieved. |
Allows the application to formulate complex rules for the order in which the message queues are searched. The pams_set_select function allows the application to create custom selection masks that can be used in the low-order word of the sel_filter argument. The format for compound selection follows:
.
Receives a PAMS Status Block containing the final completion status. The psb argument is used when sending or receiving recoverable messages. The PSB structure stores the status information from the message recovery system and may be checked after sending or receiving a message. The structure of the PSB is as follows:
Low Byte |
High Byte |
Contents |
Description |
---|---|---|---|
0 |
1 |
Type |
PSB type |
2 |
3 |
Call Dependent |
Currently not used. |
4 |
7 |
PSB Delivery Status |
The completion status of the function. It contains the status from MRS. It can also contain a value of PAMS__SUCCESS when the message is not sent recoverably. |
8 |
15 |
Message Sequence Number |
A unique number assigned to a message when it is sent and follows the message to the destination PSB. This number is input to the pams_confirm_msg function to release a recoverable message. |
16 |
19 |
PSB UMA Status |
The completion status of the undeliverable message action (UMA). The PSB UMA status indicates if the UMA was not executed or applicable. |
20 |
23 |
Function Return Status |
After a BEA MessageQ function completes execution, BEA MessageQ software writes the return value to this field. |
24 |
31 |
Not Used |
Not used. |
Receives additional information which BEA MessageQ extracts from the message header. The structure of the show_buffer argument is as follows:
Longword |
Contents |
Description |
---|---|---|
0 |
Version |
The version of the show_buffer structure. Valid values are as follows: 10 = Version 1.0 |
1 |
Transfer Status |
The status code associated with the transfer of show_buffer information into the application's buffer. Valid symbols are as follows: PAMS__SUCCESS-All available information has been transferred. PAMS__BUFFEROVF-Information was lost due to receiver buffer overflow. 0-No message returned. There is no information to transfer. |
2 |
Transfer Size |
The number of bytes transferred to the application buffer. |
3 |
Flags |
A bit array showing the status of fields in the show_buffer. A set bit indicates a valid field, while a cleared bit indicates indeterminable data or the end of the allocated show_buffer memory. The symbols for the flags field are as follows: PSYM_SHOW_VERSION |
4 |
Not Used |
Fills out the Control Section to its maximum 24 bytes. |
5 |
Not Used |
Fills out the Control Section to its maximum 24 bytes. |
6 |
Not Used |
Fills out the Control Section to its maximum 24 bytes. |
7 |
Not Used |
Fills out the Control Section to its maximum 24 bytes. |
8 |
Not Used |
Fills out the Control Section to its maximum 24 bytes. |
9 |
Not Used |
Fills out the Control Section to its maximum 24 bytes. |
10 |
Target |
The q_address of the latest message target. |
11 |
Original Target |
The q_address of the original message target. |
12 |
Source |
The q_address of the latest message source. |
13 |
Original Source |
The q_address of the original message. |
14 |
Delivery Mode |
The delivery mode that was used to queue the message. |
15 |
Priority |
The priority used to queue the message. |
16 |
Endian |
The byte ordering or encoding schemes of 2- and 4-byte integers. The possible settings are as follows: PSYM_UNKNOWN |
17 |
Correlation ID |
The 32 byte correlation ID associated with the message. |
Supplies the length in bytes of the buffer defined in the show_buffer argument. The minimum length is 40 bytes. If the buffer is too small to contain all of the information, the return code PAMS__BUFFEROVF will be in the show_buffer transfer status.
Specifies the size of the message area to receive messages larger than 32K. Also specifies the length of the message buffer when using double buffers (as indicated by PSYM_MSG_BUFFER_POINTER). This argument also stores the length of double buffers and FML32 buffers after reallocation.
Returns the actual size of the large message, double buffer message, or FML message written to the message buffer.
Reserved for BEA MessageQ internal use as a placeholder argument. This argument must be supplied as a null pointer.
Return Codes
Return Code |
Platform |
Description |
---|---|---|
PAMS__AREATOSMALL |
All |
Received message is larger than the application message area. |
PAMS__BADARGLIST |
All |
Wrong number of call arguments have been passed to this function. |
PAMS__BADHANDLE |
All |
Invalid message handle. |
PAMS__BADPARAM |
All |
Bad argument value. |
PAMS__BADPRIORITY |
All |
Invalid priority value used for receive. |
PAMS__BADSELIDX |
All |
Invalid or undefined selective receive index. |
PAMS__BADTIME |
OpenVMS |
An invalid time was specified. |
PAMS__BUFFEROVF |
UNIX |
The size specified for the show_buffer argument is too small. |
PAMS__EXHAUSTBLKS |
OpenVMS |
No more message blocks available. |
PAMS__FMLERROR |
All |
Problem detected with internal format of FML message; this can be an error in processing or data corruption. |
PAMS__INSQUEFAIL |
All |
Failed to properly queue a message buffer. |
PAMS__MSGTOSMALL |
All |
The msg_area_len argument must be positive or zero. |
PAMS__MSGUNDEL |
All |
Message returned is undeliverable. |
PAMS__NEED_BUFFER_PTR |
UNIX |
FML32 buffer received but msg_area_len argument not set to PSYM_MSG_BUFFER_PTR. |
PAMS__NETERROR |
Clients |
Network error resulted in a communications link abort. |
PAMS__NOACCESS |
All |
No access to resource. ACL check failed. |
PAMS__NOACL |
All |
The queue access control file could not be found. |
PAMS__NOMEMORY |
OpenVMS |
Insuffucient memory resources to reallocate buffer pointer. |
PAMS__NOMRQRESRC |
All |
Insufficient multireader queue resources to allow access. |
PAMS__NOTDCL |
All |
Process has not been attached to BEA MessageQ. |
PAMS__NOTSUPPORTED |
UNIX |
Specified delivery mode is not supported. |
PAMS__PAMSDOWN |
UNIX |
The specified BEA MessageQ group is not running. |
PAMS__PREVCALLBUSY |
Clients |
Previous call to CLS has not been completed. |
PAMS__QUECORRUPT |
OpenVMS |
Message buffer queue corrupt. |
PAMS__REMQUEFAIL |
All |
Failed to properly read a message buffer. |
PAMS__STALE |
All |
Resource is no longer valid and must be freed by the user. |
PAMS__STOPPED |
All |
The requested queue has been stopped. |
PAMS__SUCCESS |
All |
Successful completion. |
PAMS__TIMEOUT |
All |
Timeout period has expired. |
PAMS__CONFIRMREQ |
All |
Confirmation required for this -message. |
PAMS__PAMSDOWN |
UNIX |
The specified BEA MessageQ group is not running. |
PAMS__POSSDUPL |
All |
Message is a possible duplicate. |
PAMS__SUCCESS |
All |
Indicates successful completion. |
Block Until a Message Is Read
This example shows how to use the pams_get_msgw function. It sets an alarm to send messages to itself every 5 seconds; it uses pams_get_msgw to sit and wait for them. The queue named "queue_1" must be defined in your initialization file as a primary queue. The complete code example called x_getw.c is contained in the examples directory.
pams_locate_q
Locates the queue address for the specified queue name or queue alias. By default, this function waits for the queue address to be returned.
Syntax
int32 pams_locate_q ( q_name, q_name_len, q_address, [wait_mode],
[req_id], [resp_q], [name_space_list],
[name_space_list_len], [timeout] )
Arguments
Argument |
Data Type |
Mechanism |
Prototype |
Access |
---|---|---|---|---|
q_name |
char |
reference |
char * |
passed |
q_name_len |
int32 |
reference |
int32 * |
passed |
q_address |
q_address |
reference |
q_address * |
returned |
[wait_mode] |
int32 |
reference |
int32 * |
passed |
[req_id] |
int32 |
reference |
int32 * |
passed |
[resp_q] |
int32 |
reference |
int32 * |
passed |
[name_space_list] |
int32 array |
reference |
int32 array * |
passed |
[name_space_list_len] |
int32 |
reference |
int32 * |
passed |
[timeout] |
int32 |
reference |
int32 * |
passed |
Supplies the queue name or queue alias whose queue address is requested. The procedure that BEA MessageQ uses to find this name is controlled by the name_space_list argument, described below.
Supplies the number of characters in the q_name argument. The maximum string length on UNIX, Windows NT, and OpenVMS systems is 255 characters. For all other BEA MessageQ environments, the maximum string length is 31.
Receives the queue address assigned by BEA MessageQ when an application has successfully located the queue name.
Supplies the search mode of the pams_locate_q function. The mode indicates whether the application waits for the search completion or receives the response in an acknowledgment message. There are two predefined constants for this argument:
Supplies an application-specified transaction ID to associate with the pams_locate_q function.
Supplies an alternate queue to use for receiving the acknowledgment message of the q_address. If no response queue is specified, the acknowledgment message is sent to the sender program's primary queue. The resp_q argument has the following format:
Note that the group ID field is always equal to zero because the sender program cannot specify a response queue outside its group.
If the name_space_list argument is specified, the name_space_list_len argument must also be specified. If this argument is unspecified, then PSEL_TBL_GRP is the default.
Possible values in a name_space_list argument are as follows:
Location it represents |
Symbolic value |
---|---|
Process cache |
PSEL_TBL_PROC |
Group/group cache |
PSEL_TBL_GRP |
Global name space |
PSEL_TBL_BUS (or PSEL_TBL_BUS_MEDIUM or PSEL_TBL_BUS_LOW) |
The name_space_list argument identifies the scope of the name as follows:
The name_space_list argument also controls the cache access as follows:
Note that to lookup all caches in the global name space before looking in the master database, specify PSEL_TBL_BUS_LOW instead of PSEL_TBL_BUS.
To lookup only the slower but more up-to-date caches in the global name space before looking in the master database, specify PSEL_TBL_BUS_MEDIUM instead of PSEL_TBL_BUS.
For more information on dynamic binding of queue addresses, see the Using Naming topic.
Supplies the number of entries in the name_space_list argument. If the name_space_list_len argument is zero, BEA MessageQ uses PSEL_TBL_GRP as the default in the name_space_list argument.
Specifies the number of PAMS time units (1/10 second intervals) to allow for the locate to complete. If timeout is zero, the group's ATTACH_TMO property is used. If the ATTACH_TMO is also zero, 600 is used.
Return Values
Return Code |
Platform |
Description |
---|---|---|
PAMS__BADARGLIST |
OpenVMS |
Wrong number of call arguments. |
PAMS__BADNAME |
UNIX |
The queue name contains illegal characters. |
PAMS__BADPARAM |
All |
Invalid argument in the argument list. |
PAMS__BADRESPQ |
All |
Invalid response queue specified. |
PAMS__BOUND |
All |
Queue name in use. |
PAMS__BUSNOTSET |
UNIX |
DMQ_BUS_ID environment variable not set. |
PAMS__GROUPNOTSET |
UNIX |
DMQ_GROUP_ID environment variable not set. |
PAMS__NETERROR |
Clients |
Network error resulted in a communications link abort. |
PAMS__NOACCESS |
All |
The address of the specified name is either 0 or is in another group. |
PAMS__NOOBJECT |
All |
Could not locate queue name. |
PAMS__PAMSDOWN |
All |
The specified BEA MessageQ group is not running. |
PAMS__PREVCALLBUSY |
Clients |
Previous call to CLS has not been completed. |
PAMS__RESRCFAIL |
All |
Failed to allocate resources. |
PAMS__SUCCESS |
All |
Successful completion of an action. |
PAMS__TIMEOUT |
All |
The timeout period specified has expired. |
PAMS__UNBINDING |
All |
Queue requested is in the process of unbinding from a pams_bind_q request. |
Locate a Queue Address
This example shows how to use the pams_locate_q function by attaching to queue_1 and locating queue_3 where a message is being sent. The queues named "queue_1" and "queue_3" must be defined in your initialization file; queue_1 must be a primary queue. The complete code example called x_locate.c is contained in the examples directory.
pams_open_jrn
Opens the selected message recovery journal. The BEA MessageQ dead letter journal (DLJ) stores messages designated as recoverable that could not be delivered by the recovery system. The BEA MessageQ postconfirmation journal (PCJ) stores recoverable messages that were successfully delivered. See the Using Recoverable Messaging topic for a description of BEA MessageQ message recovery services.
Syntax
int32 pams_open_jrn ( jrn_filespec, jrn_filename_len, jrn_handle )
Arguments
Argument |
Data Type |
Mechanism |
Prototype |
Access |
---|---|---|---|---|
jrn_filespec |
char |
reference |
char * |
passed |
jrn_filename_len |
short |
reference |
short * |
passed |
jrn_handle |
int32 |
reference |
int32 * |
returned |
Supplies the file name of the message recovery journal from which the application will read stored messages.
Supplies the length of the file specification entered to the jrn_filespec argument specified (filename array) in number of bytes.
Receives the journal handle for the selected message recovery file if this function completes successfully.
Return Values
Return Code |
Platform |
Description |
---|---|---|
PAMS__BADARGLIST |
OpenVMS |
Invalid number of call arguments. |
PAMS__NOMEMORY |
OpenVMS |
Insufficient virtual memory. |
PAMS__NOSUCHPCJ |
OpenVMS |
Error occured when attempting to open the specified journal file. |
PAMS__SUCCESS |
OpenVMS |
Indicates successful completion. |
Sends a message to a target queue using a set of standard BEA MessageQ delivery modes. Applications specify buffer-style or FML-style messaging using the msg_size argument. For buffer-style messaging using message buffers up to 32K, this argument supplies the length of the message in bytes in the user's msg_area buffer. In addition, you can use the msg_size argument to specify one of the following symbols:
The delivery argument of the pams_put_msg function can be used to guarantee message delivery if a system, process, or network fails. Recoverable messages are stored on disk by the message recovery system until they can be delivered to the target queue of the receiver program. When sending a recoverable message, you must specify the uma argument if the message recovery cannot store the message. You must also supply the psb argument to receive the return status of the operation.
The optional timeout argument lets you set a maximum amount of time for the send operation to complete before the function times out. The optional resp_q argument allows you to specify an alternate queue for receiving the response messages rather than directing responses to the primary queue of the sender program.
To use a pointer to an FML32 buffer when sending a message, the sender program specifies the symbol PSYM_MSG_FML as the msg_size argument to the pams_put_msg function.
Syntax
int32 pams_put_msg ( msg_area, priority, target, class, type,
delivery, msg_size, [timeout], [psb], [uma],
[resp_q], [large_size], [correlation_id],
[nullarg_3] )
Arguments
Argument |
Data Type |
Mechanism |
Prototype |
Access |
---|---|---|---|---|
msg_area |
char |
reference |
char * |
passed |
priority |
char |
reference |
char * |
passed |
target |
q_address |
reference |
q_address * |
passed |
class |
short |
reference |
short * |
passed |
type |
short |
reference |
short * |
passed |
delivery |
char |
reference |
char * |
passed |
msg_size |
short |
reference |
short * |
passed |
[timeout] |
int32 |
reference |
int32 * |
passed |
[psb] |
struct psb |
reference |
struct psb * |
returned |
[uma] |
char |
reference |
char * |
passed |
[resp_q] |
q_address |
reference |
q_address * |
passed |
large_size |
int32 |
reference |
int32 * |
passed |
[correlation_id] |
char |
reference |
char * |
passed |
[nullarg_3] |
char |
reference |
char * |
passed |
Argument Definitions
For buffer-style messaging, supplies the address of a memory region or a message pointer containing the message to be delivered to the target queue of the receiver program. For FML-style messaging, supplies the message pointer that points to an FML32 buffer containing the message.
Supplies the priority level for selective message reception. Priority ranges from 0 (lowest priority) to 99 (highest priority).
Supplies the queue number and group ID of the receiver program's queue address in the following format:
.
Supplies the class code of message being sent. BEA MessageQ supports the use of symbolic names for class argument values. Symbolic class names should begin with MSG_CLAS_. For information on defining class symbols, see the p_typecl.h include file. On UNIX and Windows NT systems, the p_typecl.h include file cannot be edited. You must create an include file to define type and class symbols for use by your application.
Class symbols reserved by BEA MessageQ are as follows:
Reserved Class |
Symbol Value |
---|---|
MSG_CLAS_MRS |
28 |
MSG_CLAS_PAMS |
29 |
MSG_CLAS_ETHERNET |
100 |
MSG_CLAS_UCB |
102 |
MSG_CLAS_TUXEDO |
31001 |
MSG_CLAS_TUXEDO_TPSUCCESS |
31002 |
MSG_CLAS_TUXEDO_TPFAIL |
31003 |
MSG_CLAS_XXX |
30000 through 32767 (except 31001-31003) |
Supplies the type code for the message being sent. BEA MessageQ supports the use of symbolic names for type argument values. Symbolic type names begin with MSG_TYPE_. For information on defining type symbols, see the p_typecl.h include file.
BEA MessageQ has reserved the symbol value range -1 through -5000. A zero value for this argument indicates that no processing by message type is expected.
Supplies the delivery mode for the message using the following format:
And dip is one of the following delivery interest point constants:
Note: If temporary queues are used, deleted, and reused quickly, it is possible in isolated cases for an implicit ACK response from a previous temporary queue to be placed on the new temporary queue.
For buffer-style messaging using message buffers up to 32K, supplies the length of the message in bytes in the user's msg_area buffer. In addition, you can specify one of the following symbols:
Supplies the maximum amount of time the pams_put_msg function waits for a message to arrive before returning control to the application. The timeout value is entered in tenths (0.1) of a second. A value of 100 indicates a timeout of 10 seconds. If the timeout occurs before a message arrives, the status code PAMS__TIMEOUT is returned. Specifying 0 as the timeout value sets the timeout to the default value of 30 seconds.
Receives a value in the PAMS Status Block specifying the final completion status. The psb argument is used when sending or receiving recoverable messages. The PSB structure stores the status information from the message recovery system and may be checked after sending or receiving a message.
The structure of the PSB is as follows:
Low Byte |
High Byte |
Contents |
Description |
---|---|---|---|
1 |
0 |
Type |
PSB type. |
3 |
2 |
Call Dependent |
Currently not used. |
7 |
4 |
PSB Delivery Status |
The completion status of the function. It contains the status from MRS. It can also contain a value of PAMS__SUCCESS when the message is not sent recoverably. |
15 |
8 |
Message Sequence Number |
A unique number assigned to the message when it is sent and follows the message to the destination PSB. This number is input to the pams_confirm_msg function to release a recoverable message. |
19 |
16 |
PSB UMA Status |
The completion status of the undeliverable message action (UMA). The PSB UMA status indicates if the UMA was not executed or applicable. |
23 |
20 |
Function Return |
After a BEA MessageQ function completes execution, BEA MessageQ software writes the return value to this field. |
31 |
24 |
Not Used |
Not used. |
Supplies the action to be performed if the message cannot be stored at the specified -delivery interest point. The format of this argument is PDEL_UMA_XXX where XXX is one of the following symbols:
Symbol |
Description |
---|---|
DISC |
Discard message |
DISCL |
Discard after logging message |
DLJ |
Dead letter journal |
DLQ |
Dead letter queue |
RTS |
Return to sender |
SAF |
Store and Forward |
Supplies a q_address to use as the alternate queue for receiving response messages from the receiver program. The sender program must be attached to the queue specified in the resp_q argument to receive the response messages. The resp_q argument has the following format:
The group ID is always specified as zero because the sender program cannot assign a response queue outside its group.
Supplies the actual size of the large message written to the message buffer.
Supplies the correlation id, a user-defined identifier stored as a 32-byte value
Reserved for BEA MessageQ internal use as a placeholder argument. This argument must be supplied as a null pointer.
Return Values
Return Code |
Platform |
Description |
---|---|---|
PAMS__BADARGLIST |
All |
Wrong number of call arguments have been passed to this function. |
PAMS__BADDELIVERY |
All |
Invalid delivery mode. |
PAMS__BADHANDLE |
All |
Invalid message handle. |
PAMS__BADPARAM |
UNIX |
Attempt to use cross-group connection when cross-group communication is disabled. On OpenVMS systems, invalid NULL call argument. |
PAMS__BADPRIORITY |
All |
Invalid priority value on send operation. |
PAMS__BADPROCNUM |
UNIX |
Invalid target queue address specified. |
PAMS__BADRESPQ |
All |
Response queue not owned by process. |
PAMS__BADTIME |
OpenVMS |
Invalid time specified. |
PAMS__BADUMA |
All |
Undeliverable message action (UMA) is invalid. |
PAMS__EXCEEDQUOTA |
All |
Target process quota exceeded; message was not sent. |
PAMS__EXHAUSTBLKS |
OpenVMS |
No more message blocks available. |
PAMS__FMLERROR |
All |
Problem detected with internal format of FML message; this can be an error in processing or data corruption. |
PAMS__LINK_UP |
OpenVMS |
MRS has reestablished link. |
PAMS__MSGTOBIG |
All |
Message exceeded the size of the largest link list section (LLS). |
PAMS__MSGTOSMALL |
OpenVMS |
Invalid (negative) msg_size specified in the argument list. |
PAMS__NETERROR |
Clients |
Network error resulted in a communications link abort. |
PAMS__NOMRS |
OpenVMS |
MRS is not available. |
PAMS__NOTACTIVE |
All |
Target process is not currently active; message not sent. |
PAMS__NOTDCL |
All |
Process has not been attached to BEA MessageQ. |
PAMS__NOTFLD |
All |
The buffer supplied is not an FML32 buffer. |
PAMS__NOTSUPPORTED |
All |
The combination of delivery mode and uma selected is not supported. |
PAMS__PNUMNOEXIST |
OpenVMS |
Target queue number does not exist. |
PAMS__PREVCALLBUSY |
Clients |
Previous call to CLS has not been completed. |
PAMS__REMQUEFAIL |
All |
Failed to properly dequeue a message buffer. |
PAMS__STOPPED |
All |
The requested queue has been stopped. |
PAMS__SUCCESS |
All |
Successful completion. |
PAMS__TIMEOUT |
All |
Timeout period has expired. |
PAMS__UNATTACHEDQ |
All |
Message successfully sent to unattached queue. |
PAMS__WAKEFAIL |
OpenVMS |
Failed to wake up the target process. |
UMA Status |
Platform |
Description |
---|---|---|
PAMS__DISC_FAILED |
All |
Message not recoverable in destination queue file (DQF); undeliverable message action (UMA) was PDEL_UMA_DISC; message could not be discarded. |
PAMS__DISC_SUCCESS |
All |
Message not recoverable in DQF; UMA was PDEL_UMA_DISC; message -discarded. |
PAMS__DISCL_FAILED |
All |
Message not recoverable in DQF; UMA was PDEL_UMA_DISC; recoverability failure could not be logged or message could not be discarded. |
PAMS__DISCL_SUCCESS |
All |
Message not recoverable in DQF; UMA was PDEL_UMA_DISC; message discarded after logging recoverability -failure. |
PAMS__DLJ_FAILED |
All |
Message not recoverable in DQF; UMA was PDEL_UMA_DLJ; dead letter journal (DLJ) write operation failed. |
PAMS__DLJ_SUCCESS |
All |
Message not recoverable in DQF; UMA was PDEL_UMA_DLJ; message written to the DLJ. |
PAMS__DLQ_FAILED |
All |
Message not recoverable in DQF; UMA was PDEL_UMA_DLQ; message could not be queued to the DLQ. |
PAMS__DLQ_SUCCESS |
All |
Message not recoverable in DQF; UMA was PDEL_UMA_DLQ; message queued to the DLQ. |
PAMS__NO_UMA |
All |
Message is recoverable; UMA not -executed. |
PAMS__RTS_FAILED |
All |
Message not recoverable in DQF; UMA was PDEL_UMA_RTS; message could not be returned to sender. |
PAMS__RTS_SUCCESS |
All |
Message not recoverable in DQF; UMA was PDEL_UMA_RTS; message returned to sender. |
PAMS__SAF_FAILED |
All |
Message not recoverable in DQF; UMA was PDEL_UMA_SAF; store and forward (SAF) write operation failed. |
PAMS__SAF_SUCCESS |
All |
Message not recoverable in DQF; UMA was PDEL_UMA_SAF; message recoverable from SAF file. |
PAMS__UMA_NA |
All |
UMA not applicable. |
Send a Message
This example sends a number of messages to a queue. The complete code example called x_putslf.c is contained in the examples directory.
pams_read_jrn
Reads a message from a BEA MessageQ journal file. Use the pams_open_jrn function to open the dead letter journal or postconfirmation journal for a message queuing group. Use the pams_close_jrn function to close the journal file after reading selected messages. Note that on UNIX and Windows NT systems, these functions are performed by running the Journal Replay utility.
The receiver program determines whether each message is a FML buffer or a large message by reading the len_data argument. See the Sending and Receiving BEA MessageQ Messages topic for more information on working with message handles and large messages.
Syntax
int32 pams_read_jrn ( jrn_handle, msg_area, priority, source,
class, type, msg_area_len, len_data, target,
write_time, conf_val, msg_seq_num, mrs_status,
[large_area_len], [large_size], [nullarg_3] )
Arguments
Argument |
Data Type |
Mechanism |
Prototype |
Access |
---|---|---|---|---|
jrn_handle |
int32 |
reference |
int32 * |
passed |
msg_area |
char |
reference |
char * |
returned |
priority |
char |
reference |
char * |
returned |
source |
q_address |
reference |
q_address * |
returned |
class |
short |
reference |
short * |
returned |
type |
short |
reference |
short * |
returned |
msg_area_len |
short |
reference |
short * |
returned |
len_data |
short |
reference |
short* |
returned |
target |
q_address |
reference |
q_address * |
returned |
write_time |
unsigned int32 |
reference |
unsigned int32 * |
returned |
conf_val |
int32 |
reference |
int32 * |
returned |
msg_seq_num |
unsigned int32 |
reference |
unsigned int32 * |
returned |
mrs_status |
int32 |
reference |
int32 * |
returned |
[large_area_len] |
int32 |
reference |
int32 * |
returned |
[large_size] |
int32 |
reference |
int32 * |
returned |
[nullarg_3] |
char |
reference |
char * |
returned |
Supplies the journal handle of the message recovery journal from which the application has selected to read journal entries. The journal handle is returned to the application by the pams_open_jrn function.
Receives the contents of the message retrieved from the selected message recovery journal. This argument contains either the address of a memory region or a message handle where BEA MessageQ writes.
Supplies the priority level for selective message reception. Priority ranges from 0 (lowest priority) to 99 (highest priority).
Receives a structure containing the queue number and group ID of the sender program's primary queue in the following format:
Receives the class code of the retrieved message. The class is specified in the arguments of the pams_put_msg function. BEA MessageQ supports the use of symbolic names for class argument values. Symbolic class names should begin with MSG_CLAS_. For information on defining class symbols, see the p_typecl.h include file. Class symbols reserved by BEA MessageQ are as follows:
Reserved Class |
Symbol Value |
---|---|
MSG_CLAS_MRS |
28 |
MSG_CLAS_PAMS |
29 |
MSG_CLAS_ETHERNET |
100 |
MSG_CLAS_UCB |
102 |
MSG_CLAS_TUXEDO |
31001 |
MSG_CLAS_TUXEDO_TPSUCCESS |
31002 |
MSG_CLAS_TUXEDO_TPFAIL |
31003 |
MSG_CLAS_XXX |
30000 through 32767 (except 31001-31003) |
Receives the type code of the journaled message. The type is specified in the arguments of the pams_put_msg function. BEA MessageQ supports the use of symbolic names for type argument values. Symbolic type names begin with MSG_TYPE_. For information on defining type symbols, see the p_typecl.h include file. The OpenVMS symbol values range from -1 through -5000. Use of the type argument facilitates selective message reception. However, if the receiving application does not need a specific value for its processing, then use a value of 0.
Supplies the size of the buffer (in bytes) for buffer-style messages of up to 32K bytes. The msg_area buffer is used to store the retrieved message.
Receives the queue number and group ID of the receiver's queue address in the following format:
Receives the address of the quadword (an array of two int32 values) specifying the date and time that the recoverable message was confirmed. This parameter uses standard OpenVMS system time.
Receives the message confirmation value.
Receives the message sequence number generated by BEA MessageQ in the PSB of the received message. This argument should be set to the values in the PSB.
Receives the Message Recovery Services (MRS) status of the message.
Specifies the size of the message buffer to receive messages larger than 32K.
Returns the actual size of the large message written to the message buffer.
Reserved for BEA MessageQ internal use as a placeholder argument. This argument must be supplied as a null pointer.
Return Values
Return Code |
Platform |
Description |
---|---|---|
PAMS__AREASTOSMALL |
OpenVMS |
Received message is larger than the user message area. |
PAMS__BADARGLIST |
OpenVMS |
Invalid number of arguments supplied. |
PAMS__BADHANDLE |
OpenVMS |
Invalid message handle. |
PAMS__INVJH |
OpenVMS |
Invalid journal handle. |
PAMS__MSGTOBIG |
OpenVMS |
Message in journal file is larger than GROUP_MAX_MESSAGE_SIZE. |
PAMS__NOMEMORY |
OpenVMS |
Insufficient virtual memory. |
PAMS__NOMOREMSG |
OpenVMS |
No more messages in journal. |
PAMS__SUCCESS |
OpenVMS |
Indicates successful completion. |
Allows application developers to define complex selection criteria for message reception. The selection array specifies the queues to search, the priority order of message reception, two comparison keys for range checking, and an order key to determine the order in which messages are selected from the queue.
The pams_set_select function creates an index handle that is used as the sel_filter argument of BEA MessageQ functions for reading the message. When a selection index handle is passed to pams_get_msg, pams_get_msga or pams_get_msgw, each message received is compared against comparison key_1 and then comparison key_2. If the message matches both keys (a logical AND operation), the message is added to a set of matched messages. The order in which selected messages are delivered is determined by the order key.
Syntax
int32 pams_set_select ( selection_array, num_masks, index_handle )
Arguments
Argument |
Data Type |
Mechanism |
Prototype |
Access |
---|---|---|---|---|
selection_array |
selection_array_ component |
reference |
selection_array_ component * |
passed |
num_masks |
short |
reference |
short * |
passed |
index_handle |
int32 |
reference |
int32 * |
returned |
Supplies an array of selection records that contain the selection rules for each queue. The typedef structures define the C data structure for the selection array. The structure is defined in p_entry.h as follows:
typedef struct _selection_array_component {
int32 queue;
int32 priority;
int32 key_1_offset;
int32 key_1_size;
int32 key_1_value;
int32 key_1_oper;
int32 key_2_offset;
int32 key_2_size;
int32 key_2_value;
int32 key_2_oper;
int32 order_offset;
int32 order_size;
int32 order_order;
union {
pams_correlation_id correlation_id;
pams_sequence_number sequence number
} extended_key
} selection_array_component;
The selection_array_component data structure has the following components:
Component |
Description |
---|---|
Queue and Priority |
Allows the application to specify the queue number and priority. |
Comparison Key 1 |
Defines the components of the first comparison key used to enable range checking of messages. |
Comparison Key 2 |
Defines the components of the second comparison key used to enable range checking of messages. |
Order Key |
Contains the information required to provide selection of messages by FIFO, Minimum Value, or Maximum Value. |
The following tables define the content of each of the components of the selection_array_component data structure.
The following table specifies the valid values that can be applied to the arguments in this part of the Select_Queue structure:
Field |
Values |
Description |
---|---|---|
Queue |
Queue Number |
Specifies the queue number to be searched. The queue number can be any message queue for which the application has read access. The queue number can be obtained from the q_attached argument of the pams_attach_q function or q_address of the pams_locate_q function. A value of 0 for this argument specifies the application's primary queue. |
Priority |
|
Specifies the priority, using either an integer between 0 and 99 inclusive or a variable. (Using the direct interger value is the preferred method of specifying priority.) This argument also accepts the following predefined constants which are set by the application. |
|
PSEL_PRI_ANY |
Read priority 1 before reading priority 0 messages. |
|
PSEL_PRI_P0 |
Read priority 0 messages only. |
|
PSEL_PRI_P1 |
Read priority 1 messages only. |
The following table specifies the arguments and valid values that can be applied to this part of the Selection_Array_Components structure:
Field |
Values |
Description |
---|---|---|
Offset |
Contains a value that specifies where the information to be compared begins inside the message. The following predefined constants apply: |
|
|
n |
User message byte number (0 relative). |
|
PSEL_SOURCE |
Source address of message. |
|
PSEL_CLASS |
Class of the message. |
|
PSEL_TYPE |
Type of the message. |
PSEL_CORRELATION_ID |
Correlation ID of the message. May be used for key_1_offset or key_2_offset but not both. If this symbol is specified, the Size field must be set to PSEL_CORRELATION_ID_SIZE (or 32 bytes). |
|
PSEL_SEQUENCE_NUMBER |
Message sequence number acquired from the PAMS Status Buffer. If this symbol is specified, the Size field must be set to PSEL_SEQUENCE_NUMBER_SIZE (or 8 bytes). |
|
Size |
|
Specifies data type of the key to be compared. |
|
0 |
Disable use of key. |
|
1 |
Byte (8 bits). |
|
2 |
Word (16 bits). |
|
4 |
int32 (32 bits). |
PSEL_SEQUENCE_NUMBER_SIZE |
8 bytes |
|
PSEL_CORRELATION_ID_SIZE |
32 bytes |
|
Value |
n |
Contains the value for message field comparison field that is formatted as an integer of 32 bits. |
oper |
|
Relational operator comparison. |
|
PSEL_OPER_EQ |
Message field = value. |
|
PSEL_OPER_NEQ |
Message field <> value. |
|
PSEL_OPER_GTR |
Message field > value. |
|
PSEL_OPER_LT |
Message field < value. |
|
PSEL_OPER_GTRE |
Message field > or = value. |
|
PSEL_OPER_LTE |
Message field < or = value. |
The Order Key part contains variables described in the following table:
Field |
Values |
Description |
---|---|---|
Offset |
|
Byte offset of the message field. The offset variable contains a value that specifies where the information to be compared begins inside the message. |
|
n |
User message byte number (0 relative). |
|
PSEL_SOURCE |
Source address of the message. |
|
PSEL_CLASS |
Class of the message. |
|
PSEL_TYPE |
Type of the message. |
PSEL_CORRELATION_ID |
Correlation ID of the message. If this symbol is specified, the Size field must be set to PSEL_CORRELATION_ID_SIZE (or 32 bytes). |
|
PSEL_SEQUENCE_NUMBER |
Message sequence number acquired from the PAMS Status Buffer. If this symbol is specified, the Size field must be set to PSEL_SEQUENCE_NUMBER_SIZE (or 8 bytes). |
|
Size |
|
Size of the comparison. The size variable specifies the data type of the key to be compared. |
|
0 |
Disable use of key. |
|
1 |
Byte. |
|
2 |
Word. |
|
4 |
int32 (32 bits). |
PSEL_SEQUENCE_NUMBER_SIZE |
8 bytes |
|
PSEL_CORRELATION_ID_SIZE |
32 bytes |
|
Order |
|
Order operator. The order variable specifies the sequence in which the select process is to be performed. |
|
PSEL_ORDER_FIFO |
First pending. |
|
PSEL_ORDER_MIN |
Minimum value of all pending. |
|
PSEL_ORDER_MAX |
Maximum value of all pending. |
The correlation ID is a 32-byte user-defined identifier associated with a message. If PSEL_CORRELATION_ID is supplied as the value for either the key_1_offset or key_2_offset field, the correlation ID value is used to match messages with the specified correlation ID. Since there is a single correlation ID per message, PSEL_CORRELATION_ID should only be specified for one of the comparison keys; specifying the correlation ID for both keys results in a PAMS_BADPARAM error.
If PSEL_CORRELATION_ID is supplied as the value for the order_offset field, messages with the specified correlation ID are returned in the order specified by the order_order field.
The message sequence number is a unique value for each message. The sequence number is stored in the PAMS Status Buffer (PSB). Applications should acquire the message sequence number from the PSB and not modify it in any way.
Note: An application may specify only one of the two keys to select by correlation identifier or by sequnce number.
Supplies the number of records in the selection array. This argument allows a minimum of 1 record to a maximum of 256 records in the selection array.
Receives a variable containing the index handle for the selection mask as follows:
The index_handle is passed as the sel_filter argument in pams_get_msg, pams_get_msga or pams_get_msgw, and pams_cancel_select functions. OpenVMS allows a maximum number of 500 index handles. Other BEA MessageQ implementations offer 16K to 32K index handles.
Return Values
Return Code |
Platform |
Description |
---|---|---|
PAMS__BADARGLIST |
OpenVMS |
Invalid number of arguments supplied. |
PAMS__BADPARAM |
All |
Bad argument passed in the function call. |
PAMS__IDXTBLFULL |
All |
Selective receive index table is full. |
PAMS__NETERROR |
Clients |
Network error resulted in a communications link abort. |
PAMS__NOTDCL |
All |
Process has not been attached to BEA MessageQ. |
PAMS__PAMSDOWN |
UNIX |
The specified BEA MessageQ group is not running. |
PAMS__PREVCALLBUSY |
Clients |
Previous call to CLS has not been completed. |
PAMS__SUCCESS |
All |
Indicates successful completion. |
Selecting Messages Using a Complex Selection Filter
This example shows the selective reception of messages using pams_set_select to build a complex message selection filter. The queue named "queue_1" must be defined in your initialization file as a primary queue. The complete code example called x_select.c is contained in the examples directory.
pams_set_timer
Creates a timer that sends a message to an application's primary queue when a time interval expires or a time of day arrives. The message is sent as a priority 1 message with a source of PAMS_TIMER_QUEUE, a class code of PAMS, and a type code of TIMER_EXPIRED. A timer_id is returned by this function as the first int32 value in the TIMER_EXPIRED message.
Note: Prior to BEA MessageQ Version 5.0, the valid priority values were 0 and 1. In Version 5.0, the valid range is 0 to 99 (0 being the lowest priority and 99 the highest priority). Keep in mind that timer priorities are always 1 and take this into account when modifying existing programs to take advantage of the expanded priority range. Messages associated with timers have a priority of 1 and are not sent until all messages with priorities from 2 to 99 are read.
To act upon the timer message, the application uses the pams_get_msgw function to read its primary queue, block until the timer expiration message arrives, and then act upon it. To cancel a BEA MessageQ timer, use the pams_cancel_timer function with the identification code of the timer you want to cancel.
Syntax
int32 pams_set_timer ( timer_id, timer_format, p_timeout,
s_timeout )
Arguments
Argument |
Data Type |
Mechanism |
Prototype |
Access |
---|---|---|---|---|
timer_id |
int32 |
reference |
int32 * |
passed |
timer_format |
char |
reference |
char * |
passed |
p_timeout |
int32 |
reference |
int32 * |
passed |
s_timeout |
unsigned quadword |
reference |
unsigned quadword * |
passed |
Supplies a unique timer identification value created by the application. Must be greater than zero.
Supplies the time format being used. Following are the two predefined constants for this argument:
Supplies the amount of time to delay (delta) from the current time before returning a timer expiration message. If the timer_format argument is set to P, a value greater than 0 must be entered for this argument. This argument uses the PAMS timer format which expresses time in units of one tenth of one second.
On OpenVMS systems, use this argument to supply a pointer to an array of two int32 values used to set a 64-bit OpenVMS time format. The s_timeout argument can be specified as an absolute time or a delta time matching the OpenVMS time format rules. Note that if the caller exceeds the ASTLM or TQELM process quota, the process can enter the RWAST state.
On UNIX and Windows NT systems, use this argument to supply a two element array of int32 values. The values represent an absolute time (a UTC time in seconds and microseconds) at which the timer will expire. To use the s_timeout argument, developers provide a pointer to a "struct timeval" as follows:
struct timeval theTime;
nStatus = pams_set_timer(&timer_id, "S", NULL, (int32 *) &theTime);
Return Values
Return Code |
Platform |
Description |
---|---|---|
PAMS__BADARGLIST |
OpenVMS |
Invalid number of arguments supplied. |
PAMS__BADPARAM |
All |
Bad argument value. |
PAMS__INVALIDNUM |
All |
Invalid timer number passed to pams_set_timer. |
PAMS__INVFORMAT |
All |
Invalid timer format specified in the call. Should be P or S. |
PAMS__NETERROR |
Clients |
Network error resulted in a communications link abort. |
PAMS__NOTDCL |
All |
Process has not been attached to BEA MessageQ. |
PAMS__NOTSUPPORTED |
UNIX |
The S timer_format is not supported by BEA MessageQ for UNIX and Windows NT systems. |
PAMS__PAMSDOWN |
UNIX |
The specified BEA MessageQ group is not running. |
PAMS__PREVCALLBUSY |
Clients |
Previous call to CLS has not been completed. |
PAMS__RESRCFAIL |
All |
Insufficient resources to complete operation. |
PAMS__SUCCESS |
All |
Indicates successful completion. |
Set a Timer
This example shows how to use the BEA MessageQ timer functions by setting a timer to go off every 5 seconds. When the timer expires, it sends messages to itself. While not handling the timer event, it sits and waits for other incoming messages. If it is interrupted, it cancels any outstanding timers. The queue named "queue_1" must be defined in your initialization file as a primary queue. The complete code example called x_timer.c is contained in the examples directory.
pams_status_text
Receives the severity level and text description of a user-supplied PAMS API return code and moves that information to a user-supplied storage area. If the error code is not known, an error is returned and the call parameters are not filled in.
Syntax
int32 pams_status_text ( code, severity, buffer, buflen, retlen)
Arguments
Argument |
Data Type |
Mechanism |
Prototype |
Access |
---|---|---|---|---|
code |
int32 |
reference |
int32 * |
passed |
severity |
int32 |
reference |
int32 * |
returned |
buffer |
char |
reference |
char * |
returned |
buflen |
int32 |
reference |
int32 * |
passed |
retlen |
int32 |
reference |
int32 * |
returned |
Specifies the return value for which you would like the text description and severity level returned.
Receives a code indicating the severity level of the message. Severity levels apply to both success and error messages. They are designed to provide more information about the message being returned. The valid codes returned to this argument are as follows:
0 = warning
1 = success
2 = error
3 = informational
4 = fatal error
Receives the text description for the return status supplied.
Specifies the length of the buffer to store the text description returned. A buffer length of 256 bytes is adequate to store the text description for all return status codes. If the user buffer supplied is large enough, the string is zero terminated. The buffer length must be entered as a positive integer. Supplying a negative integer value to this argument causes the function to return a status of PAMS__BADPARAM. If you specify this argument as zero, no text is returned to the buffer and the function returns the status of PAMS__TRUNCATED.
Receives the size of the user-supplied buffer space that was filled by the text description returned.
Description
Application developers use the pams_status_text function to obtain a text description and severity level for each API return value. The text description contains both the symbolic name (as it is defined in the include files and described in the documentation) followed by a comma, a space, and then a description of the return value in the following format:
PAMS__SUCCESS, normal successful completion
In addition to the text description, this function returns a code indicating the severity level for both success and error messages.
For example, pams_detach_q has two possible success return codes; PAMS--__SUCCESS and PAMS__DETACHED. The PAMS__SUCCESS return code is used to indicate that you successfully detached the specified queue(s). PAMS__DETACHED is an informational return code indicating that the call was successful and that you have detached your last queue which effectively detaches your application from the message queuing bus in the same manner as the pams_exit function.
Return Values
Return Code |
Platform |
Description |
---|---|---|
PAMS__BADARGLIST |
OpenVMS |
Invalid number of call parameters specified. |
PAMS__BADPARAM |
All |
Invalid call parameter specified. |
PAMS__FAILED |
All |
There is no translation for the specified return code. |
PAMS__SUCCESS |
All |
Normal successful completion. |
PAMS__TRUNCATED |
All |
The description was returned but was -truncated. |
Requests the number of pending messages for a list of selected queues. To use the putil_show_pending function, specify the number of message queues for which you want to obtain a pending message count and the list of queue addresses for which you want to obtain a pending message count. The value returned by this function contains the total number of messages in each memory queue. On OpenVMS systems, this function also returns the number of pending messages in the local recovery journals targeted for delivery to the selected queue.
Syntax
int32 putil_show_pending ( count, in_q_list, out_pend_list )
Arguments
Argument |
Data Type |
Mechanism |
Prototype |
Access |
---|---|---|---|---|
count |
int32 |
reference |
int32 * |
passed |
in_q_list |
short array |
reference |
short array* |
passed |
out_pend_list |
int32 array |
reference |
int32 array * |
returned |
Supplies the number of queue entries in the in_q_list argument (the number of indexes in the array). The maximum allowed value is 32,000.
Supplies an array of int32 values containing the queue numbers for which the pending message count is requested.
Receives the pending message count for each selected queue.
Return Values
Return Code |
Platform |
Description |
---|---|---|
PAMS__BADARGLIST |
UNIX |
Invalid argument supplied to this function. |
PAMS__BADPARAM |
OpenVMS |
Invalid argument supplied to this function. |
PAMS__NETERROR |
Clients |
Network error resulted in a communications link abort. |
PAMS__NOTDCL |
All |
Process is not attached to BEA MessageQ. |
PAMS__RESRCFAIL |
All |
Insufficient resources to complete operation. |
PAMS__PAMSDOWN |
All |
The specified BEA MessageQ group is not running. |
PAMS__PREVCALLBUSY |
Clients |
Previous call to CLS has not been completed. |
PAMS__SUCCESS |
All |
Successful completion. |
Display Number of Pending Messages
This example shows how to use putil_show_pending to display the number of pending messages currently in the queue. A queue named "queue_1" must be defined during group configuration. The complete code example called x_shopnd.c is contained in the examples directory.
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Copyright © 2000 BEA Systems, Inc. All rights reserved.
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