This topic includes the following sections:
Note: | The Oracle Tuxedo CORBA Java client and Oracle Tuxedo CORBA Java client ORB were deprecated in Tuxedo 8.1 and are no longer supported. All Oracle Tuxedo CORBA Java client and Oracle Tuxedo CORBA Java client ORB text references, associated code samples, should only be used to help implement/run third party Java ORB libraries, and for programmer reference only. |
Note: | Technical support for third party CORBA Java ORBs should be provided by their respective vendors. Oracle Tuxedo does not provide any technical support or documentation for third party CORBA Java ORBs. |
The Oracle Tuxedo CORBA Notification Service supports two application programming interfaces. One is based on the CORBA-based Notification Service as defined by the CORBAservices: Common Object Services Specification. This interface is referred to in this document as the CosNotification Service interface. The other interface, called the Oracle Simple Events interface, is an Oracle proprietary interface designed as an easier to use alternative.
Both interfaces pass structured events as defined by the CORBA-based Notification Service specification and are compatible with each other; that is, events posted using the CosNotification Service interface can be subscribed to by the Oracle Simple Events interface and vice versa.
Before using the Notification Service APIs, consider the following topics:
To determine the persistence of the subscription and whether or not events delivery is retried following a failed delivery, subscribers specify a Quality of Service (QoS). There are two Quality of Service settings: persistent and transient Quality of Service (QoS). The QoS is a property of the subscription.
Persistent subscriptions provide strong guarantees about event delivery and the permanence of the subscription. Persistent subscriptions do come with a cost, however, as they consume more system resources (for example, disk space, CPU cycles, and so on), and require more administration (such as managing queues and detecting dead subscribers).
Persistent subscriptions exhibit the following properties:
Transient subscriptions provide the best performance with the least overhead and exhibit the following properties:
The subscription is in effect until a failed event delivery is detected. On detection of a failed delivery, the subscription is terminated. Normally, the Notification Service, for performance reasons, does not check whether it successfully delivered an event to a transient subscriber. However, occasionally, when the Notification Service delivers an event to a transient subscriber, it checks whether or not the event was successfully delivered. If it was not successfully delivered and the CORBA::TRANSIENT
exception is not returned, the Notification Service assumes that the subscription has gone away and cancels the subscription. If the Notification Service receives the CORBA::TRANSIENT
exception when an attempt to deliver fails, it assumes that the subscriber is busy and discards the event, but it does not cancel the subscription.
The automatic cancellation of dead transient subscriptions provides a cleanup mechanism for transient subscribers that forget to unsubscribe. Note, however, that the Notification Service checks for successful delivery the first time it sends an event to a subscriber, but does not perform it again until five minutes have elapsed and it delivers another event. Therefore, the interval between checks is at least five minutes, but will be longer if there is no event to deliver when five minutes have elapsed. The minimum interval of five minutes is fixed and cannot be changed. Therefore, event delivery failure is not necessarily detected on the first failed delivery attempt. It is only detected when the Notification Service checks.
The Channel Factory is used by event poster applications and subscriber applications to find the event channel. The event channel is then used to post events and to subscribe, or create subscriptions, and unsubscribe, or cancel subscriptions.
Notification Service applications use the Bootstrap object to obtain an object reference to the event channel factory. This is done by using the Tobj_Bootstrap::resolve_initial_references
operation. The Bootstrap object supports two service IDs for Notification Service applications, NotificationService
and Tobj_SimpleEventsService
. The NotificationService
object is used in applications that use the CosNotification Service API. The Tobj_SimpleEventsService
object is used in applications that use the Oracle SimpleEvents API.
Note: | Release 8.0 of Oracle Tuxedo CORBA continues to include the Oracle client environmental objects provided in previous releases of Oracle WebLogic Enterprise for use with the Tuxedo 8.0 CORBA clients. Oracle Tuxedo 8.0 clients should continue to use these environmental objects to resolve initial references bootstrapping, security and transaction objects. In release 8.0 of Oracle Tuxedo CORBA, support has been added for using the OMG Interoperable Naming Service (INS) to resolve initial references to bootstrapping, security, and transaction objects. For information on INS, see the CORBA Programming Reference. |
The behavior regarding transactions is the same for the Oracle SimpleEvents API and the CosNotification Service API. The only operation that supports transactional behavior is push_structured_event
, which is supported by the CosNotifyChannelAdmin::StructuredProxyPushConsumer
and Tobj_SimpleEvents::Channel
interfaces.
All other operations can be used in the context of a transaction, but work the same regardless of whether they are executed in a transaction or not.
The behavior when posting an event is tied to the QoS of the subscription. If an event is posted in the context of a transaction, and the event delivery QoS of the subscription is persistent, the delivery will be affected by the outcome of the transaction; that is, if the transaction is committed, the Notification Service attempts to deliver the event to subscribers as it normally would. If the transaction is rolled back, then the Notification Service does not attempt to deliver the event.
If an event is posted in the context of a transaction, and the event delivery QoS of the subscriber’s subscription is transient, one attempt will be made to deliver the event, regardless of the transaction outcome. That is, the transaction has no effect on whether the event is delivered or not, and one attempt will be made to deliver the event.
Note: | There is no transaction context associated with event delivery. However, in the case of persistent subscriptions, once the poster’s transaction commits, the Notification Service guarantees that the event will be delivered to the subscriber or put on the error queue to await administrative action. |
All events that are either pushed by posters to the Notification Service, or delivered to subscribers, are COS Structured Events; that is, they conform to the definition of Structured Events as specified by the CORBA-based Notification Service—a service which extends the CORBAservices Event Service (see Figure 2-1). If the events are to be filtered based on content (versus filtering on domain and type), or if the events are going to be subscribed to by Oracle Tuxedo applications, then additional restrictions apply. The restrictions apply to data types and filtering based on event content. These restrictions are explained below.
any
, long
, unsigned long
, short
, unsigned short
, octet, char
, float
, double
, string
, boolean
, void
, and null
. These fields can be used in filter expressions.ANY
. The value is limited to the following types: any
, long
, unsigned long
, short
, unsigned short
, octet, char
, float
, double
, string
, boolean
, void
, and null
. This field cannot be used in a filter expression.The design of events is basic to any notification service. The design impacts not only the volume of information that is delivered to matching subscriptions, but the efficiency and performance of the Notification Service as well. Therefore, careful planning should be done to ensure that your Notification Service will be able to handle your needs now and allow for future growth.
The Notification Service supports five levels of event design: (1) domain name, (2) type name, (3) priority, (4) filterable data, and (5) remainder of body. When designing an event, you must specify a domain name and a type name; priority and filterable data are optional. The domain name you choose can relate to your business. Hospitals, for example, are in the health care business, so for a Notification Service application for a hospital you might choose “HEALTHCARE” as a domain name. You might want to categorize the events by the type of insurance provider, so you may choose “HMO” or “UNINSURED” as the type name. You may want to further define the events by the entity responsible for payment, so you might choose to use the filterable data to identify the entity as “billing” for a specific “HMO_Account” or a specific or “Patient_Account.” Listing 2-1 shows an example of this type of event design.
domain_name = “HEALTHCARE”
type_name = “HMO”
#Filterable data name/value pairs.
filterable_data.name = “billing”
filterable_data.value = 4498
filterable_data.name = “patient_account”
filterable_data.value = 37621
Obviously, the more specific and precise you are in designing the events that you want your Notification Service application to post and receive, the fewer will be the events the Notification Service will have to process. This has a direct impact on system resources and configuration requirements. Therefore, a lot of thought should be given to event design.
You must create Field Manipulation Language (FML) field table files for events only if one of the following capabilities is required; otherwise FML tables are not required.
A structured event’s filterable_data
field contains a list of name/value (NV) pairs. An event’s data is typically stored in this list. The field names in the FML field table files must match the name in the structured event. The field type can be any allowable FML type (long
, short
, double
, float
, char
, string)
except carray
. The value in the structured event must be the same type as defined in the field table. Table 2-1 shows the CORBA Any Types supported by Oracle Tuxedo, and which ones can be used for data filtering and Oracle Tuxedo interoperability.
Listing 2-2 shows an example of an FML field table file. The *base
2000 is the base number for the fields. The first entry has a field name of billing, a field number of 1
relative to the base, and a field type of long.
*base 2000
#Field Name Field # Field Type Flags Comments
#----------- ------- ---------- ------ --------
billing 1 long - -
stock_name 2 string - -
price_per_share 3 double - -
number_of_shares 5 long - -
The following guidelines and restrictions apply to Oracle Tuxedo FML field table files:
For information on how to create and configure FML field table files, see field_tables
in the Oracle Tuxedo Command Reference and the Programming Oracle Tuxedo ATMI Applications Using FML.
Applications that use the Oracle Tuxedo CORBA Notification Service are interoperable with Oracle Tuxedo applications that use the Oracle Tuxedo EventBroker. An application using the Oracle Tuxedo Notification Service can post events that are delivered to Oracle Tuxedo EventBroker subscribers, and can receive events that have been posted by Oracle Tuxedo EventBroker.
To achieve this interoperability, it is necessary to understand the mapping between CosNotification Structured Events and the Oracle Tuxedo FML buffer so that the contents of the FML field tables can be coordinated by Oracle Tuxedo. There are two cases to consider: posting events that are to be received by Oracle Tuxedo applications via Oracle Tuxedo EventBroker; and receiving events that have been posted to the Notification Service Event Channel by Oracle Tuxedo applications.
For an Oracle Tuxedo application to subscribe to events posted by an Oracle Tuxedo application, you must understand how an Oracle Tuxedo structured event is mapped to FML32 and the event name at posting time. The mapping is as follows:
domain_name.type_name
to form the event name. This is the event name (eventname parameter) used on the tppost
operation.“TMEVT”
, then the event name equals the type name.
Oracle Tuxedo system events and user events can be received by Oracle Tuxedo applications. System events are generated by the Oracle Tuxedo system—not by applications. User events are generated by Oracle Tuxedo applications. For a listing of System events see EVENTS
in the Oracle Tuxedo Command Reference. System events and user events are mapped in CosNotification Structured Events as follows:
|
|||
The Oracle Tuxedo system detects and posts certain predefined events related to system warnings and failures. For example, system-generated events report on configuration changes, state changes, connection failures, and machine partitioning.
In order for an Oracle Tuxedo application to receive events posted by an Oracle Tuxedo application, it is necessary to understand how a FML buffer containing an Oracle Tuxedo event is used to fabricate an Oracle Tuxedo structured event. It is also necessary to know how the domain_name
and type_name
are related to the Oracle Tuxedo event name. There are two cases to consider: system events and user events.
Note that Oracle Tuxedo uses a leading dot (".") in the event name to distinguish system-generated events from application-defined events. An example of a system event is .SysNetworkDropped
. An example of a user event is eventsdropped
. To subscribe to these events, the Notification Service subscriber application must define the subscription as follows:
domain_name =“TMEVT”
type_name=“.SysNetworkDropped”
domain_name =“TMEVT”
type_name=“eventsdropped”
When the events are received, the Notification Service subscriber application parses each event as follows:
domain_name=”TMEVT”
type_name=””
event_name=””
variable_header=empty
Filterable_data=(content of the FML buffer)
When you create subscriptions, you can specify the following parameters. These parameters support the Oracle Simple Events API and the CosNotification Service API.
subscription_name
subscription_name
must not exceed 128 characters in length.
domain_type
domain_type
field in the Fixed Header portion of a structured event, as defined by the CORBA-based Notification Service specification. This field is a string that is used to identify a particular vertical industry domain in which the event type is defined, for example, “Telecommunications”, “Finance”, and “Health Care”. Because this parameter is a regular expression, you can also use it to set domain patterns on which to filter. For example, to subscribe to all domains that begin with the letter F, set the domain to “F.*”
. For information on how to construct regular expressions, see the recomp
command in the Oracle Tuxedo ATMI C Function Reference.
type_name
type_name
field in the Fixed Header portion of a structure event, as defined in the CORBA-based Notification Service specification. It is a string that categorizes the type of event, uniquely within the domain, for example, Comm_alarm, StockQuote, and VitalSigns. Because this parameter is a regular expression, you can also use it to set event type patterns on which to filter. For example, to subscribe to all event types that begin with the letter F, you would set the type to “F.*”
. For information on how to construct regular expressions, see the recomp
command in the Oracle Tuxedo ATMI C Function Reference.
data_filter
short
, long
, char
, float
, double
, and string
. Table 2-2 lists the Boolean expression operators that are supported.
To use data filtering, you must set up an FML table, include filters in the subscription, filter the data, and post the event. Listing 2-3 shows an example of these tasks.
//Setting up the FML Table
Field table file.
----------------
*base 2000
*Field Name Field # Field Type Flags Comments
----------- ------- --------- ------ ------
StockName 1 string - -
PricePerShare 2 double - -
CustomerId 3 long - -
CustomerName 4 string - -
//Subscription data filtering.
1) "NumberOfShares > 100 && NumberOfShares < 1000"
2) "CustomerId == 3241234"
3) "PricePerShare > 125.00"
4) "StockName == 'BEAS'"
5) "CustomerName %% '.*Jones.*'" // CustomerName contains "Jones"
6) "StockName == 'BEAS' && PricePerShare > 150.00"
//Posting the event.
// C++
CosNotification::StructuredEvent ev;
...
ev.filterable_data[0].name = CORBA::string_dup("StockName");
ev.filterable_data[0].value <<= "BEAS";
ev.filterable_data[1].name = CORBA::string_dup("PricePerShare");
ev.filterable_data[1].value <<= CORBA::Double(175.00);
ev.filterable_data[2].name = CORBA::string_dup("CustomerId");
ev.filterable_data[2].value <<= CORBA::Long(1234567);
ev.filterable_data[3].name = CORBA::string_dup("CustomerName");
ev.filterable_data[3].value <<= "Jane Jones";
push_consumer
Note: | You can use either transient or persistent object references for the callback objects. Both QoS and application run times should be taken into consideration when deciding which type of object reference to use. For information to assist you in deciding which type of object reference to use, refer to Table 2-3. |
qos
(quality of service)
CORBA::TRANSIENT
exception, it concludes that the subscriber is shutdown or otherwise not available and cancels the subscription. If the Notification Service receives the CORBA::TRANSIENT
exception when an attempt to deliver fails, it assumes that the subscriber is busy and discards the event, but it does not cancel the subscription.
For persistent subscriptions, if the first delivery attempt fails, the Notification Service holds the event in the pending queue and keeps attempting to deliver the subscription until the configurable retry limit is reached. When the retry limit is reached, the Notification Service moves the event on an error queue where it is held for disposition by the system administrator. The system administrator either removes the event from the error queue, which in effect discards it, or moves it back to the pending queue so that further attempts to deliver it can be made.
Note: | For persistent subscriptions, the Notification Service always does a two-way invoke on callback objects to deliver events. If a joint client/server does not activate a callback object (the event receiver) before it calls orb->run and then the Notification Service invokes on the callback object, as far as the POA is concerned, the callback object does not exist. In this case CORBA::OBJECT_NOT_EXIST exception is returned. If the Notification Service receives a CORBA::OBJECT_NOT_EXIST exception, it drops the subscription and the event; otherwise, the subscription is retained and the event is retried. |
Simplicity and ease-of-use are the defining characteristics of the Oracle Simple Events application programming interface (API). Its capabilities are similar to those of the Oracle Tuxedo EventBroker.
The Oracle Simple Events API consists of the following interfaces (see Figure 2-2):
The Tobj_SimpleEvents::Channel
and the Tobj_SimpleEvents::ChannelFactory
interfaces are implemented by the Notification Service and are described below.
The CosNotifyComm::StructuredPushConsumer
interface is implemented by the subscribers. For a description of this interface, see "CosNotifyComm::StructuredPushConsumer::push_structured_event" on page -51.
Note: | The CosNotification Service classes referred to in this section are fully described in the CosNotification Service IDL files, which are located in the tuxdir/include directory. |
Note: | If you use class operations that are not supported, the CORBA::NO_IMPLEMENT exception is raised. |
The Channel interface is used:
This interface provides these operations:
The CORBA IDL for this interface:
module Tobj_SimpleEvents
{
typedef long SubscriptionID;
typedef string RegularExpression;
typedef string FilterExpression;
const SubscriptionType TRANSIENT_SUBSCRIPTION = 0;
const SubscriptionType PERSISTENT_SUBSCRIPTION = 1;
interface Channel
void push_structured_event(
{
in CosNotification::StructuredEvent event);
SubscriptionID subscribe (
in string subscription_name,
in RegularExpression domain,
in RegularExpression type,
in FilterExpression data_filter,
in CosNotification::QoSProperties qos,
in CosNotifyComm::StructuredPushConsumer push_consumer);
boolean exists( in SubscriptionID id );
void unsubscribe( in SubscriptionID id );
};
};
These operations are described in the following section.
SubscriptionID subscribe (
in string subscription_name,
in RegularExpression domain,
in RegularExpression type,
in FilterExpression data_filter,
// The filter expression must length 1 and the name must
// be TRANSIENT_SUBSCRIPTION or PERSISTENT_SUBSCRIPTION.
in CosNotification::QoSProperties qos,
in CosNotifyComm::StructuredPushConsumer push_consumer
);
For a description of the parameters supported by this operation, see "Parameters Used When Creating Subscriptions" on page -11.
CORBA::BAD_PARAM
Tobj_Events::SUB_INVALID_FILTER_EXPRESSION
Tobj_Events::SUB_UNSUPPORTED_QOS_VALUE
CORBA::IMP_LIMIT
Tobj_Events::SUB_DOMAIN_BEGINS_WITH_SYSEV
Tobj_Events::SUB_EMPTY_DOMAIN
Tobj_Events::SUB_EMPTY_TYPE
Tobj_Events::SUB_DOMAIN_AND_TYPE_TOO_LONG
Tobj_Events::SUB_FILTER_TOO_LONG
Tobj_Events::SUB_NAME_TO_LONG
Tobj_Events::TRANSIENT_ONLY_CONFIGURATION
CORBA::INV_OBJREF
Note: | For more information on exceptions and corresponding minor codes, see "Exception Minor Codes" on page -53. |
Use this operation to subscribe to events. This operation is called by a subscriber application on the Notification Service to create a subscription to a particular event. The subscription name, domain name, type name, data filter, quality of service, and the object reference of the subscriber’s callback object are passed in. The callback object implements the CosNotifyComm::StructuredPushConsumer IDL interface.
Note: | For subscribers that shut down and restart, you must write the subscription_id to persistent storage. |
To use data filtering or subscribe to Oracle Tuxedo system events or events posted by an Oracle Tuxedo application, see the sections "Creating FML Field Table Files for Events" on page -7 and "Interoperability with Oracle Tuxedo Applications" on page -9.
Returns a unique subscription identifier. The effect of this operation is not instantaneous. There can be a delay between returning from this operation and the actual start of event delivery. The length of the delay period may be significant depending on your configuration. For more information on factors impacting this delay period, see "Synchronizing Databases" on page -23.
Note: | Notification Service applications that start and shut down only once can use the subscription_id to determine if their subscription has been cancelled automatically or by the system administrator. |
Note: | Code examples shown here are abbreviated. For complete code examples, see "Creating a Subscription" on page -8. |
subscription_id = channel->subscribe(
subscription_name,
"News", // domain
“Sports”, // type
"", // No data filter.
qos,
news_consumer.in()
);
void unsubscribe( in SubscriptionID id );
subscription_id
CORBA::BAD_PARAM
Note: | For more information on exceptions and corresponding minor codes, see "Exception Minor Codes" on page -53. |
Used to unsubscribe. Subscriber applications use this operation to terminate subscriptions. On return from this operation, no further events can be delivered. There is one input parameter: SubscriptionID
, which you got when you subscribed.
Note: | This operation is not instantaneous. After returning from this operation, a subscriber may continue to receive events for a period of time. The period of time may be significant depending on your configuration. For more information on factors impacting this period of time, see "Synchronizing Databases" on page -23. |
channel->unsubscribe(subscription_id);
void push_structured_event(
in CosNotification::StructuredEventnotification
);
notification
CORBA_IMP_LIMIT
Tobj_Events::POST_UNSUPPORTED_VALUE_IN_ANY
Tobj_Events::POST_UNSUPPORTED_PRIORITY_VALUE
Tobj_Events::POST_DOMAIN_CONTAINS_SEPARATOR
Tobj_Events::POST_TYPE_CONTAINS_SEPARATOR
Tobj_Events::POST_SYSTEM_EVENTS_UNSUPPORTED
Tobj_Events::POST_EMPTY_DOMAIN
Tobj_Events::POST_EMPTY_TYPE
Tobj_Events::POST_DOMAIN_AND_TYPE_TOO_LONG
Note: | For more information on exceptions and corresponding minor codes, see "Exception Minor Codes" on page -53. |
Used by the poster application to post an event to the Notification Service.
Note: | This operation has transactional behavior when used in the context of a transaction. For more information, see the section "Using Transactions" on page -4. |
Note: | Code examples shown here are abbreviated. For complete code examples, see "Creating and Posting Events" on page -3. |
channel->push_structured_event(notification);
boolean exists(in SubscriptionID subscription_id);
subscription_id
CORBA::BAD_PARAM
subscription_id
is for a subscription created using the CosNotification Service API, this exception is always returned.
Note: | For more information on exceptions and corresponding minor codes, see "Exception Minor Codes" on page -53. |
Used by subscriber applications to determine if a subscription exists. Since the system administrator can delete subscriptions manually and the Notification Service can delete transient subscriptions automatically, a subscriber application might want to use this operation so that it can recreate the subscription, if necessary. The subscription_id
used in this operation is the same one that you got when you subscribed.
Returns Boolean True of the subscription exists and False if it does not.
if channel->exists (subscription_id) {
// The subscription is still valid.
} else {
// The subscription no longer exists.
}
The ChannelFactory
interface is used to find event channels. This interface provides a single operation: find_channel
.
The CORBA IDL for this interface:
module Tobj_SimpleEvents
{
typedef long ChannelID;
interface ChannelFactory
{
Channel find_channel(
in ChannelID channel_id // Must be DEFAULT_CHANNEL
);
};
};
Channel find_channel(
in ChannelID channel_id );
In this release of Oracle Tuxedo, there can only be one event channel; therefore, the ChannelID
that is passed in must be set to Tobj_SimpleEvents::DEFAULT_CHANNEL
(for C++).
CORBA::BAD_PARAM
Note: | For more information on exceptions and corresponding minor codes, see "Exception Minor Codes" on page -53. |
Used by poster applications and subscriber applications. This operation is used to find the event channel so that it can be used by the poster to post events and by the subscriber to subscribe and unsubscribe to events.
Returns the default event channel’s object reference.
Note: | Code examples shown here are abbreviated. For complete code examples, see "Getting the Event Channel" on page -2. |
channel_factory->find_channel(
Tobj_SimpleEvents::DEFAULT_CHANNEL);
This section contains a discussion of the operations defined by the CosNotification Service that are implemented by the Oracle Tuxedo CORBA Notification Service. These operations are only a subset of the complete set of operations. This subset is a functionally complete API that can be used as an alternative to the Oracle Simple Events API.
This API is more complex then the Oracle Simple Events API. There are two reasons for this. First, the CosNotification Service API is more complex. Second, the Oracle Tuxedo implementation of the CosNotification Service API places additional restrictions on the operations that are supported. Because this complexity offers no advantages in terms of performance or flexibility, Oracle Systems, Inc. recommends that you use the Oracle Simple Events API whenever possible.
The CosNotification API is provided for those who require that a standard API be used whenever possible for purposes of portability. In regard to functionality, this API provides no benefits beyond those offered by the Simple Events API. Applications that are developed using this API will be mostly, but not completely, portable. The reason for this is that not enough of the CosNotification Service API is supported to facilitate portability. For example, the filtering grammar required by the CORBA-based Notification Service is based on the COS Trader grammar. Since Oracle Tuxedo does not support this grammar, but supports an alternative grammar based on the Oracle Tuxedo EventBroker grammar, any application that requires filtering will not be portable. The same is true for QoS, that is, the CosNotification Service API does not support the CORBA-based Notification Service standard qualities of service, but it does support alternative qualities of service.
Figure 2-3 shows the CosNotification Service classes implemented, in full or in part, in this release of Oracle Tuxedo and their relationships.
The operations supported by each class are summarized below. For more detailed descriptions, see "Detailed Descriptions of CosNotification Service Classes" on page -27.
This class is used by the event poster and subscriber applications. It supports the get_channel_factory
operation which is used to get the channel factory when posting, subscribing, and unsubscribing to events.
This class is used by event poster and subscriber applications. It supports three operations:
This class is used by event poster applications. It supports the obtain_notification_push_consumer
operation. Poster applications use this operation to create proxy push consumer objects which in turn are used to post events to the Notification Service.
This class is used by event poster applications. It supports the following operations:
connect_structured_push_supplier
—used by event poster applications to connect the proxy push supplier to the Notification Service event channel.push_structured_event
—used by event poster applications to post the event to the Notification Service event channel.disconnect_structured_push_consumer
—used by event poster applications to disconnect the proxy push supplier from the Notification Service event channel.
This class is used by event subscriber applications to create a filter object. It supports the create_filter
operation. The filter object provides all data filtering including domain, type, and filterable data.
This class is used by event subscriber applications. It supports the following operations:
This class is used by event subscriber applications. It supports the following operations:
obtain_notification_push_supplier
—used by event subscriber applications to create proxy push supplier objects which in turn are used to deliver events to the subscriber’s callback object.get_proxy_supplier
—used by event subscriber applications to retrieve the object reference for the proxy push supplier object. This operation is only used when the subscriber application shuts down then restarts and cancels the subscription. This is because subscribers need to discard the object reference from the first run and get it back again for the next run. Subscribers cannot reuse object references from one run to the next.This class is used by event subscriber applications. It supports the following operations:
connect_structured_push_consumer
—used by event subscriber applications to connect the subscriber to the proxy push supplier.set_qos
—used by event subscriber applications to set the quality of service for subscriptions.add_filter
—used by event subscriber applications to add the filter object to the subscription.get_filter
—used by event subscriber applications when performing unsubscribe operations to get the filter associated with the subscription. This operation is only used when the subscriber application shuts down then restarts.disconnect_structured_push_supplier
—used by event subscriber applications to unsubscribe.
This interface is implemented by event subscriber applications. It supports the push_structured_event
operation. The Notification Service invokes this operation to deliver events to the subscriber.
This section describes the CosNotification Service classes that this release of Oracle Tuxedo implements. These classes are fully described in the CosNotification Service IDL files, which are located in the tuxdir/include
directory.
Note: | If you use class operations that are not supported, the CORBA::NO_IMPLEMENT exception is raised. |
This class is used by event subscriber applications. The OMG IDL for this class is as follows:
Module CosNotifyFilter
{
interface Filter {
ConstraintInfoSeqadd_constraints
(
in ConstraintExpSeq constraint)
raises (InvalidConstraint);
void
destroy
();
};
}; //CosNotifyFilter
Sets the domain, type, and data filter parameters on the filter object.
ConstraintInfoSeq
add_constraints
(
in ConstraintExpSeq constraint)
raises (InvalidConstraint);
CosNotifyFilter::InvalidConstraint
CORBA::BAD_PARAM
CORBA_IMP_LIMIT
Tobj_Notification::SUB_ADD_CONS_ON_TIMED_OUT_FILTER
Tobj_Notification::SUB_MULTIPLE_CALLS_TO_ADD_CONS
Tobj_Notification::SUB_MULTIPLE_CONSTRAINTS_IN_LIST
Tobj_Notification::SUB_MULTIPLE_TYPES_IN_CONSTRAINT
Tobj_Notification::SUB_SYSTEM_EVENTS_UNSUPPORTED
Tobj_Events::SUB_DOMAIN_BEGINS_WITH_SYSEV
Tobj_Events::SUB_EMPTY_DOMAIN
Tobj_Events::SUB_EMPTY_TYPE
Tobj_Events::SUB_FILTER_TOO_LONG
Note: | For more information on exceptions and corresponding minor codes, see "Exception Minor Codes" on page -53. |
Used when subscribing. This operation is used in subscriber applications to define the kind of event to which you want to subscribe. You set the domain, type, and data filter parameters on the filter object. For a description of these parameters, see "Parameters Used When Creating Subscriptions" on page -11.
Note: | The Oracle Tuxedo implementation of the add_constraints operation (1) can only be called once, (2) must be called before the filter is added to the proxy object, and (3) must consist of only a single constraint that has a single event type. |
Returns an empty list
, which we recommend that the caller ignores.
Note: | Code examples shown here are abbreviated. For complete code examples, see "Creating a Subscription" on page -10. |
// set the filtering parameters
// (domain = "News", type, and no data filter)
CosNotifyFilter::ConstraintExpSeq constraints;
constraints.length(1);
constraints[0].event_types.length(1);
constraints[0].event_types[0].domain_name =
CORBA::string_dup("News");
constraints[0].event_types[0].type_name =
CORBA::string_dup (“Sports”);
// no data filter
constraints[0].constraint_expr = CORBA::string_dup(""); CosNotifyFilter::ConstraintInfoSeq_var
add_constraints_results = // ignore this returned value
filter->add_constraints(constraints);
CORBA::BAD_PARAM
Note: | For more information on exceptions and corresponding minor codes, see "Exception Minor Codes" on page -53. |
Used when unsubscribing. This operation is used in subscriber applications to destroy the target filter object.
Note: | Do not destroy the filter object until you are ready to cancel the corresponding subscription. |
This class is used by event subscriber applications. The OMG IDL for this class is as follows:
Module CosNotifyFilter
{
interface FilterFactory {
Filtercreate_filter
(
in string constraint_grammar)
raises (InvalidGrammar);
destroy
();
}; //
};CosNotifyFilter
Determines which events are delivered to a subscription.
Filter
create_filter
(
in string constraint_grammar)
raises (InvalidGrammar);
CosNotifyFilter::InvalidGrammar
Used in the subscriber application to create a new filter object. This filter is used to determine which events are delivered to a subscription. The subscriber must set up the filter and add it to the proxy within five minutes; otherwise, the filter will be destroyed. The filter grammar must be set to Tobj_Notification::Constraint_grammar
; otherwise, the InvalidGrammar
exception is raised.
Returns the new filter’s object reference.
Note: | Code examples shown here are abbreviated. For complete code examples, see "Creating a Subscription" on page -10. |
filter_factory->create_filter(
Tobj_Notification::CONSTRAINT_GRAMMAR
);
This class is used by event subscriber applications. The OMG IDL for this class is as follows:
Module CosNotifyChannelAdmin
{
interface StructuredProxyPushSupplier :
ProxySupplier,
CosNotifyComm::StructuredPushSupplier {
void
connect_structured_push_consumer
(
// The following operations are inherited.
in CosNotifyComm::StructuredPushConsumer push_consumer)
raises(CosEventChannelAdmin::AlreadyConnected,
CosEventChannelAdmin::TypeError );
};
void set_qos(in QoSProperties qos)
raises (UnsupportedQoS);
FilterID add_filter (in Filter new_filter );
Filter get_filter( in FilterID filter )
raises ( FilterNotFound);
void disconnect_structured_push_supplier();
readonly attribute ProxyType MyType;
};}; //CosNotifyChannelAdmin
void
connect_structured_push_consumer
(
in CosNotifyComm::StructuredPushConsumer push_consumer)
raises(CosEventChannelAdmin::AlreadyConnected,
CosEventChannelAdmin::TypeError );
CosEventChannelAdmin::TypeError
CORBA::INV_OREF
CORBA::IMP_LIMIT
Tobj_Events::SUB_DOMAIN_AND_TYPE_TOO_LONG
Tobj_Events::SUB_NAME_TO_LONG
Tobj_Events::TRANSIENT_ONLY_CONFIGURATION
Tobj_Notification::SUBSCRIPTION_DOESNT_EXIST.
CORBA::OBJECT_NOT_EXIST
CosEventChannelAdmin::AlreadyConnected
Note: | For exception definitions and corresponding minor codes, see "Exception Minor Codes" on page -53. |
Use this operation when subscribing. This operation is used in subscriber applications to subscribe to events. The push_consumer
parameter identifies the subscriber’s callback object.
Once the connect_structured_push_consumer
has been called, the Notification Service will proceed to send events to the subscriber by invoking the callback object’s push_structured_event
operation. If the connect_structured_push_consumer
has already been called, the AlreadyConnected
exception is raised.
Note: | You must call set_qos and add_filter before calling connect_structured_push_consumer . |
Note: | Code examples shown here are abbreviated. For complete code examples, see "Creating a Subscription" on page -10. |
subscription->connect_structured_push_consumer(
news_consumer.in()
);
Sets the QoS for the subscription.
void set_qos(in QoSProperties qos)
raises (UnsupportedQoS);
ORBA::IMP_LIMIT
Tobj_Notification::SUB_MULTIPLE_CALLS_TO_SET_QOS
Tobj_Notification::SUB_CANT_SET_QOS_AFTER_CONNECT
Tobj_Notification::SUBSCRIPTION_DOESNT_EXIST
Tobj_Notification::SUB_UNSUPPORTED_QOS_VALUE
Note: | For more information on exceptions and corresponding minor codes, see "Exception Minor Codes" on page -53. |
Used when subscribing. This operation is used in subscriber applications to set the QoS for the subscription. It takes as an input parameter a sequence of name-value pairs which encapsulates quality-of-service property settings that the subscriber is requesting.
There are two components of the QoS: the subscription type and the subscription name. The subscription type is set by constructing a name-value pair where the name is Tobj_Notification::SUBSCRIPTION_TYPE
and the value is either Tobj_Notification::PERSISTENT_SUBSCRIPTION
, or Tobj_Notification::TRANSIENT_SUBSCRIPTION
. For more information and additional usage details, see "Quality of Service" on page -2.
The subscription name is set by constructing a name-value pair, where the name is Tobj_Notification::SUBSCRIPTION_NAME
, and the value is a user-defined string.
For more information on this parameter, see "Parameters Used When Creating Subscriptions" on page -11.
Note: | Code examples shown here are abbreviated. For complete code examples, see "Creating a Subscription" on page -10. |
CosNotification::QoSProperties qos;
qos.length(2);
qos[0].name =
CORBA::string_dup(Tobj_Notification::SUBSCRIPTION_NAME);
qos[0].value <<= “MySubsription”;
qos[1].name =
CORBA::string_dup(Tobj_Notification::SUBSCRIPTION_TYPE);
qos[1].value <<=
Tobj_Notification::TRANSIENT_SUBSCRIPTION;
subscription->set_qos(qos);
Sets the filter object on the subscriber’s callback object.
add_filter(
in Filter new_filter);
CORBA::IMP_LIMIT
Tobj_Notification::SUB_MULTIPLE_CALLS_TO_SET_FILTER
Tobj_Notification::SUB_ADD_FILTER_AFTER_CONNECT
Tobj_Notification::SUB_NIL_FILTER_REF
Tobj_Notification::SUB_NO_CUSTOM_FILTERS
CORBA::OBJECT_NOT_EXIST
Note: | For more information on exceptions and corresponding minor codes, see "Exception Minor Codes" on page -53. |
Used when subscribing. This operation is used in subscriber applications to set the filter object to the subscriber’s callback object. If the application using this operation will be shut down and restarted, the filter_id
should be written to persistent storage.
Note: | This operation: (1) cannot be called after the subscriber callback object is connected (see connect_structured_push_consumer above), (2) cannot be called more than once, and (3) when it is called, the filter constraint expression must already be present in the filter (see CosNotifyFilter::Filter add_constraints ). |
Note: | Only filters created by the event channel’s default filter factory can be added. |
Note: | Code examples shown here are abbreviated. For complete code examples, see "Creating a Subscription" on page -10. |
CosNotifyFilter::FilterID filter_id =
subscription->add_filter(filter.in());
Gets an object reference to the filter currently associated with the subscriber’s callback object.
Filter get_filter( in FilterID filter )
raises ( FilterNotFound);
CosNotifyChannelAdmin::FilterNotFound
Used when a restartable subscriber wants to unsubscribe. This operation is used in subscriber applications to get an object reference to the filter currently associated with the subscriber’s callback object. The FilterID
that is passed in must be valid for the subscriber’s StructuredProxyPushSupplier object. If the FilterID
is not valid for any proxy object associated with the event channel, then a FilterNotFound
exception is thrown. The operation is only used by subscribers that shut down and restart.
The following usage restrictions and guidelines apply to this operation:
Returns a filter object reference to the filter currently associated with the subscriber’s callback object.
CosNotify::Filter_var filter =
subscription->get_filter( filter_id() );
Used to unsubscribe.
void disconnect_structured_push_supplier();
CORBA::OBJECT_NOT_EXIST
Note: | For more information on exceptions and corresponding minor codes, see "Exception Minor Codes" on page -53. |
Used by subscriber applications when unsubscribing. This operation is used in subscriber applications to terminate a connection between the Notification Service and the subscriber’s callback object.
Note: | This operation does not stop event delivery instantaneously. After returning from this operation, a subscriber may continue to receive events for a period of time. |
subscription->disconnect_structured_push_supplier();
Always returns CosNotifyChannelAdmin::PUSH_STRUCTURED
proxy.
readonly attribute ProxyType MyType
Always returns CosNotifyChannelAdmin::PUSH_STRUCTURED
proxy.
This class is used by event posting applications. The OMG IDL for this class is as follows:
Module CosNotifyChannelAdmin
{
interface StructuredProxyPushConsumer :
ProxyConsumer,
CosNotifyComm::StructuredPushConsumer {
void
connect_structured_push_supplier
(
in CosNotifyComm::StructuredPushSupplier push_supplier)
raises(CosEventChannelAdmin::AlreadyConnected);
// The following operations are inherited.
readonly attribute MyType;
void push_structured_event(
in CosNotification::StructuredEvent notification )
raises( CosEventComm::Disconnected );
void disconnect_structured_push_consumer();
};
}; \\StructuredProxyPushConsumer
Prepares the Notification Service to receive an event.
void
connect_structured_push_supplier
(
in CosNotifyComm::StructuredPushSupplier push_supplier)
raises(CosEventChannelAdmin::AlreadyConnected);
CosEventChannelAdmin::AlreadyConnected
Used by poster applications when posting events. You must call this operation to prepare the Notification Service to receive an event and you must pass in a NIL when you use this operation. The sequence of usage is as follows:
Note: | Code examples shown here are abbreviated. For complete code examples, see "Creating and Posting Events" on page -3. |
proxy_push_consumer->connect_structured_push_supplier(
CosNotifyComm::StructuredPushSupplier::_nil()
);
Posts events to the event channel.
void push_structured_event(
in CosNotification::StructuredEvent notification )
raises( CosEventComm::Disconnected );
CosEventComm::Disconnected
CORBA::IMP_LIMIT
Tobj_Events::POST_UNSUPPORTED_VALUE_IN_ANY
Tobj_Events::POST_UNSUPPORTED_PRIORITY_VALUE
Tobj_Events::POST_DOMAIN_CONTAINS_SEPARATOR
Tobj_Events::POST_TYPE_CONTAINS_SEPARATOR
Tobj_Events::POST_SYSTEM_EVENTS_UNSUPPORTED
Tobj_Events::POST_EMPTY_DOMAIN
Tobj_Events::POST_EMPTY_TYPE
Tobj_Events::POST_DOMAIN_AND_TYPE_TOO_LONG
Note: | For more information on exceptions and corresponding minor codes, see "Exception Minor Codes" on page -53. |
Used when posting events. This operation is used in poster applications to post events to the event channel.
Note: | This operation differs from the standard CORBA definition in the following ways: a. The Priority in the variable header section of the event, if specified, must be short value in the range of 1 to 100. b. If event filterable data filtering (versus filtering on domain and type only) is required, or if events are to be received by an Oracle Tuxedo subscriber, then additional restrictions apply. See "Structured Event Fields, Types, and Filters" on page -5 and "Interoperability with Oracle Tuxedo Applications" on page -9. |
Note: | This operation has transactional behavior when used in the context of a transaction. For more information, see Using Transactions. |
Note: | Code examples shown here are abbreviated. For complete code examples, see "Creating and Posting Events" on page -3. |
proxy_push_consumer->push_structured_event(notification);
Stops posting events.
void disconnect_structured_push_consumer();
Used when posting events. This operation is used by poster applications to stop posting events. It takes no input parameters and returns no values. The recommended usage sequence is as follows:
Note: | Code examples shown here are abbreviated. For complete code examples, see "Creating and Posting Events" on page -3. |
proxy_push_consumer->disconnect_structured_push_consumer();
Always returns CosNotifyChannelAmdmin::PUSH_STRUCTURED
proxy.
readonly attribute ProxyType MyType
Always returns CosNotifyChannelAmdmin::PUSH_STRUCTURED
proxy.
This class is used by event subscriber applications. The OMG IDL for this class is as follows:
Module CosNotifyChannelAdmin{
interface ConsumerAdmin :
CosNotification::QoSAdmin,
CosNotifyComm::NotifySubscribe,
CosNotifyFilter::FilterAdmin,
CosEventChannelAdmin::ConsumerAdmin {
ProxySupplier
obtain_notification_push_supplier
(
in ClientType ctype,
out ProxyID proxy_id)
raises ( AdminLimitExceeded )
ProxySupplier
get_proxy_supplier
(
in ProxyID proxy_id )
raises ( ProxyNotFound );
};
}; //
CosNotifyChannelAdmin
Creates proxy push supplier objects.
ProxySupplier
obtain_notification_push_supplier
(
in ClientType ctype,
out ProxyID proxy_id)
raises ( AdminLimitExceeded )
CosNotifyChannelAdmin::AdminLimitExceeded
CORBA::IMP_LIMIT
Used when subscribing. This operation is used in subscriber applications to create proxy push supplier objects. Only structured events are supported (that is, ANY_EVENT
and SEQUENCE_EVENT ClientTypes
are not supported). Therefore, the ClientType
input parameter must be set to CosNotifyComm::STRUCTURED_EVENT
. If you shut down and restart the subscriber and subscription survives more than one run of your program, the ProxyID
returned by this operation should be durably stored. The subscriber must narrow the proxy supplier to CosNotifyChannelAdmin::StructuredProxyPushSupplier
. All required operations must be completed in five minutes.
Note: | Notification Service applications that start and shut down only once can use the proxy_id to determine if their subscription has been cancelled automatically or by the system administrator. |
This operation returns the new proxy’s object reference. The new proxy_id
is also returned through the proxy_id
out parameter.
Note: | Code examples shown here are abbreviated. For complete code examples, see "Creating a Subscription" on page -10. |
CosNotifyChannelAdmin::ProxySupplier_var generic_proxy =
consumer_admin->obtain_notification_push_supplier(
CosNotifyChannelAdmin::STRUCTURED_EVENT,
proxy_id
);
CosNotifyChannelAdmin::StructuredProxyPushSupplier_var proxy =
CosNotifyChannelAdmin::StructuredProxyPushSupplier::_narrow(
generic_proxy.in ()
);
Returns the proxy push supplier object created using the consumer admin object obtain_notification_push_supplier
operation.
ProxySupplier
get_proxy_supplier
(
in ProxyID proxy_id )
raises ( ProxyNotFound );
ProxyNotFound
Used when unsubscribing. This operation is used in subscriber applications to return the proxy push supplier object created using the consumer admin object obtain_notification_push_supplier
operation. The ProxyID
input parameter uniquely identifies the proxy object. Callers should be aware that the proxy object can be destroyed either due to an error in delivering a transient subscription or through an ntsadmin
administrative command. When a proxy object is destroyed, the ProxyID
associated with it is invalidated. If the ProxyID
is invalid, a ProxyNotFound
exception is raised. The subscriber must narrow the proxy supplier to CosNotifyChannelAdmin::StructuredProxyPushSupplier
.
Returns the object reference for the existing proxy.
CosNotifyChannelAdmin::ProxySupplier_var generic_proxy =
m_consumer_admin->get_proxy_supplier(
m_subscription_info.news_proxy_id()
);
CosNotifyChannelAdmin::StructuredProxyPushSupplier_var proxy =
CosNotifyChannelAdmin::StructuredProxyPushSupplier::_narrow(
generic_proxy.in()
);
This class is used by event poster applications. The OMG IDL for this class is as follows:
Module CosNotifyChannelAdmin{
interface SupplierAdmin :
CosNotification::QoSAdmin,
CosNotifyComm::NotifyPublish,
CosNotifyFilter::FilterAdmin,
CosEventChannelAdmin::SupplierAdmin {
ProxyConsumer
obtain_notification_push_consumer
(
SupplierAdmin
in ClientType ctype,
out ProxyID proxy_id)
raises ( AdminLimitExceeded );
};
}; //
Creates proxy push consumer objects.
ProxyConsumer
obtain_notification_push_consumer
(
in ClientType ctype,
out ProxyID proxy_id)
raises ( AdminLimitExceeded );
CosNotifyChannelAdmin::AdminLimitExceeded
CORBA::IMP_LIMIT
Used when posting events. This operation is used in poster applications to create proxy push consumer objects. ClientType
must be set to “CosNotifyChannelAdmin::STRUCTURED_EVENT”
. The ProxyID
returned should be ignored. The Proxy Consumer must be narrowed the proxy supplier to CosNotifyChannelAdmin::StructuredProxyPushConsumer
.
Note: | Notification Service applications that start and shut down only once can use the proxy_id to determine if their subscription has been cancelled automatically or by the system administrator. |
This operation returns the new proxy’s object reference. The new proxy_id
is also returned through the proxy_id
out parameter.
Note: | Code examples shown here are abbreviated. For complete code examples, see "Creating and Posting Events" on page -3. |
CosNotifyChannelAdmin::ProxyConsumer_var generic_proxy_consumer =
supplier_admin->obtain_notification_push_consumer(
CosNotifyChannelAdmin::STRUCTURED_EVENT,
proxy_id
);
CosNotifyChannelAdmin::StructuredProxyPushConsumer_var
proxy_push_consumer =
CosNotifyChannelAdmin::StructuredProxyPushConsumer::_narrow(
generic_proxy_consumer
);
This class is used by event poster applications. The OMG IDL for this class is as follows:
Module CosNotifyChannelAdmin{
interface EventChannel :
CosNotification::QoSAdmin,
CosNotification::AdminPropertiesAdmin,
CosEventChannelAdmin::EventChannel {
readonly attribute
ConsumerAdmin default_consumer_admin
;
readonly attributeSupplierAdmin default_supplier_admin
;
readonly attribute CosNotifyFilter::FilterFactory
default_filter_factory
;
CosNotifyChannelAdmin
};
}; //
Gets the ConsumerAdmin object.
readonly attribute
ConsumerAdmin default_consumer_admin
;
Used when subscribing and unsubscribing. This operation is used in subscriber applications to get the ConsumerAdmin object.
Returns the object reference to the ConsumerAdmin object.
Note: | Code examples shown here are abbreviated. For complete code examples, see "Getting the Event Channel, ConsumerAdmin Object, and Filter Factory Object" on page -8. |
channel->default_consumer_admin();
Gets the SupplierAdmin object.
readonly attribute
SupplierAdmin default_supplier_admin
;
Used when posting events. This operation is used in event poster applications to get the SupplierAdmin object.
SupplierAdmin object reference.
Note: | Code examples shown here are abbreviated. For complete code examples, see "Creating and Posting Events" on page -3. |
channel->default_supplier_admin();
Gets the default FilterFactory object.
readonly attribute CosNotifyFilter::FilterFactory
default_filter_factory
;
Used when subscribing. This operation is used in subscriber applications to get the default FilterFactory object.
Default FilterFactory object reference.
Note: | Code examples shown here are abbreviated. For complete code examples, see "Getting the Event Channel, ConsumerAdmin Object, and Filter Factory Object" on page -8. |
channel->
default_filter_factory
();
This class is used by event poster applications. The OMG IDL for this class is as follows:
Module CosNotifyChannelAdmin{
interface EventChannelFactory {
EventChannelget_event_channel
( in ChannelID id )
CosNotifyChannelAdmin
raises (ChannelNotFound);
};
}; //
Gets the EventChannel
object.
EventChannel
get_event_channel
( in ChannelID id )
raises (ChannelNotFound);
CosNotifyChannelAdmin::ChannelNotFound
Used when subscribing, unsubscribing, and posting events. This operation is used in applications to get the EventChannel
object. When subscribing, the EventChannel object is used to get the filter factory object and the ConsumerAdmin object. When unsubscribing, the EventChannel object is used to get the ConsumerAdmin object.When posting an event, the EventChannel object is used to get the SupplierAdmin object. The ChannelID
parameter that is passed in must be set to Tobj_Notification::DEFAULT_CHANNEL
; otherwise, the ChannelNotFound
exception is raised.
Returns the default event channel’s object reference.
Note: | Code examples shown here are abbreviated. For complete code examples, see "Getting the Event Channel" on page -2 and "Getting the Event Channel, ConsumerAdmin Object, and Filter Factory Object" on page -8. |
channel_factory->
get_event_channel
(
Tobj_Notification::DEFAULT_CHANNEL );
This interface is used by event subscriber applications for event delivery. You must implement this interface so that the Notification Service can invoke on it to deliver events to subscribers. It has three methods which you have to implement.
The OMG IDL for this class is as follows:
Module CosNotifyComm{
interface StructuredPushConsumer : NotifyPublish {
void
push_structured_event
(
event
in CosNotification::StructuredEvent)
CosNotifyComm
raises(CosEventComm::Disconnected);
void disconnect_structured_push_consumer:
//The following operations are inherited.
void offer_change(
in CosNotification::EventTypeSeq added,
in CosNotification::EventTypeSeq removed )
raises ( InvalidEventType );
};
}; //
void
push_structured_event
(
event
in CosNotification::StructuredEvent)
raises(CosEventComm::Disconnected);
CosEventComm::
Disconnected
Used when subscribing. This operation is implemented by the subscriber’s callback object and is invoked by the Notification Service each time a structured event is delivered. This operation contains a single input parameter, which is a structured event.
Note: | This operation will not be called in a transaction. Also, when this operation is called, it must return quickly because the Notification Service might not start delivering events to other subscribers until this operation returns. |
Note: | Code examples shown here are abbreviated. For complete code examples, see "Implementing the CosNotifyComm::StructuredPushConsumer Interface" on page -5. |
virtual void push_structured_event(
const CosNotification::StructuredEvent& notification );
{
// Process the event.
}
void disconnect_structured_push_consumer;
This operation is never invoked. The subscriber application must provide a stubbed-out version of this operation.
virtual void push_structured_event(
const CosNotification::StructuredEvent& notification );
{
throw new CORBA::NO_IMPLEMENT();
}
void offer_change(
in CosNotification::EventTypeSeq added,
in CosNotification::EventTypeSeq removed )
raises ( InvalidEventType );
CosNotifyComm::InvalidEventType
This operation is never invoked. The subscriber application must provide a stubbed-out version of this operation.
virtual void offer_change(
const CosNotification::EventTypeSeq& added,
const CosNotification::EventTypeSeq& removed )
{
throw CORBA::NO_IMPLEMENT();
}
This section provides information about the Notification Service exception symbols and minor codes. The minor codes are in the Tobj_Events.idl
and Tobj_Notification.idl
files. These files are located in the tuxdir\include
directory (for Microsoft Windows systems) and tuxdir/include
directory (for UNIX systems).
Table 2-4 and Table 2-5 list the exception symbols and corresponding minor codes for the Tobj_Events and Tobj_Notification exceptions respectively. CORBA system events have a minor code field and those minor codes are also defined in these tables.
Note: | The exception symbols are organized within the tables by the higher-level exceptions (CORBA::IMP_LIMIT , CORBA::CORBA::BAD_PARAM , CORBA::BAD_INV_ORDER , CORBA::INV_OBHJREF , and CORBA::OBJECT_NOT_EXIST ) and listed in alphabetical order. |
When unsubscribing using the Simple Events API, the user specified an invalid subscription ID, that is, a non-existent or a CosNotification subscription ID.
|
||
For the Simple Events API, this means that the quality of service specified did not meet one of the following requirements:
For the CosNotification Service API, this means that the quality of service specified did not meet one of the following requirements:
|
||
A CosNotification subscriber passed a filter object that was not created by the default filter factory into
add_filter . For example, a CosNotification subscriber implemented the CosNotifyFilter::Filter interface to do some kind of "custom" filtering and passed one of those filter objects into add_filter .
|
||||
|
A CosNotification subscriber called a method on a proxy that had already been destroyed. The proxy has been destroyed by one of the following actions:
|