PURPOSE

tx_open - open a set of resource managers

SYNOPSIS


#include <tx.h>
int tx_open(void)

DESCRIPTION

tx_open() opens a set of resource managers in a portable manner. It invokes a transaction manager to read resource-manager-specific information in a transaction-manager-specific manner and pass this information to the resource managers linked to the caller.

tx_open() attempts to open all resource managers that have been linked with the application. This function is used in place of resource-manager-specific ``open'' calls and allows an application program to be free of calls which may hinder portability. Since resource managers differ in their initialization semantics, the specific information needed to ``open'' a particular resource manager must be published by each resource manager.

If tx_open() returns TX_ERROR, then no resource managers are open. If tx_open() returns TX_OK, some or all of the resource managers have been opened. Resource managers that are not open will return resource-manager-specific errors when accessed by the application. tx_open() must successfully return before a thread of control participates in global transactions.

Once tx_open() returns success, subsequent calls to tx_open() (before an intervening call to tx_close(3c)) are allowed. However, such subsequent calls will return success, and the TM will not attempt to re-open any RMs.

RETURN VALUE

Upon successful completion, tx_open() returns TX_OK, a non-negative return value.

ERRORS

Under the following conditions, tx_open() fails and returns one of these negative values:

[TX_ERROR]: Either the transaction manager or one or more of the resource managers encountered a transient error. No resource managers are open. The exact nature of the error is written to a log file.
[TX_FAIL]: Either the transaction manager or one or more of the resource managers encountered a fatal error. TX_FAIL is returned if tpinit(3c) is not called before the call to tx_open in a secure application (SECURITY APP_PW). The nature of the error is such that the transaction manager and/or one or more of the resource managers can no longer perform work on behalf of the application. The exact nature of the error is written to a log file.

WARNINGS