Using WebSphere MQ for UNIX systems

When you use WebSphere MQ on UNIX(R) systems, MQCONN sets up its own signal handler for the signals SIGSEGV and SIGBUS. User handlers for these signals are restored after every MQI call.

The remaining signals are handled differently.

If any handler for this group of signals receives an interrupt within an MQI call, the application handler must exit the application.

On non-threaded applications, WebSphere MQ uses the UNIX interval timer ITIMER_REAL to generate SIGALRM signals. Any previous SIGALRM handler and timer interval is saved on entry to MQI and restored on exit. Any timer interval set is therefore frozen while within MQI.