Signals

Onload User Guide (UG1586)

Document ID
UG1586
Release Date
2023-07-31
Revision
1.2 English

If an application receives a SIGSTOP signal, it is possible for the processing of network events to be stalled in an Onload stack used by the application. This happens if the application is holding a lock inside the stack when the application is stopped, and if the application remains stopped for a long time, this can cause TCP connections to time-out.

A signal which terminates an application can prevent threads from exiting cleanly. Refer to Multithreaded Applications Termination for more information.

Undefined content can result when a signal handler uses the third argument (ucontext) and if the signal is postponed by Onload. To avoid this, use the Onload module option safe_signals_and_exit=0 or use EF_SIGNALS_NOPOSTPONE to prevent specific signals being postponed by Onload.