8.7.2.0.5 Exception handlers

An exception handler does not necessarily execute in the context of the thread that made the exception-raising MPI-/ call; the exception handler may be executed by a thread that is distinct from the thread that will return the error code.

Rationale. The MPI-/ implementation may be multithreaded, so that part of the communication protocol may execute on a thread that is distinct from the thread that made the MPI-/ call. The design allows the exception handler to be executed on the thread where the exception occurred.(End of rationale.)

MPI-Standard for MARMOT