Target Executing a fork() or exec()

If your program does a fork(), any probes that the child encounters are logged to the same trace file. Events are annotated with a process ID, so it is possible to determine which process a particular event came from.

A thread in a multithreaded program doing a fork while the other threads are still running can cause a race conditon. For the trace file to stay uncorrupted, make sure that the other threads are quiescent when doing a fork, or else use fork1(2).

If the target program itself (not any children it might fork) does an exec(2), prex detaches from the target and exits. The user can reconnect prex with:

$ prex -p pid