Nick Craig-Wood <[EMAIL PROTECTED]> writes: >> This can still be a problem for applications that call wait in a >> dedicated thread, but the program can always ignore the processes >> it doesn't know anything about. > > Ignoring them isn't good enough because it means that the bit of > code which was waiting for that process to die with os.getpid() will > never get called, causing a deadlock in that bit of code.
It won't deadlock, it will get an ECHILD or equivalent error because it's waiting for a PID that doesn't correspond to a running child process. I agree that this can be a problem if and when you use libraries that can call system. (In that case sleeping for SIGCHLD is probably a good solution.) > What is really required is a select() like interface to wait which > takes more than one pid. I don't think there is such a thing > though, so polling is your next best option. Except for the problems outlined in my previous message. And the fact that polling becomes very expensive (O(n) per check) once the number of processes becomes large. Unless one knows that a library can and does call system, wait is the preferred solution. -- http://mail.python.org/mailman/listinfo/python-list
