The APR documentation for apr_thread_cond_signal says: Signals a single thread, if one exists, that is blocking on the given condition variable.
This is similar to, but not as complete as, the documentation for pthread_cond_signal, which says: restarts one of the threads that are waiting on the condition variable cond. If no threads are waiting on cond, nothing happens. The APR methods behave like pthread methods on Linux, but on Windows, if no threads are waiting, apr_thread_cond_signal triggers the next apr_thread_cond_wait called after the signal. If anyone is interested, I have a simple test case demonstrating the behaviors. Eddie
