During the worker MPM non-graceful shutdown, the signal_threads() function attempts to close all open sockets.
I have two major objections to this: 1) It's not necessarily safe to close a socket that another thread is using. Note that apr_socket_close() calls the pool cleanup on the pool from which the socket was allocated--bad news if one of the active worker threads happens to be, say, registering a new cleanup in the same pool at the same time. 2) It appears to be contributing to the fact that non-graceful shutdown doesn't work. Without the socket shutdown loop, the child processes shut down promptly. As I understand it, the motivation for closing the sockets during shutdown was to try to fix a race condition in which an active worker thread might be trying to write to a socket at the same time that the underlying pool was being destroyed (due to the recursive destruction of APR's global_pool during apr_terminate()). If so, I think the right solution is to add a way to create parentless pools that aren't implicitly added as children to the global pool, so that a worker thread's pool won't disappear before that thread does. Is there any specific reason why we're not doing this already? Thanks, --Brian
