From 8408cea0cdc0ccd5900acd99a9a51dd9161ae319 Mon Sep 17 00:00:00 2001 From: Antoine Pitrou Date: Sun, 5 May 2013 23:47:09 +0200 Subject: Issue #17094: Clear stale thread states after fork(). Note that this is a potentially disruptive change since it may release some system resources which would otherwise remain perpetually alive (e.g. database connections kept in thread-local storage). --- Python/ceval.c | 18 ++++++++++-------- 1 file changed, 10 insertions(+), 8 deletions(-) (limited to 'Python/ceval.c') diff --git a/Python/ceval.c b/Python/ceval.c index cbc0fabd03..d32b6fbf58 100644 --- a/Python/ceval.c +++ b/Python/ceval.c @@ -362,29 +362,28 @@ PyEval_ReleaseThread(PyThreadState *tstate) drop_gil(tstate); } -/* This function is called from PyOS_AfterFork to ensure that newly - created child processes don't hold locks referring to threads which - are not running in the child process. (This could also be done using - pthread_atfork mechanism, at least for the pthreads implementation.) */ +/* This function is called from PyOS_AfterFork to destroy all threads which are + * not running in the child process, and clear internal locks which might be + * held by those threads. (This could also be done using pthread_atfork + * mechanism, at least for the pthreads implementation.) */ void PyEval_ReInitThreads(void) { _Py_IDENTIFIER(_after_fork); PyObject *threading, *result; - PyThreadState *tstate = PyThreadState_GET(); + PyThreadState *current_tstate = PyThreadState_GET(); if (!gil_created()) return; recreate_gil(); pending_lock = PyThread_allocate_lock(); - take_gil(tstate); + take_gil(current_tstate); main_thread = PyThread_get_thread_ident(); /* Update the threading module with the new state. */ - tstate = PyThreadState_GET(); - threading = PyMapping_GetItemString(tstate->interp->modules, + threading = PyMapping_GetItemString(current_tstate->interp->modules, "threading"); if (threading == NULL) { /* threading not imported */ @@ -397,6 +396,9 @@ PyEval_ReInitThreads(void) else Py_DECREF(result); Py_DECREF(threading); + + /* Destroy all threads except the current one */ + _PyThreadState_DeleteExcept(current_tstate); } #else -- cgit v1.2.1