Issue #1856: Avoid crashes and lockups when daemon threads run while the
interpreter is shutting down; instead, these threads are now killed when
they try to take the GIL.
diff --git a/Python/ceval.c b/Python/ceval.c
index 43a5c90..705ed41 100644
--- a/Python/ceval.c
+++ b/Python/ceval.c
@@ -440,6 +440,12 @@
if (gil_created()) {
int err = errno;
take_gil(tstate);
+ /* _Py_Finalizing is protected by the GIL */
+ if (_Py_Finalizing && tstate != _Py_Finalizing) {
+ drop_gil(tstate);
+ PyThread_exit_thread();
+ assert(0); /* unreachable */
+ }
errno = err;
}
#endif
diff --git a/Python/pythonrun.c b/Python/pythonrun.c
index faaf54a..1e2dd58 100644
--- a/Python/pythonrun.c
+++ b/Python/pythonrun.c
@@ -90,6 +90,8 @@
int Py_NoUserSiteDirectory = 0; /* for -s and site.py */
int Py_UnbufferedStdioFlag = 0; /* Unbuffered binary std{in,out,err} */
+PyThreadState *_Py_Finalizing = NULL;
+
/* PyModule_GetWarningsModule is no longer necessary as of 2.6
since _warnings is builtin. This API should not be used. */
PyObject *
@@ -188,6 +190,7 @@
if (initialized)
return;
initialized = 1;
+ _Py_Finalizing = NULL;
#if defined(HAVE_LANGINFO_H) && defined(HAVE_SETLOCALE)
/* Set up the LC_CTYPE locale, so we can obtain
@@ -388,15 +391,19 @@
* the threads created via Threading.
*/
call_py_exitfuncs();
- initialized = 0;
-
- /* Flush stdout+stderr */
- flush_std_files();
/* Get current thread state and interpreter pointer */
tstate = PyThreadState_GET();
interp = tstate->interp;
+ /* Remaining threads (e.g. daemon threads) will automatically exit
+ after taking the GIL (in PyEval_RestoreThread()). */
+ _Py_Finalizing = tstate;
+ initialized = 0;
+
+ /* Flush stdout+stderr */
+ flush_std_files();
+
/* Disable signal handling */
PyOS_FiniInterrupts();
diff --git a/Python/thread_pthread.h b/Python/thread_pthread.h
index ffc791c..6bc9d55 100644
--- a/Python/thread_pthread.h
+++ b/Python/thread_pthread.h
@@ -250,9 +250,9 @@
PyThread_exit_thread(void)
{
dprintf(("PyThread_exit_thread called\n"));
- if (!initialized) {
+ if (!initialized)
exit(0);
- }
+ pthread_exit(0);
}
#ifdef USE_SEMAPHORES