avoid crashes and lockups from daemon threads during interpreter shutdown (#1856)
diff --git a/Python/ceval.c b/Python/ceval.c
index 18bc66b..b1f5e8e 100644
--- a/Python/ceval.c
+++ b/Python/ceval.c
@@ -355,6 +355,12 @@
if (interpreter_lock) {
int err = errno;
PyThread_acquire_lock(interpreter_lock, 1);
+ /* _Py_Finalizing is protected by the GIL */
+ if (_Py_Finalizing && tstate != _Py_Finalizing) {
+ PyThread_release_lock(interpreter_lock);
+ PyThread_exit_thread();
+ assert(0); /* unreachable */
+ }
errno = err;
}
#endif
diff --git a/Python/pythonrun.c b/Python/pythonrun.c
index 2a40c0b..748a63b 100644
--- a/Python/pythonrun.c
+++ b/Python/pythonrun.c
@@ -91,6 +91,8 @@
int Py_NoUserSiteDirectory = 0; /* for -s and site.py */
int Py_HashRandomizationFlag = 0; /* for -R and PYTHONHASHSEED */
+PyThreadState *_Py_Finalizing = NULL;
+
/* Hack to force loading of object files */
int (*_PyOS_mystrnicmp_hack)(const char *, const char *, Py_ssize_t) = \
@@ -163,6 +165,7 @@
if (initialized)
return;
initialized = 1;
+ _Py_Finalizing = NULL;
if ((p = Py_GETENV("PYTHONDEBUG")) && *p != '\0')
Py_DebugFlag = add_flag(Py_DebugFlag, p);
@@ -422,12 +425,16 @@
* the threads created via Threading.
*/
call_sys_exitfunc();
- initialized = 0;
/* 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;
+
/* Disable signal handling */
PyOS_FiniInterrupts();
diff --git a/Python/thread_pthread.h b/Python/thread_pthread.h
index c9ed796..0c1fdfe 100644
--- a/Python/thread_pthread.h
+++ b/Python/thread_pthread.h
@@ -242,9 +242,9 @@
PyThread_exit_thread(void)
{
dprintf(("PyThread_exit_thread called\n"));
- if (!initialized) {
+ if (!initialized)
exit(0);
- }
+ pthread_exit(0);
}
#ifdef USE_SEMAPHORES