Kaydet (Commit) ce16be91 authored tarafından Victor Stinner's avatar Victor Stinner

(Merge 3.2) Issue #11768: The signal handler of the signal module only calls

Py_AddPendingCall() for the first signal to fix a deadlock on reentrant or
parallel calls. PyErr_SetInterrupt() writes also into the wake up file.
...@@ -30,14 +30,9 @@ def handle_signals(sig,frame): ...@@ -30,14 +30,9 @@ def handle_signals(sig,frame):
# a function that will be spawned as a separate thread. # a function that will be spawned as a separate thread.
def send_signals(): def send_signals():
print("send_signals: enter (thread %s)" % thread.get_ident(), file=sys.stderr)
print("send_signals: raise SIGUSR1", file=sys.stderr)
os.kill(process_pid, signal.SIGUSR1) os.kill(process_pid, signal.SIGUSR1)
print("send_signals: raise SIGUSR2", file=sys.stderr)
os.kill(process_pid, signal.SIGUSR2) os.kill(process_pid, signal.SIGUSR2)
print("send_signals: release signalled_all", file=sys.stderr)
signalled_all.release() signalled_all.release()
print("send_signals: exit (thread %s)" % thread.get_ident(), file=sys.stderr)
class ThreadSignals(unittest.TestCase): class ThreadSignals(unittest.TestCase):
...@@ -46,12 +41,9 @@ class ThreadSignals(unittest.TestCase): ...@@ -46,12 +41,9 @@ class ThreadSignals(unittest.TestCase):
# We spawn a thread, have the thread send two signals, and # We spawn a thread, have the thread send two signals, and
# wait for it to finish. Check that we got both signals # wait for it to finish. Check that we got both signals
# and that they were run by the main thread. # and that they were run by the main thread.
print("test_signals: acquire lock (thread %s)" % thread.get_ident(), file=sys.stderr)
signalled_all.acquire() signalled_all.acquire()
self.spawnSignallingThread() self.spawnSignallingThread()
print("test_signals: wait lock (thread %s)" % thread.get_ident(), file=sys.stderr)
signalled_all.acquire() signalled_all.acquire()
print("test_signals: lock acquired", file=sys.stderr)
# the signals that we asked the kernel to send # the signals that we asked the kernel to send
# will come back, but we don't know when. # will come back, but we don't know when.
# (it might even be after the thread exits # (it might even be after the thread exits
......
...@@ -110,6 +110,10 @@ Core and Builtins ...@@ -110,6 +110,10 @@ Core and Builtins
Library Library
------- -------
- Issue #11768: The signal handler of the signal module only calls
Py_AddPendingCall() for the first signal to fix a deadlock on reentrant or
parallel calls. PyErr_SetInterrupt() writes also into the wake up file.
- Issue #11492: fix several issues with header folding in the email package. - Issue #11492: fix several issues with header folding in the email package.
- Issue #11852: Add missing imports and update tests. - Issue #11852: Add missing imports and update tests.
......
...@@ -165,6 +165,20 @@ checksignals_witharg(void * unused) ...@@ -165,6 +165,20 @@ checksignals_witharg(void * unused)
return PyErr_CheckSignals(); return PyErr_CheckSignals();
} }
static void
trip_signal(int sig_num)
{
Handlers[sig_num].tripped = 1;
if (is_tripped)
return;
/* Set is_tripped after setting .tripped, as it gets
cleared in PyErr_CheckSignals() before .tripped. */
is_tripped = 1;
Py_AddPendingCall(checksignals_witharg, NULL);
if (wakeup_fd != -1)
write(wakeup_fd, "\0", 1);
}
static void static void
signal_handler(int sig_num) signal_handler(int sig_num)
{ {
...@@ -182,13 +196,7 @@ signal_handler(int sig_num) ...@@ -182,13 +196,7 @@ signal_handler(int sig_num)
if (getpid() == main_pid) if (getpid() == main_pid)
#endif #endif
{ {
Handlers[sig_num].tripped = 1; trip_signal(sig_num);
/* Set is_tripped after setting .tripped, as it gets
cleared in PyErr_CheckSignals() before .tripped. */
is_tripped = 1;
Py_AddPendingCall(checksignals_witharg, NULL);
if (wakeup_fd != -1)
write(wakeup_fd, "\0", 1);
} }
#ifndef HAVE_SIGACTION #ifndef HAVE_SIGACTION
...@@ -946,9 +954,7 @@ PyErr_CheckSignals(void) ...@@ -946,9 +954,7 @@ PyErr_CheckSignals(void)
void void
PyErr_SetInterrupt(void) PyErr_SetInterrupt(void)
{ {
is_tripped = 1; trip_signal(SIGINT);
Handlers[SIGINT].tripped = 1;
Py_AddPendingCall((int (*)(void *))PyErr_CheckSignals, NULL);
} }
void void
......
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