Issue #12550: Add chain optional argument to faulthandler.register()
Call the previous signal handler if chain is True.
diff --git a/Lib/test/test_faulthandler.py b/Lib/test/test_faulthandler.py
index 2a254af..c8a8030 100644
--- a/Lib/test/test_faulthandler.py
+++ b/Lib/test/test_faulthandler.py
@@ -452,11 +452,13 @@
@unittest.skipIf(not hasattr(faulthandler, "register"),
"need faulthandler.register")
def check_register(self, filename=False, all_threads=False,
- unregister=False):
+ unregister=False, chain=False):
"""
Register a handler displaying the traceback on a user signal. Raise the
signal and check the written traceback.
+ If chain is True, check that the previous signal handler is called.
+
Raise an error if the output doesn't match the expected format.
"""
signum = signal.SIGUSR1
@@ -464,22 +466,41 @@
import faulthandler
import os
import signal
+import sys
def func(signum):
os.kill(os.getpid(), signum)
+def handler(signum, frame):
+ handler.called = True
+handler.called = False
+
+exitcode = 0
signum = {signum}
unregister = {unregister}
+chain = {chain}
+
if {has_filename}:
file = open({filename}, "wb")
else:
file = None
-faulthandler.register(signum, file=file, all_threads={all_threads})
+if chain:
+ signal.signal(signum, handler)
+faulthandler.register(signum, file=file,
+ all_threads={all_threads}, chain={chain})
if unregister:
faulthandler.unregister(signum)
func(signum)
+if chain and not handler.called:
+ if file is not None:
+ output = file
+ else:
+ output = sys.stderr
+ print("Error: signal handler not called!", file=output)
+ exitcode = 1
if file is not None:
file.close()
+sys.exit(exitcode)
""".strip()
code = code.format(
filename=repr(filename),
@@ -487,6 +508,7 @@
all_threads=all_threads,
signum=signum,
unregister=unregister,
+ chain=chain,
)
trace, exitcode = self.get_output(code, filename)
trace = '\n'.join(trace)
@@ -495,7 +517,7 @@
regex = 'Current thread XXX:\n'
else:
regex = 'Traceback \(most recent call first\):\n'
- regex = expected_traceback(6, 17, regex)
+ regex = expected_traceback(7, 28, regex)
self.assertRegex(trace, regex)
else:
self.assertEqual(trace, '')
@@ -517,6 +539,9 @@
def test_register_threads(self):
self.check_register(all_threads=True)
+ def test_register_chain(self):
+ self.check_register(chain=True)
+
def test_main():
support.run_unittest(FaultHandlerTests)