cpython/Lib/test/test_faulthandler.py

505 lines
14 KiB
Python

from contextlib import contextmanager
import faulthandler
import re
import signal
import subprocess
import sys
from test import support, script_helper
import tempfile
import unittest
TIMEOUT = 0.5
try:
from resource import setrlimit, RLIMIT_CORE, error as resource_error
except ImportError:
prepare_subprocess = None
else:
def prepare_subprocess():
# don't create core file
try:
setrlimit(RLIMIT_CORE, (0, 0))
except (ValueError, resource_error):
pass
def expected_traceback(lineno1, lineno2, header, count=1):
regex = header
regex += ' File "<string>", line %s in func\n' % lineno1
regex += ' File "<string>", line %s in <module>' % lineno2
if count != 1:
regex = (regex + '\n') * (count - 1) + regex
return '^' + regex + '$'
@contextmanager
def temporary_filename():
filename = tempfile.mktemp()
try:
yield filename
finally:
support.unlink(filename)
class FaultHandlerTests(unittest.TestCase):
def get_output(self, code, filename=None):
"""
Run the specified code in Python (in a new child process) and read the
output from the standard error or from a file (if filename is set).
Return the output lines as a list.
Strip the reference count from the standard error for Python debug
build, and replace "Current thread 0x00007f8d8fbd9700" by "Current
thread XXX".
"""
options = {}
if prepare_subprocess:
options['preexec_fn'] = prepare_subprocess
process = script_helper.spawn_python('-c', code, **options)
stdout, stderr = process.communicate()
exitcode = process.wait()
output = support.strip_python_stderr(stdout)
output = output.decode('ascii', 'backslashreplace')
if filename:
self.assertEqual(output, '')
with open(filename, "rb") as fp:
output = fp.read()
output = output.decode('ascii', 'backslashreplace')
output = re.sub('Current thread 0x[0-9a-f]+',
'Current thread XXX',
output)
return output.splitlines(), exitcode
def check_fatal_error(self, code, line_number, name_regex,
filename=None, all_threads=False, other_regex=None):
"""
Check that the fault handler for fatal errors is enabled and check the
traceback from the child process output.
Raise an error if the output doesn't match the expected format.
"""
if all_threads:
header = 'Current thread XXX'
else:
header = 'Traceback (most recent call first)'
regex = """
^Fatal Python error: {name}
{header}:
File "<string>", line {lineno} in <module>$
""".strip()
regex = regex.format(
lineno=line_number,
name=name_regex,
header=re.escape(header))
if other_regex:
regex += '|' + other_regex
output, exitcode = self.get_output(code, filename)
output = '\n'.join(output)
self.assertRegex(output, regex)
self.assertNotEqual(exitcode, 0)
def test_read_null(self):
self.check_fatal_error("""
import faulthandler
faulthandler.enable()
faulthandler._read_null()
""".strip(),
3,
'(?:Segmentation fault|Bus error)')
def test_sigsegv(self):
self.check_fatal_error("""
import faulthandler
faulthandler.enable()
faulthandler._sigsegv()
""".strip(),
3,
'Segmentation fault')
def test_sigabrt(self):
self.check_fatal_error("""
import faulthandler
faulthandler.enable()
faulthandler._sigabrt()
""".strip(),
3,
'Aborted')
@unittest.skipIf(sys.platform == 'win32',
"SIGFPE cannot be caught on Windows")
def test_sigfpe(self):
self.check_fatal_error("""
import faulthandler
faulthandler.enable()
faulthandler._sigfpe()
""".strip(),
3,
'Floating point exception')
@unittest.skipIf(not hasattr(faulthandler, '_sigbus'),
"need faulthandler._sigbus()")
def test_sigbus(self):
self.check_fatal_error("""
import faulthandler
faulthandler.enable()
faulthandler._sigbus()
""".strip(),
3,
'Bus error')
@unittest.skipIf(not hasattr(faulthandler, '_sigill'),
"need faulthandler._sigill()")
def test_sigill(self):
self.check_fatal_error("""
import faulthandler
faulthandler.enable()
faulthandler._sigill()
""".strip(),
3,
'Illegal instruction')
def test_fatal_error(self):
self.check_fatal_error("""
import faulthandler
faulthandler._fatal_error(b'xyz')
""".strip(),
2,
'xyz')
@unittest.skipIf(not hasattr(faulthandler, '_stack_overflow'),
'need faulthandler._stack_overflow()')
def test_stack_overflow(self):
self.check_fatal_error("""
import faulthandler
faulthandler.enable()
faulthandler._stack_overflow()
""".strip(),
3,
'(?:Segmentation fault|Bus error)',
other_regex='unable to raise a stack overflow')
def test_gil_released(self):
self.check_fatal_error("""
import faulthandler
faulthandler.enable()
faulthandler._read_null(True)
""".strip(),
3,
'(?:Segmentation fault|Bus error)')
def test_enable_file(self):
with temporary_filename() as filename:
self.check_fatal_error("""
import faulthandler
output = open({filename}, 'wb')
faulthandler.enable(output)
faulthandler._read_null()
""".strip().format(filename=repr(filename)),
4,
'(?:Segmentation fault|Bus error)',
filename=filename)
def test_enable_threads(self):
self.check_fatal_error("""
import faulthandler
faulthandler.enable(all_threads=True)
faulthandler._read_null()
""".strip(),
3,
'(?:Segmentation fault|Bus error)',
all_threads=True)
def test_disable(self):
code = """
import faulthandler
faulthandler.enable()
faulthandler.disable()
faulthandler._read_null()
""".strip()
not_expected = 'Fatal Python error'
stderr, exitcode = self.get_output(code)
stder = '\n'.join(stderr)
self.assertTrue(not_expected not in stderr,
"%r is present in %r" % (not_expected, stderr))
self.assertNotEqual(exitcode, 0)
def test_is_enabled(self):
was_enabled = faulthandler.is_enabled()
try:
faulthandler.enable()
self.assertTrue(faulthandler.is_enabled())
faulthandler.disable()
self.assertFalse(faulthandler.is_enabled())
finally:
if was_enabled:
faulthandler.enable()
else:
faulthandler.disable()
def check_dump_traceback(self, filename):
"""
Explicitly call dump_traceback() function and check its output.
Raise an error if the output doesn't match the expected format.
"""
code = """
import faulthandler
def funcB():
if {has_filename}:
with open({filename}, "wb") as fp:
faulthandler.dump_traceback(fp)
else:
faulthandler.dump_traceback()
def funcA():
funcB()
funcA()
""".strip()
code = code.format(
filename=repr(filename),
has_filename=bool(filename),
)
if filename:
lineno = 6
else:
lineno = 8
expected = [
'Traceback (most recent call first):',
' File "<string>", line %s in funcB' % lineno,
' File "<string>", line 11 in funcA',
' File "<string>", line 13 in <module>'
]
trace, exitcode = self.get_output(code, filename)
self.assertEqual(trace, expected)
self.assertEqual(exitcode, 0)
def test_dump_traceback(self):
self.check_dump_traceback(None)
def test_dump_traceback_file(self):
with temporary_filename() as filename:
self.check_dump_traceback(filename)
def check_dump_traceback_threads(self, filename):
"""
Call explicitly dump_traceback(all_threads=True) and check the output.
Raise an error if the output doesn't match the expected format.
"""
code = """
import faulthandler
from threading import Thread, Event
import time
def dump():
if {filename}:
with open({filename}, "wb") as fp:
faulthandler.dump_traceback(fp, all_threads=True)
else:
faulthandler.dump_traceback(all_threads=True)
class Waiter(Thread):
# avoid blocking if the main thread raises an exception.
daemon = True
def __init__(self):
Thread.__init__(self)
self.running = Event()
self.stop = Event()
def run(self):
self.running.set()
self.stop.wait()
waiter = Waiter()
waiter.start()
waiter.running.wait()
dump()
waiter.stop.set()
waiter.join()
""".strip()
code = code.format(filename=repr(filename))
output, exitcode = self.get_output(code, filename)
output = '\n'.join(output)
if filename:
lineno = 8
else:
lineno = 10
regex = """
^Thread 0x[0-9a-f]+:
(?: File ".*threading.py", line [0-9]+ in [_a-z]+
){{1,3}} File "<string>", line 23 in run
File ".*threading.py", line [0-9]+ in _bootstrap_inner
File ".*threading.py", line [0-9]+ in _bootstrap
Current thread XXX:
File "<string>", line {lineno} in dump
File "<string>", line 28 in <module>$
""".strip()
regex = regex.format(lineno=lineno)
self.assertRegex(output, regex)
self.assertEqual(exitcode, 0)
def test_dump_traceback_threads(self):
self.check_dump_traceback_threads(None)
def test_dump_traceback_threads_file(self):
with temporary_filename() as filename:
self.check_dump_traceback_threads(filename)
def _check_dump_tracebacks_later(self, repeat, cancel, filename):
"""
Check how many times the traceback is written in timeout x 2.5 seconds,
or timeout x 3.5 seconds if cancel is True: 1, 2 or 3 times depending
on repeat and cancel options.
Raise an error if the output doesn't match the expect format.
"""
code = """
import faulthandler
import time
def func(repeat, cancel, timeout):
if cancel:
faulthandler.cancel_dump_tracebacks_later()
pause = timeout * 2.5
# on Windows XP, b-a gives 1.249931 after sleep(1.25)
min_pause = pause * 0.9
a = time.time()
time.sleep(pause)
b = time.time()
faulthandler.cancel_dump_tracebacks_later()
# Check that sleep() was not interrupted
assert (b - a) >= min_pause, "{{}} < {{}}".format(b - a, min_pause)
timeout = {timeout}
repeat = {repeat}
cancel = {cancel}
if {has_filename}:
file = open({filename}, "wb")
else:
file = None
faulthandler.dump_tracebacks_later(timeout,
repeat=repeat, file=file)
func(repeat, cancel, timeout)
if file is not None:
file.close()
""".strip()
code = code.format(
filename=repr(filename),
has_filename=bool(filename),
repeat=repeat,
cancel=cancel,
timeout=TIMEOUT,
)
trace, exitcode = self.get_output(code, filename)
trace = '\n'.join(trace)
if not cancel:
if repeat:
count = 2
else:
count = 1
header = 'Thread 0x[0-9a-f]+:\n'
regex = expected_traceback(12, 27, header, count=count)
self.assertRegex(trace, regex)
else:
self.assertEqual(trace, '')
self.assertEqual(exitcode, 0)
@unittest.skipIf(not hasattr(faulthandler, 'dump_tracebacks_later'),
'need faulthandler.dump_tracebacks_later()')
def check_dump_tracebacks_later(self, repeat=False, cancel=False,
file=False):
if file:
with temporary_filename() as filename:
self._check_dump_tracebacks_later(repeat, cancel, filename)
else:
self._check_dump_tracebacks_later(repeat, cancel, None)
def test_dump_tracebacks_later(self):
self.check_dump_tracebacks_later()
def test_dump_tracebacks_later_repeat(self):
self.check_dump_tracebacks_later(repeat=True)
def test_dump_tracebacks_later_cancel(self):
self.check_dump_tracebacks_later(cancel=True)
def test_dump_tracebacks_later_file(self):
self.check_dump_tracebacks_later(file=True)
@unittest.skipIf(not hasattr(faulthandler, "register"),
"need faulthandler.register")
def check_register(self, filename=False, all_threads=False,
unregister=False):
"""
Register a handler displaying the traceback on a user signal. Raise the
signal and check the written traceback.
Raise an error if the output doesn't match the expected format.
"""
signum = signal.SIGUSR1
code = """
import faulthandler
import os
import signal
def func(signum):
os.kill(os.getpid(), signum)
signum = {signum}
unregister = {unregister}
if {has_filename}:
file = open({filename}, "wb")
else:
file = None
faulthandler.register(signum, file=file, all_threads={all_threads})
if unregister:
faulthandler.unregister(signum)
func(signum)
if file is not None:
file.close()
""".strip()
code = code.format(
filename=repr(filename),
has_filename=bool(filename),
all_threads=all_threads,
signum=signum,
unregister=unregister,
)
trace, exitcode = self.get_output(code, filename)
trace = '\n'.join(trace)
if not unregister:
if all_threads:
regex = 'Current thread XXX:\n'
else:
regex = 'Traceback \(most recent call first\):\n'
regex = expected_traceback(6, 17, regex)
self.assertRegex(trace, regex)
else:
self.assertEqual(trace, '')
if unregister:
self.assertNotEqual(exitcode, 0)
else:
self.assertEqual(exitcode, 0)
def test_register(self):
self.check_register()
def test_unregister(self):
self.check_register(unregister=True)
def test_register_file(self):
with temporary_filename() as filename:
self.check_register(filename=filename)
def test_register_threads(self):
self.check_register(all_threads=True)
def test_main():
support.run_unittest(FaultHandlerTests)
if __name__ == "__main__":
test_main()