diff options
Diffstat (limited to 'Lib/multiprocessing/semaphore_tracker.py')
| -rw-r--r-- | Lib/multiprocessing/semaphore_tracker.py | 20 |
1 files changed, 17 insertions, 3 deletions
diff --git a/Lib/multiprocessing/semaphore_tracker.py b/Lib/multiprocessing/semaphore_tracker.py index d5f259c..3e31bf8 100644 --- a/Lib/multiprocessing/semaphore_tracker.py +++ b/Lib/multiprocessing/semaphore_tracker.py @@ -29,6 +29,7 @@ class SemaphoreTracker(object): def __init__(self): self._lock = threading.Lock() self._fd = None + self._pid = None def getfd(self): self.ensure_running() @@ -40,8 +41,20 @@ class SemaphoreTracker(object): This can be run from any process. Usually a child process will use the semaphore created by its parent.''' with self._lock: - if self._fd is not None: - return + if self._pid is not None: + # semaphore tracker was launched before, is it still running? + pid, status = os.waitpid(self._pid, os.WNOHANG) + if not pid: + # => still alive + return + # => dead, launch it again + os.close(self._fd) + self._fd = None + self._pid = None + + warnings.warn('semaphore_tracker: process died unexpectedly, ' + 'relaunching. Some semaphores might leak.') + fds_to_pass = [] try: fds_to_pass.append(sys.stderr.fileno()) @@ -55,12 +68,13 @@ class SemaphoreTracker(object): exe = spawn.get_executable() args = [exe] + util._args_from_interpreter_flags() args += ['-c', cmd % r] - util.spawnv_passfds(exe, args, fds_to_pass) + pid = util.spawnv_passfds(exe, args, fds_to_pass) except: os.close(w) raise else: self._fd = w + self._pid = pid finally: os.close(r) |