[3.7] bpo-33929: multiprocessing: fix handle leak on race condition (GH-7921) by miss-islington · Pull Request #7960 · python/cpython

Expand Up @@ -18,6 +18,12 @@ WINEXE = (sys.platform == 'win32' and getattr(sys, 'frozen', False)) WINSERVICE = sys.executable.lower().endswith("pythonservice.exe")

def _close_handles(*handles): for handle in handles: _winapi.CloseHandle(handle)

# # We define a Popen class similar to the one from subprocess, but # whose constructor takes a process object as its argument. Expand All @@ -32,8 +38,12 @@ class Popen(object): def __init__(self, process_obj): prep_data = spawn.get_preparation_data(process_obj._name)
# read end of pipe will be "stolen" by the child process # read end of pipe will be duplicated by the child process # -- see spawn_main() in spawn.py. # # bpo-33929: Previously, the read end of pipe was "stolen" by the child # process, but it leaked a handle if the child process had been # terminated before it could steal the handle from the parent process. rhandle, whandle = _winapi.CreatePipe(None, 0) wfd = msvcrt.open_osfhandle(whandle, 0) cmd = spawn.get_command_line(parent_pid=os.getpid(), Expand All @@ -56,7 +66,8 @@ def __init__(self, process_obj): self.returncode = None self._handle = hp self.sentinel = int(hp) self.finalizer = util.Finalize(self, _winapi.CloseHandle, (self.sentinel,)) self.finalizer = util.Finalize(self, _close_handles, (self.sentinel, int(rhandle)))
# send information to child set_spawning_popen(self) Expand Down