Fix SpawnProcess._pipe_logger_exit to wait for process exit status asynchronously, in order to avoid event loop recursion. This is required for asyncio compatibility, and also protects emerge from exceeding the maximum recursion depth limit like in bug 402335.
X-Gentoo-bug: 613990 X-Gentoo-bug-url: https://bugs.gentoo.org/show_bug.cgi?id=613990 --- pym/_emerge/SpawnProcess.py | 3 +-- pym/_emerge/SubProcess.py | 23 ++++++++++++++++++++++- 2 files changed, 23 insertions(+), 3 deletions(-) diff --git a/pym/_emerge/SpawnProcess.py b/pym/_emerge/SpawnProcess.py index e046640..7326254 100644 --- a/pym/_emerge/SpawnProcess.py +++ b/pym/_emerge/SpawnProcess.py @@ -170,8 +170,7 @@ class SpawnProcess(SubProcess): def _pipe_logger_exit(self, pipe_logger): self._pipe_logger = None - self._unregister() - self.wait() + self._async_waitpid() def _waitpid_loop(self): SubProcess._waitpid_loop(self) diff --git a/pym/_emerge/SubProcess.py b/pym/_emerge/SubProcess.py index 13d9382..b81cfd5 100644 --- a/pym/_emerge/SubProcess.py +++ b/pym/_emerge/SubProcess.py @@ -12,7 +12,7 @@ import errno class SubProcess(AbstractPollTask): __slots__ = ("pid",) + \ - ("_dummy_pipe_fd", "_files", "_reg_id") + ("_dummy_pipe_fd", "_files", "_reg_id", "_waitpid_id") # This is how much time we allow for waitpid to succeed after # we've sent a kill signal to our subprocess. @@ -101,6 +101,23 @@ class SubProcess(AbstractPollTask): return self.returncode + def _async_waitpid(self): + """ + Wait for exit status of self.pid asynchronously, and then + set the returncode and notify exit listeners. This is + prefered over _waitpid_loop, since the synchronous nature + of _waitpid_loop can cause event loop recursion. + """ + if self._waitpid_id is None: + self._waitpid_id = self.scheduler.child_watch_add( + self.pid, self._async_waitpid_cb) + + def _async_waitpid_cb(self, pid, condition, user_data=None): + if pid != self.pid: + raise AssertionError("expected pid %s, got %s" % (self.pid, pid)) + self._set_returncode((pid, condition)) + self.wait() + def _waitpid_loop(self): source_id = self.scheduler.child_watch_add( self.pid, self._waitpid_cb) @@ -129,6 +146,10 @@ class SubProcess(AbstractPollTask): self.scheduler.source_remove(self._reg_id) self._reg_id = None + if self._waitpid_id is not None: + self.scheduler.source_remove(self._waitpid_id) + self._waitpid_id = None + if self._files is not None: for f in self._files.values(): if isinstance(f, int): -- 2.10.2
