diff options
| -rw-r--r-- | pym/portage/util/_eventloop/EventLoop.py | 32 |
1 files changed, 22 insertions, 10 deletions
diff --git a/pym/portage/util/_eventloop/EventLoop.py b/pym/portage/util/_eventloop/EventLoop.py index e38134258..7f171fb8c 100644 --- a/pym/portage/util/_eventloop/EventLoop.py +++ b/pym/portage/util/_eventloop/EventLoop.py @@ -57,6 +57,7 @@ class EventLoop(object): self._child_handlers = {} self._sigchld_read = None self._sigchld_write = None + self._sigchld_src_id = None self._pid = os.getpid() def _poll(self, timeout=None): @@ -246,19 +247,26 @@ class EventLoop(object): source_id = self._event_handler_id self._child_handlers[source_id] = self._child_callback_class( callback=callback, data=data, pid=pid, source_id=source_id) + if self._sigchld_read is None: - self._sigchld_init() + self._sigchld_read, self._sigchld_write = os.pipe() + fcntl.fcntl(self._sigchld_read, fcntl.F_SETFL, + fcntl.fcntl(self._sigchld_read, fcntl.F_GETFL) | os.O_NONBLOCK) + + # The IO watch is dynamically registered and unregistered as + # needed, since we don't want to consider it as a valid source + # of events when there are no child listeners. It's important + # to distinguish when there are no valid sources of IO events, + # in order to avoid an endless poll call if there's no timeout. + if self._sigchld_src_id is None: + self._sigchld_src_id = self.io_add_watch( + self._sigchld_read, self.IO_IN, self._sigchld_io_cb) + signal.signal(signal.SIGCHLD, self._sigchld_sig_cb) + # poll now, in case the SIGCHLD has already arrived self._poll_child_processes() return source_id - def _sigchld_init(self): - self._sigchld_read, self._sigchld_write = os.pipe() - fcntl.fcntl(self._sigchld_read, fcntl.F_SETFL, - fcntl.fcntl(self._sigchld_read, fcntl.F_GETFL) | os.O_NONBLOCK) - self.io_add_watch(self._sigchld_read, self.IO_IN, self._sigchld_io_cb) - signal.signal(signal.SIGCHLD, self._sigchld_sig_cb) - def _sigchld_sig_cb(self, signum, frame): # If this signal handler was not installed by the # current process then the signal doesn't belong to @@ -292,14 +300,14 @@ class EventLoop(object): if e.errno != errno.ECHILD: raise del e - self._child_handlers.pop(x.source_id, None) + self.source_remove(x.source_id) else: # With waitpid and WNOHANG, only check the # first element of the tuple since the second # element may vary (bug #337465). if wait_retval[0] != 0: calls += 1 - self._child_handlers.pop(x.source_id, None) + self.source_remove(x.source_id) x.callback(x.pid, wait_retval[1], x.data) return bool(calls) @@ -429,6 +437,10 @@ class EventLoop(object): """ x = self._child_handlers.pop(reg_id, None) if x is not None: + if not self._child_handlers: + signal.signal(signal.SIGCHLD, signal.SIG_DFL) + self.source_remove(self._sigchld_src_id) + self._sigchld_src_id = None return True idle_callback = self._idle_callbacks.pop(reg_id, None) if idle_callback is not None: |