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-rw-r--r--pym/portage/util/_eventloop/EventLoop.py32
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: