@@ -121,11 +121,10 @@ def worker_child_fire(event, d):
data = b"<event>" + pickle.dumps(event) + b"</event>"
try:
- worker_pipe_lock.acquire()
- while(len(data)):
- written = worker_pipe.write(data)
- data = data[written:]
- worker_pipe_lock.release()
+ with bb.utils.lock_timeout(worker_pipe_lock):
+ while(len(data)):
+ written = worker_pipe.write(data)
+ data = data[written:]
except IOError:
sigterm_handler(None, None)
raise
@@ -251,14 +251,14 @@ class BBCooker:
self.notifier = pyinotify.Notifier(self.watcher, self.notifications)
def process_inotify_updates(self):
- with self.inotify_threadlock:
+ with bb.utils.lock_timeout(self.inotify_threadlock):
for n in [self.confignotifier, self.notifier]:
if n and n.check_events(timeout=0):
# read notified events and enqueue them
n.read_events()
def process_inotify_updates_apply(self):
- with self.inotify_threadlock:
+ with bb.utils.lock_timeout(self.inotify_threadlock):
for n in [self.confignotifier, self.notifier]:
if n and n.check_events(timeout=0):
n.read_events()
@@ -184,7 +184,7 @@ def fire_ui_handlers(event, d):
ui_queue.append(event)
return
- with _thread_lock:
+ with bb.utils.lock_timeout(_thread_lock):
errors = []
for h in _ui_handlers:
#print "Sending event %s" % event
@@ -315,7 +315,7 @@ def set_eventfilter(func):
_eventfilter = func
def register_UIHhandler(handler, mainui=False):
- with _thread_lock:
+ with bb.utils.lock_timeout(_thread_lock):
bb.event._ui_handler_seq = bb.event._ui_handler_seq + 1
_ui_handlers[_ui_handler_seq] = handler
level, debug_domains = bb.msg.constructLogOptions()
@@ -329,7 +329,7 @@ def unregister_UIHhandler(handlerNum, mainui=False):
if mainui:
global _uiready
_uiready = False
- with _thread_lock:
+ with bb.utils.lock_timeout(_thread_lock):
if handlerNum in _ui_handlers:
del _ui_handlers[handlerNum]
return
@@ -113,7 +113,7 @@ class ProcessServer():
def register_idle_function(self, function, data):
"""Register a function to be called while the server is idle"""
assert hasattr(function, '__call__')
- with self._idlefuncsLock:
+ with bb.utils.lock_timeout(self._idlefuncsLock):
self._idlefuns[function] = data
handlers = len(self._idlefuns)
serverlog("Registering idle function %s (%s handlers)" % (str(function), str(handlers)))
@@ -380,7 +380,7 @@ class ProcessServer():
def idle_thread(self):
def remove_idle_func(function):
- with self._idlefuncsLock:
+ with bb.utils.lock_timeout(self._idlefuncsLock):
del self._idlefuns[function]
self.idle_cond.notify_all()
@@ -389,7 +389,7 @@ class ProcessServer():
nextsleep = 0.1
fds = []
- with self._idlefuncsLock:
+ with bb.utils.lock_timeout(self._idlefuncsLock):
items = list(self._idlefuns.items())
for function, data in items:
@@ -751,7 +751,7 @@ class BBUIEventQueue:
self.t.start()
def getEvent(self):
- with self.eventQueueLock:
+ with bb.utils.lock_timeout(self.eventQueueLock):
if len(self.eventQueue) == 0:
return None
@@ -766,7 +766,7 @@ class BBUIEventQueue:
return self.getEvent()
def queue_event(self, event):
- with self.eventQueueLock:
+ with bb.utils.lock_timeout(self.eventQueueLock):
self.eventQueue.append(event)
self.eventQueueNotify.set()
@@ -802,7 +802,7 @@ class ConnectionReader(object):
return self.reader.poll(timeout)
def get(self):
- with self.rlock:
+ with bb.utils.lock_timeout(self.rlock):
res = self.reader.recv_bytes()
return multiprocessing.reduction.ForkingPickler.loads(res)
@@ -823,7 +823,7 @@ class ConnectionWriter(object):
def _send(self, obj):
gc.disable()
- with self.wlock:
+ with bb.utils.lock_timeout(self.wlock):
self.writer.send_bytes(obj)
gc.enable()
@@ -836,7 +836,7 @@ class ConnectionWriter(object):
# pthread_sigmask block/unblock would be nice but doesn't work, https://bugs.python.org/issue47139
process = multiprocessing.current_process()
if process and hasattr(process, "queue_signals"):
- with process.signal_threadlock:
+ with bb.utils.lock_timeout(process.signal_threadlock):
process.queue_signals = True
self._send(obj)
process.queue_signals = False
@@ -70,30 +70,22 @@ class BBUIEventQueue:
self.t.start()
def getEvent(self):
-
- self.eventQueueLock.acquire()
-
- if not self.eventQueue:
- self.eventQueueLock.release()
- return None
-
- item = self.eventQueue.pop(0)
-
- if not self.eventQueue:
- self.eventQueueNotify.clear()
-
- self.eventQueueLock.release()
- return item
+ with bb.utils.lock_timeout(self.eventQueueLock):
+ if not self.eventQueue:
+ return None
+ item = self.eventQueue.pop(0)
+ if not self.eventQueue:
+ self.eventQueueNotify.clear()
+ return item
def waitEvent(self, delay):
self.eventQueueNotify.wait(delay)
return self.getEvent()
def queue_event(self, event):
- self.eventQueueLock.acquire()
- self.eventQueue.append(event)
- self.eventQueueNotify.set()
- self.eventQueueLock.release()
+ with bb.utils.lock_timeout(self.eventQueueLock):
+ self.eventQueue.append(event)
+ self.eventQueueNotify.set()
def send_event(self, event):
self.queue_event(pickle.loads(event))
@@ -1841,3 +1841,16 @@ def mkstemp(suffix=None, prefix=None, dir=None, text=False):
else:
prefix = tempfile.gettempprefix() + entropy
return tempfile.mkstemp(suffix=suffix, prefix=prefix, dir=dir, text=text)
+
+# If we don't have a timeout of some kind and a process/thread exits badly (for example
+# OOM killed) and held a lock, we'd just hang in the lock futex forever. It is better
+# we exit at some point than hang. 5 minutes with no progress means we're probably deadlocked.
+@contextmanager
+def lock_timeout(lock):
+ held = lock.acquire(timeout=5*60)
+ try:
+ if not held:
+ os._exit(1)
+ yield held
+ finally:
+ lock.release()
The thread/process locks we use translate to futexes in Linux. If a process dies holding the lock, anything else trying to take the lock will hang indefinitely. An example would be the OOM killer taking out a parser process. To avoid bitbake processes just hanging indefinitely, add a timeout to our lock calls using a context manager. If we can't obtain the lock after waiting 5 minutes, hard exit out using os._exit(1). Use _exit() to avoid locking in any other places trying to write error messages to event handler queues (which also need locks). Whilst a bit harsh, this should mean we stop having lots of long running processes in cases where things are never going to work out and also avoids hanging builds on the autobuilder. Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org> --- bin/bitbake-worker | 9 ++++----- lib/bb/cooker.py | 4 ++-- lib/bb/event.py | 6 +++--- lib/bb/server/process.py | 16 ++++++++-------- lib/bb/ui/uievent.py | 28 ++++++++++------------------ lib/bb/utils.py | 13 +++++++++++++ 6 files changed, 40 insertions(+), 36 deletions(-)