def _discard_session(self, session, should_discard):
if session.connection_count > 0:
raise RuntimeError("Should not be discarding a session with open connections")
log.debug("Discarding session %r last in use %r milliseconds ago", session.id, session.milliseconds_since_last_unsubscribe)
session_context = self._session_contexts[session.id]
# session.destroy() wants the document lock so it can shut down the document
# callbacks.
def do_discard():
# while we yielded for the document lock, the discard-worthiness of the
# session may have changed.
# However, since we have the document lock, our own lock will cause the
# block count to be 1. If there's any other block count besides our own,
# we want to skip session destruction though.
if should_discard(session) and session.expiration_blocked_count == 1:
session.destroy()
del self._sessions[session.id]
del self._session_contexts[session.id]
else:
log.debug("Session %r was scheduled to discard but came back to life", session.id)
yield session.with_document_locked(do_discard)
# session lifecycle hooks are supposed to be called outside the document lock,
# we only run these if we actually ended up destroying the session.
if session_context.destroyed:
try:
result = self._application.on_session_destroyed(session_context)
yield yield_for_all_futures(result)
except Exception as e:
log.error("Failed to run session destroy hooks %r", e, exc_info=True)
raise gen.Return(None)
def with_locked_document(self, func):
if self._session is None:
# this means we are in on_session_created, so no locking yet,
# we have exclusive access
yield yield_for_all_futures(func(self._document))
else:
self._session.with_document_locked(func, self._document)
def with_locked_document(self, func):
if self._session is None:
# this means we are in on_session_created, so no locking yet,
# we have exclusive access
yield yield_for_all_futures(func(self._document))
else:
self._session.with_document_locked(func, self._document)
def test__yield_for_all_futures():
loop = IOLoop()
loop.make_current()
@gen.coroutine
def several_steps():
value = 0
value += yield async_value(1)
value += yield async_value(2)
value += yield async_value(3)
raise gen.Return(value)
result = {}
def on_done(future):
result["value"] = future.result()
loop.stop()
loop.add_future(yield_for_all_futures(several_steps()), on_done)
try:
loop.start()
except KeyboardInterrupt as e:
print("keyboard interrupt")
assert 6 == result["value"]
loop.close()
def _discard_session(self, session, should_discard):
if session.connection_count > 0:
raise RuntimeError("Should not be discarding a session with open connections")
log.debug("Discarding session %r last in use %r milliseconds ago", session.id, session.milliseconds_since_last_unsubscribe)
session_context = self._session_contexts[session.id]
# session.destroy() wants the document lock so it can shut down the document
# callbacks.
def do_discard():
# while we yielded for the document lock, the discard-worthiness of the
# session may have changed.
# However, since we have the document lock, our own lock will cause the
# block count to be 1. If there's any other block count besides our own,
# we want to skip session destruction though.
if should_discard(session) and session.expiration_blocked_count == 1:
session.destroy()
del self._sessions[session.id]
del self._session_contexts[session.id]
else:
log.debug("Session %r was scheduled to discard but came back to life", session.id)
yield session.with_document_locked(do_discard)
# session lifecycle hooks are supposed to be called outside the document lock,
# we only run these if we actually ended up destroying the session.
if session_context.destroyed:
try:
result = self._application.on_session_destroyed(session_context)
yield yield_for_all_futures(result)
except Exception as e:
log.error("Failed to run session destroy hooks %r", e, exc_info=True)
raise gen.Return(None)
def test__yield_for_all_futures():
loop = IOLoop()
loop.make_current()
@gen.coroutine
def several_steps():
value = 0
value += yield async_value(1)
value += yield async_value(2)
value += yield async_value(3)
raise gen.Return(value)
result = {}
def on_done(future):
result['value'] = future.result()
loop.stop()
loop.add_future(yield_for_all_futures(several_steps()), on_done)
try:
loop.start()
except KeyboardInterrupt:
print("keyboard interrupt")
assert 6 == result['value']
loop.close()
def _needs_document_lock_wrapper(self, *args, **kwargs):
# while we wait for and hold the lock, prevent the session
# from being discarded. This avoids potential weirdness
# with the session vanishing in the middle of some async
# task.
self.block_expiration()
try:
with (yield self._lock.acquire()):
if self._pending_writes is not None:
raise RuntimeError("internal class invariant violated: _pending_writes " + \
"should be None if lock is not held")
self._pending_writes = []
try:
result = yield yield_for_all_futures(
func(self, *args, **kwargs))
finally:
# we want to be very sure we reset this or we'll
# keep hitting the RuntimeError above as soon as
# any callback goes wrong
pending_writes = self._pending_writes
self._pending_writes = None
for p in pending_writes:
yield p
raise gen.Return(result)
finally:
self.unblock_expiration()
def _needs_document_lock_wrapper(self, *args, **kwargs):
# while we wait for and hold the lock, prevent the session
# from being discarded. This avoids potential weirdness
# with the session vanishing in the middle of some async
# task.
self.block_expiration()
try:
with (yield self._lock.acquire()):
if self._pending_writes is not None:
raise RuntimeError("internal class invariant violated: _pending_writes " + \
"should be None if lock is not held")
self._pending_writes = []
try:
result = yield yield_for_all_futures(func(self, *args, **kwargs))
finally:
# we want to be very sure we reset this or we'll
# keep hitting the RuntimeError above as soon as
# any callback goes wrong
pending_writes = self._pending_writes
self._pending_writes = None
for p in pending_writes:
yield p
raise gen.Return(result)
finally:
self.unblock_expiration()
def create_session_if_needed(self, session_id, request=None):
# this is because empty session_ids would be "falsey" and
# potentially open up a way for clients to confuse us
if len(session_id) == 0:
raise ProtocolError("Session ID must not be empty")
if session_id not in self._sessions and \
session_id not in self._pending_sessions:
future = self._pending_sessions[session_id] = gen.Future()
doc = Document()
session_context = BokehSessionContext(session_id,
self.server_context,
doc)
# using private attr so users only have access to a read-only property
session_context._request = request
# expose the session context to the document
# use the _attribute to set the public property .session_context
doc._session_context = session_context
try:
yield yield_for_all_futures(self._application.on_session_created(session_context))
except Exception as e:
log.error("Failed to run session creation hooks %r", e, exc_info=True)
self._application.initialize_document(doc)
session = ServerSession(session_id, doc, io_loop=self._loop)
del self._pending_sessions[session_id]
self._sessions[session_id] = session
session_context._set_session(session)
self._session_contexts[session_id] = session_context
# notify anyone waiting on the pending session
future.set_result(session)
if session_id in self._pending_sessions:
# another create_session_if_needed is working on
# creating this session
session = yield self._pending_sessions[session_id]
else:
session = self._sessions[session_id]
raise gen.Return(session)
def create_session_if_needed(self, session_id, request=None):
# this is because empty session_ids would be "falsey" and
# potentially open up a way for clients to confuse us
if len(session_id) == 0:
raise ProtocolError("Session ID must not be empty")
if session_id not in self._sessions and \
session_id not in self._pending_sessions:
future = self._pending_sessions[session_id] = gen.Future()
doc = Document()
session_context = BokehSessionContext(session_id,
self.server_context, doc)
# using private attr so users only have access to a read-only property
session_context._request = _RequestProxy(request)
# expose the session context to the document
# use the _attribute to set the public property .session_context
doc._session_context = session_context
try:
yield yield_for_all_futures(
self._application.on_session_created(session_context))
except Exception as e:
log.error("Failed to run session creation hooks %r",
e,
exc_info=True)
self._application.initialize_document(doc)
session = ServerSession(session_id, doc, io_loop=self._loop)
del self._pending_sessions[session_id]
self._sessions[session_id] = session
session_context._set_session(session)
self._session_contexts[session_id] = session_context
# notify anyone waiting on the pending session
future.set_result(session)
if session_id in self._pending_sessions:
# another create_session_if_needed is working on
# creating this session
session = yield self._pending_sessions[session_id]
else:
session = self._sessions[session_id]
raise gen.Return(session)
def create_session_if_needed(self, session_id):
# this is because empty session_ids would be "falsey" and
# potentially open up a way for clients to confuse us
if len(session_id) == 0:
raise ProtocolError("Session ID must not be empty")
if session_id not in self._sessions and \
session_id not in self._pending_sessions:
future = self._pending_sessions[session_id] = gen.Future()
doc = Document()
session_context = BokehSessionContext(session_id,
self._server_context, doc)
try:
result = yield yield_for_all_futures(
self._application.on_session_created(session_context))
except Exception as e:
log.error("Failed to run session creation hooks %r",
e,
exc_info=True)
self._application.initialize_document(doc)
session = ServerSession(session_id, doc, io_loop=self._loop)
del self._pending_sessions[session_id]
self._sessions[session_id] = session
session_context._set_session(session)
self._session_contexts[session_id] = session_context
# notify anyone waiting on the pending session
future.set_result(session)
if session_id in self._pending_sessions:
# another create_session_if_needed is working on
# creating this session
session = yield self._pending_sessions[session_id]
else:
session = self._sessions[session_id]
raise gen.Return(session)
