diff --git a/synapse/util/async.py b/synapse/util/async.py
index 5d0fb39130..a7094e2fb4 100644
--- a/synapse/util/async.py
+++ b/synapse/util/async.py
@@ -1,5 +1,6 @@
# -*- coding: utf-8 -*-
# Copyright 2014-2016 OpenMarket Ltd
+# Copyright 2018 New Vector Ltd.
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
@@ -12,7 +13,7 @@
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.
-
+import collections
import logging
from contextlib import contextmanager
@@ -156,54 +157,72 @@ def concurrently_execute(func, args, limit):
class Linearizer(object):
- """Linearizes access to resources based on a key. Useful to ensure only one
- thing is happening at a time on a given resource.
+ """Limits concurrent access to resources based on a key. Useful to ensure
+ only a few things happen at a time on a given resource.
Example:
- with (yield linearizer.queue("test_key")):
+ with (yield limiter.queue("test_key")):
# do some work.
"""
- def __init__(self, name=None, clock=None):
+ def __init__(self, name=None, max_count=1, clock=None):
+ """
+ Args:
+ max_count(int): The maximum number of concurrent accesses
+ """
if name is None:
self.name = id(self)
else:
self.name = name
- self.key_to_defer = {}
if not clock:
from twisted.internet import reactor
clock = Clock(reactor)
self._clock = clock
+ self.max_count = max_count
+
+ # key_to_defer is a map from the key to a 2 element list where
+ # the first element is the number of things executing, and
+ # the second element is an OrderedDict, where the keys are deferreds for the
+ # things blocked from executing.
+ self.key_to_defer = {}
@defer.inlineCallbacks
def queue(self, key):
- # If there is already a deferred in the queue, we pull it out so that
- # we can wait on it later.
- # Then we replace it with a deferred that we resolve *after* the
- # context manager has exited.
- # We only return the context manager after the previous deferred has
- # resolved.
- # This all has the net effect of creating a chain of deferreds that
- # wait for the previous deferred before starting their work.
- current_defer = self.key_to_defer.get(key)
+ entry = self.key_to_defer.setdefault(key, [0, collections.OrderedDict()])
- new_defer = defer.Deferred()
- self.key_to_defer[key] = new_defer
+ # If the number of things executing is greater than the maximum
+ # then add a deferred to the list of blocked items
+ # When on of the things currently executing finishes it will callback
+ # this item so that it can continue executing.
+ if entry[0] >= self.max_count:
+ new_defer = defer.Deferred()
+ entry[1][new_defer] = 1
- if current_defer:
logger.info(
- "Waiting to acquire linearizer lock %r for key %r", self.name, key
+ "Waiting to acquire linearizer lock %r for key %r", self.name, key,
)
try:
- with PreserveLoggingContext():
- yield current_defer
- except Exception:
- logger.exception("Unexpected exception in Linearizer")
-
- logger.info("Acquired linearizer lock %r for key %r", self.name,
- key)
+ yield make_deferred_yieldable(new_defer)
+ except Exception as e:
+ if isinstance(e, CancelledError):
+ logger.info(
+ "Cancelling wait for linearizer lock %r for key %r",
+ self.name, key,
+ )
+ else:
+ logger.warn(
+ "Unexpected exception waiting for linearizer lock %r for key %r",
+ self.name, key,
+ )
+
+ # we just have to take ourselves back out of the queue.
+ del entry[1][new_defer]
+ raise
+
+ logger.info("Acquired linearizer lock %r for key %r", self.name, key)
+ entry[0] += 1
# if the code holding the lock completes synchronously, then it
# will recursively run the next claimant on the list. That can
@@ -213,15 +232,15 @@ class Linearizer(object):
# In order to break the cycle, we add a cheeky sleep(0) here to
# ensure that we fall back to the reactor between each iteration.
#
- # (There's no particular need for it to happen before we return
- # the context manager, but it needs to happen while we hold the
- # lock, and the context manager's exit code must be synchronous,
- # so actually this is the only sensible place.
+ # (This needs to happen while we hold the lock, and the context manager's exit
+ # code must be synchronous, so this is the only sensible place.)
yield self._clock.sleep(0)
else:
- logger.info("Acquired uncontended linearizer lock %r for key %r",
- self.name, key)
+ logger.info(
+ "Acquired uncontended linearizer lock %r for key %r", self.name, key,
+ )
+ entry[0] += 1
@contextmanager
def _ctx_manager():
@@ -229,73 +248,15 @@ class Linearizer(object):
yield
finally:
logger.info("Releasing linearizer lock %r for key %r", self.name, key)
- with PreserveLoggingContext():
- new_defer.callback(None)
- current_d = self.key_to_defer.get(key)
- if current_d is new_defer:
- self.key_to_defer.pop(key, None)
-
- defer.returnValue(_ctx_manager())
-
-
-class Limiter(object):
- """Limits concurrent access to resources based on a key. Useful to ensure
- only a few thing happen at a time on a given resource.
-
- Example:
-
- with (yield limiter.queue("test_key")):
- # do some work.
-
- """
- def __init__(self, max_count):
- """
- Args:
- max_count(int): The maximum number of concurrent access
- """
- self.max_count = max_count
-
- # key_to_defer is a map from the key to a 2 element list where
- # the first element is the number of things executing
- # the second element is a list of deferreds for the things blocked from
- # executing.
- self.key_to_defer = {}
-
- @defer.inlineCallbacks
- def queue(self, key):
- entry = self.key_to_defer.setdefault(key, [0, []])
-
- # If the number of things executing is greater than the maximum
- # then add a deferred to the list of blocked items
- # When on of the things currently executing finishes it will callback
- # this item so that it can continue executing.
- if entry[0] >= self.max_count:
- new_defer = defer.Deferred()
- entry[1].append(new_defer)
-
- logger.info("Waiting to acquire limiter lock for key %r", key)
- with PreserveLoggingContext():
- yield new_defer
- logger.info("Acquired limiter lock for key %r", key)
- else:
- logger.info("Acquired uncontended limiter lock for key %r", key)
-
- entry[0] += 1
-
- @contextmanager
- def _ctx_manager():
- try:
- yield
- finally:
- logger.info("Releasing limiter lock for key %r", key)
# We've finished executing so check if there are any things
# blocked waiting to execute and start one of them
entry[0] -= 1
if entry[1]:
- next_def = entry[1].pop(0)
+ (next_def, _) = entry[1].popitem(last=False)
+ # we need to run the next thing in the sentinel context.
with PreserveLoggingContext():
next_def.callback(None)
elif entry[0] == 0:
diff --git a/synapse/util/caches/descriptors.py b/synapse/util/caches/descriptors.py
index f8a07df6b8..861c24809c 100644
--- a/synapse/util/caches/descriptors.py
+++ b/synapse/util/caches/descriptors.py
@@ -473,105 +473,101 @@ class CacheListDescriptor(_CacheDescriptorBase):
@functools.wraps(self.orig)
def wrapped(*args, **kwargs):
- # If we're passed a cache_context then we'll want to call its invalidate()
- # whenever we are invalidated
+ # If we're passed a cache_context then we'll want to call its
+ # invalidate() whenever we are invalidated
invalidate_callback = kwargs.pop("on_invalidate", None)
arg_dict = inspect.getcallargs(self.orig, obj, *args, **kwargs)
keyargs = [arg_dict[arg_nm] for arg_nm in self.arg_names]
list_args = arg_dict[self.list_name]
- # cached is a dict arg -> deferred, where deferred results in a
- # 2-tuple (`arg`, `result`)
results = {}
- cached_defers = {}
- missing = []
+
+ def update_results_dict(res, arg):
+ results[arg] = res
+
+ # list of deferreds to wait for
+ cached_defers = []
+
+ missing = set()
# If the cache takes a single arg then that is used as the key,
# otherwise a tuple is used.
if num_args == 1:
- def cache_get(arg):
- return cache.get(arg, callback=invalidate_callback)
+ def arg_to_cache_key(arg):
+ return arg
else:
- key = list(keyargs)
+ keylist = list(keyargs)
- def cache_get(arg):
- key[self.list_pos] = arg
- return cache.get(tuple(key), callback=invalidate_callback)
+ def arg_to_cache_key(arg):
+ keylist[self.list_pos] = arg
+ return tuple(keylist)
for arg in list_args:
try:
- res = cache_get(arg)
-
+ res = cache.get(arg_to_cache_key(arg),
+ callback=invalidate_callback)
if not isinstance(res, ObservableDeferred):
results[arg] = res
elif not res.has_succeeded():
res = res.observe()
- res.addCallback(lambda r, arg: (arg, r), arg)
- cached_defers[arg] = res
+ res.addCallback(update_results_dict, arg)
+ cached_defers.append(res)
else:
results[arg] = res.get_result()
except KeyError:
- missing.append(arg)
+ missing.add(arg)
if missing:
+ # we need an observable deferred for each entry in the list,
+ # which we put in the cache. Each deferred resolves with the
+ # relevant result for that key.
+ deferreds_map = {}
+ for arg in missing:
+ deferred = defer.Deferred()
+ deferreds_map[arg] = deferred
+ key = arg_to_cache_key(arg)
+ observable = ObservableDeferred(deferred)
+ cache.set(key, observable, callback=invalidate_callback)
+
+ def complete_all(res):
+ # the wrapped function has completed. It returns a
+ # a dict. We can now resolve the observable deferreds in
+ # the cache and update our own result map.
+ for e in missing:
+ val = res.get(e, None)
+ deferreds_map[e].callback(val)
+ results[e] = val
+
+ def errback(f):
+ # the wrapped function has failed. Invalidate any cache
+ # entries we're supposed to be populating, and fail
+ # their deferreds.
+ for e in missing:
+ key = arg_to_cache_key(e)
+ cache.invalidate(key)
+ deferreds_map[e].errback(f)
+
+ # return the failure, to propagate to our caller.
+ return f
+
args_to_call = dict(arg_dict)
- args_to_call[self.list_name] = missing
+ args_to_call[self.list_name] = list(missing)
- ret_d = defer.maybeDeferred(
+ cached_defers.append(defer.maybeDeferred(
logcontext.preserve_fn(self.function_to_call),
**args_to_call
- )
-
- ret_d = ObservableDeferred(ret_d)
-
- # We need to create deferreds for each arg in the list so that
- # we can insert the new deferred into the cache.
- for arg in missing:
- observer = ret_d.observe()
- observer.addCallback(lambda r, arg: r.get(arg, None), arg)
-
- observer = ObservableDeferred(observer)
-
- if num_args == 1:
- cache.set(
- arg, observer,
- callback=invalidate_callback
- )
-
- def invalidate(f, key):
- cache.invalidate(key)
- return f
- observer.addErrback(invalidate, arg)
- else:
- key = list(keyargs)
- key[self.list_pos] = arg
- cache.set(
- tuple(key), observer,
- callback=invalidate_callback
- )
-
- def invalidate(f, key):
- cache.invalidate(key)
- return f
- observer.addErrback(invalidate, tuple(key))
-
- res = observer.observe()
- res.addCallback(lambda r, arg: (arg, r), arg)
-
- cached_defers[arg] = res
+ ).addCallbacks(complete_all, errback))
if cached_defers:
- def update_results_dict(res):
- results.update(res)
- return results
-
- return logcontext.make_deferred_yieldable(defer.gatherResults(
- list(cached_defers.values()),
+ d = defer.gatherResults(
+ cached_defers,
consumeErrors=True,
- ).addCallback(update_results_dict).addErrback(
+ ).addCallbacks(
+ lambda _: results,
unwrapFirstError
- ))
+ )
+ return logcontext.make_deferred_yieldable(d)
else:
return results
@@ -625,7 +621,8 @@ def cachedList(cached_method_name, list_name, num_args=None, inlineCallbacks=Fal
cache.
Args:
- cache (Cache): The underlying cache to use.
+ cached_method_name (str): The name of the single-item lookup method.
+ This is only used to find the cache to use.
list_name (str): The name of the argument that is the list to use to
do batch lookups in the cache.
num_args (int): Number of arguments to use as the key in the cache
diff --git a/synapse/util/caches/expiringcache.py b/synapse/util/caches/expiringcache.py
index 4abca91f6d..ce85b2ae11 100644
--- a/synapse/util/caches/expiringcache.py
+++ b/synapse/util/caches/expiringcache.py
@@ -16,6 +16,7 @@
import logging
from collections import OrderedDict
+from synapse.metrics.background_process_metrics import run_as_background_process
from synapse.util.caches import register_cache
logger = logging.getLogger(__name__)
@@ -63,7 +64,10 @@ class ExpiringCache(object):
return
def f():
- self._prune_cache()
+ return run_as_background_process(
+ "prune_cache_%s" % self._cache_name,
+ self._prune_cache,
+ )
self._clock.looping_call(f, self._expiry_ms / 2)
diff --git a/synapse/util/distributor.py b/synapse/util/distributor.py
index 734331caaa..194da87639 100644
--- a/synapse/util/distributor.py
+++ b/synapse/util/distributor.py
@@ -17,20 +17,18 @@ import logging
from twisted.internet import defer
-from synapse.util import unwrapFirstError
-from synapse.util.logcontext import PreserveLoggingContext
+from synapse.metrics.background_process_metrics import run_as_background_process
+from synapse.util.logcontext import make_deferred_yieldable, run_in_background
logger = logging.getLogger(__name__)
def user_left_room(distributor, user, room_id):
- with PreserveLoggingContext():
- distributor.fire("user_left_room", user=user, room_id=room_id)
+ distributor.fire("user_left_room", user=user, room_id=room_id)
def user_joined_room(distributor, user, room_id):
- with PreserveLoggingContext():
- distributor.fire("user_joined_room", user=user, room_id=room_id)
+ distributor.fire("user_joined_room", user=user, room_id=room_id)
class Distributor(object):
@@ -44,9 +42,7 @@ class Distributor(object):
model will do for today.
"""
- def __init__(self, suppress_failures=True):
- self.suppress_failures = suppress_failures
-
+ def __init__(self):
self.signals = {}
self.pre_registration = {}
@@ -56,7 +52,6 @@ class Distributor(object):
self.signals[name] = Signal(
name,
- suppress_failures=self.suppress_failures,
)
if name in self.pre_registration:
@@ -75,10 +70,18 @@ class Distributor(object):
self.pre_registration[name].append(observer)
def fire(self, name, *args, **kwargs):
+ """Dispatches the given signal to the registered observers.
+
+ Runs the observers as a background process. Does not return a deferred.
+ """
if name not in self.signals:
raise KeyError("%r does not have a signal named %s" % (self, name))
- return self.signals[name].fire(*args, **kwargs)
+ run_as_background_process(
+ name,
+ self.signals[name].fire,
+ *args, **kwargs
+ )
class Signal(object):
@@ -91,9 +94,8 @@ class Signal(object):
method into all of the observers.
"""
- def __init__(self, name, suppress_failures):
+ def __init__(self, name):
self.name = name
- self.suppress_failures = suppress_failures
self.observers = []
def observe(self, observer):
@@ -103,7 +105,6 @@ class Signal(object):
Each observer callable may return a Deferred."""
self.observers.append(observer)
- @defer.inlineCallbacks
def fire(self, *args, **kwargs):
"""Invokes every callable in the observer list, passing in the args and
kwargs. Exceptions thrown by observers are logged but ignored. It is
@@ -121,22 +122,17 @@ class Signal(object):
failure.type,
failure.value,
failure.getTracebackObject()))
- if not self.suppress_failures:
- return failure
return defer.maybeDeferred(observer, *args, **kwargs).addErrback(eb)
- with PreserveLoggingContext():
- deferreds = [
- do(observer)
- for observer in self.observers
- ]
-
- res = yield defer.gatherResults(
- deferreds, consumeErrors=True
- ).addErrback(unwrapFirstError)
+ deferreds = [
+ run_in_background(do, o)
+ for o in self.observers
+ ]
- defer.returnValue(res)
+ return make_deferred_yieldable(defer.gatherResults(
+ deferreds, consumeErrors=True,
+ ))
def __repr__(self):
return "<Signal name=%r>" % (self.name,)
diff --git a/synapse/util/frozenutils.py b/synapse/util/frozenutils.py
index 581c6052ac..014edea971 100644
--- a/synapse/util/frozenutils.py
+++ b/synapse/util/frozenutils.py
@@ -13,7 +13,7 @@
# See the License for the specific language governing permissions and
# limitations under the License.
-from six import string_types
+from six import binary_type, text_type
from canonicaljson import json
from frozendict import frozendict
@@ -26,7 +26,7 @@ def freeze(o):
if isinstance(o, frozendict):
return o
- if isinstance(o, string_types):
+ if isinstance(o, (binary_type, text_type)):
return o
try:
@@ -41,7 +41,7 @@ def unfreeze(o):
if isinstance(o, (dict, frozendict)):
return dict({k: unfreeze(v) for k, v in o.items()})
- if isinstance(o, string_types):
+ if isinstance(o, (binary_type, text_type)):
return o
try:
diff --git a/synapse/util/logcontext.py b/synapse/util/logcontext.py
index f6c7175f74..8dcae50b39 100644
--- a/synapse/util/logcontext.py
+++ b/synapse/util/logcontext.py
@@ -99,6 +99,17 @@ class ContextResourceUsage(object):
self.db_sched_duration_sec = 0
self.evt_db_fetch_count = 0
+ def __repr__(self):
+ return ("<ContextResourceUsage ru_stime='%r', ru_utime='%r', "
+ "db_txn_count='%r', db_txn_duration_sec='%r', "
+ "db_sched_duration_sec='%r', evt_db_fetch_count='%r'>") % (
+ self.ru_stime,
+ self.ru_utime,
+ self.db_txn_count,
+ self.db_txn_duration_sec,
+ self.db_sched_duration_sec,
+ self.evt_db_fetch_count,)
+
def __iadd__(self, other):
"""Add another ContextResourceUsage's stats to this one's.
diff --git a/synapse/util/metrics.py b/synapse/util/metrics.py
index 6ba7107896..97f1267380 100644
--- a/synapse/util/metrics.py
+++ b/synapse/util/metrics.py
@@ -104,12 +104,19 @@ class Measure(object):
logger.warn("Expected context. (%r)", self.name)
return
- usage = context.get_resource_usage() - self.start_usage
- block_ru_utime.labels(self.name).inc(usage.ru_utime)
- block_ru_stime.labels(self.name).inc(usage.ru_stime)
- block_db_txn_count.labels(self.name).inc(usage.db_txn_count)
- block_db_txn_duration.labels(self.name).inc(usage.db_txn_duration_sec)
- block_db_sched_duration.labels(self.name).inc(usage.db_sched_duration_sec)
+ current = context.get_resource_usage()
+ usage = current - self.start_usage
+ try:
+ block_ru_utime.labels(self.name).inc(usage.ru_utime)
+ block_ru_stime.labels(self.name).inc(usage.ru_stime)
+ block_db_txn_count.labels(self.name).inc(usage.db_txn_count)
+ block_db_txn_duration.labels(self.name).inc(usage.db_txn_duration_sec)
+ block_db_sched_duration.labels(self.name).inc(usage.db_sched_duration_sec)
+ except ValueError:
+ logger.warn(
+ "Failed to save metrics! OLD: %r, NEW: %r",
+ self.start_usage, current
+ )
if self.created_context:
self.start_context.__exit__(exc_type, exc_val, exc_tb)
|
