diff --git a/synapse/util/logcontext.py b/synapse/util/logcontext.py
deleted file mode 100644
index 30dfa1d6b2..0000000000
--- a/synapse/util/logcontext.py
+++ /dev/null
@@ -1,693 +0,0 @@
-# Copyright 2014-2016 OpenMarket Ltd
-#
-# Licensed under the Apache License, Version 2.0 (the "License");
-# you may not use this file except in compliance with the License.
-# You may obtain a copy of the License at
-#
-# http://www.apache.org/licenses/LICENSE-2.0
-#
-# Unless required by applicable law or agreed to in writing, software
-# distributed under the License is distributed on an "AS IS" BASIS,
-# 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.
-
-""" Thread-local-alike tracking of log contexts within synapse
-
-This module provides objects and utilities for tracking contexts through
-synapse code, so that log lines can include a request identifier, and so that
-CPU and database activity can be accounted for against the request that caused
-them.
-
-See doc/log_contexts.rst for details on how this works.
-"""
-
-import logging
-import threading
-import types
-
-from twisted.internet import defer, threads
-
-logger = logging.getLogger(__name__)
-
-try:
- import resource
-
- # Python doesn't ship with a definition of RUSAGE_THREAD but it's defined
- # to be 1 on linux so we hard code it.
- RUSAGE_THREAD = 1
-
- # If the system doesn't support RUSAGE_THREAD then this should throw an
- # exception.
- resource.getrusage(RUSAGE_THREAD)
-
- def get_thread_resource_usage():
- return resource.getrusage(RUSAGE_THREAD)
-
-
-except Exception:
- # If the system doesn't support resource.getrusage(RUSAGE_THREAD) then we
- # won't track resource usage by returning None.
- def get_thread_resource_usage():
- return None
-
-
-# get an id for the current thread.
-#
-# threading.get_ident doesn't actually return an OS-level tid, and annoyingly,
-# on Linux it actually returns the same value either side of a fork() call. However
-# we only fork in one place, so it's not worth the hoop-jumping to get a real tid.
-#
-get_thread_id = threading.get_ident
-
-
-class ContextResourceUsage(object):
- """Object for tracking the resources used by a log context
-
- Attributes:
- ru_utime (float): user CPU time (in seconds)
- ru_stime (float): system CPU time (in seconds)
- db_txn_count (int): number of database transactions done
- db_sched_duration_sec (float): amount of time spent waiting for a
- database connection
- db_txn_duration_sec (float): amount of time spent doing database
- transactions (excluding scheduling time)
- evt_db_fetch_count (int): number of events requested from the database
- """
-
- __slots__ = [
- "ru_stime",
- "ru_utime",
- "db_txn_count",
- "db_txn_duration_sec",
- "db_sched_duration_sec",
- "evt_db_fetch_count",
- ]
-
- def __init__(self, copy_from=None):
- """Create a new ContextResourceUsage
-
- Args:
- copy_from (ContextResourceUsage|None): if not None, an object to
- copy stats from
- """
- if copy_from is None:
- self.reset()
- else:
- self.ru_utime = copy_from.ru_utime
- self.ru_stime = copy_from.ru_stime
- self.db_txn_count = copy_from.db_txn_count
-
- self.db_txn_duration_sec = copy_from.db_txn_duration_sec
- self.db_sched_duration_sec = copy_from.db_sched_duration_sec
- self.evt_db_fetch_count = copy_from.evt_db_fetch_count
-
- def copy(self):
- return ContextResourceUsage(copy_from=self)
-
- def reset(self):
- self.ru_stime = 0.0
- self.ru_utime = 0.0
- self.db_txn_count = 0
-
- self.db_txn_duration_sec = 0
- 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.
-
- Args:
- other (ContextResourceUsage): the other resource usage object
- """
- self.ru_utime += other.ru_utime
- self.ru_stime += other.ru_stime
- self.db_txn_count += other.db_txn_count
- self.db_txn_duration_sec += other.db_txn_duration_sec
- self.db_sched_duration_sec += other.db_sched_duration_sec
- self.evt_db_fetch_count += other.evt_db_fetch_count
- return self
-
- def __isub__(self, other):
- self.ru_utime -= other.ru_utime
- self.ru_stime -= other.ru_stime
- self.db_txn_count -= other.db_txn_count
- self.db_txn_duration_sec -= other.db_txn_duration_sec
- self.db_sched_duration_sec -= other.db_sched_duration_sec
- self.evt_db_fetch_count -= other.evt_db_fetch_count
- return self
-
- def __add__(self, other):
- res = ContextResourceUsage(copy_from=self)
- res += other
- return res
-
- def __sub__(self, other):
- res = ContextResourceUsage(copy_from=self)
- res -= other
- return res
-
-
-class LoggingContext(object):
- """Additional context for log formatting. Contexts are scoped within a
- "with" block.
-
- If a parent is given when creating a new context, then:
- - logging fields are copied from the parent to the new context on entry
- - when the new context exits, the cpu usage stats are copied from the
- child to the parent
-
- Args:
- name (str): Name for the context for debugging.
- parent_context (LoggingContext|None): The parent of the new context
- """
-
- __slots__ = [
- "previous_context",
- "name",
- "parent_context",
- "_resource_usage",
- "usage_start",
- "main_thread",
- "alive",
- "request",
- "tag",
- ]
-
- thread_local = threading.local()
-
- class Sentinel(object):
- """Sentinel to represent the root context"""
-
- __slots__ = []
-
- def __str__(self):
- return "sentinel"
-
- def copy_to(self, record):
- pass
-
- def start(self):
- pass
-
- def stop(self):
- pass
-
- def add_database_transaction(self, duration_sec):
- pass
-
- def add_database_scheduled(self, sched_sec):
- pass
-
- def record_event_fetch(self, event_count):
- pass
-
- def __nonzero__(self):
- return False
-
- __bool__ = __nonzero__ # python3
-
- sentinel = Sentinel()
-
- def __init__(self, name=None, parent_context=None, request=None):
- self.previous_context = LoggingContext.current_context()
- self.name = name
-
- # track the resources used by this context so far
- self._resource_usage = ContextResourceUsage()
-
- # If alive has the thread resource usage when the logcontext last
- # became active.
- self.usage_start = None
-
- self.main_thread = get_thread_id()
- self.request = None
- self.tag = ""
- self.alive = True
-
- self.parent_context = parent_context
-
- if self.parent_context is not None:
- self.parent_context.copy_to(self)
-
- if request is not None:
- # the request param overrides the request from the parent context
- self.request = request
-
- def __str__(self):
- if self.request:
- return str(self.request)
- return "%s@%x" % (self.name, id(self))
-
- @classmethod
- def current_context(cls):
- """Get the current logging context from thread local storage
-
- Returns:
- LoggingContext: the current logging context
- """
- return getattr(cls.thread_local, "current_context", cls.sentinel)
-
- @classmethod
- def set_current_context(cls, context):
- """Set the current logging context in thread local storage
- Args:
- context(LoggingContext): The context to activate.
- Returns:
- The context that was previously active
- """
- current = cls.current_context()
-
- if current is not context:
- current.stop()
- cls.thread_local.current_context = context
- context.start()
- return current
-
- def __enter__(self):
- """Enters this logging context into thread local storage"""
- old_context = self.set_current_context(self)
- if self.previous_context != old_context:
- logger.warn(
- "Expected previous context %r, found %r",
- self.previous_context,
- old_context,
- )
- self.alive = True
-
- return self
-
- def __exit__(self, type, value, traceback):
- """Restore the logging context in thread local storage to the state it
- was before this context was entered.
- Returns:
- None to avoid suppressing any exceptions that were thrown.
- """
- current = self.set_current_context(self.previous_context)
- if current is not self:
- if current is self.sentinel:
- logger.warning("Expected logging context %s was lost", self)
- else:
- logger.warning(
- "Expected logging context %s but found %s", self, current
- )
- self.previous_context = None
- self.alive = False
-
- # if we have a parent, pass our CPU usage stats on
- if self.parent_context is not None and hasattr(
- self.parent_context, "_resource_usage"
- ):
- self.parent_context._resource_usage += self._resource_usage
-
- # reset them in case we get entered again
- self._resource_usage.reset()
-
- def copy_to(self, record):
- """Copy logging fields from this context to a log record or
- another LoggingContext
- """
-
- # 'request' is the only field we currently use in the logger, so that's
- # all we need to copy
- record.request = self.request
-
- def start(self):
- if get_thread_id() != self.main_thread:
- logger.warning("Started logcontext %s on different thread", self)
- return
-
- # If we haven't already started record the thread resource usage so
- # far
- if not self.usage_start:
- self.usage_start = get_thread_resource_usage()
-
- def stop(self):
- if get_thread_id() != self.main_thread:
- logger.warning("Stopped logcontext %s on different thread", self)
- return
-
- # When we stop, let's record the cpu used since we started
- if not self.usage_start:
- logger.warning("Called stop on logcontext %s without calling start", self)
- return
-
- utime_delta, stime_delta = self._get_cputime()
- self._resource_usage.ru_utime += utime_delta
- self._resource_usage.ru_stime += stime_delta
-
- self.usage_start = None
-
- def get_resource_usage(self):
- """Get resources used by this logcontext so far.
-
- Returns:
- ContextResourceUsage: a *copy* of the object tracking resource
- usage so far
- """
- # we always return a copy, for consistency
- res = self._resource_usage.copy()
-
- # If we are on the correct thread and we're currently running then we
- # can include resource usage so far.
- is_main_thread = get_thread_id() == self.main_thread
- if self.alive and self.usage_start and is_main_thread:
- utime_delta, stime_delta = self._get_cputime()
- res.ru_utime += utime_delta
- res.ru_stime += stime_delta
-
- return res
-
- def _get_cputime(self):
- """Get the cpu usage time so far
-
- Returns: Tuple[float, float]: seconds in user mode, seconds in system mode
- """
- current = get_thread_resource_usage()
-
- utime_delta = current.ru_utime - self.usage_start.ru_utime
- stime_delta = current.ru_stime - self.usage_start.ru_stime
-
- # sanity check
- if utime_delta < 0:
- logger.error(
- "utime went backwards! %f < %f",
- current.ru_utime,
- self.usage_start.ru_utime,
- )
- utime_delta = 0
-
- if stime_delta < 0:
- logger.error(
- "stime went backwards! %f < %f",
- current.ru_stime,
- self.usage_start.ru_stime,
- )
- stime_delta = 0
-
- return utime_delta, stime_delta
-
- def add_database_transaction(self, duration_sec):
- if duration_sec < 0:
- raise ValueError("DB txn time can only be non-negative")
- self._resource_usage.db_txn_count += 1
- self._resource_usage.db_txn_duration_sec += duration_sec
-
- def add_database_scheduled(self, sched_sec):
- """Record a use of the database pool
-
- Args:
- sched_sec (float): number of seconds it took us to get a
- connection
- """
- if sched_sec < 0:
- raise ValueError("DB scheduling time can only be non-negative")
- self._resource_usage.db_sched_duration_sec += sched_sec
-
- def record_event_fetch(self, event_count):
- """Record a number of events being fetched from the db
-
- Args:
- event_count (int): number of events being fetched
- """
- self._resource_usage.evt_db_fetch_count += event_count
-
-
-class LoggingContextFilter(logging.Filter):
- """Logging filter that adds values from the current logging context to each
- record.
- Args:
- **defaults: Default values to avoid formatters complaining about
- missing fields
- """
-
- def __init__(self, **defaults):
- self.defaults = defaults
-
- def filter(self, record):
- """Add each fields from the logging contexts to the record.
- Returns:
- True to include the record in the log output.
- """
- context = LoggingContext.current_context()
- for key, value in self.defaults.items():
- setattr(record, key, value)
-
- # context should never be None, but if it somehow ends up being, then
- # we end up in a death spiral of infinite loops, so let's check, for
- # robustness' sake.
- if context is not None:
- context.copy_to(record)
-
- return True
-
-
-class PreserveLoggingContext(object):
- """Captures the current logging context and restores it when the scope is
- exited. Used to restore the context after a function using
- @defer.inlineCallbacks is resumed by a callback from the reactor."""
-
- __slots__ = ["current_context", "new_context", "has_parent"]
-
- def __init__(self, new_context=None):
- if new_context is None:
- new_context = LoggingContext.sentinel
- self.new_context = new_context
-
- def __enter__(self):
- """Captures the current logging context"""
- self.current_context = LoggingContext.set_current_context(self.new_context)
-
- if self.current_context:
- self.has_parent = self.current_context.previous_context is not None
- if not self.current_context.alive:
- logger.debug("Entering dead context: %s", self.current_context)
-
- def __exit__(self, type, value, traceback):
- """Restores the current logging context"""
- context = LoggingContext.set_current_context(self.current_context)
-
- if context != self.new_context:
- if context is LoggingContext.sentinel:
- logger.warning("Expected logging context %s was lost", self.new_context)
- else:
- logger.warning(
- "Expected logging context %s but found %s",
- self.new_context,
- context,
- )
-
- if self.current_context is not LoggingContext.sentinel:
- if not self.current_context.alive:
- logger.debug("Restoring dead context: %s", self.current_context)
-
-
-def nested_logging_context(suffix, parent_context=None):
- """Creates a new logging context as a child of another.
-
- The nested logging context will have a 'request' made up of the parent context's
- request, plus the given suffix.
-
- CPU/db usage stats will be added to the parent context's on exit.
-
- Normal usage looks like:
-
- with nested_logging_context(suffix):
- # ... do stuff
-
- Args:
- suffix (str): suffix to add to the parent context's 'request'.
- parent_context (LoggingContext|None): parent context. Will use the current context
- if None.
-
- Returns:
- LoggingContext: new logging context.
- """
- if parent_context is None:
- parent_context = LoggingContext.current_context()
- return LoggingContext(
- parent_context=parent_context, request=parent_context.request + "-" + suffix
- )
-
-
-def preserve_fn(f):
- """Function decorator which wraps the function with run_in_background"""
-
- def g(*args, **kwargs):
- return run_in_background(f, *args, **kwargs)
-
- return g
-
-
-def run_in_background(f, *args, **kwargs):
- """Calls a function, ensuring that the current context is restored after
- return from the function, and that the sentinel context is set once the
- deferred returned by the function completes.
-
- Useful for wrapping functions that return a deferred or coroutine, which you don't
- yield or await on (for instance because you want to pass it to
- deferred.gatherResults()).
-
- Note that if you completely discard the result, you should make sure that
- `f` doesn't raise any deferred exceptions, otherwise a scary-looking
- CRITICAL error about an unhandled error will be logged without much
- indication about where it came from.
- """
- current = LoggingContext.current_context()
- try:
- res = f(*args, **kwargs)
- except: # noqa: E722
- # the assumption here is that the caller doesn't want to be disturbed
- # by synchronous exceptions, so let's turn them into Failures.
- return defer.fail()
-
- if isinstance(res, types.CoroutineType):
- res = defer.ensureDeferred(res)
-
- if not isinstance(res, defer.Deferred):
- return res
-
- if res.called and not res.paused:
- # The function should have maintained the logcontext, so we can
- # optimise out the messing about
- return res
-
- # The function may have reset the context before returning, so
- # we need to restore it now.
- ctx = LoggingContext.set_current_context(current)
-
- # The original context will be restored when the deferred
- # completes, but there is nothing waiting for it, so it will
- # get leaked into the reactor or some other function which
- # wasn't expecting it. We therefore need to reset the context
- # here.
- #
- # (If this feels asymmetric, consider it this way: we are
- # effectively forking a new thread of execution. We are
- # probably currently within a ``with LoggingContext()`` block,
- # which is supposed to have a single entry and exit point. But
- # by spawning off another deferred, we are effectively
- # adding a new exit point.)
- res.addBoth(_set_context_cb, ctx)
- return res
-
-
-def make_deferred_yieldable(deferred):
- """Given a deferred, make it follow the Synapse logcontext rules:
-
- If the deferred has completed (or is not actually a Deferred), essentially
- does nothing (just returns another completed deferred with the
- result/failure).
-
- If the deferred has not yet completed, resets the logcontext before
- returning a deferred. Then, when the deferred completes, restores the
- current logcontext before running callbacks/errbacks.
-
- (This is more-or-less the opposite operation to run_in_background.)
- """
- if not isinstance(deferred, defer.Deferred):
- return deferred
-
- if deferred.called and not deferred.paused:
- # it looks like this deferred is ready to run any callbacks we give it
- # immediately. We may as well optimise out the logcontext faffery.
- return deferred
-
- # ok, we can't be sure that a yield won't block, so let's reset the
- # logcontext, and add a callback to the deferred to restore it.
- prev_context = LoggingContext.set_current_context(LoggingContext.sentinel)
- deferred.addBoth(_set_context_cb, prev_context)
- return deferred
-
-
-def _set_context_cb(result, context):
- """A callback function which just sets the logging context"""
- LoggingContext.set_current_context(context)
- return result
-
-
-def defer_to_thread(reactor, f, *args, **kwargs):
- """
- Calls the function `f` using a thread from the reactor's default threadpool and
- returns the result as a Deferred.
-
- Creates a new logcontext for `f`, which is created as a child of the current
- logcontext (so its CPU usage metrics will get attributed to the current
- logcontext). `f` should preserve the logcontext it is given.
-
- The result deferred follows the Synapse logcontext rules: you should `yield`
- on it.
-
- Args:
- reactor (twisted.internet.base.ReactorBase): The reactor in whose main thread
- the Deferred will be invoked, and whose threadpool we should use for the
- function.
-
- Normally this will be hs.get_reactor().
-
- f (callable): The function to call.
-
- args: positional arguments to pass to f.
-
- kwargs: keyword arguments to pass to f.
-
- Returns:
- Deferred: A Deferred which fires a callback with the result of `f`, or an
- errback if `f` throws an exception.
- """
- return defer_to_threadpool(reactor, reactor.getThreadPool(), f, *args, **kwargs)
-
-
-def defer_to_threadpool(reactor, threadpool, f, *args, **kwargs):
- """
- A wrapper for twisted.internet.threads.deferToThreadpool, which handles
- logcontexts correctly.
-
- Calls the function `f` using a thread from the given threadpool and returns
- the result as a Deferred.
-
- Creates a new logcontext for `f`, which is created as a child of the current
- logcontext (so its CPU usage metrics will get attributed to the current
- logcontext). `f` should preserve the logcontext it is given.
-
- The result deferred follows the Synapse logcontext rules: you should `yield`
- on it.
-
- Args:
- reactor (twisted.internet.base.ReactorBase): The reactor in whose main thread
- the Deferred will be invoked. Normally this will be hs.get_reactor().
-
- threadpool (twisted.python.threadpool.ThreadPool): The threadpool to use for
- running `f`. Normally this will be hs.get_reactor().getThreadPool().
-
- f (callable): The function to call.
-
- args: positional arguments to pass to f.
-
- kwargs: keyword arguments to pass to f.
-
- Returns:
- Deferred: A Deferred which fires a callback with the result of `f`, or an
- errback if `f` throws an exception.
- """
- logcontext = LoggingContext.current_context()
-
- def g():
- with LoggingContext(parent_context=logcontext):
- return f(*args, **kwargs)
-
- return make_deferred_yieldable(threads.deferToThreadPool(reactor, threadpool, g))
|
