973 lines
32 KiB
Python
973 lines
32 KiB
Python
# Copyright 2014-2016 OpenMarket Ltd
|
|
# Copyright 2019 The Matrix.org Foundation C.I.C.
|
|
#
|
|
# 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 typing
|
|
import warnings
|
|
from types import TracebackType
|
|
from typing import (
|
|
TYPE_CHECKING,
|
|
Awaitable,
|
|
Callable,
|
|
Optional,
|
|
Tuple,
|
|
Type,
|
|
TypeVar,
|
|
Union,
|
|
overload,
|
|
)
|
|
|
|
import attr
|
|
from typing_extensions import Literal, ParamSpec
|
|
|
|
from twisted.internet import defer, threads
|
|
from twisted.python.threadpool import ThreadPool
|
|
|
|
if TYPE_CHECKING:
|
|
from synapse.logging.scopecontextmanager import _LogContextScope
|
|
from synapse.types import ISynapseReactor
|
|
|
|
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)
|
|
|
|
is_thread_resource_usage_supported = True
|
|
|
|
def get_thread_resource_usage() -> "Optional[resource.struct_rusage]":
|
|
return resource.getrusage(RUSAGE_THREAD)
|
|
|
|
except Exception:
|
|
# If the system doesn't support resource.getrusage(RUSAGE_THREAD) then we
|
|
# won't track resource usage.
|
|
is_thread_resource_usage_supported = False
|
|
|
|
def get_thread_resource_usage() -> "Optional[resource.struct_rusage]":
|
|
return None
|
|
|
|
|
|
# a hook which can be set during testing to assert that we aren't abusing logcontexts.
|
|
def logcontext_error(msg: str) -> None:
|
|
logger.warning(msg)
|
|
|
|
|
|
# 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 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: "Optional[ContextResourceUsage]" = None) -> None:
|
|
"""Create a new ContextResourceUsage
|
|
|
|
Args:
|
|
copy_from: if not None, an object to copy stats from
|
|
"""
|
|
if copy_from is None:
|
|
self.reset()
|
|
else:
|
|
# FIXME: mypy can't infer the types set via reset() above, so specify explicitly for now
|
|
self.ru_utime: float = copy_from.ru_utime
|
|
self.ru_stime: float = copy_from.ru_stime
|
|
self.db_txn_count: int = copy_from.db_txn_count
|
|
|
|
self.db_txn_duration_sec: float = copy_from.db_txn_duration_sec
|
|
self.db_sched_duration_sec: float = copy_from.db_sched_duration_sec
|
|
self.evt_db_fetch_count: int = copy_from.evt_db_fetch_count
|
|
|
|
def copy(self) -> "ContextResourceUsage":
|
|
return ContextResourceUsage(copy_from=self)
|
|
|
|
def reset(self) -> None:
|
|
self.ru_stime = 0.0
|
|
self.ru_utime = 0.0
|
|
self.db_txn_count = 0
|
|
|
|
self.db_txn_duration_sec = 0.0
|
|
self.db_sched_duration_sec = 0.0
|
|
self.evt_db_fetch_count = 0
|
|
|
|
def __repr__(self) -> str:
|
|
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: "ContextResourceUsage") -> "ContextResourceUsage":
|
|
"""Add another ContextResourceUsage's stats to this one's.
|
|
|
|
Args:
|
|
other: 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: "ContextResourceUsage") -> "ContextResourceUsage":
|
|
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: "ContextResourceUsage") -> "ContextResourceUsage":
|
|
res = ContextResourceUsage(copy_from=self)
|
|
res += other
|
|
return res
|
|
|
|
def __sub__(self, other: "ContextResourceUsage") -> "ContextResourceUsage":
|
|
res = ContextResourceUsage(copy_from=self)
|
|
res -= other
|
|
return res
|
|
|
|
|
|
@attr.s(slots=True, auto_attribs=True)
|
|
class ContextRequest:
|
|
"""
|
|
A bundle of attributes from the SynapseRequest object.
|
|
|
|
This exists to:
|
|
|
|
* Avoid a cycle between LoggingContext and SynapseRequest.
|
|
* Be a single variable that can be passed from parent LoggingContexts to
|
|
their children.
|
|
"""
|
|
|
|
request_id: str
|
|
ip_address: str
|
|
site_tag: str
|
|
requester: Optional[str]
|
|
authenticated_entity: Optional[str]
|
|
method: str
|
|
url: str
|
|
protocol: str
|
|
user_agent: str
|
|
|
|
|
|
LoggingContextOrSentinel = Union["LoggingContext", "_Sentinel"]
|
|
|
|
|
|
class _Sentinel:
|
|
"""Sentinel to represent the root context"""
|
|
|
|
__slots__ = ["previous_context", "finished", "request", "scope", "tag"]
|
|
|
|
def __init__(self) -> None:
|
|
# Minimal set for compatibility with LoggingContext
|
|
self.previous_context = None
|
|
self.finished = False
|
|
self.request = None
|
|
self.scope = None
|
|
self.tag = None
|
|
|
|
def __str__(self) -> str:
|
|
return "sentinel"
|
|
|
|
def start(self, rusage: "Optional[resource.struct_rusage]") -> None:
|
|
pass
|
|
|
|
def stop(self, rusage: "Optional[resource.struct_rusage]") -> None:
|
|
pass
|
|
|
|
def add_database_transaction(self, duration_sec: float) -> None:
|
|
pass
|
|
|
|
def add_database_scheduled(self, sched_sec: float) -> None:
|
|
pass
|
|
|
|
def record_event_fetch(self, event_count: int) -> None:
|
|
pass
|
|
|
|
def __bool__(self) -> Literal[False]:
|
|
return False
|
|
|
|
|
|
SENTINEL_CONTEXT = _Sentinel()
|
|
|
|
|
|
class LoggingContext:
|
|
"""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: Name for the context for logging. If this is omitted, it is
|
|
inherited from the parent context.
|
|
parent_context (LoggingContext|None): The parent of the new context
|
|
"""
|
|
|
|
__slots__ = [
|
|
"previous_context",
|
|
"name",
|
|
"parent_context",
|
|
"_resource_usage",
|
|
"usage_start",
|
|
"main_thread",
|
|
"finished",
|
|
"request",
|
|
"tag",
|
|
"scope",
|
|
]
|
|
|
|
def __init__(
|
|
self,
|
|
name: Optional[str] = None,
|
|
parent_context: "Optional[LoggingContext]" = None,
|
|
request: Optional[ContextRequest] = None,
|
|
) -> None:
|
|
self.previous_context = current_context()
|
|
|
|
# track the resources used by this context so far
|
|
self._resource_usage = ContextResourceUsage()
|
|
|
|
# The thread resource usage when the logcontext became active. None
|
|
# if the context is not currently active.
|
|
self.usage_start: Optional[resource.struct_rusage] = None
|
|
|
|
self.main_thread = get_thread_id()
|
|
self.request = None
|
|
self.tag = ""
|
|
self.scope: Optional["_LogContextScope"] = None
|
|
|
|
# keep track of whether we have hit the __exit__ block for this context
|
|
# (suggesting that the the thing that created the context thinks it should
|
|
# be finished, and that re-activating it would suggest an error).
|
|
self.finished = False
|
|
|
|
self.parent_context = parent_context
|
|
|
|
if self.parent_context is not None:
|
|
# we track the current request_id
|
|
self.request = self.parent_context.request
|
|
|
|
# we also track the current scope:
|
|
self.scope = self.parent_context.scope
|
|
|
|
if request is not None:
|
|
# the request param overrides the request from the parent context
|
|
self.request = request
|
|
|
|
# if we don't have a `name`, but do have a parent context, use its name.
|
|
if self.parent_context and name is None:
|
|
name = str(self.parent_context)
|
|
if name is None:
|
|
raise ValueError(
|
|
"LoggingContext must be given either a name or a parent context"
|
|
)
|
|
self.name = name
|
|
|
|
def __str__(self) -> str:
|
|
return self.name
|
|
|
|
@classmethod
|
|
def current_context(cls) -> LoggingContextOrSentinel:
|
|
"""Get the current logging context from thread local storage
|
|
|
|
This exists for backwards compatibility. ``current_context()`` should be
|
|
called directly.
|
|
|
|
Returns:
|
|
The current logging context
|
|
"""
|
|
warnings.warn(
|
|
"synapse.logging.context.LoggingContext.current_context() is deprecated "
|
|
"in favor of synapse.logging.context.current_context().",
|
|
DeprecationWarning,
|
|
stacklevel=2,
|
|
)
|
|
return current_context()
|
|
|
|
@classmethod
|
|
def set_current_context(
|
|
cls, context: LoggingContextOrSentinel
|
|
) -> LoggingContextOrSentinel:
|
|
"""Set the current logging context in thread local storage
|
|
|
|
This exists for backwards compatibility. ``set_current_context()`` should be
|
|
called directly.
|
|
|
|
Args:
|
|
context: The context to activate.
|
|
|
|
Returns:
|
|
The context that was previously active
|
|
"""
|
|
warnings.warn(
|
|
"synapse.logging.context.LoggingContext.set_current_context() is deprecated "
|
|
"in favor of synapse.logging.context.set_current_context().",
|
|
DeprecationWarning,
|
|
stacklevel=2,
|
|
)
|
|
return set_current_context(context)
|
|
|
|
def __enter__(self) -> "LoggingContext":
|
|
"""Enters this logging context into thread local storage"""
|
|
old_context = set_current_context(self)
|
|
if self.previous_context != old_context:
|
|
logcontext_error(
|
|
"Expected previous context %r, found %r"
|
|
% (
|
|
self.previous_context,
|
|
old_context,
|
|
)
|
|
)
|
|
return self
|
|
|
|
def __exit__(
|
|
self,
|
|
type: Optional[Type[BaseException]],
|
|
value: Optional[BaseException],
|
|
traceback: Optional[TracebackType],
|
|
) -> None:
|
|
"""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 = set_current_context(self.previous_context)
|
|
if current is not self:
|
|
if current is SENTINEL_CONTEXT:
|
|
logcontext_error("Expected logging context %s was lost" % (self,))
|
|
else:
|
|
logcontext_error(
|
|
"Expected logging context %s but found %s" % (self, current)
|
|
)
|
|
|
|
# the fact that we are here suggests that the caller thinks that everything
|
|
# is done and dusted for this logcontext, and further activity will not get
|
|
# recorded against the correct metrics.
|
|
self.finished = True
|
|
|
|
def start(self, rusage: "Optional[resource.struct_rusage]") -> None:
|
|
"""
|
|
Record that this logcontext is currently running.
|
|
|
|
This should not be called directly: use set_current_context
|
|
|
|
Args:
|
|
rusage: the resources used by the current thread, at the point of
|
|
switching to this logcontext. May be None if this platform doesn't
|
|
support getrusuage.
|
|
"""
|
|
if get_thread_id() != self.main_thread:
|
|
logcontext_error("Started logcontext %s on different thread" % (self,))
|
|
return
|
|
|
|
if self.finished:
|
|
logcontext_error("Re-starting finished log context %s" % (self,))
|
|
|
|
# If we haven't already started record the thread resource usage so
|
|
# far
|
|
if self.usage_start:
|
|
logcontext_error("Re-starting already-active log context %s" % (self,))
|
|
else:
|
|
self.usage_start = rusage
|
|
|
|
def stop(self, rusage: "Optional[resource.struct_rusage]") -> None:
|
|
"""
|
|
Record that this logcontext is no longer running.
|
|
|
|
This should not be called directly: use set_current_context
|
|
|
|
Args:
|
|
rusage: the resources used by the current thread, at the point of
|
|
switching away from this logcontext. May be None if this platform
|
|
doesn't support getrusuage.
|
|
"""
|
|
|
|
try:
|
|
if get_thread_id() != self.main_thread:
|
|
logcontext_error("Stopped logcontext %s on different thread" % (self,))
|
|
return
|
|
|
|
if not rusage:
|
|
return
|
|
|
|
# Record the cpu used since we started
|
|
if not self.usage_start:
|
|
logcontext_error(
|
|
"Called stop on logcontext %s without recording a start rusage"
|
|
% (self,)
|
|
)
|
|
return
|
|
|
|
utime_delta, stime_delta = self._get_cputime(rusage)
|
|
self.add_cputime(utime_delta, stime_delta)
|
|
finally:
|
|
self.usage_start = None
|
|
|
|
def get_resource_usage(self) -> ContextResourceUsage:
|
|
"""Get resources used by this logcontext so far.
|
|
|
|
Returns:
|
|
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.usage_start and is_main_thread:
|
|
rusage = get_thread_resource_usage()
|
|
assert rusage is not None
|
|
utime_delta, stime_delta = self._get_cputime(rusage)
|
|
res.ru_utime += utime_delta
|
|
res.ru_stime += stime_delta
|
|
|
|
return res
|
|
|
|
def _get_cputime(self, current: "resource.struct_rusage") -> Tuple[float, float]:
|
|
"""Get the cpu usage time between start() and the given rusage
|
|
|
|
Args:
|
|
rusage: the current resource usage
|
|
|
|
Returns: Tuple[float, float]: seconds in user mode, seconds in system mode
|
|
"""
|
|
assert self.usage_start is not None
|
|
|
|
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_cputime(self, utime_delta: float, stime_delta: float) -> None:
|
|
"""Update the CPU time usage of this context (and any parents, recursively).
|
|
|
|
Args:
|
|
utime_delta: additional user time, in seconds, spent in this context.
|
|
stime_delta: additional system time, in seconds, spent in this context.
|
|
"""
|
|
self._resource_usage.ru_utime += utime_delta
|
|
self._resource_usage.ru_stime += stime_delta
|
|
if self.parent_context:
|
|
self.parent_context.add_cputime(utime_delta, stime_delta)
|
|
|
|
def add_database_transaction(self, duration_sec: float) -> None:
|
|
"""Record the use of a database transaction and the length of time it took.
|
|
|
|
Args:
|
|
duration_sec: The number of seconds the database transaction took.
|
|
"""
|
|
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
|
|
if self.parent_context:
|
|
self.parent_context.add_database_transaction(duration_sec)
|
|
|
|
def add_database_scheduled(self, sched_sec: float) -> None:
|
|
"""Record a use of the database pool
|
|
|
|
Args:
|
|
sched_sec: 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
|
|
if self.parent_context:
|
|
self.parent_context.add_database_scheduled(sched_sec)
|
|
|
|
def record_event_fetch(self, event_count: int) -> None:
|
|
"""Record a number of events being fetched from the db
|
|
|
|
Args:
|
|
event_count: number of events being fetched
|
|
"""
|
|
self._resource_usage.evt_db_fetch_count += event_count
|
|
if self.parent_context:
|
|
self.parent_context.record_event_fetch(event_count)
|
|
|
|
|
|
class LoggingContextFilter(logging.Filter):
|
|
"""Logging filter that adds values from the current logging context to each
|
|
record.
|
|
"""
|
|
|
|
def __init__(self, request: str = ""):
|
|
self._default_request = request
|
|
|
|
def filter(self, record: logging.LogRecord) -> Literal[True]:
|
|
"""Add each fields from the logging contexts to the record.
|
|
Returns:
|
|
True to include the record in the log output.
|
|
"""
|
|
context = current_context()
|
|
record.request = self._default_request
|
|
|
|
# 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:
|
|
# Logging is interested in the request ID. Note that for backwards
|
|
# compatibility this is stored as the "request" on the record.
|
|
record.request = str(context)
|
|
|
|
# Add some data from the HTTP request.
|
|
request = context.request
|
|
if request is None:
|
|
return True
|
|
|
|
record.ip_address = request.ip_address
|
|
record.site_tag = request.site_tag
|
|
record.requester = request.requester
|
|
record.authenticated_entity = request.authenticated_entity
|
|
record.method = request.method
|
|
record.url = request.url
|
|
record.protocol = request.protocol
|
|
record.user_agent = request.user_agent
|
|
|
|
return True
|
|
|
|
|
|
class PreserveLoggingContext:
|
|
"""Context manager which replaces the logging context
|
|
|
|
The previous logging context is restored on exit."""
|
|
|
|
__slots__ = ["_old_context", "_new_context"]
|
|
|
|
def __init__(
|
|
self, new_context: LoggingContextOrSentinel = SENTINEL_CONTEXT
|
|
) -> None:
|
|
self._new_context = new_context
|
|
|
|
def __enter__(self) -> None:
|
|
self._old_context = set_current_context(self._new_context)
|
|
|
|
def __exit__(
|
|
self,
|
|
type: Optional[Type[BaseException]],
|
|
value: Optional[BaseException],
|
|
traceback: Optional[TracebackType],
|
|
) -> None:
|
|
context = set_current_context(self._old_context)
|
|
|
|
if context != self._new_context:
|
|
if not context:
|
|
logcontext_error(
|
|
"Expected logging context %s was lost" % (self._new_context,)
|
|
)
|
|
else:
|
|
logcontext_error(
|
|
"Expected logging context %s but found %s"
|
|
% (
|
|
self._new_context,
|
|
context,
|
|
)
|
|
)
|
|
|
|
|
|
_thread_local = threading.local()
|
|
_thread_local.current_context = SENTINEL_CONTEXT
|
|
|
|
|
|
def current_context() -> LoggingContextOrSentinel:
|
|
"""Get the current logging context from thread local storage"""
|
|
return getattr(_thread_local, "current_context", SENTINEL_CONTEXT)
|
|
|
|
|
|
def set_current_context(context: LoggingContextOrSentinel) -> LoggingContextOrSentinel:
|
|
"""Set the current logging context in thread local storage
|
|
Args:
|
|
context: The context to activate.
|
|
|
|
Returns:
|
|
The context that was previously active
|
|
"""
|
|
# everything blows up if we allow current_context to be set to None, so sanity-check
|
|
# that now.
|
|
if context is None:
|
|
raise TypeError("'context' argument may not be None")
|
|
|
|
current = current_context()
|
|
|
|
if current is not context:
|
|
rusage = get_thread_resource_usage()
|
|
current.stop(rusage)
|
|
_thread_local.current_context = context
|
|
context.start(rusage)
|
|
|
|
return current
|
|
|
|
|
|
def nested_logging_context(suffix: str) -> LoggingContext:
|
|
"""Creates a new logging context as a child of another.
|
|
|
|
The nested logging context will have a 'name' made up of the parent context's
|
|
name, 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: suffix to add to the parent context's 'name'.
|
|
|
|
Returns:
|
|
A new logging context.
|
|
"""
|
|
curr_context = current_context()
|
|
if not curr_context:
|
|
logger.warning(
|
|
"Starting nested logging context from sentinel context: metrics will be lost"
|
|
)
|
|
parent_context = None
|
|
else:
|
|
assert isinstance(curr_context, LoggingContext)
|
|
parent_context = curr_context
|
|
prefix = str(curr_context)
|
|
return LoggingContext(
|
|
prefix + "-" + suffix,
|
|
parent_context=parent_context,
|
|
)
|
|
|
|
|
|
P = ParamSpec("P")
|
|
R = TypeVar("R")
|
|
|
|
|
|
async def _unwrap_awaitable(awaitable: Awaitable[R]) -> R:
|
|
"""Unwraps an arbitrary awaitable by awaiting it."""
|
|
return await awaitable
|
|
|
|
|
|
@overload
|
|
def preserve_fn(
|
|
f: Callable[P, Awaitable[R]],
|
|
) -> Callable[P, "defer.Deferred[R]"]:
|
|
# The `type: ignore[misc]` above suppresses
|
|
# "Overloaded function signatures 1 and 2 overlap with incompatible return types"
|
|
...
|
|
|
|
|
|
@overload
|
|
def preserve_fn(f: Callable[P, R]) -> Callable[P, "defer.Deferred[R]"]:
|
|
...
|
|
|
|
|
|
def preserve_fn(
|
|
f: Union[
|
|
Callable[P, R],
|
|
Callable[P, Awaitable[R]],
|
|
]
|
|
) -> Callable[P, "defer.Deferred[R]"]:
|
|
"""Function decorator which wraps the function with run_in_background"""
|
|
|
|
def g(*args: P.args, **kwargs: P.kwargs) -> "defer.Deferred[R]":
|
|
return run_in_background(f, *args, **kwargs)
|
|
|
|
return g
|
|
|
|
|
|
@overload
|
|
def run_in_background(
|
|
f: Callable[P, Awaitable[R]], *args: P.args, **kwargs: P.kwargs
|
|
) -> "defer.Deferred[R]":
|
|
# The `type: ignore[misc]` above suppresses
|
|
# "Overloaded function signatures 1 and 2 overlap with incompatible return types"
|
|
...
|
|
|
|
|
|
@overload
|
|
def run_in_background(
|
|
f: Callable[P, R], *args: P.args, **kwargs: P.kwargs
|
|
) -> "defer.Deferred[R]":
|
|
...
|
|
|
|
|
|
def run_in_background( # type: ignore[misc]
|
|
# The `type: ignore[misc]` above suppresses
|
|
# "Overloaded function implementation does not accept all possible arguments of signature 1"
|
|
# "Overloaded function implementation does not accept all possible arguments of signature 2"
|
|
# which seems like a bug in mypy.
|
|
f: Union[
|
|
Callable[P, R],
|
|
Callable[P, Awaitable[R]],
|
|
],
|
|
*args: P.args,
|
|
**kwargs: P.kwargs,
|
|
) -> "defer.Deferred[R]":
|
|
"""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()).
|
|
|
|
If f returns a Coroutine object, it will be wrapped into a Deferred (which will have
|
|
the side effect of executing the coroutine).
|
|
|
|
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 = current_context()
|
|
try:
|
|
res = f(*args, **kwargs)
|
|
except Exception:
|
|
# 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()
|
|
|
|
# `res` may be a coroutine, `Deferred`, some other kind of awaitable, or a plain
|
|
# value. Convert it to a `Deferred`.
|
|
d: "defer.Deferred[R]"
|
|
if isinstance(res, typing.Coroutine):
|
|
# Wrap the coroutine in a `Deferred`.
|
|
d = defer.ensureDeferred(res)
|
|
elif isinstance(res, defer.Deferred):
|
|
d = res
|
|
elif isinstance(res, Awaitable):
|
|
# `res` is probably some kind of completed awaitable, such as a `DoneAwaitable`
|
|
# or `Future` from `make_awaitable`.
|
|
d = defer.ensureDeferred(_unwrap_awaitable(res))
|
|
else:
|
|
# `res` is a plain value. Wrap it in a `Deferred`.
|
|
d = defer.succeed(res)
|
|
|
|
if d.called and not d.paused:
|
|
# The function should have maintained the logcontext, so we can
|
|
# optimise out the messing about
|
|
return d
|
|
|
|
# The function may have reset the context before returning, so
|
|
# we need to restore it now.
|
|
ctx = 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.)
|
|
d.addBoth(_set_context_cb, ctx)
|
|
return d
|
|
|
|
|
|
T = TypeVar("T")
|
|
|
|
|
|
def make_deferred_yieldable(deferred: "defer.Deferred[T]") -> "defer.Deferred[T]":
|
|
"""Given a deferred, make it follow the Synapse logcontext rules:
|
|
|
|
If the deferred has completed, 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 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 = set_current_context(SENTINEL_CONTEXT)
|
|
deferred.addBoth(_set_context_cb, prev_context)
|
|
return deferred
|
|
|
|
|
|
ResultT = TypeVar("ResultT")
|
|
|
|
|
|
def _set_context_cb(result: ResultT, context: LoggingContextOrSentinel) -> ResultT:
|
|
"""A callback function which just sets the logging context"""
|
|
set_current_context(context)
|
|
return result
|
|
|
|
|
|
def defer_to_thread(
|
|
reactor: "ISynapseReactor", f: Callable[P, R], *args: P.args, **kwargs: P.kwargs
|
|
) -> "defer.Deferred[R]":
|
|
"""
|
|
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: 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: The function to call.
|
|
|
|
args: positional arguments to pass to f.
|
|
|
|
kwargs: keyword arguments to pass to f.
|
|
|
|
Returns:
|
|
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: "ISynapseReactor",
|
|
threadpool: ThreadPool,
|
|
f: Callable[P, R],
|
|
*args: P.args,
|
|
**kwargs: P.kwargs,
|
|
) -> "defer.Deferred[R]":
|
|
"""
|
|
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: The reactor in whose main thread the Deferred will be invoked.
|
|
Normally this will be hs.get_reactor().
|
|
|
|
threadpool: The threadpool to use for running `f`. Normally this will be
|
|
hs.get_reactor().getThreadPool().
|
|
|
|
f: The function to call.
|
|
|
|
args: positional arguments to pass to f.
|
|
|
|
kwargs: keyword arguments to pass to f.
|
|
|
|
Returns:
|
|
A Deferred which fires a callback with the result of `f`, or an
|
|
errback if `f` throws an exception.
|
|
"""
|
|
curr_context = current_context()
|
|
if not curr_context:
|
|
logger.warning(
|
|
"Calling defer_to_threadpool from sentinel context: metrics will be lost"
|
|
)
|
|
parent_context = None
|
|
else:
|
|
assert isinstance(curr_context, LoggingContext)
|
|
parent_context = curr_context
|
|
|
|
def g() -> R:
|
|
with LoggingContext(str(curr_context), parent_context=parent_context):
|
|
return f(*args, **kwargs)
|
|
|
|
return make_deferred_yieldable(threads.deferToThreadPool(reactor, threadpool, g))
|