12 files changed, 42 insertions, 39 deletions
diff --git a/synapse/app/_base.py b/synapse/app/_base.py
index d50a9840d4..1ebb7ae539 100644
--- a/synapse/app/_base.py
+++ b/synapse/app/_base.py
@@ -27,7 +27,7 @@ from twisted.protocols.tls import TLSMemoryBIOFactory
 import synapse
 from synapse.app import check_bind_error
 from synapse.crypto import context_factory
-from synapse.util import PreserveLoggingContext
+from synapse.logging.context import PreserveLoggingContext
 from synapse.util.async_helpers import Linearizer
 from synapse.util.rlimit import change_resource_limit
 from synapse.util.versionstring import get_version_string
@@ -93,33 +93,36 @@ def start_reactor(
     install_dns_limiter(reactor)
 
     def run():
-        # make sure that we run the reactor with the sentinel log context,
-        # otherwise other PreserveLoggingContext instances will get confused
-        # and complain when they see the logcontext arbitrarily swapping
-        # between the sentinel and `run` logcontexts.
-        with PreserveLoggingContext():
-            logger.info("Running")
-
-            change_resource_limit(soft_file_limit)
-            if gc_thresholds:
-                gc.set_threshold(*gc_thresholds)
-            reactor.run()
-
-    if daemonize:
-        if print_pidfile:
-            print(pid_file)
-
-        daemon = Daemonize(
-            app=appname,
-            pid=pid_file,
-            action=run,
-            auto_close_fds=False,
-            verbose=True,
-            logger=logger,
-        )
-        daemon.start()
-    else:
-        run()
+        logger.info("Running")
+        change_resource_limit(soft_file_limit)
+        if gc_thresholds:
+            gc.set_threshold(*gc_thresholds)
+        reactor.run()
+
+    # make sure that we run the reactor with the sentinel log context,
+    # otherwise other PreserveLoggingContext instances will get confused
+    # and complain when they see the logcontext arbitrarily swapping
+    # between the sentinel and `run` logcontexts.
+    #
+    # We also need to drop the logcontext before forking if we're daemonizing,
+    # otherwise the cputime metrics get confused about the per-thread resource usage
+    # appearing to go backwards.
+    with PreserveLoggingContext():
+        if daemonize:
+            if print_pidfile:
+                print(pid_file)
+
+            daemon = Daemonize(
+                app=appname,
+                pid=pid_file,
+                action=run,
+                auto_close_fds=False,
+                verbose=True,
+                logger=logger,
+            )
+            daemon.start()
+        else:
+            run()
 
 
 def quit_with_error(error_string):
diff --git a/synapse/app/appservice.py b/synapse/app/appservice.py
index 9120bdb143..be44249ed6 100644
--- a/synapse/app/appservice.py
+++ b/synapse/app/appservice.py
@@ -26,6 +26,7 @@ from synapse.config._base import ConfigError
 from synapse.config.homeserver import HomeServerConfig
 from synapse.config.logger import setup_logging
 from synapse.http.site import SynapseSite
+from synapse.logging.context import LoggingContext, run_in_background
 from synapse.metrics import RegistryProxy
 from synapse.metrics.resource import METRICS_PREFIX, MetricsResource
 from synapse.replication.slave.storage.appservice import SlavedApplicationServiceStore
@@ -36,7 +37,6 @@ from synapse.replication.tcp.client import ReplicationClientHandler
 from synapse.server import HomeServer
 from synapse.storage.engines import create_engine
 from synapse.util.httpresourcetree import create_resource_tree
-from synapse.util.logcontext import LoggingContext, run_in_background
 from synapse.util.manhole import manhole
 from synapse.util.versionstring import get_version_string
 
diff --git a/synapse/app/client_reader.py b/synapse/app/client_reader.py
index 90bc79cdda..ff11beca82 100644
--- a/synapse/app/client_reader.py
+++ b/synapse/app/client_reader.py
@@ -27,6 +27,7 @@ from synapse.config.homeserver import HomeServerConfig
 from synapse.config.logger import setup_logging
 from synapse.http.server import JsonResource
 from synapse.http.site import SynapseSite
+from synapse.logging.context import LoggingContext
 from synapse.metrics import RegistryProxy
 from synapse.metrics.resource import METRICS_PREFIX, MetricsResource
 from synapse.replication.slave.storage._base import BaseSlavedStore
@@ -64,7 +65,6 @@ from synapse.rest.client.versions import VersionsRestServlet
 from synapse.server import HomeServer
 from synapse.storage.engines import create_engine
 from synapse.util.httpresourcetree import create_resource_tree
-from synapse.util.logcontext import LoggingContext
 from synapse.util.manhole import manhole
 from synapse.util.versionstring import get_version_string
 
diff --git a/synapse/app/event_creator.py b/synapse/app/event_creator.py
index ff522e4499..cacad25eac 100644
--- a/synapse/app/event_creator.py
+++ b/synapse/app/event_creator.py
@@ -27,6 +27,7 @@ from synapse.config.homeserver import HomeServerConfig
 from synapse.config.logger import setup_logging
 from synapse.http.server import JsonResource
 from synapse.http.site import SynapseSite
+from synapse.logging.context import LoggingContext
 from synapse.metrics import RegistryProxy
 from synapse.metrics.resource import METRICS_PREFIX, MetricsResource
 from synapse.replication.slave.storage._base import BaseSlavedStore
@@ -59,7 +60,6 @@ from synapse.server import HomeServer
 from synapse.storage.engines import create_engine
 from synapse.storage.user_directory import UserDirectoryStore
 from synapse.util.httpresourcetree import create_resource_tree
-from synapse.util.logcontext import LoggingContext
 from synapse.util.manhole import manhole
 from synapse.util.versionstring import get_version_string
 
diff --git a/synapse/app/federation_reader.py b/synapse/app/federation_reader.py
index 9421420930..11e80dbae0 100644
--- a/synapse/app/federation_reader.py
+++ b/synapse/app/federation_reader.py
@@ -28,6 +28,7 @@ from synapse.config.homeserver import HomeServerConfig
 from synapse.config.logger import setup_logging
 from synapse.federation.transport.server import TransportLayerServer
 from synapse.http.site import SynapseSite
+from synapse.logging.context import LoggingContext
 from synapse.metrics import RegistryProxy
 from synapse.metrics.resource import METRICS_PREFIX, MetricsResource
 from synapse.replication.slave.storage._base import BaseSlavedStore
@@ -48,7 +49,6 @@ from synapse.rest.key.v2 import KeyApiV2Resource
 from synapse.server import HomeServer
 from synapse.storage.engines import create_engine
 from synapse.util.httpresourcetree import create_resource_tree
-from synapse.util.logcontext import LoggingContext
 from synapse.util.manhole import manhole
 from synapse.util.versionstring import get_version_string
 
diff --git a/synapse/app/federation_sender.py b/synapse/app/federation_sender.py
index 969be58d0b..97da7bdcbf 100644
--- a/synapse/app/federation_sender.py
+++ b/synapse/app/federation_sender.py
@@ -27,6 +27,7 @@ from synapse.config.homeserver import HomeServerConfig
 from synapse.config.logger import setup_logging
 from synapse.federation import send_queue
 from synapse.http.site import SynapseSite
+from synapse.logging.context import LoggingContext, run_in_background
 from synapse.metrics import RegistryProxy
 from synapse.metrics.background_process_metrics import run_as_background_process
 from synapse.metrics.resource import METRICS_PREFIX, MetricsResource
@@ -44,7 +45,6 @@ from synapse.storage.engines import create_engine
 from synapse.types import ReadReceipt
 from synapse.util.async_helpers import Linearizer
 from synapse.util.httpresourcetree import create_resource_tree
-from synapse.util.logcontext import LoggingContext, run_in_background
 from synapse.util.manhole import manhole
 from synapse.util.versionstring import get_version_string
 
diff --git a/synapse/app/frontend_proxy.py b/synapse/app/frontend_proxy.py
index 2fd7d57ebf..417a10bbd2 100644
--- a/synapse/app/frontend_proxy.py
+++ b/synapse/app/frontend_proxy.py
@@ -29,6 +29,7 @@ from synapse.config.logger import setup_logging
 from synapse.http.server import JsonResource
 from synapse.http.servlet import RestServlet, parse_json_object_from_request
 from synapse.http.site import SynapseSite
+from synapse.logging.context import LoggingContext
 from synapse.metrics import RegistryProxy
 from synapse.metrics.resource import METRICS_PREFIX, MetricsResource
 from synapse.replication.slave.storage._base import BaseSlavedStore
@@ -41,7 +42,6 @@ from synapse.rest.client.v2_alpha._base import client_patterns
 from synapse.server import HomeServer
 from synapse.storage.engines import create_engine
 from synapse.util.httpresourcetree import create_resource_tree
-from synapse.util.logcontext import LoggingContext
 from synapse.util.manhole import manhole
 from synapse.util.versionstring import get_version_string
 
diff --git a/synapse/app/homeserver.py b/synapse/app/homeserver.py
index 49da105cf6..639b1429c0 100755
--- a/synapse/app/homeserver.py
+++ b/synapse/app/homeserver.py
@@ -54,6 +54,7 @@ from synapse.federation.transport.server import TransportLayerServer
 from synapse.http.additional_resource import AdditionalResource
 from synapse.http.server import RootRedirect
 from synapse.http.site import SynapseSite
+from synapse.logging.context import LoggingContext
 from synapse.metrics import RegistryProxy
 from synapse.metrics.background_process_metrics import run_as_background_process
 from synapse.metrics.resource import METRICS_PREFIX, MetricsResource
@@ -72,7 +73,6 @@ from synapse.storage.engines import IncorrectDatabaseSetup, create_engine
 from synapse.storage.prepare_database import UpgradeDatabaseException, prepare_database
 from synapse.util.caches import CACHE_SIZE_FACTOR
 from synapse.util.httpresourcetree import create_resource_tree
-from synapse.util.logcontext import LoggingContext
 from synapse.util.manhole import manhole
 from synapse.util.module_loader import load_module
 from synapse.util.rlimit import change_resource_limit
diff --git a/synapse/app/media_repository.py b/synapse/app/media_repository.py
index cf0e2036c3..f23b9b6eda 100644
--- a/synapse/app/media_repository.py
+++ b/synapse/app/media_repository.py
@@ -27,6 +27,7 @@ from synapse.config._base import ConfigError
 from synapse.config.homeserver import HomeServerConfig
 from synapse.config.logger import setup_logging
 from synapse.http.site import SynapseSite
+from synapse.logging.context import LoggingContext
 from synapse.metrics import RegistryProxy
 from synapse.metrics.resource import METRICS_PREFIX, MetricsResource
 from synapse.replication.slave.storage._base import BaseSlavedStore
@@ -40,7 +41,6 @@ from synapse.server import HomeServer
 from synapse.storage.engines import create_engine
 from synapse.storage.media_repository import MediaRepositoryStore
 from synapse.util.httpresourcetree import create_resource_tree
-from synapse.util.logcontext import LoggingContext
 from synapse.util.manhole import manhole
 from synapse.util.versionstring import get_version_string
 
diff --git a/synapse/app/pusher.py b/synapse/app/pusher.py
index df29ea5ecb..4f929edf86 100644
--- a/synapse/app/pusher.py
+++ b/synapse/app/pusher.py
@@ -26,6 +26,7 @@ from synapse.config._base import ConfigError
 from synapse.config.homeserver import HomeServerConfig
 from synapse.config.logger import setup_logging
 from synapse.http.site import SynapseSite
+from synapse.logging.context import LoggingContext, run_in_background
 from synapse.metrics import RegistryProxy
 from synapse.metrics.resource import METRICS_PREFIX, MetricsResource
 from synapse.replication.slave.storage._base import __func__
@@ -38,7 +39,6 @@ from synapse.server import HomeServer
 from synapse.storage import DataStore
 from synapse.storage.engines import create_engine
 from synapse.util.httpresourcetree import create_resource_tree
-from synapse.util.logcontext import LoggingContext, run_in_background
 from synapse.util.manhole import manhole
 from synapse.util.versionstring import get_version_string
 
diff --git a/synapse/app/synchrotron.py b/synapse/app/synchrotron.py
index 858949910d..de4797fddc 100644
--- a/synapse/app/synchrotron.py
+++ b/synapse/app/synchrotron.py
@@ -31,6 +31,7 @@ from synapse.config.logger import setup_logging
 from synapse.handlers.presence import PresenceHandler, get_interested_parties
 from synapse.http.server import JsonResource
 from synapse.http.site import SynapseSite
+from synapse.logging.context import LoggingContext, run_in_background
 from synapse.metrics import RegistryProxy
 from synapse.metrics.resource import METRICS_PREFIX, MetricsResource
 from synapse.replication.slave.storage._base import BaseSlavedStore, __func__
@@ -57,7 +58,6 @@ from synapse.server import HomeServer
 from synapse.storage.engines import create_engine
 from synapse.storage.presence import UserPresenceState
 from synapse.util.httpresourcetree import create_resource_tree
-from synapse.util.logcontext import LoggingContext, run_in_background
 from synapse.util.manhole import manhole
 from synapse.util.stringutils import random_string
 from synapse.util.versionstring import get_version_string
diff --git a/synapse/app/user_dir.py b/synapse/app/user_dir.py
index 2d9d2e1bbc..1177ddd72e 100644
--- a/synapse/app/user_dir.py
+++ b/synapse/app/user_dir.py
@@ -28,6 +28,7 @@ from synapse.config.homeserver import HomeServerConfig
 from synapse.config.logger import setup_logging
 from synapse.http.server import JsonResource
 from synapse.http.site import SynapseSite
+from synapse.logging.context import LoggingContext, run_in_background
 from synapse.metrics import RegistryProxy
 from synapse.metrics.resource import METRICS_PREFIX, MetricsResource
 from synapse.replication.slave.storage._base import BaseSlavedStore
@@ -46,7 +47,6 @@ from synapse.storage.engines import create_engine
 from synapse.storage.user_directory import UserDirectoryStore
 from synapse.util.caches.stream_change_cache import StreamChangeCache
 from synapse.util.httpresourcetree import create_resource_tree
-from synapse.util.logcontext import LoggingContext, run_in_background
 from synapse.util.manhole import manhole
 from synapse.util.versionstring import get_version_string