Patch inlinecallbacks for log contexts

synapse/__init__.py

@@ -17,8 +17,11 @@
 """ This is a reference implementation of a Matrix home server.
 """
 
+import os
 import sys
 
+from tests.patch_inline_callbacks import do_patch
+
 # Check that we're not running on an unsupported Python version.
 if sys.version_info < (3, 5):
     print("Synapse requires Python 3.5 or above.")
@@ -36,3 +39,6 @@ except ImportError:
     pass
 
 __version__ = "1.4.0rc1"
+
+if bool(os.environ.get("SYNAPSE_TEST_PATCH_LOG_CONTEXTS", False)):
+    do_patch()

synapse/handlers/room_member.py

@@ -213,11 +213,11 @@ class RoomMemberHandler(object):
 
             if predecessor:
                 # It is an upgraded room. Copy over old tags
-                self.copy_room_tags_and_direct_to_room(
+                yield self.copy_room_tags_and_direct_to_room(
                     predecessor["room_id"], room_id, user_id
                 )
                 # Move over old push rules
-                self.store.move_push_rules_from_room_to_room_for_user(
+                yield self.store.move_push_rules_from_room_to_room_for_user(
                     predecessor["room_id"], room_id, user_id
                 )
         elif event.membership == Membership.LEAVE:

synapse/storage/_base.py

@@ -30,7 +30,7 @@ from prometheus_client import Histogram
 from twisted.internet import defer
 
 from synapse.api.errors import StoreError
-from synapse.logging.context import LoggingContext, PreserveLoggingContext
+from synapse.logging.context import LoggingContext, make_deferred_yieldable
 from synapse.metrics.background_process_metrics import run_as_background_process
 from synapse.storage.engines import PostgresEngine, Sqlite3Engine
 from synapse.types import get_domain_from_id
@@ -550,8 +550,9 @@ class SQLBaseStore(object):
 
                 return func(conn, *args, **kwargs)
 
-        with PreserveLoggingContext():
+        result = yield make_deferred_yieldable(
-            result = yield self._db_pool.runWithConnection(inner_func, *args, **kwargs)
+            self._db_pool.runWithConnection(inner_func, *args, **kwargs)
+        )
 
         return result
 

synapse/storage/push_rule.py

@@ -235,7 +235,7 @@ class PushRulesWorkerStore(
                 (c.get("key") == "room_id" and c.get("pattern") == old_room_id)
                 for c in conditions
             ):
-                self.move_push_rule_from_room_to_room(new_room_id, user_id, rule)
+                yield self.move_push_rule_from_room_to_room(new_room_id, user_id, rule)
 
     @defer.inlineCallbacks
     def bulk_get_push_rules_for_room(self, event, context):

tests/patch_inline_callbacks.py

@@ -15,6 +15,7 @@
 
 from __future__ import print_function
 
+import inspect
 import functools
 import sys
 
@@ -33,17 +34,19 @@ def do_patch():
     orig_inline_callbacks = defer.inlineCallbacks
 
     def new_inline_callbacks(f):
-
-        orig = orig_inline_callbacks(f)
-
         @functools.wraps(f)
         def wrapped(*args, **kwargs):
             start_context = LoggingContext.current_context()
+            changes = []
+            orig = orig_inline_callbacks(_check_yield_points(f, changes, start_context))
 
             try:
                 res = orig(*args, **kwargs)
             except Exception:
                 if LoggingContext.current_context() != start_context:
+                    for err in changes:
+                        print(err, file=sys.stderr)
+
                     err = "%s changed context from %s to %s on exception" % (
                         f,
                         start_context,
@@ -55,7 +58,10 @@ def do_patch():
 
             if not isinstance(res, Deferred) or res.called:
                 if LoggingContext.current_context() != start_context:
-                    err = "%s changed context from %s to %s" % (
+                    for err in changes:
+                        print(err, file=sys.stderr)
+
+                    err = "Completed %s changed context from %s to %s" % (
                         f,
                         start_context,
                         LoggingContext.current_context(),
@@ -76,6 +82,8 @@ def do_patch():
 
             def check_ctx(r):
                 if LoggingContext.current_context() != start_context:
+                    for err in changes:
+                        print(err, file=sys.stderr)
                     err = "%s completion of %s changed context from %s to %s" % (
                         "Failure" if isinstance(r, Failure) else "Success",
                         f,
@@ -92,3 +100,73 @@ def do_patch():
         return wrapped
 
     defer.inlineCallbacks = new_inline_callbacks
+
+
+def _check_yield_points(f, changes, start_context):
+    from synapse.logging.context import LoggingContext
+
+    @functools.wraps(f)
+    def check_yield_points_inner(*args, **kwargs):
+        gen = f(*args, **kwargs)
+
+        last_yield_line_no = 1
+        result = None
+        while True:
+            try:
+                isFailure = isinstance(result, Failure)
+                if isFailure:
+                    d = result.throwExceptionIntoGenerator(gen)
+                else:
+                    d = gen.send(result)
+            except (StopIteration, defer._DefGen_Return) as e:
+                if LoggingContext.current_context() != start_context:
+                    # This happens when the context is lost sometime *after* the
+                    # final yield and returning. E.g. we forgot to yield on a
+                    # function that returns a deferred.
+                    err = (
+                        "%s returned and changed context from %s to %s, in %s between %d and end of func"
+                        % (
+                            f.__qualname__,
+                            start_context,
+                            LoggingContext.current_context(),
+                            f.__code__.co_filename,
+                            last_yield_line_no,
+                        )
+                    )
+                    changes.append(err)
+                    # print(err, file=sys.stderr)
+                    # raise Exception(err)
+                return getattr(e, "value", None)
+
+            try:
+                result = yield d
+            except Exception as e:
+                result = Failure(e)
+
+            frame = gen.gi_frame
+            if frame.f_code.co_name == "check_yield_points_inner":
+                frame = inspect.getgeneratorlocals(gen)["gen"].gi_frame
+
+            if LoggingContext.current_context() != start_context:
+                # This happens because the context is lost sometime *after* the
+                # previous yield and *after* the current yield. E.g. the
+                # deferred we waited on didn't follow the rules, or we forgot to
+                # yield on a function between the two yield points.
+                err = (
+                    "%s changed context from %s to %s, happened between lines %d and %d in %s"
+                    % (
+                        frame.f_code.co_name,
+                        start_context,
+                        LoggingContext.current_context(),
+                        last_yield_line_no,
+                        frame.f_lineno,
+                        frame.f_code.co_filename,
+                    )
+                )
+                changes.append(err)
+                # print(err, file=sys.stderr)
+                # raise Exception(err)
+
+            last_yield_line_no = frame.f_lineno
+
+    return check_yield_points_inner