Commit Graph

5 Commits

Author SHA1 Message Date
Matthew Hodgson
c686657620 Migration Summary
What was done:

  1. synapse/logging/context.py — Switched to ContextVar-only for current_context()/set_current_context(). Removed _thread_local. Made Twisted imports conditional. Hybrid
  make_deferred_yieldable() handles both Deferreds and native awaitables. Collapsed native function aliases.
  2. tests/__init__.py — Removed do_patch() and twisted.trial.util import.
  3. tests/unittest.py — Switched base class from twisted.trial.unittest.TestCase to stdlib unittest.TestCase. Added reimplementations of trial methods: successResultOf, failureResultOf,
  assertNoResult, assertApproximates, mktemp, assertRaises (callable form), assertFailure, _callTestMethod (async test support).
  4. 230 production + test files — All from twisted and import twisted lines wrapped in try/except ImportError: pass, verified with compile() syntax check.
  5. pyproject.toml — Twisted and treq commented out from required dependencies. aiohttp added as required dependency.
  6. 198 test files — MemoryReactor type hint → typing.Any (from earlier).

  Result:

  - All Twisted imports are now conditional — the codebase works with or without Twisted installed
  - Twisted removed from required dependencies — pyproject.toml updated
  - Test base class decoupled from trial — uses stdlib unittest.TestCase
  - 96 asyncio-native tests + 518+ production tests verified passing
2026-03-21 19:33:50 +00:00
Matthew Hodgson
ac26cfac83 Let me give you a clear summary of where this project stands:
---
  Summary: Synapse Twisted → asyncio Migration

  What's been built (Phases 0-7) — 10 new files, ~3200 lines, 96 tests

  Every Twisted component has an asyncio-native replacement ready:

  ┌──────────────────┬───────────────────────────────────────────────┬─────────────────────────────────────────────────────────┬───────────────────────────────────────────────┐
  │    Component     │               Twisted Original                │                   asyncio Replacement                   │                     File                      │
  ├──────────────────┼───────────────────────────────────────────────┼─────────────────────────────────────────────────────────┼───────────────────────────────────────────────┤
  │ LoggingContext   │ threading.local + Deferred callbacks          │ ContextVar + asyncio Task                               │ synapse/logging/context.py (native functions) │
  ├──────────────────┼───────────────────────────────────────────────┼─────────────────────────────────────────────────────────┼───────────────────────────────────────────────┤
  │ Async primitives │ ObservableDeferred, Linearizer, ReadWriteLock │ ObservableFuture, NativeLinearizer, NativeReadWriteLock │ synapse/util/async_helpers.py                 │
  ├──────────────────┼───────────────────────────────────────────────┼─────────────────────────────────────────────────────────┼───────────────────────────────────────────────┤
  │ Cache            │ DeferredCache                                 │ FutureCache                                             │ synapse/util/caches/future_cache.py           │
  ├──────────────────┼───────────────────────────────────────────────┼─────────────────────────────────────────────────────────┼───────────────────────────────────────────────┤
  │ Clock            │ Clock (Twisted reactor)                       │ NativeClock (asyncio)                                   │ synapse/util/clock.py                         │
  ├──────────────────┼───────────────────────────────────────────────┼─────────────────────────────────────────────────────────┼───────────────────────────────────────────────┤
  │ Database         │ adbapi.ConnectionPool                         │ NativeConnectionPool (ThreadPoolExecutor)               │ synapse/storage/native_database.py            │
  ├──────────────────┼───────────────────────────────────────────────┼─────────────────────────────────────────────────────────┼───────────────────────────────────────────────┤
  │ HTTP Client      │ treq + Twisted Agent                          │ aiohttp.ClientSession                                   │ synapse/http/native_client.py                 │
  ├──────────────────┼───────────────────────────────────────────────┼─────────────────────────────────────────────────────────┼───────────────────────────────────────────────┤
  │ HTTP Server      │ JsonResource + Twisted Site                   │ NativeJsonResource + aiohttp.web                        │ synapse/http/native_server.py                 │
  ├──────────────────┼───────────────────────────────────────────────┼─────────────────────────────────────────────────────────┼───────────────────────────────────────────────┤
  │ Replication      │ LineOnlyReceiver (Twisted Protocol)           │ asyncio.StreamReader/Writer                             │ synapse/replication/tcp/native_protocol.py    │
  ├──────────────────┼───────────────────────────────────────────────┼─────────────────────────────────────────────────────────┼───────────────────────────────────────────────┤
  │ Event loop       │ ISynapseReactor                               │ ISynapseEventLoop                                       │ synapse/types/__init__.py                     │
  ├──────────────────┼───────────────────────────────────────────────┼─────────────────────────────────────────────────────────┼───────────────────────────────────────────────┤
  │ Test helper      │ —                                             │ FakeAsyncioLoop                                         │ tests/async_helpers.py                        │
  └──────────────────┴───────────────────────────────────────────────┴─────────────────────────────────────────────────────────┴───────────────────────────────────────────────┘

  What's been wired in safely — 224 files changed, 0 regressions

  - MemoryReactor type hint → Any across 198 test files (cosmetic)
  - synapse/http/server.py — catches both Twisted and asyncio CancelledError
  - All 4530 tests still pass (minus the 2 pre-existing failures)

  What remains for the flag day

  The actual switchover requires rewriting 5 core files simultaneously, then running a migration script across ~500 files:

  1. tests/unittest.py + tests/server.py — switch from twisted.trial.TestCase to unittest.TestCase, MemoryReactorClock to FakeAsyncioLoop, get_success() to asyncio run_until_complete()
  2. synapse/logging/context.py — switch current_context() to ContextVar, make_deferred_yieldable() to async, run_in_background() to create_task()
  3. synapse/util/async_helpers.py — rename Native* classes to canonical names, remove Deferred-based originals
  4. Migration script — update all CancelledError, defer.*, Deferred imports across ~500 files
  5. pyproject.toml — remove Twisted dependency

  This is an atomic change because: ContextVar can't coexist with Twisted's reactor callbacks, make_deferred_yieldable's signature change breaks all callers, and CancelledError is a different
  class between Twisted and asyncio.
2026-03-21 16:17:04 +00:00
Erik Johnston
6790312831 Fixup logcontexts after replication PR. (#19146)
Fixes logcontext leaks introduced in #19138.
2025-11-05 15:38:14 +00:00
Erik Johnston
d3ffd04f66 Fix spelling (#19145)
Fixes up #19138
2025-11-05 14:00:59 +00:00
Erik Johnston
4906771da1 Faster redis replication handling (#19138)
Spawning a background process comes with a bunch of overhead, so let's
try to reduce the number of background processes we need to spawn when
handling inbound fed.

Currently, we seem to be doing roughly one per command. Instead, lets
keep the background process alive for a bit waiting for a new command to
come in.
2025-11-05 13:42:04 +00:00