Commit Graph

11 Commits

Author SHA1 Message Date
Matthew Hodgson
8e1c26067b ⏺ Summary of remaining Twisted defer usage:
- 0 @defer.inlineCallbacks — all converted to async def
  - 12 defer.ensureDeferred — reactor entry points (startup, shutdown, render)
  - 22 defer.Deferred() — in Linearizer, ReadWriteLock, AwakenableSleeper, DeferredEvent (old implementations)
  - 21 defer.gatherResults — in fallback paths and old implementations
  - 11 defer.succeed/fail — immediate value wrapping in old implementations
  - 3 defer.FirstError — in fallback paths
  - 13 defer.TimeoutError — in timeout_deferred and its callers

  The majority (22 + 21 + 11 + 13 = 67) are in the old Deferred-based utility implementations (Linearizer, ReadWriteLock, ObservableDeferred, timeout_deferred, etc.) that already have native replacements (NativeLinearizer,
  NativeReadWriteLock, ObservableFuture, native_timeout, etc.). These will be removed when callers switch to the native versions.

  The 12 defer.ensureDeferred are in reactor entry points that will be removed when reactor.run() → asyncio.run().

  The codebase is now in a clean transitional state where:
  1. All Twisted imports are conditional (try/except ImportError)
  2. ContextVar is the primary logcontext storage
  3. Test base class is stdlib (unittest.TestCase)
  4. CancelledError is asyncio.CancelledError in production code
  5. @defer.inlineCallbacks is eliminated (0 remaining)
  6. yieldable_gather_results uses asyncio.gather (with Twisted fallback)
  7. Module API is fully async (no more Deferred return types)
  8. Twisted is optional in pyproject.toml
2026-03-21 20:54:28 +00:00
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
2c73e8daef Allow long lived syncs to be cancelled if client has gone away (#19499) 2026-02-26 21:41:06 +00:00
Erik Johnston
1bddd25a85 Port Clock functions to use Duration class (#19229)
This changes the arguments in clock functions to be `Duration` and
converts call sites and constants into `Duration`. There are still some
more functions around that should be converted (e.g.
`timeout_deferred`), but we leave that to another PR.

We also changes `.as_secs()` to return a float, as the rounding broke
things subtly. The only reason to keep it (its the same as
`timedelta.total_seconds()`) is for symmetry with `as_millis()`.

Follows on from https://github.com/element-hq/synapse/pull/19223
2025-12-01 13:55:06 +00:00
Eric Eastwood
88785dbaeb Refactor cache metrics to be homeserver-scoped (#18604)
(add `server_name` label to cache metrics).

Part of https://github.com/element-hq/synapse/issues/18592
2025-07-16 16:04:57 -05:00
Erik Johnston
23740eaa3d Correctly mention previous copyright (#16820)
During the migration the automated script to update the copyright
headers accidentally got rid of some of the existing copyright lines.
Reinstate them.
2024-01-23 11:26:48 +00:00
Patrick Cloke
8e1e62c9e0 Update license headers 2023-11-21 15:29:58 -05:00
Patrick Cloke
4ae967cf63 Add missing type hints to test.util.caches (#14529) 2022-11-22 17:35:54 -05:00
Richard van der Hoff
c3e38b88f2 Improve opentracing support for ResponseCache (#11607)
This adds some opentracing annotations to ResponseCache, to make it easier to see what's going on; in particular, it adds a link back to the initial trace which is actually doing the work of generating the response.
2021-12-20 18:12:08 +00:00
Richard van der Hoff
d7808a2dde Extend ResponseCache to pass a context object into the callback (#10157)
This is the first of two PRs which seek to address #8518. This first PR lays the groundwork by extending ResponseCache; a second PR (#10158) will update the SyncHandler to actually use it, and fix the bug.

The idea here is that we allow the callback given to ResponseCache.wrap to decide whether its result should be cached or not. We do that by (optionally) passing a ResponseCacheContext into it, which it can modify.
2021-06-14 10:26:09 +01:00