Reorganise the Concurrency code so that it's possible to completely
implement executors (both main and global) in Swift.
Provide API to choose the desired executors for your application.
Also make `Task.Sleep` wait using the current executor, not the global
executor, and expose APIs on `Clock` to allow for conversion between
time bases.
rdar://141348916
Instead, use the `%target-swift-5.1-abi-triple` substitution to compile the tests
for deployment to the minimum OS versions required for use of _Concurrency APIs.
The concurrency runtime now deploys back to macOS 10.15, iOS 13.0, watchOS 6.0, tvOS 13.0, which corresponds to the 5.1 release of the stdlib.
Adjust macro usages accordingly.
Rather than blanket-disabling concurrency tests when we aren't using a
just-built concurrency library, enable them whenever we have a
suitable concurrency runtime, either just-built, in the OS, or via the
back-deployment libraries.
The pass uses SILBuilder instant to create instructions and does not
set SILDebugScope.
Due to this, SILVerifier correctly asserts that basic blocks contain non-contiguous
lexical scopes at -Onone.
The long term fix would be to replace SILBuilder instance in the pass with
SILBuilderContext and use SILBuilderWithScope so that such bugs do not come up.
* Synchronize both versions of actor_counters.swift test
* Synchronize on Job address
Make sure to synchronize on Job address (AsyncTasks are Jobs, but not
all Jobs are AsyncTasks).
* Add fprintf debug output for TSan acquire/release
* Add tsan_release edge on task creation
without this, we are getting false data races between when a task
is created and immediately scheduled on a different thread.
False positive for `Sanitizers/tsan/actor_counters.swift` test:
```
WARNING: ThreadSanitizer: data race (pid=81452)
Read of size 8 at 0x7b2000000560 by thread T5:
#0 Counter.next() <null>:2 (a.out:x86_64+0x1000047f8)
#1 (1) suspend resume partial function for worker(identity:counters:numIterations:) <null>:2 (a.out:x86_64+0x100005961)
#2 swift::runJobInEstablishedExecutorContext(swift::Job*) <null>:2 (libswift_Concurrency.dylib:x86_64+0x280ef)
Previous write of size 8 at 0x7b2000000560 by main thread:
#0 Counter.init(maxCount:) <null>:2 (a.out:x86_64+0x1000046af)
#1 Counter.__allocating_init(maxCount:) <null>:2 (a.out:x86_64+0x100004619)
#2 runTest(numCounters:numWorkers:numIterations:) <null>:2 (a.out:x86_64+0x100006d2e)
#3 swift::runJobInEstablishedExecutorContext(swift::Job*) <null>:2 (libswift_Concurrency.dylib:x86_64+0x280ef)
#4 main <null>:2 (a.out:x86_64+0x10000a175)
```
New edge with this change:
```
[4357150208] allocate task 0x7b3800000000, parent = 0x0
[4357150208] creating task 0x7b3800000000 with parent 0x0
[4357150208] tsan_release on 0x7b3800000000 <<< new release edge
[139088221442048] tsan_acquire on 0x7b3800000000
[139088221442048] trying to switch from executor 0x0 to 0x7ff85e2d9a00
[139088221442048] switch failed, task 0x7b3800000000 enqueued on executor 0x7ff85e2d9a00
[139088221442048] enqueue job 0x7b3800000000 on executor 0x7ff85e2d9a00
[139088221442048] tsan_release on 0x7b3800000000
[139088221442048] tsan_release on 0x7b3800000000
[4357150208] tsan_acquire on 0x7b3800000000
counters: 1, workers: 1, iterations: 1
[4357150208] allocate task 0x7b3c00000000, parent = 0x0
[4357150208] creating task 0x7b3c00000000 with parent 0x0
[4357150208] tsan_release on 0x7b3c00000000 <<< new release edge
[139088221442048] tsan_acquire on 0x7b3c00000000
[4357150208] task 0x7b3800000000 waiting on task 0x7b3c00000000, going to sleep
[4357150208] tsan_release on 0x7b3800000000
[4357150208] tsan_release on 0x7b3800000000
[139088221442048] getting current executor 0x0
[139088221442048] tsan_release on 0x7b3c00000000
...
```
rdar://78932849
* Add static_cast<Job *>()
* Move TSan release edge to swift_task_enqueueGlobal()
Move the TSan release edge from `swift_task_create_commonImpl()` to
`swift_task_enqueueGlobalImpl()`. Task creation itself is not an event
that needs synchronization, but rather that task creation "happens
before" execution of that task on another thread.
This edge is usually added when the task is scheduled via
`swift_task_enqueue()` (which then usually calls
`swift_task_enqueueGlobal()`). However, not all task scheduling goes
through the `swift_task_enqueue()` funnel as some places call the more
specific `swift_task_enqueueGlobal()` directly. So let's annotate this
function (duplicate edges aren't harmful) to ensure we cover all
schedule events, including newly-created tasks (our original problem
here).
rdar://78932849
Co-authored-by: Julian Lettner <julian.lettner@apple.com>
This allows programs to target older OSes while using Concurrency behind an availability check. When targeting older OSes, the symbols are weak-linked and the compiler will require the use of Concurrency features to be guarded by an availability check.
rdar://75850003
`UnsafeMutableBufferPointer.allocate` returns uninitialized memory which
is read by `assert(scratchBuffer[current] == 0)`. We need to initialize
it before reading.
Also remove the scratchBuffer that is never used and likely a
refactoring leftover.
Radar-Id: rdar://72439642
We're not quite ready to commit to the flow-sensitive check that would
allow a concurrent function to read from a mutable local capture so
long as the captured variable wasn't changed after the point of
capture. Put it behind a flag and implement the more restrictive rule
(no access to mutable local captures in concurrent code). We can relax
it later.
This patch updates the `actor class` spelling to `actor` in almost all
of the tests. There are places where I verify that we sanely handle
`actor` as an attribute though. These include:
- test/decl/class/actor/basic.swift
- test/decl/protocol/special/Actor.swift
- test/SourceKit/CursorInfo/cursor_info_concurrency.swift
- test/attr/attr_objc_async.swift
- test/ModuleInterface/actor_protocol.swift
The `try await` ordering is both easier to read and indicates the order
of operations better, because the suspension point occurs first and
then one can observe a thrown error.
