* [Concurrency] Initial steps for startSynchronously for Task
* [Concurrency] Rename to _startSynchronously while in development
* [Concurrency] StartSynchronously special executor to avoid switching
* startSynchronously bring back more info output
* [Concurrency] startSynchronously with more custom executor tests
* add missing ABI additions to test for x86
* [Concurrency] gyb generate _startSynchronously
* [Concurrency] %import dispatch for Linux startSynchronously test
* [Concurrency] Add TaskGroup.startTaskSynchronously funcs
* [Concurrency] DispatchSerialQueue does not exist on linux still
It cannot be used for executing general-purpose work, because such function would need to have a different signature to pass isolated actor instance.
And being explicit about using this method only for deinit allows to use object pointer for comparison with executor identity.
* [Concurrency] Fix task excutor handling of default actor isolation
The task executor API did not properly account for taking the default
actor locking into account when running code on it, we just took the job
and ran it without checking with the serial executor at all, which
resulted in potential concurrent executions inside the actor --
violating actor isolation.
Here we change the TaskExecutor enqueue API to accept the "target"
serial executor, which in practice will be either generic or a specific
default actor, and coordinate with it when we perform a
runSynchronously.
The SE proposal needs to be amended to showcase this new API, however
without this change we are introducing races so we must do this before
the API is stable.
* Remove _swift_task_enqueueOnTaskExecutor as we don't use it anymore
* no need for the new protocol requirement
* remove the enqueue(_ job: UnownedJob, isolatedTo unownedSerialExecutor: UnownedSerialExecutor)
Thankfully we dont need it after all
* Don't add swift_defaultActor_enqueue_withTaskExecutor and centralize the task executor getting to enqueue()
* move around extern definitions
The name of the `TaskExecutor` protocol was recently changed to remove
underscores after the feature was accepted in Swift Evolution. An implication
of that rename is that the `buildOrdinaryTaskExecutorRef` builtin changed
the type that it expected as the argument. However, the original change
landed in the standard library which as since produced swiftinterfaces
that contain the following inlinable code:
```
@inlinable public init<E>(ordinary executor: __shared E) where E : _Concurrency._TaskExecutor {
#if $BuiltinBuildTaskExecutor
self.executor = Builtin.buildOrdinaryTaskExecutorRef(executor)
#else
fatalError("Swift compiler is incompatible with this SDK version")
#endif
}
```
When a compiler containing the protocol rename attempts to type check the
above inlinable code, it crashes because the builtin is expecting an argument
conforming to `TaskExecutor`, which doesn't exist in this version of the
standard library. The issue is that the current compiler still supports
the `$BuiltinBuildTaskExecutor` feature guard, but the builtin supported
has since changed.
To resolve this issue, we need to stop supporting the `$BuiltinBuildTaskExecutor`
feature guard and introduce a new one that is only supported by compiler versions
that contain the rename. This approach relies on nothing having adopted the
API, otherwise we would need to stage in the rename as a parallel set of APIs,
and only remove the old APIs once nothing is relying on the old _Concurrency
swiftinterfaces.
which executor for which type of setting, is consolidated and we have a
single knob we use to determine when to use dispatch as our global
executor.
Radar-Id: rdar://problem/119416196
With this deprecation emitted by the compiler some codebases that
support many old Swift versions have been forced into warnings they
cannot avoid due to the compatibility promises they made.
This removes the warning but changes no functionality.
SWIFT_STDLIB_SINGLE_THREADED_RUNTIME is too much of a blunt instrument here.
It covers both the Concurrency runtime and the rest of the runtime, but we'd
like to be able to have e.g. a single-threaded Concurrency runtime while
the rest of the runtime is still thread safe (for instance).
So: rename it to SWIFT_STDLIB_SINGLE_THREADED_CONCURRENCY and make it just
control the Concurrency runtime, then add a SWIFT_STDLIB_THREADING_PACKAGE
setting at the CMake/build-script level, which defines
SWIFT_STDLIB_THREADING_xxx where xxx depends on the chosen threading package.
This is especially useful on systems where there may be a choice of threading
package that you could use.
rdar://90776105
SWIFT_STDLIB_SINGLE_THREADED_RUNTIME is too much of a blunt instrument here.
It covers both the Concurrency runtime and the rest of the runtime, but we'd
like to be able to have e.g. a single-threaded Concurrency runtime while
the rest of the runtime is still thread safe (for instance).
So: rename it to SWIFT_STDLIB_SINGLE_THREADED_CONCURRENCY and make it just
control the Concurrency runtime, then add a SWIFT_STDLIB_THREADING_PACKAGE
setting at the CMake/build-script level, which defines
SWIFT_STDLIB_THREADING_xxx where xxx depends on the chosen threading package.
This is especially useful on systems where there may be a choice of threading
package that you could use.
rdar://90776105
