This changes the isIsolatingCurrentContext function to return `Bool?`
and removes all the witness table trickery we did previously to detect
if it was implemented or not. This comes at a cost of trying to invoke
it always, before `checkIsolated`, but it makes for an simpler
implementation and more checkable even by third party Swift code which
may want to ask this question.
Along with the `withSerialExecutor` function, this now enables us to
check the isolation at runtime when we have an `any Actor` e.g. from
`#isolation`.
Updates SE-0471 according to
https://forums.swift.org/t/se-0471-improved-custom-serialexecutor-isolation-checking-for-concurrency-runtime/78834/
review discussions
This memory is part of the conformance cache concurrent hash map, so
when we clear the conformance cache, record each of the allocated
pointers within the concurrent map's free list. This way, it'll be
freed with the rest of the concurrent map when it's safe to do so.
Previously there was still a sneaky hop which caused ordering issues.
This introduced a specific test startSynchronously_order which checks
that the task enqueues indeed are "immediate" and cleans up how we
handle this.
This also prepares for the being discussed in SE review direction of
this API that it SHOULD be ALLOWED to actually hop and NOT be
synchronous at all IF the isolation is specified on the closure and is
DIFFERENT than the callers dynamic isolation.
This effectively implements "synchronously run right now if dynamically
on the exact isolation as requested by the closure; otherwise enqueue
the task as usual".
resolves rdar://149284186
cc @drexin
Function types aren't always trivially copyable, e.g. with address-discriminated signed pointers on ARM64e. Introduce a function_cast helper and use that instead.
* [SUA][IRGen] Add stub for swift_coroFrameAlloc that weakly links against the runtime function
This commit modifies IRGen to emit a stub function `__swift_coroFrameAllocStub` instead of the
newly introduced swift-rt function `swift_coroFrameAlloc`. The stub checks whether the runtime has the symbol
`swift_coroFrameAlloc` and dispatches to it if it exists, uses `malloc` otherwise. This ensures the
ability to back deploy the feature to older OS targets.
rdar://145239850
It's hard to tell why a crash occurred with just "Could not allocate memory." Modify the message to include the size/alignment, which will help distinguish between an actual lack of memory and a request for an excessively large allocation.
While we're in there, add \n to a bunch of other fatal error helper functions that didn't have it.
* [Concurrency] Detect non-default impls of isIsolatingCurrentContext
* [Concurrency] No need for trailing info about isIsolating... in conformance
* Apply changes from review
We don't emit signposts until something else has set them up, to avoid deadlocks when we're running in code that's involved in setting them up. But this means that Instruments will miss Concurrency events in a simple program that doesn't otherwise trigger setup of the logging system.
Since we must be in a platform binary if we're running in code that's setting up logging, we can check for that and only be lazy in platform binaries. Non-platform binaries can safely emit signposts eagerly.
rdar://142483658
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
Replace the pair of global actor type/conformance we are passing around with
a general "conformance execution context" that could grow new functionality
over time. Add three external symbols to the runtime:
* swift_conformsToProtocolWithExecutionContext: a conforms-to-protocol check
that also captures the execution context that should be checked before
using the conformance for anything. The only execution context right now
is for an isolated conformance.
* swift_isInConformanceExecutionContext: checks whether the function is
being executed in the given execution context, i.e., running on the
executor for the given global actor.
* swift_ConformanceExecutionContextSize: the size of the conformance
execution context. Client code outside of the Swift runtime can allocate
a pointer-aligned region of memory of this size to use with the runtime
functions above.
In the prior implementation of runtime resolution of isolated conformances,
the runtime had to look in both the protocol conformance descriptor and
in all conditional conformance requirements (recursively) to find any
isolated conformances. If it found one, it had to demangle the global
actor type to metadata. Since swift_conformsToProtocol is a hot path through
the runtime, we can't afford this non-constant-time work in the common
case.
Instead, cache the resolved global actor and witness table as part of the
conformance cache, so that we have access to this information every time
we look up a witness table for a conformance. Propagate this up through
various callers (e.g., generic requirement checking) to the point where
we either stash it in the cache or check it at runtime. This gets us down
to a very quick check (basically, NULL-or-not) for nonisolated conformances,
and just one check for isolated conformances.
Following the approach taken with the concurrency-specific type
descriptors, register a hook function for the "is current global actor"
check used for isolated conformances.
* [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
This function is part of the Swift standard library, not the *C*
standard library. Correct the library name for the module to ensure that
it is properly exported.
[SUA][Runtime] Define `swift_coroFrameAlloc` function that allocates typed memory
Define `swift_coroFrameAlloc` that allocates typed memory if SWIFT_STDLIB_HAS_MALLOC_TYPE is defined.
This function will be used by IRGen to emit typed memory allocations for property accessors.
rdar://141235539
Remove the multiple definitions of `std::bit_cast` into a header. While
this is still not great, it does reduce the duplication. This also
silently works towards reducing a bit of the UB introduced here by
adding an inline namespace for `std` which you are not technically
allowed to use. However, by doing this, we have a clear migration path
away from this once we adopt C++20.
Adjust the declarations to match the definitions and then remove the
conditional declaration which was marked with a FIXME. This allows
building the runtime without warnings in the new Runtimes build.
This adjusts the runtime function declaration handling to track the
owning module for the well known functions. This allows us to ensure
that we are able to properly identify if the symbol should be imported
or not when building the shared libraries. This will require a
subsequent tweak to allow for checking for static library linkage to
ensure that we do not mark the symbol as DLLImport when doing static
linking.
