This function is used by the executor to help schedule the async job.
While not currently available on Windows on main, this allows correctly
handling the presence of the symbol for static linking.
Although we would like these to be dynamic, we currently cannot build
them properly due to limitations of the build system. Adjust the build
to pass in additional flags to properly build the runtimes for that
environment as a temporary measure.
Requests to sleep until a negative timestamp would result in sleeping
until `UINT64_MAX` nanoseconds from the start of the relevant clock,
which is about 585 years.
rdar://154346018
This only modifies the runtime function `swift_task_enqueueGlobalWithDeadline` to take new clock primitive to
interoperate with existing dispatch wall clock values.
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.
Added an `-executor-factory` argument to the compiler to let you safely
specify the executors you wish to use (by naming a type that returns
them).
Also added some tests of the new functionality.
rdar://141348916
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
The `-Winvalid-offsetof` warning is valid in this case. `offsetof` is
being applied to types with a non-standard layout. The layout of this
type is undefined by the specification. There is no guarantee that the
type layout is uniform across all ABIs. It is not possible to portably
compute the offset statically, especially efficiently.
Sink this check into a unit test to avoid performing this test at
runtime. In order to do this in the standard library, we would need to
do this check through a global constructor.
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.
The C++ standard does not guarantee that the code and data pointers are
interchangeable. Recent enhancements to clang now properly identify the
improper `reinterpret_cast` between function types. Silence the warning
by switching to `std::bit_cast`. Unfortunately, this is a C++20 feature
and we are still on C++17. In the case that the compiler doesn't have a
`bit_cast` implementation, fallback with some UB to a local definition.
In the Dispatch implementation, clamp the delay to INT64_MAX. Swift's nanoseconds value is unsigned, but we ultimately use it with dispatch_time, which takes a signed int64_t. Extremely large values get interpreted as negative, which results in not sleeping.
INT64_MAX nanoseconds is about 292 years, so it should be difficult to notice a practical effect from sleeping for less time than requested due to the clamping.
rdar://143278824
Define `NOMINMAX` and `WIN32_LEAN_AND_MEAN` when including `<Windows.h>`.
Don't export the interface from DLLs.
Make sure we include `<new>` when using placement operator new.
rdar://135380149
`ExecutorHooks.h` is now nothing to do with hooks, so rename it. Also
there are some additional functions it should declare, and a couple of
places where we've slightly messed up the boundary, for instance
`swift_task_asyncMainDrainQueue` was defined in `Task.cpp` rather than
in the executor implementations, which is wrong, so fix that too.
`CooperativeGlobalExecutor.cpp` now builds against the interface from
`ExecutorImpl.h`, rather than including the all the concurrency headers.
rdar://135380149
C++ executor implementations were `#include`ed into `GlobalExecutor.cpp`,
which makes it difficult to replace the global executor when using the
Embedded Concurrency library. Refactor things so that they build into
separate objects, which means replacing them is just a matter of writing
the relevant functions yourself.
rdar://135380149
