This adds an `appendInterpolation` overload to
`DefaultStringInterpolation` that includes a parameter for providing a
default string when the value to interpolate is `nil`. This allows this
kind of usage:
```swift
let age: Int? = nil
print("Your age is \(age, default: "timeless")")
// Prints "Your age is timeless"
```
The change includes an additional fixit when optional values are
interpolated, with a suggestion to use this `default:` parameter.
These TODOs aren’t particularly actionable. What we really want is a way to define `_overrideLifetime()` in a not-unsafe way, and that will probably be a `Builtin` operation.
Dispatch uses unsigned times, and cannot cope with times before its
clock started. As such, passing negative times from Swift through to
the C++ code results in large unsigned values, which then causes us to
wait forever. This is undesirable.
rdar://148899609
... that would import that as a result of importing Darwin from the SDK.
Amend my previous change to Differentiation and Distributed in this
sense.
Addresses rdar://150400049
The use of SendableCompletionHandlers here is completely incidental,
because it happened to be introduced at roughly the same time as the
bits we needed for MutableSpan. Fixes rdar://148072153.
The runtime functions for locking end up referencing a symbol that is
not publicly emitted. This leads to broken linux builds.
Since that interface is not public and does not offer a stable mechanism
and Synchronization cannot be used (due to it being a higher deployment
target) instead it has to revert to implementing locking from scratch
for all platforms.
This is mostly replicated from the swift-async-algorithms package and
should be usable enough to accomplish the goals of this module.
Resolves rdar://150060874
SE-0329 defines the following static factory methods:
```
public static func seconds<T: BinaryInteger>(_ seconds: T) -> Duration
public static func seconds(_ seconds: Double) -> Duration
public static func milliseconds<T: BinaryInteger>(_ milliseconds: T) -> Duration
public static func milliseconds(_ milliseconds: Double) -> Duration
public static func microseconds<T: BinaryInteger>(_ microseconds: T) -> Duration
public static func microseconds(_ microseconds: Double) -> Duration
public static func nanoseconds<T: BinaryInteger>(_ value: T) -> Duration
```
For no good reason, the obvious additional method:
```
public static func nanoseconds(_ nanoseconds: Double) -> Duration
```
was omitted. After talking this through with the LSG, we have decided
that this is simply a bug, and we will add this method without formal
evolution review.
We missed to sign the handler. Along the way the signature of it
changed, so adjust for that.
How to get the number:
```
func PROPER(bar: (TaskPriority, TaskPriority) -> Void) {
let p = TaskPriority.default
bar(p, p)
}
```
```
-> % swiftc -target arm64e-apple-macos13 example.swift -S -o - | swift demangle | grep -a3 autda
stur x8, [x29, #-64]
mov x17, x8
movk x17, #11839, lsl #48 <<<<<<<<<
autda x16, x17
ldr x8, [x16, #64]
lsr x8, x8, #0
add x8, x8, #15
```
Resolves rdar://150378890
If the preloaded status is locked, then we need to reload it in order to distinguish between the current thread holding the lock and another thread holding the lock. Without this, if another thread holds the lock, then we won't set the is-locked bit. We'll still actually hold the lock, but other threads may perform operations locklessly if the bit is not set, which can cause a crash. By reloading status in that case, we ensure that the bit is always set correctly.
This manifested as crashes in task cancellation but could cause other task-related issues as well.
Also remove an assert of !isStatusRecordLocked() in AsyncTask::complete(). We allow other threads to access tasks and take the lock for things like cancellation, so the lock may legitimately be held at that point.
rdar://150327908
We were failing to switch executors to Dispatch queues, where those
were being used as executors, which caused a variety of unusual
symptoms.
rdar://150310927
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
