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// RUN: %target-run-simple-swift(-parse-as-library -Xfrontend -disable-availability-checking %import-libdispatch -sanitize=thread) | %FileCheck %s
// REQUIRES: executable_test
// REQUIRES: concurrency
// REQUIRES: libdispatch
// REQUIRES: tsan_runtime
// UNSUPPORTED: use_os_stdlib
// UNSUPPORTED: threading_none
import Dispatch
/// @returns true iff the expected answer is actually the case, i.e., correct.
/// If the current queue does not match expectations, this function may return
/// false or just crash the program with non-zero exit code, depending on SDK.
func checkIfMainQueue(expectedAnswer expected: Bool) -> Bool {
if #available(macOS 10.12, iOS 10, tvOS 10, watchOS 3, *) {
dispatchPrecondition(condition: expected ? .onQueue(DispatchQueue.main)
: .notOnQueue(DispatchQueue.main))
}
return true
}
actor A {
func onCorrectQueue(_ count : Int) -> Int {
if checkIfMainQueue(expectedAnswer: false) {
print("on actor instance's queue")
return count + 1
}
print("ERROR: not on actor instance's queue")
return -10
}
}
@MainActor func checkAnotherFn(_ count : Int) -> Int {
if checkIfMainQueue(expectedAnswer: true) {
print("on main queue again!")
return count + 1
} else {
print("ERROR: left the main queue?")
return -10
}
}
@MainActor func enterMainActor(_ initialCount : Int) async -> Int {
if checkIfMainQueue(expectedAnswer: true) {
print("hello from main actor!")
} else {
print("ERROR: not on correct queue!")
}
// try calling a function on another actor.
let count = await A().onCorrectQueue(initialCount)
guard checkIfMainQueue(expectedAnswer: true) else {
print("ERROR: did not switch back to main actor!")
return -10
}
return checkAnotherFn(count) + 1
}
@Sendable func someFunc() async -> Int {
// NOTE: the "return" counter is just to make sure we're properly returning values.
// the expected number should be equal to the number of "plus-one" expressions.
// since there are no loops or duplicate function calls
return await enterMainActor(0) + 1
}
// CHECK: starting
// CHECK-NOT: ERROR
// CHECK: hello from main actor!
// CHECK-NOT: ERROR
// CHECK: on actor instance's queue
// CHECK-NOT: ERROR
// CHECK: on main queue again!
// CHECK-NOT: ERROR
// CHECK: finished with return counter = 4
@main struct RunIt {
static func main() async {
print("starting")
let result = await someFunc()
print("finished with return counter = \(result)")
}
}
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