How to use releaseWaitingLock method of AssertionWaitLock class

...12    }13}14internal protocol WaitLock {15    func acquireWaitingLock(fnName: String, file: String, line: UInt)16    func releaseWaitingLock()17    func isWaitingLocked() -> Bool18}19internal class AssertionWaitLock: WaitLock {20    private var currentWaiter: WaitingInfo? = nil21    init() { }22    func acquireWaitingLock(fnName: String, file: String, line: UInt) {23        let info = WaitingInfo(name: fnName, file: file, lineNumber: line)24        nimblePrecondition(25            NSThread.isMainThread(),26            "InvalidNimbleAPIUsage",27            "\(fnName) can only run on the main thread."28        )29        nimblePrecondition(30            currentWaiter == nil,31            "InvalidNimbleAPIUsage",32            "Nested async expectations are not allowed to avoid creating flaky tests.\n\n" +33            "The call to\n\t\(info)\n" +34            "triggered this exception because\n\t\(currentWaiter!)\n" +35            "is currently managing the main run loop."36        )37        currentWaiter = info38    }39    func isWaitingLocked() -> Bool {40        return currentWaiter != nil41    }42    func releaseWaitingLock() {43        currentWaiter = nil44    }45}46internal enum AwaitResult<T> {47    /// Incomplete indicates None (aka - this value hasn't been fulfilled yet)48    case Incomplete49    /// TimedOut indicates the result reached its defined timeout limit before returning50    case TimedOut51    /// BlockedRunLoop indicates the main runloop is too busy processing other blocks to trigger52    /// the timeout code.53    ///54    /// This may also mean the async code waiting upon may have never actually ran within the55    /// required time because other timers & sources are running on the main run loop.56    case BlockedRunLoop57    /// The async block successfully executed and returned a given result58    case Completed(T)59    /// When a Swift Error is thrown60    case ErrorThrown(ErrorType)61    /// When an Objective-C Exception is raised62    case RaisedException(NSException)63    func isIncomplete() -> Bool {64        switch self {65        case .Incomplete: return true66        default: return false67        }68    }69    func isCompleted() -> Bool {70        switch self {71        case .Completed(_): return true72        default: return false73        }74    }75}76/// Holds the resulting value from an asynchronous expectation.77/// This class is thread-safe at receiving an "response" to this promise.78internal class AwaitPromise<T> {79    private(set) internal var asyncResult: AwaitResult<T> = .Incomplete80    private var signal: dispatch_semaphore_t81    init() {82        signal = dispatch_semaphore_create(1)83    }84    /// Resolves the promise with the given result if it has not been resolved. Repeated calls to85    /// this method will resolve in a no-op.86    ///87    /// @returns a Bool that indicates if the async result was accepted or rejected because another88    ///          value was recieved first.89    func resolveResult(result: AwaitResult<T>) -> Bool {90        if dispatch_semaphore_wait(signal, DISPATCH_TIME_NOW) == 0 {91            self.asyncResult = result92            return true93        } else {94            return false95        }96    }97}98internal struct AwaitTrigger {99    let timeoutSource: dispatch_source_t100    let actionSource: dispatch_source_t?101    let start: () throws -> Void102}103/// Factory for building fully configured AwaitPromises and waiting for their results.104///105/// This factory stores all the state for an async expectation so that Await doesn't106/// doesn't have to manage it.107internal class AwaitPromiseBuilder<T> {108    let awaiter: Awaiter109    let waitLock: WaitLock110    let trigger: AwaitTrigger111    let promise: AwaitPromise<T>112    internal init(113        awaiter: Awaiter,114        waitLock: WaitLock,115        promise: AwaitPromise<T>,116        trigger: AwaitTrigger) {117            self.awaiter = awaiter118            self.waitLock = waitLock119            self.promise = promise120            self.trigger = trigger121    }122    func timeout(timeoutInterval: NSTimeInterval, forcefullyAbortTimeout: NSTimeInterval) -> Self {123        // = Discussion =124        //125        // There's a lot of technical decisions here that is useful to elaborate on. This is126        // definitely more lower-level than the previous NSRunLoop based implementation.127        //128        //129        // Why Dispatch Source?130        //131        //132        // We're using a dispatch source to have better control of the run loop behavior.133        // A timer source gives us deferred-timing control without having to rely as much on134        // a run loop's traditional dispatching machinery (eg - NSTimers, DefaultRunLoopMode, etc.)135        // which is ripe for getting corrupted by application code.136        //137        // And unlike dispatch_async(), we can control how likely our code gets prioritized to138        // executed (see leeway parameter) + DISPATCH_TIMER_STRICT.139        //140        // This timer is assumed to run on the HIGH priority queue to ensure it maintains the141        // highest priority over normal application / test code when possible.142        //143        //144        // Run Loop Management145        //146        // In order to properly interrupt the waiting behavior performed by this factory class,147        // this timer stops the main run loop to tell the waiter code that the result should be148        // checked.149        //150        // In addition, stopping the run loop is used to halt code executed on the main run loop.151        dispatch_source_set_timer(152            trigger.timeoutSource,153            dispatch_time(DISPATCH_TIME_NOW, Int64(timeoutInterval * Double(NSEC_PER_SEC))),154            DISPATCH_TIME_FOREVER,155            timeoutLeeway156        )157        dispatch_source_set_event_handler(trigger.timeoutSource) {158            guard self.promise.asyncResult.isIncomplete() else { return }159            let timedOutSem = dispatch_semaphore_create(0)160            let semTimedOutOrBlocked = dispatch_semaphore_create(0)161            dispatch_semaphore_signal(semTimedOutOrBlocked)162            let runLoop = CFRunLoopGetMain()163            CFRunLoopPerformBlock(runLoop, kCFRunLoopDefaultMode) {164                if dispatch_semaphore_wait(semTimedOutOrBlocked, DISPATCH_TIME_NOW) == 0 {165                    dispatch_semaphore_signal(timedOutSem)166                    dispatch_semaphore_signal(semTimedOutOrBlocked)167                    if self.promise.resolveResult(.TimedOut) {168                        CFRunLoopStop(CFRunLoopGetMain())169                    }170                }171            }172            // potentially interrupt blocking code on run loop to let timeout code run173            CFRunLoopStop(runLoop)174            let now = dispatch_time(DISPATCH_TIME_NOW, Int64(forcefullyAbortTimeout * Double(NSEC_PER_SEC)))175            let didNotTimeOut = dispatch_semaphore_wait(timedOutSem, now) != 0176            let timeoutWasNotTriggered = dispatch_semaphore_wait(semTimedOutOrBlocked, 0) == 0177            if didNotTimeOut && timeoutWasNotTriggered {178                if self.promise.resolveResult(.BlockedRunLoop) {179                    CFRunLoopStop(CFRunLoopGetMain())180                }181            }182        }183        return self184    }185    /// Blocks for an asynchronous result.186    ///187    /// @discussion188    /// This function must be executed on the main thread and cannot be nested. This is because189    /// this function (and it's related methods) coordinate through the main run loop. Tampering190    /// with the run loop can cause undesireable behavior.191    ///192    /// This method will return an AwaitResult in the following cases:193    ///194    /// - The main run loop is blocked by other operations and the async expectation cannot be195    ///   be stopped.196    /// - The async expectation timed out197    /// - The async expectation succeeded198    /// - The async expectation raised an unexpected exception (objc)199    /// - The async expectation raised an unexpected error (swift)200    ///201    /// The returned AwaitResult will NEVER be .Incomplete.202    func wait(fnName: String = __FUNCTION__, file: String = __FILE__, line: UInt = __LINE__) -> AwaitResult<T> {203        waitLock.acquireWaitingLock(204            fnName,205            file: file,206            line: line)207        let capture = NMBExceptionCapture(handler: ({ exception in208            self.promise.resolveResult(.RaisedException(exception))209        }), finally: ({210            self.waitLock.releaseWaitingLock()211        }))212        capture.tryBlock {213            do {214                try self.trigger.start()215            } catch let error {216                self.promise.resolveResult(.ErrorThrown(error))217            }218            dispatch_resume(self.trigger.timeoutSource)219            while self.promise.asyncResult.isIncomplete() {220                // Stopping the run loop does not work unless we run only 1 mode221                NSRunLoop.currentRunLoop().runMode(NSDefaultRunLoopMode, beforeDate: NSDate.distantFuture())222            }223            dispatch_suspend(self.trigger.timeoutSource)224            dispatch_source_cancel(self.trigger.timeoutSource)...

1AssertionWaitLock.waitingLock.releaseWaitingLock()2AssertionWaitLock.waitingLock.releaseWaitingLock()3AssertionWaitLock.waitingLock.releaseWaitingLock()4AssertionWaitLock.waitingLock.releaseWaitingLock()5AssertionWaitLock.waitingLock.releaseWaitingLock()6AssertionWaitLock.waitingLock.releaseWaitingLock()7AssertionWaitLock.waitingLock.releaseWaitingLock()8AssertionWaitLock.waitingLock.releaseWaitingLock()9AssertionWaitLock.waitingLock.releaseWaitingLock()10AssertionWaitLock.waitingLock.releaseWaitingLock()11AssertionWaitLock.waitingLock.releaseWaitingLock()12AssertionWaitLock.waitingLock.releaseWaitingLock()13AssertionWaitLock.waitingLock.releaseWaitingLock()14AssertionWaitLock.waitingLock.releaseWaitingLock()15AssertionWaitLock.waitingLock.releaseWaitingLock()16AssertionWaitLock.waitingLock.releaseWaitingLock()

1let lock = AssertionWaitLock()AssertionWaitLock.waitingLock.releaseWaitingLock()2let lock2 = ock()3lock.lock()4lock2.lock()5lreleaseWaitingLock(lock2)6lock2.unlock()7lock.unlock()8let lock = AssertionWaitLock()9let lock2 = AssertionWaitLock()10lock.lock()11lock2.lock()12lock.releaseWaitingLock(lock2)13lock2.unlock()14lock.unlock()15let lock = AssertionWaitLock()16let lock2 = AssertionWaitLock()17lock.lock()18lock2.lock()19lock.releaseWaitingLock(lock2)20lock2.unlock()21lock.unlock()22let lock = AssertionWaitLock()23let lock2 = AssertionWaitLock()24lock.lock()25lock2.lock()26lock.releaseWaitingLock(lock2)27lock2.unlock()28lock.unlock()29let lock = AssertionWaitLock()30let lock2 = AssertionWaitLock()31lock.lock()32lock2.lock()33lock.releaseWaitingLock(lock2)34lock2.unlock()35lock.unlock()36let lock = AssertionWaitLock()37let lock2 = AssertionWaitLock()38lock.lock()39lock2.lock()40lock.releaseWaitingLock(lock2)41lock2.unlock()42lock.unlock()43let lock = AssertionWaitLock()44let lock2 = AssertionWaitLock()45lock.lock()46lock2.lock()47lock.releaseWaitingLock(lock2)48lock2.unlock()49lock.unlock()50let lock = AssertionWaitLock()51let lock2 = AssertionWaitLock()52lock.lock()53lock2.lock()54lock.releaseWaitingLock(lock2)55lock2.unlock()56lock.unlock()57let lock = AssertionWaitLock()58let lock2 = AssertionWaitLock()59lock.lock()60lock2.lock()61lock.releaseWaitingLock(lock2)62lock2.unlock()63lock.unlock()

1import Foundation2let assertionWaitLock = AssertionWaitLock()3assertionWaitLock.releaseWaitingLock()4AssertionWaitLock.waitingLock.releaseWaitingLock()5AssertionWaitLock.waitingLock.releaseWaitingLock()6AssertionWaitLock.waitingLock.releaseWaitingLock()7AssertionWaitLock.waitingLock.releaseWaitingLock()8AssertionWaitLock.waitingLock.releaseWaitingLock()9AssertionWaitLock.waitingLock.releaseWaitingLock()10AssertionWaitLock.waitingLock.releaseWaitingLock()11AssertionWaitLock.waitingLock.releaseWaitingLock()12AssertionWaitLock.waitingLock.releaseWaitingLock()13AssertionWaitLock.waitingLock.releaseWaitingLock()14AssertionWaitLock.waitingLock.releaseWaitingLock()

1import Foundation2let lock = AssertionWaitLock()3let thread = Thread {4    print("Thread started")5    lock.releaseWaitingLock()6    print("Thread finished")7}8thread.start()9lock.wait()10print("Main thread finished")11import Foundation12let lock = AssertionWaitLock()13let thread = Thread {14    print("Thread started")15    lock.releaseWaitingLock()16    print("Thread finished")17}18thread.start()19lock.wait()20print("Main thread finished")21import Foundation22let lock = AssertionWaitLock()23let thread = Thread {24    print("Thread started")25    lock.releaseWaitingLock()26    print("Thread finished")27}28thread.start()29lock.wait()30print("Main thread finished")31import Foundation32let lock = AssertionWaitLock()33let thread = Thread {34    print("Thread started")35    lock.releaseWaitingLock()36    print("Thread finished")37}38thread.start()39lock.wait()40print("Main thread finished")