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/*
This source file is part of the Swift.org open source project
Copyright (c) 2014 - 2017 Apple Inc. and the Swift project authors
Licensed under Apache License v2.0 with Runtime Library Exception
See http://swift.org/LICENSE.txt for license information
See http://swift.org/CONTRIBUTORS.txt for Swift project authors
*/
import Foundation
/// Simple wrapper around NSCondition.
/// - SeeAlso: NSCondition
public struct Condition {
private let _condition = NSCondition()
/// Create a new condition.
public init() {}
/// Wait for the condition to become available.
public func wait() {
_condition.wait()
}
/// Blocks the current thread until the condition is signaled or the specified time limit is reached.
///
/// - Returns: true if the condition was signaled; otherwise, false if the time limit was reached.
public func wait(until limit: Date) -> Bool {
return _condition.wait(until: limit)
}
/// Signal the availability of the condition (awake one thread waiting on
/// the condition).
public func signal() {
_condition.signal()
}
/// Broadcast the availability of the condition (awake all threads waiting
/// on the condition).
public func broadcast() {
_condition.broadcast()
}
/// A helper method to execute the given body while condition is locked.
/// - Note: Will ensure condition unlocks even if `body` throws.
public func whileLocked<T>(_ body: () throws -> T) rethrows -> T {
_condition.lock()
defer { _condition.unlock() }
return try body()
}
}
#if compiler(>=5.7)
extension Condition: Sendable {}
#endif
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