mirror of
https://github.com/apple/swift.git
synced 2025-12-14 20:36:38 +01:00
dd6c235a2d
os_unfair_lock is much smaller than pthread_mutex_t (4 bytes versus 64) and a bit faster. However, it doesn't support condition variables. Most of our uses of Mutex don't use condition variables, but a few do. Introduce ConditionMutex and StaticConditionMutex, which allow condition variables and continue to use pthread_mutex_t. On all other platforms, we continue to use the same backing mutex type for both Mutex and ConditionMutex. rdar://problem/45412121
74 lines
2.6 KiB
C++
74 lines
2.6 KiB
C++
//===--- MutexSingleThreaded.h - --------------------------------*- C++ -*-===//
|
|
//
|
|
// This source file is part of the Swift.org open source project
|
|
//
|
|
// Copyright (c) 2014 - 2020 Apple Inc. and the Swift project authors
|
|
// Licensed under Apache License v2.0 with Runtime Library Exception
|
|
//
|
|
// See https://swift.org/LICENSE.txt for license information
|
|
// See https://swift.org/CONTRIBUTORS.txt for the list of Swift project authors
|
|
//
|
|
//===----------------------------------------------------------------------===//
|
|
//
|
|
// No-op implementation of locks for single-threaded environments.
|
|
//
|
|
//===----------------------------------------------------------------------===//
|
|
|
|
#ifndef SWIFT_RUNTIME_MUTEX_SINGLE_THREADED_H
|
|
#define SWIFT_RUNTIME_MUTEX_SINGLE_THREADED_H
|
|
|
|
#include "swift/Runtime/Debug.h"
|
|
|
|
namespace swift {
|
|
|
|
typedef void* ConditionHandle;
|
|
typedef void* ConditionMutexHandle;
|
|
typedef void* MutexHandle;
|
|
typedef void* ReadWriteLockHandle;
|
|
|
|
#define SWIFT_CONDITION_SUPPORTS_CONSTEXPR 1
|
|
#define SWIFT_MUTEX_SUPPORTS_CONSTEXPR 1
|
|
#define SWIFT_READWRITELOCK_SUPPORTS_CONSTEXPR 1
|
|
|
|
struct ConditionPlatformHelper {
|
|
static constexpr ConditionHandle staticInit() {
|
|
return nullptr;
|
|
};
|
|
static void init(ConditionHandle &condition) {}
|
|
static void destroy(ConditionHandle &condition) {}
|
|
static void notifyOne(ConditionHandle &condition) {}
|
|
static void notifyAll(ConditionHandle &condition) {}
|
|
static void wait(ConditionHandle &condition, MutexHandle &mutex) {
|
|
fatalError(0, "single-threaded runtime cannot wait for condition");
|
|
}
|
|
};
|
|
|
|
struct MutexPlatformHelper {
|
|
static constexpr MutexHandle staticInit() { return nullptr; }
|
|
static constexpr ConditionMutexHandle conditionStaticInit() {
|
|
return nullptr;
|
|
}
|
|
static void init(MutexHandle &mutex, bool checked = false) {}
|
|
static void destroy(MutexHandle &mutex) {}
|
|
static void lock(MutexHandle &mutex) {}
|
|
static void unlock(MutexHandle &mutex) {}
|
|
static bool try_lock(MutexHandle &mutex) { return true; }
|
|
static void unsafeLock(MutexHandle &mutex) {}
|
|
static void unsafeUnlock(MutexHandle &mutex) {}
|
|
};
|
|
|
|
struct ReadWriteLockPlatformHelper {
|
|
static constexpr ReadWriteLockHandle staticInit() { return nullptr; }
|
|
static void init(ReadWriteLockHandle &rwlock) {}
|
|
static void destroy(ReadWriteLockHandle &rwlock) {}
|
|
static void readLock(ReadWriteLockHandle &rwlock) {}
|
|
static bool try_readLock(ReadWriteLockHandle &rwlock) { return true; }
|
|
static void readUnlock(ReadWriteLockHandle &rwlock) {}
|
|
static void writeLock(ReadWriteLockHandle &rwlock) {}
|
|
static bool try_writeLock(ReadWriteLockHandle &rwlock) { return true; }
|
|
static void writeUnlock(ReadWriteLockHandle &rwlock) {}
|
|
};
|
|
}
|
|
|
|
#endif
|