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swift-mirror/stdlib/public/SwiftShims/swift/shims/_SynchronizationShims.h
2024-07-12 10:07:42 -07:00

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C

//===----------------------------------------------------------------------===//
//
// This source file is part of the Swift.org open source project
//
// Copyright (c) 2024 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
//
//===----------------------------------------------------------------------===//
#ifndef SWIFT_STDLIB_SYNCHRONIZATION_SHIMS_H
#define SWIFT_STDLIB_SYNCHRONIZATION_SHIMS_H
#include "SwiftStdbool.h"
#include "SwiftStdint.h"
#if defined(__linux__)
#include <errno.h>
#include <linux/futex.h>
#include <sys/syscall.h>
#include <unistd.h>
static inline __swift_uint32_t _swift_stdlib_gettid() {
static __thread __swift_uint32_t tid = 0;
if (tid == 0) {
tid = syscall(SYS_gettid);
}
return tid;
}
static inline __swift_uint32_t _swift_stdlib_futex_lock(__swift_uint32_t *lock) {
int ret = syscall(SYS_futex, lock, FUTEX_LOCK_PI_PRIVATE,
/* val */ 0, // this value is ignored by this futex op
/* timeout */ NULL); // block indefinitely
if (ret == 0) {
return ret;
}
return errno;
}
static inline __swift_uint32_t _swift_stdlib_futex_trylock(__swift_uint32_t *lock) {
int ret = syscall(SYS_futex, lock, FUTEX_TRYLOCK_PI);
if (ret == 0) {
return ret;
}
return errno;
}
static inline __swift_uint32_t _swift_stdlib_futex_unlock(__swift_uint32_t *lock) {
int ret = syscall(SYS_futex, lock, FUTEX_UNLOCK_PI_PRIVATE);
if (ret == 0) {
return ret;
}
return errno;
}
#endif // defined(__linux__)
#endif // SWIFT_STDLIB_SYNCHRONIZATION_SHIMS_H