| // Copyright 2016 The Fuchsia Authors. All rights reserved. |
| // Use of this source code is governed by a BSD-style license that can be |
| // found in the LICENSE file. |
| |
| #pragma once |
| |
| #include <magenta/compiler.h> |
| #include <magenta/types.h> |
| |
| #include <stdatomic.h> |
| |
| __BEGIN_CDECLS |
| |
| typedef struct { |
| atomic_int futex; |
| } mxr_mutex_t; |
| |
| #define MXR_MUTEX_INIT ((mxr_mutex_t){}) |
| |
| #pragma GCC visibility push(hidden) |
| |
| // Attempts to take the lock without blocking. Returns MX_OK if the |
| // lock is obtained, and MX_ERR_BAD_STATE if not. |
| mx_status_t mxr_mutex_trylock(mxr_mutex_t* mutex); |
| |
| // Attempts to take the lock before the timeout expires. This takes an |
| // absolute time. Returns MX_OK if the lock is acquired, and |
| // MX_ERR_TIMED_OUT if the timeout expires. |
| // |
| // This function is only for use by mtx_timedlock(). |
| mx_status_t __mxr_mutex_timedlock(mxr_mutex_t* mutex, mx_time_t abstime); |
| |
| // Blocks until the lock is obtained. |
| void mxr_mutex_lock(mxr_mutex_t* mutex); |
| |
| // Unlocks the lock. |
| void mxr_mutex_unlock(mxr_mutex_t* mutex); |
| |
| // This is the same as mxr_mutex_lock() except that it always marks the |
| // mutex as having a waiter. This is intended for use by condvar |
| // implementations. This means that a thread waiting on a condvar futex |
| // can be requeued onto the mutex's futex, so that a later call to |
| // mxr_mutex_unlock() will wake that thread. |
| void mxr_mutex_lock_with_waiter(mxr_mutex_t* mutex); |
| |
| #pragma GCC visibility pop |
| |
| __END_CDECLS |
