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1// Copyright (c) Facebook, Inc. and its affiliates. (http://www.facebook.com)
2#include "mutex.h"
3
4#include <pthread.h>
5
6#include <cerrno>
7
8#include "utils.h"
9
10namespace py {
11
12Mutex::Mutex() {
13 static_assert(sizeof(Mutex::Data) >= sizeof(pthread_mutex_t),
14 "Mutex::Data too small for pthread_mutex_t");
15 static_assert(alignof(Mutex::Data) >= alignof(pthread_mutex_t),
16 "Mutex::Data alignment too small for pthread_mutex_t");
17
18 pthread_mutex_t* lock = reinterpret_cast<pthread_mutex_t*>(mutex());
19 DCHECK(lock != nullptr, "lock should not be null");
20 int result = pthread_mutex_init(lock, nullptr);
21 CHECK(result == 0, "lock creation failed");
22}
23
24Mutex::~Mutex() {
25 CHECK(tryLock(), "cannot destroy locked lock");
26 unlock();
27 pthread_mutex_t* lock = reinterpret_cast<pthread_mutex_t*>(mutex());
28 int result = pthread_mutex_destroy(lock);
29 CHECK(result == 0, "could not destroy lock");
30}
31
32void Mutex::lock() {
33 pthread_mutex_t* lock = reinterpret_cast<pthread_mutex_t*>(mutex());
34 int result = pthread_mutex_lock(lock);
35 DCHECK(result == 0, "failed to lock mutex with error code of %d", result);
36}
37
38bool Mutex::tryLock() {
39 pthread_mutex_t* lock = reinterpret_cast<pthread_mutex_t*>(mutex());
40 int result = pthread_mutex_trylock(lock);
41 if (result == EBUSY) {
42 return false;
43 }
44 DCHECK(result == 0, "failed to lock mutex with error code of %d", result);
45 return true;
46}
47
48void Mutex::unlock() {
49 pthread_mutex_t* lock = reinterpret_cast<pthread_mutex_t*>(mutex());
50 int result = pthread_mutex_unlock(lock);
51 DCHECK(result == 0, "failed to unlock mutex with error code of %d", result);
52}
53
54} // namespace py