1  // SPDX-License-Identifier: GPL-2.0
2  #include "mutex.h"
3  
4  #include "debug.h"
5  #include <linux/string.h>
6  #include <errno.h>
7  
check_err(const char * fn,int err)8  static void check_err(const char *fn, int err)
9  {
10  	char sbuf[STRERR_BUFSIZE];
11  
12  	if (err == 0)
13  		return;
14  
15  	pr_err("%s error: '%s'\n", fn, str_error_r(err, sbuf, sizeof(sbuf)));
16  }
17  
18  #define CHECK_ERR(err) check_err(__func__, err)
19  
__mutex_init(struct mutex * mtx,bool pshared)20  static void __mutex_init(struct mutex *mtx, bool pshared)
21  {
22  	pthread_mutexattr_t attr;
23  
24  	CHECK_ERR(pthread_mutexattr_init(&attr));
25  
26  #ifndef NDEBUG
27  	/* In normal builds enable error checking, such as recursive usage. */
28  	CHECK_ERR(pthread_mutexattr_settype(&attr, PTHREAD_MUTEX_ERRORCHECK));
29  #endif
30  	if (pshared)
31  		CHECK_ERR(pthread_mutexattr_setpshared(&attr, PTHREAD_PROCESS_SHARED));
32  
33  	CHECK_ERR(pthread_mutex_init(&mtx->lock, &attr));
34  	CHECK_ERR(pthread_mutexattr_destroy(&attr));
35  }
36  
mutex_init(struct mutex * mtx)37  void mutex_init(struct mutex *mtx)
38  {
39  	__mutex_init(mtx, /*pshared=*/false);
40  }
41  
mutex_init_pshared(struct mutex * mtx)42  void mutex_init_pshared(struct mutex *mtx)
43  {
44  	__mutex_init(mtx, /*pshared=*/true);
45  }
46  
mutex_destroy(struct mutex * mtx)47  void mutex_destroy(struct mutex *mtx)
48  {
49  	CHECK_ERR(pthread_mutex_destroy(&mtx->lock));
50  }
51  
mutex_lock(struct mutex * mtx)52  void mutex_lock(struct mutex *mtx)
53  	NO_THREAD_SAFETY_ANALYSIS
54  {
55  	CHECK_ERR(pthread_mutex_lock(&mtx->lock));
56  }
57  
mutex_unlock(struct mutex * mtx)58  void mutex_unlock(struct mutex *mtx)
59  	NO_THREAD_SAFETY_ANALYSIS
60  {
61  	CHECK_ERR(pthread_mutex_unlock(&mtx->lock));
62  }
63  
mutex_trylock(struct mutex * mtx)64  bool mutex_trylock(struct mutex *mtx)
65  {
66  	int ret = pthread_mutex_trylock(&mtx->lock);
67  
68  	if (ret == 0)
69  		return true; /* Lock acquired. */
70  
71  	if (ret == EBUSY)
72  		return false; /* Lock busy. */
73  
74  	/* Print error. */
75  	CHECK_ERR(ret);
76  	return false;
77  }
78  
__cond_init(struct cond * cnd,bool pshared)79  static void __cond_init(struct cond *cnd, bool pshared)
80  {
81  	pthread_condattr_t attr;
82  
83  	CHECK_ERR(pthread_condattr_init(&attr));
84  	if (pshared)
85  		CHECK_ERR(pthread_condattr_setpshared(&attr, PTHREAD_PROCESS_SHARED));
86  
87  	CHECK_ERR(pthread_cond_init(&cnd->cond, &attr));
88  	CHECK_ERR(pthread_condattr_destroy(&attr));
89  }
90  
cond_init(struct cond * cnd)91  void cond_init(struct cond *cnd)
92  {
93  	__cond_init(cnd, /*pshared=*/false);
94  }
95  
cond_init_pshared(struct cond * cnd)96  void cond_init_pshared(struct cond *cnd)
97  {
98  	__cond_init(cnd, /*pshared=*/true);
99  }
100  
cond_destroy(struct cond * cnd)101  void cond_destroy(struct cond *cnd)
102  {
103  	CHECK_ERR(pthread_cond_destroy(&cnd->cond));
104  }
105  
cond_wait(struct cond * cnd,struct mutex * mtx)106  void cond_wait(struct cond *cnd, struct mutex *mtx)
107  {
108  	CHECK_ERR(pthread_cond_wait(&cnd->cond, &mtx->lock));
109  }
110  
cond_signal(struct cond * cnd)111  void cond_signal(struct cond *cnd)
112  {
113  	CHECK_ERR(pthread_cond_signal(&cnd->cond));
114  }
115  
cond_broadcast(struct cond * cnd)116  void cond_broadcast(struct cond *cnd)
117  {
118  	CHECK_ERR(pthread_cond_broadcast(&cnd->cond));
119  }
120