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