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
  8static 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
 20static 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
 37void mutex_init(struct mutex *mtx)
 38{
 39	__mutex_init(mtx, /*pshared=*/false);
 40}
 41
 42void mutex_init_pshared(struct mutex *mtx)
 43{
 44	__mutex_init(mtx, /*pshared=*/true);
 45}
 46
 47void mutex_destroy(struct mutex *mtx)
 48{
 49	CHECK_ERR(pthread_mutex_destroy(&mtx->lock));
 50}
 51
 52void mutex_lock(struct mutex *mtx)
 53	NO_THREAD_SAFETY_ANALYSIS
 54{
 55	CHECK_ERR(pthread_mutex_lock(&mtx->lock));
 56}
 57
 58void mutex_unlock(struct mutex *mtx)
 59	NO_THREAD_SAFETY_ANALYSIS
 60{
 61	CHECK_ERR(pthread_mutex_unlock(&mtx->lock));
 62}
 63
 64bool 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
 79static 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
 91void cond_init(struct cond *cnd)
 92{
 93	__cond_init(cnd, /*pshared=*/false);
 94}
 95
 96void cond_init_pshared(struct cond *cnd)
 97{
 98	__cond_init(cnd, /*pshared=*/true);
 99}
100
101void cond_destroy(struct cond *cnd)
102{
103	CHECK_ERR(pthread_cond_destroy(&cnd->cond));
104}
105
106void cond_wait(struct cond *cnd, struct mutex *mtx)
107{
108	CHECK_ERR(pthread_cond_wait(&cnd->cond, &mtx->lock));
109}
110
111void cond_signal(struct cond *cnd)
112{
113	CHECK_ERR(pthread_cond_signal(&cnd->cond));
114}
115
116void cond_broadcast(struct cond *cnd)
117{
118	CHECK_ERR(pthread_cond_broadcast(&cnd->cond));
119}