mutex.c

  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, bool recursive)
 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 (recursive)
 31		CHECK_ERR(pthread_mutexattr_settype(&attr, PTHREAD_MUTEX_RECURSIVE));
 32	if (pshared)
 33		CHECK_ERR(pthread_mutexattr_setpshared(&attr, PTHREAD_PROCESS_SHARED));
 34	CHECK_ERR(pthread_mutex_init(&mtx->lock, &attr));
 35	CHECK_ERR(pthread_mutexattr_destroy(&attr));
 36}
 37
 38void mutex_init(struct mutex *mtx)
 39{
 40	__mutex_init(mtx, /*pshared=*/false, /*recursive=*/false);
 41}
 42
 43void mutex_init_pshared(struct mutex *mtx)
 44{
 45	__mutex_init(mtx, /*pshared=*/true, /*recursive=*/false);
 46}
 47
 48void mutex_init_recursive(struct mutex *mtx)
 49{
 50	__mutex_init(mtx, /*pshared=*/false, /*recursive=*/true);
 51}
 52
 53void mutex_destroy(struct mutex *mtx)
 54{
 55	CHECK_ERR(pthread_mutex_destroy(&mtx->lock));
 56}
 57
 58void mutex_lock(struct mutex *mtx)
 59	NO_THREAD_SAFETY_ANALYSIS
 60{
 61	CHECK_ERR(pthread_mutex_lock(&mtx->lock));
 62}
 63
 64void mutex_unlock(struct mutex *mtx)
 65	NO_THREAD_SAFETY_ANALYSIS
 66{
 67	CHECK_ERR(pthread_mutex_unlock(&mtx->lock));
 68}
 69
 70bool mutex_trylock(struct mutex *mtx)
 71{
 72	int ret = pthread_mutex_trylock(&mtx->lock);
 73
 74	if (ret == 0)
 75		return true; /* Lock acquired. */
 76
 77	if (ret == EBUSY)
 78		return false; /* Lock busy. */
 79
 80	/* Print error. */
 81	CHECK_ERR(ret);
 82	return false;
 83}
 84
 85static void __cond_init(struct cond *cnd, bool pshared)
 86{
 87	pthread_condattr_t attr;
 88
 89	CHECK_ERR(pthread_condattr_init(&attr));
 90	if (pshared)
 91		CHECK_ERR(pthread_condattr_setpshared(&attr, PTHREAD_PROCESS_SHARED));
 92
 93	CHECK_ERR(pthread_cond_init(&cnd->cond, &attr));
 94	CHECK_ERR(pthread_condattr_destroy(&attr));
 95}
 96
 97void cond_init(struct cond *cnd)
 98{
 99	__cond_init(cnd, /*pshared=*/false);
100}
101
102void cond_init_pshared(struct cond *cnd)
103{
104	__cond_init(cnd, /*pshared=*/true);
105}
106
107void cond_destroy(struct cond *cnd)
108{
109	CHECK_ERR(pthread_cond_destroy(&cnd->cond));
110}
111
112void cond_wait(struct cond *cnd, struct mutex *mtx)
113{
114	CHECK_ERR(pthread_cond_wait(&cnd->cond, &mtx->lock));
115}
116
117void cond_signal(struct cond *cnd)
118{
119	CHECK_ERR(pthread_cond_signal(&cnd->cond));
120}
121
122void cond_broadcast(struct cond *cnd)
123{
124	CHECK_ERR(pthread_cond_broadcast(&cnd->cond));
125}