互斥锁使用范例

#define OBSERVER "Observer"

#include <pthread.h>
#include "log.h"
#include "observer.h"

static GList* observers;
static pthread_mutexattr_t mutexattr;//创建互斥锁
static pthread_mutex_t mutex;

void
observer_init()
{

pthread_mutexattr_init(&mutexattr);
pthread_mutexattr_settype(&mutexattr, PTHREAD_MUTEX_RECURSIVE_NP);
//设置属性

pthread_mutex_init(&mutex, &mutexattr);//初始化互斥锁

log_debug(OBSERVER, "Observer module is initialized.");
}

void
observer_exit()
{
pthread_mutexattr_destroy(&mutexattr);
pthread_mutex_destroy(&mutex);//注销互斥锁

log_debug(OBSERVER, "Observer module exits.");
}

void
observer_register(OBSERVER_UPDATE update_func)
{
pthread_mutex_lock(&mutex);//加锁
observers = g_list_append(observers, update_func);
pthread_mutex_unlock(&mutex);//解锁
}

void
observer_notify(int module, int event, void* userdata)
{
int i;
int len;
OBSERVER_UPDATE update;

pthread_mutex_lock(&mutex);

len = g_list_length(observers);
for (i = 0; i < len; i++) {
update = (OBSERVER_UPDATE)g_list_nth_data(observers, i);
if (update == NULL) {
continue;
}

update(module, event, userdata);
}
pthread_mutex_unlock(&mutex);