一、互斥锁的基本概念
进程中的线程在使用某一临界资源时，为了保证临界资源在某一时刻只能被一个任务使用，约定：在使用临界资源之前，都要对临界资源上锁（上锁过程会被堵塞），然后再使用这个资源，用完之后解锁。
二、互斥锁相关API
1、互斥锁初始化
int pthread_mutex_init(pthread_mutex_t *mutex, const pthread_mutex‐attr_t *mutexattr);
mutex:互斥锁变量的地址
mutexarr:互斥锁属性变量的地址 NULL
代码段：
pthread_mutex_t mut; int pthread_mutex_init_ret = pthread_mutex_init(&mut, NULL); if (pthread_mutex_init_ret != 0) { perror("pthread_mutex_init"); exit(-1); }
2、互斥锁上锁、解锁与销毁
int pthread_mutex_lock(pthread_mutex_t *mutex);
int pthread_mutex_unlock(pthread_mutex_t *mutex);
int pthread_mutex_destroy(pthread_mutex_t *mutex);
返回值：成功返回0，失败返回非0
代码段：
#include <stdio.h> #include <errno.h> #include <pthread.h> #include <unistd.h> #include <stdlib.h> #include <string.h> #include <signal.h> int data = 0; void *Pthread_Task(void *arg) { pthread_mutex_t *mut = (pthread_mutex_t *)arg; for (int i = 0; i < 10; i++) { //先上锁 int pthread_mutex_lock_ret = pthread_mutex_lock(&mut); if (pthread_mutex_lock_ret != 0) { perror("pthread_mutex_lock"); exit(-1); } //输出 printf("%d\n", data++); //再解锁 int pthread_mutex_unlock_ret = pthread_mutex_unlock(&mut); if (pthread_mutex_unlock_ret != 0) { perror("pthread_mutex_unlock"); exit(-1); } } } int main() { //1初始化互斥锁 pthread_mutex_t mut; int pthread_mutex_init_ret = pthread_mutex_init(&mut, NULL); if (pthread_mutex_init_ret != 0) { perror("pthread_mutex_init"); exit(-1); } //2静态初始化互斥锁 //pthread_mutex_t fastmutex = PTHREAD_MUTEX_INITIALIZER; //创建线程 pthread_t pid1, pid2; int pthread_create_ret1 = pthread_create(&pid1, NULL, Pthread_Task, (void *)&mut); int pthread_create_ret2 = pthread_create(&pid2, NULL, Pthread_Task, (void *)&mut); if (pthread_create_ret1 != 0 || pthread_create_ret2 != 0) { perror("pthread_create"); exit(-1); } pause(); return 0; }
