线程同步的方法有哪些？Linux下实现线程同步的三种方法
线程同步的方法有哪些？在linux下，系统提供了很多种方式来实现线程同步，其中最常用的便是互斥锁、条件变量和信号量这三种方式，可能还有很多伙伴对于这三种方法都不熟悉，下面就给大家详细介绍下。
Linux下实现线程同步的三种方法：
一、互斥锁（mutex）
通过锁机制实现线程间的同步。
1、初始化锁。在Linux下，线程的互斥量数据类型是pthread_mutex_t。在使用前，要对它进行初始化。
静态分配：pthread_mutex_t mutex = PTHREAD_MUTEX_INITIALIZER；
动态分配：int pthread_mutex_init（pthread_mutex_t *mutex， const pthread_mutex_attr_t *mutexattr）；
2、加锁。对共享资源的访问，要对互斥量进行加锁，如果互斥量已经上了锁，调用线程会阻塞，直到互斥量被解锁。
int pthread_mutex_lock（pthread_mutex *mutex）；
int pthread_mutex_trylock（pthread_mutex_t *mutex）；
3、解锁。在完成了对共享资源的访问后，要对互斥量进行解锁。
int pthread_mutex_unlock（pthread_mutex_t *mutex）；
4、销毁锁。锁在是使用完成后，需要进行销毁以释放资源。
int pthread_mutex_destroy（pthread_mutex *mutex）；
01#include
02#include
03#include
04#include
05#include "iostream"
06using namespace std;
07pthread_mutex_t mutex = PTHREAD_MUTEX_INITIALIZER;
08int tmp;
09void* thread(void *arg)
10{
11cout << "thread id is " << pthread_self() << endl;
12pthread_mutex_lock(&mutex);
13tmp = 12;
14cout << "Now a is " << tmp << endl;
15pthread_mutex_unlock(&mutex);
16return NULL;
17}
18int main()
19{
20pthread_t id;
21cout << "main thread id is " << pthread_self() << endl;
22tmp = 3;
23cout << "In main func tmp = " << tmp << endl;
24if (!pthread_create(&id, NULL, thread, NULL))
25{
26cout << "Create thread success!" << endl;
27}
28else
29{
30cout << "Create thread failed!" << endl;
31}
32pthread_join(id, NULL);
33pthread_mutex_destroy(&mutex);
34return 0;
35}
36//编译：g++ -o thread testthread.cpp -lpthread
复制代码#include#include "iostream"using namespace std;pthread_mutex_t mutex = PTHREAD_MUTEX_INITIALIZER;int tmp;void* thread(void *arg){cout << "thread id is " << pthread_self() << endl;pthread_mutex_lock(&mutex);tmp = 12;cout << "Now a is " << tmp << endl;pthread_mutex_unlock(&mutex);return NULL;}int main(){pthread_t id;cout << "main thread id is " << pthread_self() << endl;tmp = 3;cout << "In main func tmp = " << tmp << endl;if (!pthread_create(&id, NULL, thread, NULL)){cout << "Create thread success!" << endl;}else{cout << "Create thread failed!" << endl;}pthread_join(id, NULL);pthread_mutex_destroy(&mutex);return 0;}//编译：g++ -o thread testthread.cpp -lpthread
