多线程同步机制详解-优快云博客

1. thread的创建

#include <pthread.h>

void* thread_function(void *arg) {
    ....
    return NULL;
}

pthread_t mythread;
if ( pthread_create( &mythread, NULL, thread_function, NULL/*args*/) ) {
    printf("error creating thread.");
    abort();
}

2.mutex的代码事例

pthread_mutex_t mymutex=PTHREAD_MUTEX_INITIALIZER;

pthread_mutex_lock(&mymutex);
//....
pthread_mutex_unlock(&mymutex);

pthread_mutex_t mutex;
if(pthread_mutex_init(&mutex, NULL))
{
    printf("Unable to initialize a mutex\n");
    return -1;
}
pthread_mutex_lock(&mymutex);
//....
pthread_mutex_unlock(&mymutex);
// Clean up the mutex
pthread_mutex_destroy(&mutex);

两种方式的参考：http://stackoverflow.com/questions/14320041/pthread-mutex-initializer-vs-pthread-mutex-init-mutex-param

3.Semaphores的代码事例

#include <semaphore.h>
#include <pthread.h>

sem_t OKToBuyMilk;
if(sem_init(&OKToBuyMilk, 0, 1)) {
    printf("Could not initialize a semaphore\n");
    return -1;
}
sem_wait(&OKToBuyMilk);
//....
sem_post(&OKToBuyMilk);
sem_destroy(&OKToBuyMilk);

4.ConditionVariables的代码事例

pthread_cond_t count_threshold_cv;
pthread_cond_init (&count_threshold_cv, NULL);

// one thread
pthread_mutex_lock(&count_mutex);
if (count == COUNT_LIMIT) {
      pthread_cond_signal(&count_threshold_cv);
}
pthread_mutex_unlock(&count_mutex);

// -other thread
pthread_mutex_lock(&count_mutex);
while (count<COUNT_LIMIT) {
    pthread_cond_wait(&count_threshold_cv, &count_mutex);
}
pthread_mutex_unlock(&count_mutex);

pthread_cond_destroy(&count_threshold_cv);