线程同步

线程同步的两种方法：

1. 信号量

2. 互斥量

信号量：

 

#include <stdio.h>

#include <unistd.h>

#include <stdlib.h>

#include <string.h>

#include <pthread.h>

#include <semaphore.h>



void *thread_function(void *arg);

sem_t bin_sem;



#define WORK_SIZE 1024

char work_area[WORK_SIZE];



int main() {

	int res;

	pthread_t a_thread;

	void *thread_result;



	res = sem_init(&bin_sem, 0, 0);

	if(res != 0) {

		perror("Semaphore initialization failed");

		exit(EXIT_FAILURE);

	}

	res = pthread_create(&a_thread, NULL, thread_function, NULL);

	if(res != 0) {

		perror("Thread creation failed");

		exit(EXIT_FAILURE);

	}

	printf("Input some text. Enter 'end' to finish\n");

	while(strncmp("end",work_area, 3) != 0) {

		fgets(work_area, WORK_SIZE, stdin);

		sem_post(&bin_sem);

	}

	printf("\nWaiting for thread to finish....\n");

	res = pthread_join(a_thread, &thread_result);

	if(res !=0) {

		perror("Thread join failed");

		exit(EXIT_FAILURE);

	}

	printf("Thread join\n");

	sem_destroy(&bin_sem);

	exit(EXIT_SUCCESS);

}



void *thread_function(void *arg) {

	sem_wait(&bin_sem);

	while(strncmp("end", work_area, 3) != 0) {

		printf("You input %d characters\n", strlen(work_area) - 1);

		sem_wait(&bin_sem);

	}

	pthread_exit(NULL);

}