Linux多进程多线程互斥同步例子

Linux多进程多线程互斥同步例子，运行顺序:先运行进程1,再运行进程2。进程1#include <stdio.h>
#include <stdlib.h>
#include <string.h>#include <sys/shm.h>
#include <pthread.h>
#include <errno.h>#define DEBUG 1
#define SHARE_KEY 0x1234
#define THREAD_NUM 4typedef struct{
pthread_mutex_t lock;
pthread_cond_t cond;
char msg[180];
int num;
}Share_Stuff;static Share_Stuff* stuff[THREAD_NUM];void* threadB（void *prm）;
int main（int argc,char** argv）
{
void *share_addr=NULL;
pthread_t tid[THREAD_NUM];
int shmid = -1;
int ret=0;
int i=0;#if DEBUG
printf（"______%s______%s______ ",__DATE__,__TIME__）;
#endif////////////////////////////////////////////share menory////////////////////////////////////////////
shmid = shmget（SHARE_KEY,sizeof（Share_Stuff）, 0666|IPC_CREAT）;
if（shmid == -1）{
printf（"Create share memory fail！ - %s ",strerror（errno））;
} share_addr=（void*）shmat（shmid,（void*）0,0）;
if（share_addr < 0）{
printf（"Get share memory address error！ - %s ",strerror（errno））;
}////////////////////////////////////////////get the addr////////////////////////////////////////////
#if DEBUG
printf（"share_addr:%x ",（unsigned int）share_addr）;
#endif for（;i<THREAD_NUM;i++）{
stuff[i]=（Share_Stuff*）share_addr+i;
stuff[i]->num=i;
#if DEBUG
printf（"stuff"s addr:%x ",（unsigned int）stuff[i]）;
#endif
} i=0;
////////////////////////////////////////////create_thread////////////////////////////////////////////
pthread_condattr_t cond_attr;
pthread_condattr_init（&cond_attr）;
pthread_condattr_setpshared（&cond_attr, PTHREAD_PROCESS_SHARED）; pthread_mutexattr_t mutex_attr;
pthread_mutexattr_init（&mutex_attr）;
pthread_mutexattr_setpshared（&mutex_attr, PTHREAD_PROCESS_SHARED）;

for（;i<THREAD_NUM;i++）{
pthread_cond_init（&stuff[i]->cond, &cond_attr）;
pthread_mutex_init（&stuff[i]->lock, &mutex_attr）;
ret=pthread_create（&tid[i],0,threadB,（void*）stuff[i]）;
if（ret！=0）{
printf（"ThreadA%d create error！ ",i）;
}
} pthread_condattr_destroy（&cond_attr）;
pthread_mutexattr_destroy（&mutex_attr）; i=0;
////////////////////////////////////////////wait_for_done////////////////////////////////////////////
for（;i<THREAD_NUM;i++）{
ret=pthread_join（tid[i],NULL）;
}#if DEBUG
printf（"all thread done！ "）;
#endif return 0;
}
void* threadB（void *prm）
{
Share_Stuff *stuff;

#if DEBUG
printf（"thread"s prm:%x ",（unsigned int）prm）;
#endif stuff=（Share_Stuff *）prm;
while（1）{
sleep（1）;
//printf（"pthread_cond_wait "）;
pthread_cond_wait（&stuff->cond,&stuff->lock）;
printf（"message:%s",stuff->msg）;
/*******************************************************/
sleep（3）;
//printf（"pthread_mutex_lock "）;
pthread_mutex_lock（&stuff->lock）;
sprintf（stuff->msg,"threadA--%d ",stuff->num）;
// printf（"pthread_cond_signal "）;
pthread_cond_signal（&stuff->cond）;
//printf（"pthread_mutex_unlock "）;
pthread_mutex_unlock（&stuff->lock）;
}
}