#include <stdio.h>
#include <sys/types.h>
#include <sys/ipc.h>
#include <string.h>
#include <stdlib.h>
#include <pthread.h>
#include <sys/mman.h>
static pthread_mutex_t *mutex;
static volatile int i;
void* Thread_Process(void* arg)
{
printf("thread 2 id=%lu i=%d\n", pthread_self(), i);
i+=100;
printf("Process 2 lock...\n");
pthread_mutex_lock(mutex);
printf("Process 2 locked ok\n");
sleep(1);
printf("i=%d\n",i);
printf("Process 2 unlock\n");
pthread_mutex_unlock(mutex);
}
int main(int argc, char* argv[])
{
pthread_t pid;
pthread_mutexattr_t attr;
mutex=mmap(NULL,sizeof(pthread_mutex_t),PROT_READ|PROT_WRITE,MAP_SHARED|MAP_ANON,-1,0);
pthread_mutexattr_init(&attr);
pthread_mutexattr_setpshared(&attr,PTHREAD_PROCESS_SHARED);
if(0!=pthread_create(&pid,NULL,Thread_Process,NULL)){
perror("pthread_cerate");
}
i=100;
printf("Process 1 lock...\n");
pthread_mutex_lock(mutex);
printf("Process 1 locked ok\n");
sleep(1);
printf("thread 1 id=%lu i=%d\n", pthread_self(), i);
printf("Process 1 unlock\n");
pthread_mutex_unlock(mutex);
}
//share pthread mutex for process
int main(int argc, char* argv[])
{
static pthread_mutex_t *mutex;
int i;
pthread_mutexattr_t attr;
mutex=mmap(NULL,sizeof(pthread_mutex_t),PROT_READ|PROT_WRITE,MAP_SHARED|MAP_ANON,-1,0);
pthread_mutexattr_init(&attr);
pthread_mutexattr_setpshared(&attr,PTHREAD_PROCESS_SHARED);
pthread_mutex_init(mutex,&attr);
int *sharedPtr=mmap(NULL,101,PROT_READ|PROT_WRITE,MAP_SHARED|MAP_ANON,-1,0);
sharedPtr[0]=9;
pid_t pid=fork();
if(pid==0){
printf("Process 1 pid=%d lock...\n", getpid() );
pthread_mutex_lock(mutex);
printf("Process 1 locked ok sharedPtr[0]=%d\n", sharedPtr[0]);
sharedPtr[0] += 10;
printf("Process 1 pid=%d unlock\n", getpid() );
pthread_mutex_unlock(mutex);
}else{
printf("Process 2 pid=%d lock...\n", getpid() );
pthread_mutex_lock(mutex);
printf("Process 2 lock ok! sharedPtr[0]=%d\n", sharedPtr[0]);
sharedPtr[0] += 100;
pthread_mutex_unlock(mutex);
printf("Process 2 pid=%d unlock ok\n", getpid() );
}
wait(NULL);
printf("pid=%d sharedPtr[0]=%d\n", getpid(), sharedPtr[0] );
munmap(sharedPtr,101);
return 0;
}