用Pthreads进行共享内存编程----HelloWorld

用Pthreads进行共享内存编程----HelloWorld

1、编译

gcc -g -Wall -o pth_hello pth_hello.c -lpthread

2、运行

./pth_hello <number of threads>

例：运行4个线程，./pth_hello 4

3、源代码

#include <stdio.h>
#include <stdlib.h>
#include <pthread.h>

int thread_count;

void * Hello(void * rank);

int main(int argc, char * argv[])
{
    long thread;
 pthread_t * thread_handles;

 thread_count = strtol(argv[1], NULL, 10);

 thread_handles = malloc(thread_count * sizeof(pthread_t));

 for(thread=0 ; thread<thread_count; thread++)
  pthread_create(&thread_handles[thread], NULL, Hello, (void *)thread);

 printf("Hello from the main thread\n");

 for(thread=0; thread<thread_count; thread++)
  pthread_join(thread_handles[thread], NULL);

 free(thread_handles);
 return 0;
}

void * Hello(void * rank)
{
    long my_rank = (long)rank;
 printf("Hello from thread %ld of %d\n", my_rank, thread_count);
 return NULL;
}