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目前我很困惑,为什么下面的代码不会打印以下:了解并行线程
My value is 0
My value is 1
My value is 2
每次我运行此我要么得到1-2印刷线或没有,程序只是坐在他们直到我ctrl-c。我觉得这可能与我使用3个不同的线程使用相同的条件变量和互斥量有关,这是否正确?任何解释都非常感谢。
#include <stdio.h>
#include <pthread.h>
#include <assert.h>
#include <unistd.h>
#include <stdlib.h>
struct id_holder
{
int id;
};
pthread_mutex_t intersectionMutex = PTHREAD_MUTEX_INITIALIZER;
pthread_cond_t directionCondition = PTHREAD_COND_INITIALIZER;
struct id_holder * holder;
void * logic(void* val)
{
struct id_holder * id_struct = (struct id_holder *) val;
pthread_cond_wait(&directionCondition, &intersectionMutex);
printf("My value is %d\n", id_struct->id);
free(id_struct);
return NULL;
}
int main(void)
{
pthread_t threads[3];
for(int i = 0; i <3; i++)
{
holder = (struct id_holder *) malloc(sizeof(struct id_holder));
holder->id = i;
pthread_create(&threads[i], NULL, logic, holder);
}
for(int i = 0; i < 3; i++)
{
sleep(1);
pthread_cond_signal(&directionCondition);
}
for(int i = 0; i < 3; i++)
{
pthread_join(threads[i], NULL);
}
return 0;
}