55 lines
1.4 KiB
C
55 lines
1.4 KiB
C
#include <stdio.h>
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#include <stdlib.h>
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#include <pthread.h>
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#include <unistd.h>
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#include "common.h"
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#include "common_threads.h"
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pthread_mutex_t L1 = PTHREAD_MUTEX_INITIALIZER;
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pthread_mutex_t L2 = PTHREAD_MUTEX_INITIALIZER;
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void *thread1(void *arg) {
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printf("t1: begin\n");
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printf("t1: try to acquire L1...\n");
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Pthread_mutex_lock(&L1);
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printf("t1: L1 acquired\n");
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printf("t1: try to acquire L2...\n");
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Pthread_mutex_lock(&L2);
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printf("t1: L2 acquired\n");
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Pthread_mutex_unlock(&L1);
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Pthread_mutex_unlock(&L2);
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return NULL;
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}
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void *thread2(void *arg) {
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printf(" t2: begin\n");
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printf(" t2: try to acquire L2...\n");
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Pthread_mutex_lock(&L2);
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printf(" t2: L2 acquired\n");
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printf(" t2: try to acquire L1...\n");
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Pthread_mutex_lock(&L1);
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printf(" t2: L1 acquired\n");
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Pthread_mutex_unlock(&L1);
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Pthread_mutex_unlock(&L2);
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return NULL;
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}
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int main(int argc, char *argv[]) {
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if (argc != 1) {
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fprintf(stderr, "usage: main\n");
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exit(1);
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}
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pthread_t p1, p2;
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printf("main: begin\n");
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Pthread_create(&p1, NULL, thread1, NULL);
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Pthread_create(&p2, NULL, thread2, NULL);
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// join waits for the threads to finish
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Pthread_join(p1, NULL);
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Pthread_join(p2, NULL);
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printf("main: end\n");
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return 0;
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}
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