mirror of https://github.com/t1meshift/os_labs.git
56 lines
1.1 KiB
C
56 lines
1.1 KiB
C
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#include <stdio.h>
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#include "mythread.h"
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//
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// simple synchronizer: allows one thread to wait for another
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// structure "synchronizer_t" has all the needed data
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// methods are:
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// init (called by one thread)
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// wait (to wait for a thread)
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// done (to indicate thread is done)
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//
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typedef struct __synchronizer_t {
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pthread_mutex_t lock;
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pthread_cond_t cond;
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int done;
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} synchronizer_t;
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synchronizer_t s;
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void signal_init(synchronizer_t *s) {
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Pthread_mutex_init(&s->lock, NULL);
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Pthread_cond_init(&s->cond, NULL);
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s->done = 0;
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}
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void signal_done(synchronizer_t *s) {
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Pthread_mutex_lock(&s->lock);
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s->done = 1;
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Pthread_cond_signal(&s->cond);
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Pthread_mutex_unlock(&s->lock);
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}
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void signal_wait(synchronizer_t *s) {
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Pthread_mutex_lock(&s->lock);
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while (s->done == 0)
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Pthread_cond_wait(&s->cond, &s->lock);
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Pthread_mutex_unlock(&s->lock);
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}
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void* worker(void* arg) {
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printf("this should print first\n");
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signal_done(&s);
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return NULL;
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}
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int main(int argc, char *argv[]) {
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pthread_t p;
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signal_init(&s);
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Pthread_create(&p, NULL, worker, NULL);
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signal_wait(&s);
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printf("this should print last\n");
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return 0;
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}
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