unpv13e/threads/example02.lc

#include    "unpthread.h"##  1 ##src/threads/example02.c##

#define NLOOP 5000##  2 ##src/threads/example02.c##

int     counter;                /* this is incremented by the threads */##  3 ##src/threads/example02.c##
pthread_mutex_t counter_mutex = PTHREAD_MUTEX_INITIALIZER;##  4 ##src/threads/example02.c##

void   *doit(void *);##  5 ##src/threads/example02.c##

int##  6 ##src/threads/example02.c##
main(int argc, char **argv)##  7 ##src/threads/example02.c##
{##  8 ##src/threads/example02.c##
    pthread_t tidA, tidB;##  9 ##src/threads/example02.c##

    Pthread_create(&tidA, NULL, &doit, NULL);## 10 ##src/threads/example02.c##
    Pthread_create(&tidB, NULL, &doit, NULL);## 11 ##src/threads/example02.c##

    /* 4wait for both threads to terminate */## 12 ##src/threads/example02.c##
    Pthread_join(tidA, NULL);## 13 ##src/threads/example02.c##
    Pthread_join(tidB, NULL);## 14 ##src/threads/example02.c##

    exit(0);## 15 ##src/threads/example02.c##
}## 16 ##src/threads/example02.c##

void   *## 17 ##src/threads/example02.c##
doit(void *vptr)## 18 ##src/threads/example02.c##
{## 19 ##src/threads/example02.c##
    int     i, val;## 20 ##src/threads/example02.c##

    /* ## 21 ##src/threads/example02.c##
     * Each thread fetches, prints, and increments the counter NLOOP times.## 22 ##src/threads/example02.c##
     * The value of the counter should increase monotonically.## 23 ##src/threads/example02.c##
     */## 24 ##src/threads/example02.c##

    for (i = 0; i < NLOOP; i++) {## 25 ##src/threads/example02.c##
        Pthread_mutex_lock(&counter_mutex);## 26 ##src/threads/example02.c##

        val = counter;## 27 ##src/threads/example02.c##
        printf("%d: %d\n", pthread_self(), val + 1);## 28 ##src/threads/example02.c##
        counter = val + 1;## 29 ##src/threads/example02.c##

        Pthread_mutex_unlock(&counter_mutex);## 30 ##src/threads/example02.c##
    }## 31 ##src/threads/example02.c##

    return (NULL);## 32 ##src/threads/example02.c##
}## 33 ##src/threads/example02.c##