101 lines
2.3 KiB
C
101 lines
2.3 KiB
C
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#include <stdio.h>
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#include <string.h>
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#include <errno.h>
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#include <semaphore.h>
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#include <pthread.h>
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#include <unistd.h>
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//#define TST_TEST_MODE 1
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#define __HAVE_64B_ATOMICS 1
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/* Semaphore variable structure. */
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// taken from nptl/sysdeps/unix/sysv/linux/internaltypes.h
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struct new_sem
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{
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#if __HAVE_64B_ATOMICS
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/* The data field holds both value (in the least-significant 32 bytes) and
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nwaiters. */
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# if __BYTE_ORDER == __LITTLE_ENDIAN
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# define SEM_VALUE_OFFSET 0
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# elif __BYTE_ORDER == __BIG_ENDIAN
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# define SEM_VALUE_OFFSET 1
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# else
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# error Unsupported byte order.
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# endif
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# define SEM_NWAITERS_SHIFT 32
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# define SEM_VALUE_MASK (~(unsigned int)0)
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unsigned long int data;
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int private;
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int pad;
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#else
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# define SEM_VALUE_SHIFT 1
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# define SEM_NWAITERS_MASK ((unsigned int)1)
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unsigned int value;
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int private;
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int pad;
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unsigned int nwaiters;
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#endif
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};
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#if TST_TEST_MODE
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void func(sem_t *semp) {
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struct timespec ts1 = {10, 1};
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struct timespec ts2 = {10, 1};
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struct timespec ts3 = {10, 1};
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printf("Starting thread\n");
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if (sem_post(semp) == -1) {
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printf("sem_post error\n");
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sem_timedwait(semp, &ts1);
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}
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if (sem_post(semp) == -1) {
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printf("sem_post error\n");
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sem_timedwait(semp, &ts2);
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}
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if (sem_timedwait(semp, &ts3) < 0)
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printf("THREAD ERR: sem_timedwait() failed (errno=%d: %s)\n", errno, strerror(errno));
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sleep(10);
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printf("Finishing thread\n");
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}
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#endif
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int main(void)
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{
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#if TST_TEST_MODE
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pthread_t thread1,thread2,thread3;
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struct timespec ts = {10, 1}; // set incorrect nanoseconds
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#else
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struct timespec ts = {0, -1}; // set incorrect nanoseconds
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#endif
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sem_t sem;
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struct new_sem *isem = (struct new_sem *)&sem;
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sem_init(&sem, 0, 0);
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#if TST_TEST_MODE
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pthread_create(&thread1, NULL, (void *)&func, (void *)&sem);
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sleep(1);
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pthread_create(&thread2, NULL, (void *)&func, (void *)&sem);
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sleep(1);
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pthread_create(&thread3, NULL, (void *)&func, (void *)&sem);
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sleep(1);
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#endif
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unsigned int *pres;
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pres=(unsigned int*) &isem->data;
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printf("before sem_timedwait(): new_sem->nwaiters = 0x%x\n", *pres );
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if (sem_timedwait(&sem, &ts) < 0)
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printf("ERR: sem_timedwait() failed (errno=%d: %s)\n", errno, strerror(errno));
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pres=(unsigned int*) &isem->data;
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printf("after sem_timedwait(): new_sem->nwaiters = 0x%x\n", *pres );
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return 0;
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}
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