void *wakeup_test_thread(void *thread_arg) {
struct ThreadState *thread = thread_arg;
ANNOTATE_IGNORE_WRITES_BEGIN();
thread->state = STATE_ABOUT_TO_WAIT;
ANNOTATE_IGNORE_WRITES_END();
int rc = futex_wait(thread->futex_value, *thread->futex_value, NULL);
ASSERT_EQ(rc, 0);
ANNOTATE_IGNORE_WRITES_BEGIN();
thread->state = STATE_WAIT_RETURNED;
ANNOTATE_IGNORE_WRITES_END();
return NULL;
}
int main(int argc, char** argv)
{
const struct timespec delay = { 0, 100 * 1000 * 1000 };
int optchar;
int ign_rw = 1;
pthread_t tid;
while ((optchar = getopt(argc, argv, "r")) != EOF)
{
switch (optchar)
{
case 'r':
ign_rw = 0;
break;
default:
assert(0);
}
}
pthread_create(&tid, 0, thread_func, 0);
/* Let the code in the created thread run first. */
nanosleep(&delay, 0);
if (ign_rw)
ANNOTATE_IGNORE_WRITES_BEGIN();
/* Read s_b and modify s_a. */
s_a = s_b;
if (ign_rw)
ANNOTATE_IGNORE_WRITES_END();
/*
* Insert a delay here in order to make sure the load of s_c happens
* after s_c has been modified.
*/
nanosleep(&delay, 0);
/* Read s_c and modify s_a. */
s_a = s_c;
pthread_join(tid, 0);
fprintf(stderr, "Finished.\n");
return 0;
}
void check_futex_wake(volatile int *futex_value, int nwake,
int expected_woken) {
/*
* Change *futex_value just in case our nanosleep() call did not
* wait long enough for futex_wait() to enter the wait queue,
* although that is unlikely. This prevents the test from hanging
* if that happens, though the test will fail because futex_wake()
* will return a count of 0.
*/
ANNOTATE_IGNORE_WRITES_BEGIN();
(*futex_value)++;
ANNOTATE_IGNORE_WRITES_END();
int count = 9999; /* Dummy value: should be overwritten. */
int rc = futex_wake(futex_value, nwake, &count);
ASSERT_EQ(rc, 0);
/* This could fail if futex_wait() gets a spurious wakeup. */
ASSERT_EQ(count, expected_woken);
}
