/* $OpenBSD: test_cancel.c,v 1.4 2001/01/16 21:47:12 brad Exp $ */ /* David Leonard , 1999. Public Domain. */ #include #include #include #include #include #include "test.h" static pthread_cond_t cond; static pthread_mutex_t mutex; static struct timespec expiretime; static int pv_state = 0; void p() { CHECKr(pthread_mutex_lock(&mutex)); if (pv_state <= 0) { CHECKr(pthread_cond_timedwait(&cond, &mutex, &expiretime)); } pv_state--; CHECKr(pthread_mutex_unlock(&mutex)); } void v() { int needsignal; CHECKr(pthread_mutex_lock(&mutex)); pv_state++; needsignal = (pv_state == 1); if (needsignal) CHECKr(pthread_cond_signal(&cond)); CHECKr(pthread_mutex_unlock(&mutex)); } void c1handler(void *fd) { CHECKe(close((int)fd)); v(); } void * child1fn(arg) void *arg; { int fd; char buf[1024]; int len; SET_NAME("c1"); CHECKr(pthread_setcanceltype(PTHREAD_CANCEL_ASYNCHRONOUS, NULL)); /* something that will block */ CHECKe(fd = open("/dev/tty", O_RDONLY)); pthread_cleanup_push(c1handler, (void *)fd); v(); while (1) { CHECKe(len = read(fd, &buf, sizeof buf)); printf("child 1 read %d bytes\n", len); } PANIC("child 1"); } static int c2_in_test = 0; void c2handler(void *arg) { ASSERT(c2_in_test); v(); } static int message_seen = 0; void * child2fn(arg) void *arg; { SET_NAME("c2"); CHECKr(pthread_setcanceltype(PTHREAD_CANCEL_DEFERRED, NULL)); pthread_cleanup_push(c2handler, NULL); v(); while (1) { struct timespec now; struct timespec end; /* * XXX Be careful not to call any cancellation points * until pthread_testcancel() */ CHECKe(clock_gettime(CLOCK_REALTIME, &end)); end.tv_sec ++; while (1) { CHECKe(clock_gettime(CLOCK_REALTIME, &now)); if (timespeccmp(&now, &end, >=)) break; pthread_yield(); } /* XXX write() contains a cancellation point */ /* printf("child 2 testing for cancel\n"); */ c2_in_test = 1; pthread_testcancel(); printf("you should see this message exactly once\n"); message_seen++; c2_in_test = 0; ASSERT(message_seen == 1); } PANIC("child 2"); } static int c3_cancel_survived; void c3handler(void *arg) { printf("(fyi, cancellation of self %s instantaneous)\n", (c3_cancel_survived ? "was not" : "was")); v(); } void * child3fn(arg) void *arg; { SET_NAME("c3"); pthread_cleanup_push(c3handler, NULL); /* Cancel myself */ CHECKr(pthread_setcanceltype(PTHREAD_CANCEL_ASYNCHRONOUS, NULL)); c3_cancel_survived = 0; pthread_cancel(pthread_self()); c3_cancel_survived = 1; pthread_testcancel(); PANIC("child 3"); } int main() { pthread_t child1, child2, child3; /* Set up our control flow */ CHECKr(pthread_mutex_init(&mutex, NULL)); CHECKr(pthread_cond_init(&cond, NULL)); CHECKe(clock_gettime(CLOCK_REALTIME, &expiretime)); expiretime.tv_sec += 5; /* this test shouldn't run over 5 seconds */ CHECKr(pthread_create(&child1, NULL, child1fn, NULL)); CHECKr(pthread_create(&child2, NULL, child2fn, NULL)); p(); p(); CHECKr(pthread_cancel(child1)); p(); /* Give thread 2 a chance to go through its deferred loop once */ sleep(2); CHECKr(pthread_cancel(child2)); p(); /* Child 3 cancels itself */ CHECKr(pthread_create(&child3, NULL, child3fn, NULL)); p(); /* Make sure they're all gone */ CHECKr(pthread_join(child3, NULL)); CHECKr(pthread_join(child2, NULL)); CHECKr(pthread_join(child1, NULL)); exit(0); }