static dispatch_queue_t _CFMachPortQueue() {
static volatile dispatch_queue_t __CFMachPortQueue = NULL;
static dispatch_once_t onceToken;
dispatch_once(&onceToken, ^{
dispatch_queue_attr_t dqattr = dispatch_queue_attr_make_with_qos_class(DISPATCH_QUEUE_SERIAL, QOS_CLASS_BACKGROUND, 0);
__CFMachPortQueue = dispatch_queue_create("com.apple.CFMachPort", dqattr);
});
CF_INLINE void LOCKED(dispatch_block_t work) {
static dispatch_once_t guard;
static dispatch_queue_t CFUUIDGlobalDataLock;
dispatch_once(&guard, ^{
dispatch_queue_attr_t dqattr = dispatch_queue_attr_make_with_qos_class(DISPATCH_QUEUE_SERIAL, qos_class_main(), 0);
CFUUIDGlobalDataLock = dispatch_queue_create("com.apple.CFUUID", dqattr);
});
printf("Thread %ld starts\n", i);
while (clock_gettime_nsec_np(CLOCK_MONOTONIC)) {
#if defined(__x86_64__) || defined(__i386__)
__asm__("pause");
#elif defined(__arm__) || defined(__arm64__)
__asm__("wfe");
#endif
}
}
T_DECL(thread_request_32848402, "repro for rdar://32848402")
{
dispatch_queue_attr_t bg_attr, in_attr;
bg_attr = dispatch_queue_attr_make_with_qos_class(DISPATCH_QUEUE_CONCURRENT,
QOS_CLASS_BACKGROUND, 0);
in_attr = dispatch_queue_attr_make_with_qos_class(DISPATCH_QUEUE_CONCURRENT,
QOS_CLASS_USER_INITIATED, 0);
dispatch_queue_t a = dispatch_queue_create_with_target("in", in_attr, NULL);
dispatch_queue_t b = dispatch_queue_create_with_target("bg", bg_attr, NULL);
end_spin = clock_gettime_nsec_np(CLOCK_MONOTONIC) + 2 * NSEC_PER_SEC;
dispatch_async_f(a, (void *)0, spin_and_pause);
long n_threads = MIN((long)get_ncpu(),
pthread_qos_max_parallelism(QOS_CLASS_BACKGROUND, 0));
for (long i = 1; i < n_threads; i++) {
dispatch_async_f(b, (void *)i, spin);
}
