tests/rdar_32848402.c

   1 #include <stdio.h>
   2 #include <stdlib.h>
   3 #include <dispatch/dispatch.h>
   4 #include <dispatch/private.h>
   5 #include <sys/time.h>
   6 #include <sys/sysctl.h>
   7
   8 #include "darwintest_defaults.h"
   9 #include <darwintest_utils.h>
  10
  11 static uint64_t end_spin;
  12
  13 static uint32_t
  14 get_ncpu(void)
  15 {
  16         static uint32_t activecpu;
  17         if (!activecpu) {
  18                 uint32_t n;
  19                 size_t s = sizeof(activecpu);
  20                 sysctlbyname("hw.activecpu", &n, &s, NULL, 0);
  21                 activecpu = n;
  22         }
  23         return activecpu;
  24 }
  25
  26 static void
  27 spin_and_pause(void *ctx)
  28 {
  29         long i = (long)ctx;
  30
  31         printf("Thread %ld starts\n", i);
  32
  33         while (clock_gettime_nsec_np(CLOCK_MONOTONIC) < end_spin) {
  34 #if defined(__x86_64__) || defined(__i386__)
  35                 __asm__("pause");
  36 #elif defined(__arm__) || defined(__arm64__)
  37                 __asm__("wfe");
  38 #endif
  39         }
  40         printf("Thread %ld blocks\n", i);
  41         pause();
  42 }
  43
  44 static void
  45 spin(void *ctx)
  46 {
  47         long i = (long)ctx;
  48
  49         printf("Thread %ld starts\n", i);
  50
  51         while (clock_gettime_nsec_np(CLOCK_MONOTONIC)) {
  52 #if defined(__x86_64__) || defined(__i386__)
  53                 __asm__("pause");
  54 #elif defined(__arm__) || defined(__arm64__)
  55                 __asm__("wfe");
  56 #endif
  57         }
  58 }
  59
  60 T_DECL(thread_request_32848402, "repro for rdar://32848402")
  61 {
  62         dispatch_queue_attr_t bg_attr, in_attr;
  63
  64         bg_attr = dispatch_queue_attr_make_with_qos_class(DISPATCH_QUEUE_CONCURRENT,
  65                         QOS_CLASS_BACKGROUND, 0);
  66         in_attr = dispatch_queue_attr_make_with_qos_class(DISPATCH_QUEUE_CONCURRENT,
  67                         QOS_CLASS_USER_INITIATED, 0);
  68
  69         dispatch_queue_t a = dispatch_queue_create_with_target("in", in_attr, NULL);
  70         dispatch_queue_t b = dispatch_queue_create_with_target("bg", bg_attr, NULL);
  71
  72         end_spin = clock_gettime_nsec_np(CLOCK_MONOTONIC) + 2 * NSEC_PER_SEC;
  73
  74         dispatch_async_f(a, (void *)0, spin_and_pause);
  75         for (long i = 1; i < get_ncpu(); i++) {
  76                 dispatch_async_f(b, (void *)i, spin);
  77         }
  78
  79         dispatch_async(b, ^{
  80                 T_PASS("The NCPU+1-nth block got scheduled");
  81                 T_END;
  82         });
  83
  84         sleep(10);
  85         T_FAIL("The NCPU+1-nth block didn't get scheduled");
  86 }