testing/dispatch_readsync.c

   1 #include <dispatch/dispatch.h>
   2 #include <pthread.h>
   3 #include <stdio.h>
   4 #include <stdint.h>
   5 #include <limits.h>
   6 #include <assert.h>
   7
   8 #include "dispatch_test.h"
   9
  10 #define LAPS 10000
  11 #define INTERVAL 100
  12
  13 static size_t r_count = LAPS;
  14 static size_t w_count = LAPS / INTERVAL;
  15
  16 static void
  17 writer(void *ctxt __attribute__((unused)))
  18 {
  19         if (--w_count == 0) {
  20                 if (r_count == 0) {
  21                         test_stop();
  22                 }
  23         }
  24 }
  25
  26 static void
  27 reader(void *ctxt __attribute__((unused)))
  28 {
  29         if (__sync_sub_and_fetch(&r_count, 1) == 0) {
  30                 if (r_count == 0) {
  31                         test_stop();
  32                 }
  33         }
  34 }
  35
  36 int
  37 main(void)
  38 {
  39         dispatch_queue_t dq;
  40
  41         test_start("Dispatch Reader/Writer Queues");
  42
  43         dq = dispatch_queue_create("com.apple.libdispatch.test_readsync", NULL);
  44         assert(dq);
  45
  46         dispatch_queue_set_width(dq, LONG_MAX);
  47
  48         dispatch_apply(LAPS, dispatch_get_concurrent_queue(0), ^(size_t idx) {
  49                 dispatch_sync_f(dq, NULL, reader);
  50
  51                 if (idx % INTERVAL) {
  52                         dispatch_barrier_async_f(dq, NULL, writer);
  53                 }
  54         });
  55
  56         dispatch_release(dq);
  57
  58         dispatch_main();
  59 }