146 lines · c
1#include <stdatomic.h>2#include <string.h>3#include <unistd.h>4#include <dispatch/dispatch.h>5#include <pthread.h>6 7atomic_int finished_enqueueing_work = 0;8atomic_int thread_count = 0;9 10void11doing_the_work_1(void *in)12{13 // This is only counted once because the first job in the queue14 // starves all the others.15 atomic_fetch_add(&thread_count, 1);16 while (1)17 sleep (1);18}19 20void21submit_work_1a(void *in)22{23 dispatch_queue_t *work_performer_1 = (dispatch_queue_t*) in;24 dispatch_async_f (*work_performer_1, NULL, doing_the_work_1);25 dispatch_async_f (*work_performer_1, NULL, doing_the_work_1);26}27 28void29submit_work_1b(void *in)30{31 dispatch_queue_t *work_performer_1 = (dispatch_queue_t*) in;32 dispatch_async_f (*work_performer_1, NULL, doing_the_work_1);33 dispatch_async_f (*work_performer_1, NULL, doing_the_work_1);34 atomic_fetch_add(&thread_count, 1);35 while (1)36 sleep (1);37}38 39void40doing_the_work_2(void *in)41{42 atomic_fetch_add(&thread_count, 1);43 while (1)44 sleep (1);45}46 47void48submit_work_2(void *in)49{50 dispatch_queue_t *work_performer_2 = (dispatch_queue_t*) in;51 int i = 0;52 while (i++ < 5000)53 {54 dispatch_async_f (*work_performer_2, NULL, doing_the_work_2);55 dispatch_async_f (*work_performer_2, NULL, doing_the_work_2);56 }57 atomic_fetch_add(&finished_enqueueing_work, 1);58}59 60 61void62doing_the_work_3(void *in)63{64 // This counts four times, since the queue is marked as CONCURRENT.65 atomic_fetch_add(&thread_count, 1);66 while (1)67 sleep (1);68}69 70void71submit_work_3(void *in)72{73 dispatch_queue_t *work_performer_3 = (dispatch_queue_t*) in;74 dispatch_async_f (*work_performer_3, NULL, doing_the_work_3);75 dispatch_async_f (*work_performer_3, NULL, doing_the_work_3);76 dispatch_async_f (*work_performer_3, NULL, doing_the_work_3);77 dispatch_async_f (*work_performer_3, NULL, doing_the_work_3);78}79 80 81void82stopper ()83{84 while (1)85 sleep (1);86}87 88 89int main (int argc, const char **argv)90{91 dispatch_queue_t work_submittor_1 = dispatch_queue_create ("com.apple.work_submittor_1", DISPATCH_QUEUE_SERIAL);92 dispatch_queue_t work_submittor_2 = dispatch_queue_create ("com.apple.work_submittor_and_quit_2", DISPATCH_QUEUE_SERIAL);93 dispatch_queue_t work_submittor_3 = dispatch_queue_create ("com.apple.work_submittor_3", DISPATCH_QUEUE_SERIAL);94 95 dispatch_queue_t work_performer_1 = dispatch_queue_create ("com.apple.work_performer_1", DISPATCH_QUEUE_SERIAL);96 dispatch_queue_t work_performer_2 = dispatch_queue_create ("com.apple.work_performer_2", DISPATCH_QUEUE_SERIAL);97 98 dispatch_queue_t work_performer_3 = dispatch_queue_create ("com.apple.work_performer_3", DISPATCH_QUEUE_CONCURRENT);99 100 dispatch_async_f (work_submittor_1, (void*) &work_performer_1, submit_work_1a);101 dispatch_async_f (work_submittor_1, (void*) &work_performer_1, submit_work_1b);102 103 dispatch_async_f (work_submittor_2, (void*) &work_performer_2, submit_work_2);104 105 dispatch_async_f (work_submittor_3, (void*) &work_performer_3, submit_work_3);106 107 108 // Spin up threads with each of the different libdispatch QoS values.109 dispatch_async (dispatch_get_global_queue(QOS_CLASS_USER_INITIATED, 0), ^{110 pthread_setname_np ("user initiated QoS");111 atomic_fetch_add(&thread_count, 1);112 while (1)113 sleep (10);114 });115 dispatch_async (dispatch_get_global_queue(QOS_CLASS_USER_INTERACTIVE, 0), ^{116 pthread_setname_np ("user interactive QoS");117 atomic_fetch_add(&thread_count, 1);118 while (1)119 sleep (10);120 });121 dispatch_async (dispatch_get_global_queue(QOS_CLASS_DEFAULT, 0), ^{122 pthread_setname_np ("default QoS");123 atomic_fetch_add(&thread_count, 1);124 while (1)125 sleep (10);126 });127 dispatch_async (dispatch_get_global_queue(QOS_CLASS_UTILITY, 0), ^{128 pthread_setname_np ("utility QoS");129 atomic_fetch_add(&thread_count, 1);130 while (1)131 sleep (10);132 });133 dispatch_async (dispatch_get_global_queue(QOS_CLASS_BACKGROUND, 0), ^{134 pthread_setname_np ("background QoS");135 atomic_fetch_add(&thread_count, 1);136 while (1)137 sleep (10);138 });139 140 // Unfortunately there is no pthread_barrier on darwin.141 while ((atomic_load(&thread_count) < 12) || (finished_enqueueing_work == 0))142 sleep (1);143 144 stopper ();145}146