libdispatch-84.5.3.tar.gz

[apple/libdispatch.git] / testing / dispatch_priority.c

diff --git a/testing/dispatch_priority.c b/testing/dispatch_priority.c
new file mode 100644 (file)
index 0000000..a964765
--- /dev/null
+++ b/testing/dispatch_priority.c
@@ -0,0 +1,126 @@
+#include <stdio.h>
+#include <dispatch/dispatch.h>
+#include <dispatch/queue_private.h>
+#include <unistd.h>
+#include <stdlib.h>
+#include <assert.h>
+#include <TargetConditionals.h>
+
+#include "dispatch_test.h"
+
+int done = 0;
+
+#define BLOCKS 128
+#define PRIORITIES 3
+
+#if TARGET_OS_EMBEDDED
+#define LOOP_COUNT 2000000
+#else
+#define LOOP_COUNT 100000000
+#endif
+
+char *labels[PRIORITIES] = { "LOW", "DEFAULT", "HIGH" };
+int priorities[PRIORITIES] = { DISPATCH_QUEUE_PRIORITY_LOW, DISPATCH_QUEUE_PRIORITY_DEFAULT, DISPATCH_QUEUE_PRIORITY_HIGH };
+
+union {
+       size_t count;
+       char padding[64];
+} counts[PRIORITIES];
+
+#define ITERATIONS (size_t)(PRIORITIES * BLOCKS * 0.50)
+size_t iterations = ITERATIONS;
+
+void
+histogram(void) {
+       size_t maxcount = BLOCKS;
+       size_t sc[PRIORITIES];
+       
+       size_t total = 0;
+       
+       size_t x,y;
+       for (y = 0; y < PRIORITIES; ++y) {
+               sc[y] = counts[y].count;
+       }
+
+       for (y = 0; y < PRIORITIES; ++y) {
+               printf("%s: %ld\n", labels[y], sc[y]);
+               total += sc[y];
+               
+               double fraction = (double)sc[y] / (double)maxcount;
+               double value = fraction * (double)80;
+               for (x = 0; x < 80; ++x) {
+                       printf("%s", (value > x) ? "*" : " ");
+               }
+               printf("\n");
+       }
+       
+       test_long("blocks completed", total, ITERATIONS);
+       test_long_less_than("high priority precedence", (long)sc[0], (long)sc[2]);
+}
+
+void
+cpubusy(void* context)
+{
+       size_t *count = context;
+       size_t iterdone;
+
+       size_t idx;
+       for (idx = 0; idx < LOOP_COUNT; ++idx) {
+               if (done) break;
+       }
+       
+       if ((iterdone = __sync_sub_and_fetch(&iterations, 1)) == 0) {
+               __sync_add_and_fetch(&done, 1);
+               __sync_add_and_fetch(count, 1);
+               histogram();
+               test_stop();
+               exit(0);
+       } else if (iterdone > 0) {
+               __sync_add_and_fetch(count, 1);
+       }
+}
+
+void
+submit_work(dispatch_queue_t queue, void* context)
+{
+       int i;
+
+       for (i = 0; i < BLOCKS; ++i) {
+               dispatch_async_f(queue, context, cpubusy);
+       }
+
+#if USE_SET_TARGET_QUEUE
+       dispatch_release(queue);
+#endif
+}
+
+int
+main(int argc __attribute__((unused)), char* argv[] __attribute__((unused)))
+{
+       dispatch_queue_t q[PRIORITIES];
+       int i;
+
+#if USE_SET_TARGET_QUEUE
+       test_start("Dispatch Priority (Set Target Queue)");
+       for(i = 0; i < PRIORITIES; i++) {
+               q[i] = dispatch_queue_create(labels[i], NULL);
+               test_ptr_notnull("q[i]", q[i]);
+               assert(q[i]);
+               dispatch_set_target_queue(q[i], dispatch_get_global_queue(priorities[i], 0));
+               dispatch_queue_set_width(q[i], DISPATCH_QUEUE_WIDTH_MAX_LOGICAL_CPUS);
+       }
+#else
+       test_start("Dispatch Priority");
+       for(i = 0; i < PRIORITIES; i++) {
+               q[i] = dispatch_get_global_queue(priorities[i], 0);
+       }
+#endif
+       
+       for(i = 0; i < PRIORITIES; i++) {
+               submit_work(q[i], &counts[i].count);
+       }
+
+       dispatch_main();
+
+       return 0;
+}