File: dispatch_timer_short.c

package info (click to toggle)
swiftlang 6.0.3-2
  • links: PTS, VCS
  • area: main
  • in suites: forky, sid, trixie
  • size: 2,519,992 kB
  • sloc: cpp: 9,107,863; ansic: 2,040,022; asm: 1,135,751; python: 296,500; objc: 82,456; f90: 60,502; lisp: 34,951; pascal: 19,946; sh: 18,133; perl: 7,482; ml: 4,937; javascript: 4,117; makefile: 3,840; awk: 3,535; xml: 914; fortran: 619; cs: 573; ruby: 573
file content (135 lines) | stat: -rw-r--r-- 3,701 bytes parent folder | download
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
/*
 * Copyright (c) 2010-2011 Apple Inc. All rights reserved.
 *
 * @APPLE_APACHE_LICENSE_HEADER_START@
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 *
 * @APPLE_APACHE_LICENSE_HEADER_END@
 */

#include <stdlib.h>
#include <assert.h>
#include <stdio.h>
#include <string.h>
#include <math.h>
#ifdef __APPLE__
#include <mach/mach_time.h>
#include <libkern/OSAtomic.h>
#endif

#include <dispatch/dispatch.h>

#include <bsdtests.h>
#include "dispatch_test.h"

#define delay (1ull * NSEC_PER_SEC)
#define interval (5ull * NSEC_PER_USEC)

#define N 25000

static dispatch_source_t t[N];
static dispatch_queue_t q;
static dispatch_group_t g;

static volatile int32_t count;
static mach_timebase_info_data_t tbi;
static uint64_t start, last;

#define elapsed_ms(x) (((now-(x))*tbi.numer/tbi.denom)/(1000ull*NSEC_PER_USEC))

static
void
test_fin(void *cxt)
{
	uint32_t finalCount = (uint32_t)count;
	fprintf(stderr, "Called back every %llu us on average\n",
			(delay/finalCount)/NSEC_PER_USEC);
	test_long_less_than("Frequency", 1,
		(long)ceil((double)delay/(double)(finalCount*interval)));
	int i;
	for (i = 0; i < N; i++) {
		dispatch_source_cancel(t[i]);
		dispatch_release(t[i]);
	}
	dispatch_resume(q);
	dispatch_release(q);
	dispatch_release(g);
	test_ptr("finalizer ran", cxt, cxt);
	test_stop();
}

static
void
test_short_timer(void)
{
	// Add a large number of timers with suspended target queue in front of
	// the timer being measured <rdar://problem/7401353>
	g = dispatch_group_create();
	q = dispatch_queue_create("q", NULL);
	int i;
	for (i = 0; i < N; i++) {
		t[i] = dispatch_source_create(DISPATCH_SOURCE_TYPE_TIMER, 0, 0, q);
		dispatch_source_set_timer(t[i], DISPATCH_TIME_NOW, interval, 0);
		dispatch_group_enter(g);
		dispatch_source_set_registration_handler(t[i], ^{
			dispatch_suspend(t[i]);
			dispatch_group_leave(g);
		});
		dispatch_resume(t[i]);
	}
	// Wait for registration & configuration of all timers
	dispatch_group_wait(g, DISPATCH_TIME_FOREVER);
	dispatch_suspend(q);
	for (i = 0; i < N; i++) {
		dispatch_resume(t[i]);
	}

	dispatch_source_t s = dispatch_source_create(DISPATCH_SOURCE_TYPE_TIMER,
			0, 0, dispatch_get_global_queue(0, 0));
	test_ptr_notnull("dispatch_source_create", s);
	dispatch_source_set_timer(s, DISPATCH_TIME_NOW, interval, 0);
	dispatch_source_set_event_handler(s, ^{
		uint64_t now = mach_absolute_time();
		if (!count) {
			dispatch_after(dispatch_time(DISPATCH_TIME_NOW, delay),
					dispatch_get_global_queue(0, 0), ^{
				dispatch_source_cancel(s);
				dispatch_release(s);
			});
			fprintf(stderr, "First timer callback  (after %4llu ms)\n",
					elapsed_ms(start));
		}
		OSAtomicIncrement32(&count);
		if (elapsed_ms(last) >= 100) {
			fprintf(stderr, "%5d timer callbacks (after %4llu ms)\n", count,
					elapsed_ms(start));
			last = now;
		}
	});
	dispatch_set_context(s, s);
	dispatch_set_finalizer_f(s, test_fin);
	fprintf(stderr, "Scheduling %llu us timer\n", interval/NSEC_PER_USEC);
	start = last = mach_absolute_time();
	dispatch_resume(s);
}

int
main(void)
{
	dispatch_test_start("Dispatch Short Timer"); // <rdar://problem/7765184>
	mach_timebase_info(&tbi);
	test_short_timer();
	dispatch_main();
	return 0;
}