1/*
2 * Copyright (C) 2016 Apple Inc. All rights reserved.
3 *
4 * Redistribution and use in source and binary forms, with or without
5 * modification, are permitted provided that the following conditions
6 * are met:
7 * 1. Redistributions of source code must retain the above copyright
8 * notice, this list of conditions and the following disclaimer.
9 * 2. Redistributions in binary form must reproduce the above copyright
10 * notice, this list of conditions and the following disclaimer in the
11 * documentation and/or other materials provided with the distribution.
12 *
13 * THIS SOFTWARE IS PROVIDED BY APPLE INC. ``AS IS'' AND ANY
14 * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
15 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
16 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL APPLE INC. OR
17 * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
18 * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
19 * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
20 * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY
21 * OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
22 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
23 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
24 */
25
26#include "config.h"
27#include "SuperSampler.h"
28
29#include "MacroAssembler.h"
30#include "Options.h"
31#include <wtf/DataLog.h>
32#include <wtf/Lock.h>
33#include <wtf/Threading.h>
34
35namespace JSC {
36
37volatile uint32_t g_superSamplerCount;
38
39static Lock lock;
40static double in;
41static double out;
42
43void initializeSuperSampler()
44{
45 if (!Options::useSuperSampler())
46 return;
47
48 Thread::create(
49 "JSC Super Sampler",
50 [] () {
51 const int sleepQuantum = 10;
52 const int printingPeriod = 1000;
53 for (;;) {
54 for (int ms = 0; ms < printingPeriod; ms += sleepQuantum) {
55 {
56 LockHolder locker(lock);
57 if (g_superSamplerCount)
58 in++;
59 else
60 out++;
61 }
62 sleep(Seconds::fromMilliseconds(sleepQuantum));
63 }
64 printSuperSamplerState();
65 if (static_cast<int32_t>(g_superSamplerCount) < 0)
66 dataLog("WARNING: Super sampler undercount detected!\n");
67 }
68 });
69}
70
71void resetSuperSamplerState()
72{
73 LockHolder locker(lock);
74 in = 0;
75 out = 0;
76}
77
78void printSuperSamplerState()
79{
80 if (!Options::useSuperSampler())
81 return;
82
83 LockHolder locker(lock);
84 double percentage = 100.0 * in / (in + out);
85 if (percentage != percentage)
86 percentage = 0.0;
87 dataLog("Percent time behind super sampler flag: ", percentage, "\n");
88}
89
90} // namespace JSC
91
92