1 /*
2 * Copyright 2012 Google Inc.
3 *
4 * Use of this source code is governed by a BSD-style license that can be
5 * found in the LICENSE file.
6 */
7
8 #include "SkTypes.h"
9
10 #include "SkThreadUtils.h"
11 #include "SkThreadUtils_win.h"
12
SkThread_WinData(SkThread::entryPointProc entryPoint,void * data)13 SkThread_WinData::SkThread_WinData(SkThread::entryPointProc entryPoint, void* data)
14 : fHandle(NULL)
15 , fParam(data)
16 , fThreadId(0)
17 , fEntryPoint(entryPoint)
18 , fStarted(false)
19 {
20 fCancelEvent = CreateEvent(
21 NULL, // default security attributes
22 false, //auto reset
23 false, //not signaled
24 NULL); //no name
25 }
26
~SkThread_WinData()27 SkThread_WinData::~SkThread_WinData() {
28 CloseHandle(fCancelEvent);
29 }
30
thread_start(LPVOID data)31 static DWORD WINAPI thread_start(LPVOID data) {
32 SkThread_WinData* winData = static_cast<SkThread_WinData*>(data);
33
34 //See if this thread was canceled before starting.
35 if (WaitForSingleObject(winData->fCancelEvent, 0) == WAIT_OBJECT_0) {
36 return 0;
37 }
38
39 winData->fEntryPoint(winData->fParam);
40 return 0;
41 }
42
SkThread(entryPointProc entryPoint,void * data)43 SkThread::SkThread(entryPointProc entryPoint, void* data) {
44 SkThread_WinData* winData = new SkThread_WinData(entryPoint, data);
45 fData = winData;
46
47 if (NULL == winData->fCancelEvent) {
48 return;
49 }
50
51 winData->fHandle = CreateThread(
52 NULL, // default security attributes
53 0, // use default stack size
54 thread_start, // thread function name (proxy)
55 winData, // argument to thread function (proxy args)
56 CREATE_SUSPENDED, // create suspended so affinity can be set
57 &winData->fThreadId); // returns the thread identifier
58 }
59
~SkThread()60 SkThread::~SkThread() {
61 if (fData != NULL) {
62 SkThread_WinData* winData = static_cast<SkThread_WinData*>(fData);
63 // If created thread but start was never called, kill the thread.
64 if (winData->fHandle != NULL && !winData->fStarted) {
65 if (SetEvent(winData->fCancelEvent) != 0) {
66 if (this->start()) {
67 this->join();
68 }
69 } else {
70 //kill with prejudice
71 TerminateThread(winData->fHandle, -1);
72 }
73 }
74 delete winData;
75 }
76 }
77
start()78 bool SkThread::start() {
79 SkThread_WinData* winData = static_cast<SkThread_WinData*>(fData);
80 if (NULL == winData->fHandle) {
81 return false;
82 }
83
84 if (winData->fStarted) {
85 return false;
86 }
87 winData->fStarted = -1 != ResumeThread(winData->fHandle);
88 return winData->fStarted;
89 }
90
join()91 void SkThread::join() {
92 SkThread_WinData* winData = static_cast<SkThread_WinData*>(fData);
93 if (NULL == winData->fHandle || !winData->fStarted) {
94 return;
95 }
96
97 WaitForSingleObject(winData->fHandle, INFINITE);
98 }
99
num_bits_set(DWORD_PTR mask)100 static unsigned int num_bits_set(DWORD_PTR mask) {
101 unsigned int count;
102 for (count = 0; mask; ++count) {
103 mask &= mask - 1;
104 }
105 return count;
106 }
107
nth_set_bit(unsigned int n,DWORD_PTR mask)108 static unsigned int nth_set_bit(unsigned int n, DWORD_PTR mask) {
109 n %= num_bits_set(mask);
110 for (unsigned int setBitsSeen = 0, currentBit = 0; true; ++currentBit) {
111 if (mask & (static_cast<DWORD_PTR>(1) << currentBit)) {
112 ++setBitsSeen;
113 if (setBitsSeen > n) {
114 return currentBit;
115 }
116 }
117 }
118 }
119
setProcessorAffinity(unsigned int processor)120 bool SkThread::setProcessorAffinity(unsigned int processor) {
121 SkThread_WinData* winData = static_cast<SkThread_WinData*>(fData);
122 if (NULL == winData->fHandle) {
123 return false;
124 }
125
126 DWORD_PTR processAffinityMask;
127 DWORD_PTR systemAffinityMask;
128 if (0 == GetProcessAffinityMask(GetCurrentProcess(),
129 &processAffinityMask,
130 &systemAffinityMask)) {
131 return false;
132 }
133
134 DWORD_PTR threadAffinityMask = 1 << nth_set_bit(processor, processAffinityMask);
135 return 0 != SetThreadAffinityMask(winData->fHandle, threadAffinityMask);
136 }
137