michael@0: /*
michael@0:  * Copyright 2012 Google Inc.
michael@0:  *
michael@0:  * Use of this source code is governed by a BSD-style license that can be
michael@0:  * found in the LICENSE file.
michael@0:  */
michael@0: 
michael@0: #include "SkTypes.h"
michael@0: 
michael@0: #include "SkThreadUtils.h"
michael@0: #include "SkThreadUtils_win.h"
michael@0: 
michael@0: SkThread_WinData::SkThread_WinData(SkThread::entryPointProc entryPoint, void* data)
michael@0:     : fHandle(NULL)
michael@0:     , fParam(data)
michael@0:     , fThreadId(0)
michael@0:     , fEntryPoint(entryPoint)
michael@0:     , fStarted(false)
michael@0: {
michael@0:     fCancelEvent = CreateEvent(
michael@0:         NULL,  // default security attributes
michael@0:         false, //auto reset
michael@0:         false, //not signaled
michael@0:         NULL); //no name
michael@0: }
michael@0: 
michael@0: SkThread_WinData::~SkThread_WinData() {
michael@0:     CloseHandle(fCancelEvent);
michael@0: }
michael@0: 
michael@0: static DWORD WINAPI thread_start(LPVOID data) {
michael@0:     SkThread_WinData* winData = static_cast<SkThread_WinData*>(data);
michael@0: 
michael@0:     //See if this thread was canceled before starting.
michael@0:     if (WaitForSingleObject(winData->fCancelEvent, 0) == WAIT_OBJECT_0) {
michael@0:         return 0;
michael@0:     }
michael@0: 
michael@0:     winData->fEntryPoint(winData->fParam);
michael@0:     return 0;
michael@0: }
michael@0: 
michael@0: SkThread::SkThread(entryPointProc entryPoint, void* data) {
michael@0:     SkThread_WinData* winData = new SkThread_WinData(entryPoint, data);
michael@0:     fData = winData;
michael@0: 
michael@0:     if (NULL == winData->fCancelEvent) {
michael@0:         return;
michael@0:     }
michael@0: 
michael@0:     winData->fHandle = CreateThread(
michael@0:         NULL,                   // default security attributes
michael@0:         0,                      // use default stack size
michael@0:         thread_start,           // thread function name (proxy)
michael@0:         winData,                // argument to thread function (proxy args)
michael@0:         CREATE_SUSPENDED,       // create suspended so affinity can be set
michael@0:         &winData->fThreadId);   // returns the thread identifier
michael@0: }
michael@0: 
michael@0: SkThread::~SkThread() {
michael@0:     if (fData != NULL) {
michael@0:         SkThread_WinData* winData = static_cast<SkThread_WinData*>(fData);
michael@0:         // If created thread but start was never called, kill the thread.
michael@0:         if (winData->fHandle != NULL && !winData->fStarted) {
michael@0:             if (SetEvent(winData->fCancelEvent) != 0) {
michael@0:                 if (this->start()) {
michael@0:                     this->join();
michael@0:                 }
michael@0:             } else {
michael@0:                 //kill with prejudice
michael@0:                 TerminateThread(winData->fHandle, -1);
michael@0:             }
michael@0:         }
michael@0:         delete winData;
michael@0:     }
michael@0: }
michael@0: 
michael@0: bool SkThread::start() {
michael@0:     SkThread_WinData* winData = static_cast<SkThread_WinData*>(fData);
michael@0:     if (NULL == winData->fHandle) {
michael@0:         return false;
michael@0:     }
michael@0: 
michael@0:     if (winData->fStarted) {
michael@0:         return false;
michael@0:     }
michael@0:     winData->fStarted = -1 != ResumeThread(winData->fHandle);
michael@0:     return winData->fStarted;
michael@0: }
michael@0: 
michael@0: void SkThread::join() {
michael@0:     SkThread_WinData* winData = static_cast<SkThread_WinData*>(fData);
michael@0:     if (NULL == winData->fHandle || !winData->fStarted) {
michael@0:         return;
michael@0:     }
michael@0: 
michael@0:     WaitForSingleObject(winData->fHandle, INFINITE);
michael@0: }
michael@0: 
michael@0: static unsigned int num_bits_set(DWORD_PTR mask) {
michael@0:     unsigned int count;
michael@0:     for (count = 0; mask; ++count) {
michael@0:         mask &= mask - 1;
michael@0:     }
michael@0:     return count;
michael@0: }
michael@0: 
michael@0: static unsigned int nth_set_bit(unsigned int n, DWORD_PTR mask) {
michael@0:     n %= num_bits_set(mask);
michael@0:     for (unsigned int setBitsSeen = 0, currentBit = 0; true; ++currentBit) {
michael@0:         if (mask & (static_cast<DWORD_PTR>(1) << currentBit)) {
michael@0:             ++setBitsSeen;
michael@0:             if (setBitsSeen > n) {
michael@0:                 return currentBit;
michael@0:             }
michael@0:         }
michael@0:     }
michael@0: }
michael@0: 
michael@0: bool SkThread::setProcessorAffinity(unsigned int processor) {
michael@0:     SkThread_WinData* winData = static_cast<SkThread_WinData*>(fData);
michael@0:     if (NULL == winData->fHandle) {
michael@0:         return false;
michael@0:     }
michael@0: 
michael@0:     DWORD_PTR processAffinityMask;
michael@0:     DWORD_PTR systemAffinityMask;
michael@0:     if (0 == GetProcessAffinityMask(GetCurrentProcess(),
michael@0:                                     &processAffinityMask,
michael@0:                                     &systemAffinityMask)) {
michael@0:         return false;
michael@0:     }
michael@0: 
michael@0:     DWORD_PTR threadAffinityMask = 1 << nth_set_bit(processor, processAffinityMask);
michael@0:     return 0 != SetThreadAffinityMask(winData->fHandle, threadAffinityMask);
michael@0: }