803 lines
25 KiB
C++
803 lines
25 KiB
C++
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#include "LinearMath/btMinMax.h"
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#include "LinearMath/btAlignedObjectArray.h"
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#include "LinearMath/btThreads.h"
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#include "LinearMath/btQuickprof.h"
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#include <stdio.h>
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#include <algorithm>
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#if BT_THREADSAFE
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#include "btThreadSupportInterface.h"
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#if defined( _WIN32 )
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#define WIN32_LEAN_AND_MEAN
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#include <windows.h>
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#endif
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typedef unsigned long long btU64;
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static const int kCacheLineSize = 64;
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void btSpinPause()
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{
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#if defined( _WIN32 )
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YieldProcessor();
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#endif
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}
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struct WorkerThreadStatus
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{
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enum Type
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{
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kInvalid,
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kWaitingForWork,
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kWorking,
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kSleeping,
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};
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};
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ATTRIBUTE_ALIGNED64(class) WorkerThreadDirectives
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{
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static const int kMaxThreadCount = BT_MAX_THREAD_COUNT;
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// directives for all worker threads packed into a single cacheline
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char m_threadDirs[kMaxThreadCount];
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public:
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enum Type
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{
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kInvalid,
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kGoToSleep, // go to sleep
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kStayAwakeButIdle, // wait for not checking job queue
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kScanForJobs, // actively scan job queue for jobs
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};
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WorkerThreadDirectives()
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{
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for ( int i = 0; i < kMaxThreadCount; ++i )
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{
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m_threadDirs[ i ] = 0;
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}
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}
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Type getDirective(int threadId)
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{
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btAssert(threadId < kMaxThreadCount);
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return static_cast<Type>(m_threadDirs[threadId]);
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}
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void setDirectiveByRange(int threadBegin, int threadEnd, Type dir)
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{
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btAssert( threadBegin < threadEnd );
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btAssert( threadEnd <= kMaxThreadCount );
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char dirChar = static_cast<char>(dir);
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for ( int i = threadBegin; i < threadEnd; ++i )
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{
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m_threadDirs[ i ] = dirChar;
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}
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}
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};
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class JobQueue;
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ATTRIBUTE_ALIGNED64(struct) ThreadLocalStorage
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{
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int m_threadId;
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WorkerThreadStatus::Type m_status;
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int m_numJobsFinished;
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btSpinMutex m_mutex;
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btScalar m_sumResult;
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WorkerThreadDirectives * m_directive;
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JobQueue* m_queue;
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btClock* m_clock;
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unsigned int m_cooldownTime;
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};
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struct IJob
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{
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virtual void executeJob(int threadId) = 0;
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};
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class ParallelForJob : public IJob
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{
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const btIParallelForBody* m_body;
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int m_begin;
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int m_end;
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public:
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ParallelForJob( int iBegin, int iEnd, const btIParallelForBody& body )
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{
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m_body = &body;
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m_begin = iBegin;
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m_end = iEnd;
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}
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virtual void executeJob(int threadId) BT_OVERRIDE
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{
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BT_PROFILE( "executeJob" );
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// call the functor body to do the work
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m_body->forLoop( m_begin, m_end );
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}
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};
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class ParallelSumJob : public IJob
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{
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const btIParallelSumBody* m_body;
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ThreadLocalStorage* m_threadLocalStoreArray;
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int m_begin;
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int m_end;
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public:
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ParallelSumJob( int iBegin, int iEnd, const btIParallelSumBody& body, ThreadLocalStorage* tls )
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{
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m_body = &body;
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m_threadLocalStoreArray = tls;
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m_begin = iBegin;
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m_end = iEnd;
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}
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virtual void executeJob( int threadId ) BT_OVERRIDE
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{
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BT_PROFILE( "executeJob" );
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// call the functor body to do the work
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btScalar val = m_body->sumLoop( m_begin, m_end );
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#if BT_PARALLEL_SUM_DETERMINISTISM
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// by truncating bits of the result, we can make the parallelSum deterministic (at the expense of precision)
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const float TRUNC_SCALE = float(1<<19);
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val = floor(val*TRUNC_SCALE+0.5f)/TRUNC_SCALE; // truncate some bits
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#endif
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m_threadLocalStoreArray[threadId].m_sumResult += val;
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}
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};
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ATTRIBUTE_ALIGNED64(class) JobQueue
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{
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btThreadSupportInterface* m_threadSupport;
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btCriticalSection* m_queueLock;
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btSpinMutex m_mutex;
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btAlignedObjectArray<IJob*> m_jobQueue;
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char* m_jobMem;
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int m_jobMemSize;
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bool m_queueIsEmpty;
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int m_tailIndex;
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int m_headIndex;
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int m_allocSize;
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bool m_useSpinMutex;
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btAlignedObjectArray<JobQueue*> m_neighborContexts;
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char m_cachePadding[kCacheLineSize]; // prevent false sharing
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void freeJobMem()
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{
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if ( m_jobMem )
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{
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// free old
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btAlignedFree(m_jobMem);
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m_jobMem = NULL;
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}
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}
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void resizeJobMem(int newSize)
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{
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if (newSize > m_jobMemSize)
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{
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freeJobMem();
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m_jobMem = static_cast<char*>(btAlignedAlloc(newSize, kCacheLineSize));
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m_jobMemSize = newSize;
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}
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}
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public:
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JobQueue()
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{
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m_jobMem = NULL;
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m_jobMemSize = 0;
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m_threadSupport = NULL;
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m_queueLock = NULL;
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m_headIndex = 0;
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m_tailIndex = 0;
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m_useSpinMutex = false;
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}
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~JobQueue()
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{
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exit();
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}
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void exit()
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{
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freeJobMem();
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if (m_queueLock && m_threadSupport)
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{
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m_threadSupport->deleteCriticalSection(m_queueLock);
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m_queueLock = NULL;
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m_threadSupport = 0;
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}
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}
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void init(btThreadSupportInterface* threadSup, btAlignedObjectArray<JobQueue>* contextArray)
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{
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m_threadSupport = threadSup;
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if (threadSup)
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{
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m_queueLock = m_threadSupport->createCriticalSection();
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}
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setupJobStealing(contextArray, contextArray->size());
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}
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void setupJobStealing(btAlignedObjectArray<JobQueue>* contextArray, int numActiveContexts)
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{
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btAlignedObjectArray<JobQueue>& contexts = *contextArray;
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int selfIndex = 0;
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for (int i = 0; i < contexts.size(); ++i)
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{
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if ( this == &contexts[ i ] )
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{
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selfIndex = i;
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break;
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}
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}
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int numNeighbors = btMin(2, contexts.size() - 1);
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int neighborOffsets[ ] = {-1, 1, -2, 2, -3, 3};
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int numOffsets = sizeof(neighborOffsets)/sizeof(neighborOffsets[0]);
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m_neighborContexts.reserve( numNeighbors );
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m_neighborContexts.resizeNoInitialize(0);
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for (int i = 0; i < numOffsets && m_neighborContexts.size() < numNeighbors; i++)
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{
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int neighborIndex = selfIndex + neighborOffsets[i];
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if ( neighborIndex >= 0 && neighborIndex < numActiveContexts)
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{
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m_neighborContexts.push_back( &contexts[ neighborIndex ] );
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}
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}
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}
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bool isQueueEmpty() const {return m_queueIsEmpty;}
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void lockQueue()
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{
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if ( m_useSpinMutex )
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{
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m_mutex.lock();
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}
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else
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{
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m_queueLock->lock();
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}
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}
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void unlockQueue()
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{
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if ( m_useSpinMutex )
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{
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m_mutex.unlock();
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}
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else
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{
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m_queueLock->unlock();
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}
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}
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void clearQueue(int jobCount, int jobSize)
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{
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lockQueue();
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m_headIndex = 0;
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m_tailIndex = 0;
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m_allocSize = 0;
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m_queueIsEmpty = true;
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int jobBufSize = jobSize * jobCount;
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// make sure we have enough memory allocated to store jobs
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if ( jobBufSize > m_jobMemSize )
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{
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resizeJobMem( jobBufSize );
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}
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// make sure job queue is big enough
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if ( jobCount > m_jobQueue.capacity() )
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{
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m_jobQueue.reserve( jobCount );
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}
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unlockQueue();
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m_jobQueue.resizeNoInitialize( 0 );
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}
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void* allocJobMem(int jobSize)
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{
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btAssert(m_jobMemSize >= (m_allocSize + jobSize));
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void* jobMem = &m_jobMem[m_allocSize];
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m_allocSize += jobSize;
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return jobMem;
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}
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void submitJob( IJob* job )
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{
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btAssert( reinterpret_cast<char*>( job ) >= &m_jobMem[ 0 ] && reinterpret_cast<char*>( job ) < &m_jobMem[ 0 ] + m_allocSize );
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m_jobQueue.push_back( job );
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lockQueue();
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m_tailIndex++;
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m_queueIsEmpty = false;
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unlockQueue();
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}
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IJob* consumeJobFromOwnQueue()
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{
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if ( m_queueIsEmpty )
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{
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// lock free path. even if this is taken erroneously it isn't harmful
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return NULL;
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}
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IJob* job = NULL;
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lockQueue();
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if ( !m_queueIsEmpty )
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{
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job = m_jobQueue[ m_headIndex++ ];
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btAssert( reinterpret_cast<char*>( job ) >= &m_jobMem[ 0 ] && reinterpret_cast<char*>( job ) < &m_jobMem[ 0 ] + m_allocSize );
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if ( m_headIndex == m_tailIndex )
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{
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m_queueIsEmpty = true;
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}
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}
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unlockQueue();
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return job;
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}
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IJob* consumeJob()
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{
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if (IJob* job = consumeJobFromOwnQueue())
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{
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return job;
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}
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// own queue is empty, try to steal from neighbor
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for (int i = 0; i < m_neighborContexts.size(); ++i)
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{
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JobQueue* otherContext = m_neighborContexts[ i ];
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if ( IJob* job = otherContext->consumeJobFromOwnQueue() )
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{
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return job;
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}
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}
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return NULL;
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}
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};
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static void WorkerThreadFunc( void* userPtr )
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{
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BT_PROFILE( "WorkerThreadFunc" );
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ThreadLocalStorage* localStorage = (ThreadLocalStorage*) userPtr;
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JobQueue* jobQueue = localStorage->m_queue;
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bool shouldSleep = false;
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int threadId = localStorage->m_threadId;
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while (! shouldSleep)
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{
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// do work
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localStorage->m_mutex.lock();
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while ( IJob* job = jobQueue->consumeJob() )
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{
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localStorage->m_status = WorkerThreadStatus::kWorking;
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job->executeJob( threadId );
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localStorage->m_numJobsFinished++;
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}
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localStorage->m_status = WorkerThreadStatus::kWaitingForWork;
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localStorage->m_mutex.unlock();
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btU64 clockStart = localStorage->m_clock->getTimeMicroseconds();
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// while queue is empty,
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while (jobQueue->isQueueEmpty())
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{
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// todo: spin wait a bit to avoid hammering the empty queue
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btSpinPause();
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if ( localStorage->m_directive->getDirective(threadId) == WorkerThreadDirectives::kGoToSleep )
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{
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shouldSleep = true;
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break;
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}
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// if jobs are incoming,
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if ( localStorage->m_directive->getDirective( threadId ) == WorkerThreadDirectives::kScanForJobs )
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{
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clockStart = localStorage->m_clock->getTimeMicroseconds(); // reset clock
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}
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else
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{
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for ( int i = 0; i < 50; ++i )
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{
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btSpinPause();
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btSpinPause();
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btSpinPause();
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btSpinPause();
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if (localStorage->m_directive->getDirective( threadId ) == WorkerThreadDirectives::kScanForJobs || !jobQueue->isQueueEmpty())
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{
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break;
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}
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}
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// if no jobs incoming and queue has been empty for the cooldown time, sleep
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btU64 timeElapsed = localStorage->m_clock->getTimeMicroseconds() - clockStart;
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if (timeElapsed > localStorage->m_cooldownTime)
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{
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shouldSleep = true;
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break;
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}
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}
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}
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}
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{
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BT_PROFILE("sleep");
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// go sleep
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localStorage->m_mutex.lock();
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localStorage->m_status = WorkerThreadStatus::kSleeping;
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localStorage->m_mutex.unlock();
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}
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}
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class btTaskSchedulerDefault : public btITaskScheduler
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{
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btThreadSupportInterface* m_threadSupport;
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WorkerThreadDirectives* m_workerDirective;
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btAlignedObjectArray<JobQueue> m_jobQueues;
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btAlignedObjectArray<JobQueue*> m_perThreadJobQueues;
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btAlignedObjectArray<ThreadLocalStorage> m_threadLocalStorage;
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btSpinMutex m_antiNestingLock; // prevent nested parallel-for
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btClock m_clock;
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int m_numThreads;
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int m_numWorkerThreads;
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int m_numActiveJobQueues;
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int m_maxNumThreads;
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int m_numJobs;
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static const int kFirstWorkerThreadId = 1;
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public:
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btTaskSchedulerDefault() : btITaskScheduler("ThreadSupport")
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{
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m_threadSupport = NULL;
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m_workerDirective = NULL;
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}
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virtual ~btTaskSchedulerDefault()
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{
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waitForWorkersToSleep();
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for ( int i = 0; i < m_jobQueues.size(); ++i )
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{
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m_jobQueues[i].exit();
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}
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if (m_threadSupport)
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{
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delete m_threadSupport;
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m_threadSupport = NULL;
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}
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if (m_workerDirective)
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{
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btAlignedFree(m_workerDirective);
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m_workerDirective = NULL;
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}
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}
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void init()
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{
|
||
|
btThreadSupportInterface::ConstructionInfo constructionInfo( "TaskScheduler", WorkerThreadFunc );
|
||
|
m_threadSupport = btThreadSupportInterface::create( constructionInfo );
|
||
|
m_workerDirective = static_cast<WorkerThreadDirectives*>(btAlignedAlloc(sizeof(*m_workerDirective), 64));
|
||
|
|
||
|
m_numWorkerThreads = m_threadSupport->getNumWorkerThreads();
|
||
|
m_maxNumThreads = m_threadSupport->getNumWorkerThreads() + 1;
|
||
|
m_numThreads = m_maxNumThreads;
|
||
|
// ideal to have one job queue for each physical processor (except for the main thread which needs no queue)
|
||
|
int numThreadsPerQueue = m_threadSupport->getLogicalToPhysicalCoreRatio();
|
||
|
int numJobQueues = (numThreadsPerQueue == 1) ? (m_maxNumThreads-1) : (m_maxNumThreads / numThreadsPerQueue);
|
||
|
m_jobQueues.resize(numJobQueues);
|
||
|
m_numActiveJobQueues = numJobQueues;
|
||
|
for ( int i = 0; i < m_jobQueues.size(); ++i )
|
||
|
{
|
||
|
m_jobQueues[i].init( m_threadSupport, &m_jobQueues );
|
||
|
}
|
||
|
m_perThreadJobQueues.resize(m_numThreads);
|
||
|
for ( int i = 0; i < m_numThreads; i++ )
|
||
|
{
|
||
|
JobQueue* jq = NULL;
|
||
|
// only worker threads get a job queue
|
||
|
if (i > 0)
|
||
|
{
|
||
|
if (numThreadsPerQueue == 1)
|
||
|
{
|
||
|
// one queue per worker thread
|
||
|
jq = &m_jobQueues[ i - kFirstWorkerThreadId ];
|
||
|
}
|
||
|
else
|
||
|
{
|
||
|
// 2 threads share each queue
|
||
|
jq = &m_jobQueues[ i / numThreadsPerQueue ];
|
||
|
}
|
||
|
}
|
||
|
m_perThreadJobQueues[i] = jq;
|
||
|
}
|
||
|
m_threadLocalStorage.resize(m_numThreads);
|
||
|
for ( int i = 0; i < m_numThreads; i++ )
|
||
|
{
|
||
|
ThreadLocalStorage& storage = m_threadLocalStorage[i];
|
||
|
storage.m_threadId = i;
|
||
|
storage.m_directive = m_workerDirective;
|
||
|
storage.m_status = WorkerThreadStatus::kSleeping;
|
||
|
storage.m_cooldownTime = 100; // 100 microseconds, threads go to sleep after this long if they have nothing to do
|
||
|
storage.m_clock = &m_clock;
|
||
|
storage.m_queue = m_perThreadJobQueues[i];
|
||
|
}
|
||
|
setWorkerDirectives( WorkerThreadDirectives::kGoToSleep ); // no work for them yet
|
||
|
setNumThreads( m_threadSupport->getCacheFriendlyNumThreads() );
|
||
|
}
|
||
|
|
||
|
void setWorkerDirectives(WorkerThreadDirectives::Type dir)
|
||
|
{
|
||
|
m_workerDirective->setDirectiveByRange(kFirstWorkerThreadId, m_numThreads, dir);
|
||
|
}
|
||
|
|
||
|
virtual int getMaxNumThreads() const BT_OVERRIDE
|
||
|
{
|
||
|
return m_maxNumThreads;
|
||
|
}
|
||
|
|
||
|
virtual int getNumThreads() const BT_OVERRIDE
|
||
|
{
|
||
|
return m_numThreads;
|
||
|
}
|
||
|
|
||
|
virtual void setNumThreads( int numThreads ) BT_OVERRIDE
|
||
|
{
|
||
|
m_numThreads = btMax( btMin(numThreads, int(m_maxNumThreads)), 1 );
|
||
|
m_numWorkerThreads = m_numThreads - 1;
|
||
|
m_numActiveJobQueues = 0;
|
||
|
// if there is at least 1 worker,
|
||
|
if ( m_numWorkerThreads > 0 )
|
||
|
{
|
||
|
// re-setup job stealing between queues to avoid attempting to steal from an inactive job queue
|
||
|
JobQueue* lastActiveContext = m_perThreadJobQueues[ m_numThreads - 1 ];
|
||
|
int iLastActiveContext = lastActiveContext - &m_jobQueues[0];
|
||
|
m_numActiveJobQueues = iLastActiveContext + 1;
|
||
|
for ( int i = 0; i < m_jobQueues.size(); ++i )
|
||
|
{
|
||
|
m_jobQueues[ i ].setupJobStealing( &m_jobQueues, m_numActiveJobQueues );
|
||
|
}
|
||
|
}
|
||
|
m_workerDirective->setDirectiveByRange(m_numThreads, BT_MAX_THREAD_COUNT, WorkerThreadDirectives::kGoToSleep);
|
||
|
}
|
||
|
|
||
|
void waitJobs()
|
||
|
{
|
||
|
BT_PROFILE( "waitJobs" );
|
||
|
// have the main thread work until the job queues are empty
|
||
|
int numMainThreadJobsFinished = 0;
|
||
|
for ( int i = 0; i < m_numActiveJobQueues; ++i )
|
||
|
{
|
||
|
while ( IJob* job = m_jobQueues[i].consumeJob() )
|
||
|
{
|
||
|
job->executeJob( 0 );
|
||
|
numMainThreadJobsFinished++;
|
||
|
}
|
||
|
}
|
||
|
|
||
|
// done with jobs for now, tell workers to rest (but not sleep)
|
||
|
setWorkerDirectives( WorkerThreadDirectives::kStayAwakeButIdle );
|
||
|
|
||
|
btU64 clockStart = m_clock.getTimeMicroseconds();
|
||
|
// wait for workers to finish any jobs in progress
|
||
|
while ( true )
|
||
|
{
|
||
|
int numWorkerJobsFinished = 0;
|
||
|
for ( int iThread = kFirstWorkerThreadId; iThread < m_numThreads; ++iThread )
|
||
|
{
|
||
|
ThreadLocalStorage* storage = &m_threadLocalStorage[iThread];
|
||
|
storage->m_mutex.lock();
|
||
|
numWorkerJobsFinished += storage->m_numJobsFinished;
|
||
|
storage->m_mutex.unlock();
|
||
|
}
|
||
|
if (numWorkerJobsFinished + numMainThreadJobsFinished == m_numJobs)
|
||
|
{
|
||
|
break;
|
||
|
}
|
||
|
btU64 timeElapsed = m_clock.getTimeMicroseconds() - clockStart;
|
||
|
btAssert(timeElapsed < 1000);
|
||
|
if (timeElapsed > 100000)
|
||
|
{
|
||
|
break;
|
||
|
}
|
||
|
btSpinPause();
|
||
|
}
|
||
|
}
|
||
|
|
||
|
void wakeWorkers(int numWorkersToWake)
|
||
|
{
|
||
|
BT_PROFILE( "wakeWorkers" );
|
||
|
btAssert( m_workerDirective->getDirective(1) == WorkerThreadDirectives::kScanForJobs );
|
||
|
int numDesiredWorkers = btMin(numWorkersToWake, m_numWorkerThreads);
|
||
|
int numActiveWorkers = 0;
|
||
|
for ( int iWorker = 0; iWorker < m_numWorkerThreads; ++iWorker )
|
||
|
{
|
||
|
// note this count of active workers is not necessarily totally reliable, because a worker thread could be
|
||
|
// just about to put itself to sleep. So we may on occasion fail to wake up all the workers. It should be rare.
|
||
|
ThreadLocalStorage& storage = m_threadLocalStorage[ kFirstWorkerThreadId + iWorker ];
|
||
|
if (storage.m_status != WorkerThreadStatus::kSleeping)
|
||
|
{
|
||
|
numActiveWorkers++;
|
||
|
}
|
||
|
}
|
||
|
for ( int iWorker = 0; iWorker < m_numWorkerThreads && numActiveWorkers < numDesiredWorkers; ++iWorker )
|
||
|
{
|
||
|
ThreadLocalStorage& storage = m_threadLocalStorage[ kFirstWorkerThreadId + iWorker ];
|
||
|
if (storage.m_status == WorkerThreadStatus::kSleeping)
|
||
|
{
|
||
|
m_threadSupport->runTask( iWorker, &storage );
|
||
|
numActiveWorkers++;
|
||
|
}
|
||
|
}
|
||
|
}
|
||
|
|
||
|
void waitForWorkersToSleep()
|
||
|
{
|
||
|
BT_PROFILE( "waitForWorkersToSleep" );
|
||
|
setWorkerDirectives( WorkerThreadDirectives::kGoToSleep );
|
||
|
m_threadSupport->waitForAllTasks();
|
||
|
for ( int i = kFirstWorkerThreadId; i < m_numThreads; i++ )
|
||
|
{
|
||
|
ThreadLocalStorage& storage = m_threadLocalStorage[i];
|
||
|
btAssert( storage.m_status == WorkerThreadStatus::kSleeping );
|
||
|
}
|
||
|
}
|
||
|
|
||
|
virtual void sleepWorkerThreadsHint() BT_OVERRIDE
|
||
|
{
|
||
|
BT_PROFILE( "sleepWorkerThreadsHint" );
|
||
|
// hint the task scheduler that we may not be using these threads for a little while
|
||
|
setWorkerDirectives( WorkerThreadDirectives::kGoToSleep );
|
||
|
}
|
||
|
|
||
|
void prepareWorkerThreads()
|
||
|
{
|
||
|
for ( int i = kFirstWorkerThreadId; i < m_numThreads; ++i )
|
||
|
{
|
||
|
ThreadLocalStorage& storage = m_threadLocalStorage[i];
|
||
|
storage.m_mutex.lock();
|
||
|
storage.m_numJobsFinished = 0;
|
||
|
storage.m_mutex.unlock();
|
||
|
}
|
||
|
setWorkerDirectives( WorkerThreadDirectives::kScanForJobs );
|
||
|
}
|
||
|
|
||
|
virtual void parallelFor( int iBegin, int iEnd, int grainSize, const btIParallelForBody& body ) BT_OVERRIDE
|
||
|
{
|
||
|
BT_PROFILE( "parallelFor_ThreadSupport" );
|
||
|
btAssert( iEnd >= iBegin );
|
||
|
btAssert( grainSize >= 1 );
|
||
|
int iterationCount = iEnd - iBegin;
|
||
|
if ( iterationCount > grainSize && m_numWorkerThreads > 0 && m_antiNestingLock.tryLock() )
|
||
|
{
|
||
|
typedef ParallelForJob JobType;
|
||
|
int jobCount = ( iterationCount + grainSize - 1 ) / grainSize;
|
||
|
m_numJobs = jobCount;
|
||
|
btAssert( jobCount >= 2 ); // need more than one job for multithreading
|
||
|
int jobSize = sizeof( JobType );
|
||
|
|
||
|
for (int i = 0; i < m_numActiveJobQueues; ++i)
|
||
|
{
|
||
|
m_jobQueues[i].clearQueue( jobCount, jobSize );
|
||
|
}
|
||
|
// prepare worker threads for incoming work
|
||
|
prepareWorkerThreads();
|
||
|
// submit all of the jobs
|
||
|
int iJob = 0;
|
||
|
int iThread = kFirstWorkerThreadId; // first worker thread
|
||
|
for ( int i = iBegin; i < iEnd; i += grainSize )
|
||
|
{
|
||
|
btAssert( iJob < jobCount );
|
||
|
int iE = btMin( i + grainSize, iEnd );
|
||
|
JobQueue* jq = m_perThreadJobQueues[ iThread ];
|
||
|
btAssert(jq);
|
||
|
btAssert((jq - &m_jobQueues[0]) < m_numActiveJobQueues);
|
||
|
void* jobMem = jq->allocJobMem(jobSize);
|
||
|
JobType* job = new ( jobMem ) ParallelForJob( i, iE, body ); // placement new
|
||
|
jq->submitJob( job );
|
||
|
iJob++;
|
||
|
iThread++;
|
||
|
if ( iThread >= m_numThreads )
|
||
|
{
|
||
|
iThread = kFirstWorkerThreadId; // first worker thread
|
||
|
}
|
||
|
}
|
||
|
wakeWorkers( jobCount - 1 );
|
||
|
|
||
|
// put the main thread to work on emptying the job queue and then wait for all workers to finish
|
||
|
waitJobs();
|
||
|
m_antiNestingLock.unlock();
|
||
|
}
|
||
|
else
|
||
|
{
|
||
|
BT_PROFILE( "parallelFor_mainThread" );
|
||
|
// just run on main thread
|
||
|
body.forLoop( iBegin, iEnd );
|
||
|
}
|
||
|
}
|
||
|
virtual btScalar parallelSum( int iBegin, int iEnd, int grainSize, const btIParallelSumBody& body ) BT_OVERRIDE
|
||
|
{
|
||
|
BT_PROFILE( "parallelSum_ThreadSupport" );
|
||
|
btAssert( iEnd >= iBegin );
|
||
|
btAssert( grainSize >= 1 );
|
||
|
int iterationCount = iEnd - iBegin;
|
||
|
if ( iterationCount > grainSize && m_numWorkerThreads > 0 && m_antiNestingLock.tryLock() )
|
||
|
{
|
||
|
typedef ParallelSumJob JobType;
|
||
|
int jobCount = ( iterationCount + grainSize - 1 ) / grainSize;
|
||
|
m_numJobs = jobCount;
|
||
|
btAssert( jobCount >= 2 ); // need more than one job for multithreading
|
||
|
int jobSize = sizeof( JobType );
|
||
|
for (int i = 0; i < m_numActiveJobQueues; ++i)
|
||
|
{
|
||
|
m_jobQueues[i].clearQueue( jobCount, jobSize );
|
||
|
}
|
||
|
|
||
|
// initialize summation
|
||
|
for ( int iThread = 0; iThread < m_numThreads; ++iThread )
|
||
|
{
|
||
|
m_threadLocalStorage[iThread].m_sumResult = btScalar(0);
|
||
|
}
|
||
|
|
||
|
// prepare worker threads for incoming work
|
||
|
prepareWorkerThreads();
|
||
|
// submit all of the jobs
|
||
|
int iJob = 0;
|
||
|
int iThread = kFirstWorkerThreadId; // first worker thread
|
||
|
for ( int i = iBegin; i < iEnd; i += grainSize )
|
||
|
{
|
||
|
btAssert( iJob < jobCount );
|
||
|
int iE = btMin( i + grainSize, iEnd );
|
||
|
JobQueue* jq = m_perThreadJobQueues[ iThread ];
|
||
|
btAssert(jq);
|
||
|
btAssert((jq - &m_jobQueues[0]) < m_numActiveJobQueues);
|
||
|
void* jobMem = jq->allocJobMem(jobSize);
|
||
|
JobType* job = new ( jobMem ) ParallelSumJob( i, iE, body, &m_threadLocalStorage[0] ); // placement new
|
||
|
jq->submitJob( job );
|
||
|
iJob++;
|
||
|
iThread++;
|
||
|
if ( iThread >= m_numThreads )
|
||
|
{
|
||
|
iThread = kFirstWorkerThreadId; // first worker thread
|
||
|
}
|
||
|
}
|
||
|
wakeWorkers( jobCount - 1 );
|
||
|
|
||
|
// put the main thread to work on emptying the job queue and then wait for all workers to finish
|
||
|
waitJobs();
|
||
|
|
||
|
// add up all the thread sums
|
||
|
btScalar sum = btScalar(0);
|
||
|
for ( int iThread = 0; iThread < m_numThreads; ++iThread )
|
||
|
{
|
||
|
sum += m_threadLocalStorage[ iThread ].m_sumResult;
|
||
|
}
|
||
|
m_antiNestingLock.unlock();
|
||
|
return sum;
|
||
|
}
|
||
|
else
|
||
|
{
|
||
|
BT_PROFILE( "parallelSum_mainThread" );
|
||
|
// just run on main thread
|
||
|
return body.sumLoop( iBegin, iEnd );
|
||
|
}
|
||
|
}
|
||
|
};
|
||
|
|
||
|
|
||
|
|
||
|
btITaskScheduler* btCreateDefaultTaskScheduler()
|
||
|
{
|
||
|
btTaskSchedulerDefault* ts = new btTaskSchedulerDefault();
|
||
|
ts->init();
|
||
|
return ts;
|
||
|
}
|
||
|
|
||
|
#else // #if BT_THREADSAFE
|
||
|
|
||
|
btITaskScheduler* btCreateDefaultTaskScheduler()
|
||
|
{
|
||
|
return NULL;
|
||
|
}
|
||
|
|
||
|
#endif // #else // #if BT_THREADSAFE
|