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ChunkGenerator: rewritten thread-locking using the new RAII CSLock class

git-svn-id: http://mc-server.googlecode.com/svn/trunk@186 0a769ca7-a7f5-676a-18bf-c427514a06d6
This commit is contained in:
madmaxoft@gmail.com 2012-01-29 14:29:26 +00:00
parent f08295ab25
commit e2ad02f50a
6 changed files with 212 additions and 83 deletions

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@ -20,6 +20,7 @@
OutputDirectory="Debug"
IntermediateDirectory="Debug"
ConfigurationType="1"
CharacterSet="2"
>
<Tool
Name="VCPreBuildEventTool"

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@ -15,116 +15,123 @@
typedef std::pair<int, int> ChunkCoord;
typedef std::list< ChunkCoord > ChunkCoordList;
#define MAX_SEMAPHORES 1000
/// If the generation queue size exceeds this number, a warning will be output
#define QUEUE_WARNING_LIMIT 1000
struct cChunkGenerator::sChunkGeneratorState
{
sChunkGeneratorState()
: pCriticalSection( 0 )
, pSemaphore( 0 )
cCriticalSection m_CriticalSection; // For protecting the variables in this struct
ChunkCoordList GenerateQueue;
ChunkCoord CurrentlyGeneratingCoords;
cChunk* pCurrentlyGenerating;
bool bCurrentlyGenerating;
cSemaphore m_Semaphore;
cThread * pThread;
bool bStop;
sChunkGeneratorState(void)
: m_Semaphore(1, 0)
, pThread( 0 )
, bStop( false )
, bCurrentlyGenerating( false )
, pCurrentlyGenerating( false )
, pChunkCriticalSection( 0 )
{}
ChunkCoordList GenerateQueue; // Protected by pCriticalSection
ChunkCoord CurrentlyGeneratingCoords; // Protected by pCriticalSection
cChunk* pCurrentlyGenerating; // Protected by pCriticalSection
bool bCurrentlyGenerating; // Protected by pCriticalSection
cCriticalSection* pCriticalSection;
cSemaphore* pSemaphore;
cThread* pThread;
cCriticalSection* pChunkCriticalSection;// Specially for protecting the actual chunk that is currently being generated, and not just the variables in this struct
bool bStop;
};
cChunkGenerator::cChunkGenerator( cChunkMap* a_pChunkMap )
: m_pState( new sChunkGeneratorState )
, m_pChunkMap( a_pChunkMap )
{
m_pState->pCriticalSection = new cCriticalSection();
m_pState->pSemaphore = new cSemaphore( MAX_SEMAPHORES, 0 );
m_pState->pChunkCriticalSection = new cCriticalSection();
m_pState->pThread = new cThread( GenerateThread, this, "cChunkGenerator::GenerateThread" );
m_pState->pThread->Start( true );
}
cChunkGenerator::~cChunkGenerator()
{
m_pState->bStop = true;
m_pState->pSemaphore->Signal(); // Signal so thread can continue and exit
m_pState->m_Semaphore.Signal(); // Signal so thread can continue and exit
delete m_pState->pThread;
delete m_pState->pSemaphore;
delete m_pState->pCriticalSection;
delete m_pState->pChunkCriticalSection;
delete m_pState; m_pState = 0;
delete m_pState;
}
void cChunkGenerator::GenerateChunk( int a_X, int a_Z )
{
m_pState->pCriticalSection->Lock();
cCSLock Lock(&m_pState->m_CriticalSection);
if( m_pState->bCurrentlyGenerating )
if (m_pState->bCurrentlyGenerating)
{
if( m_pState->CurrentlyGeneratingCoords.first == a_X && m_pState->CurrentlyGeneratingCoords.second == a_Z )
if ((m_pState->CurrentlyGeneratingCoords.first == a_X) && (m_pState->CurrentlyGeneratingCoords.second == a_Z))
{
m_pState->pCriticalSection->Unlock();
return; // Already generating this chunk, so ignore
}
}
int SizeBefore = m_pState->GenerateQueue.size();
m_pState->GenerateQueue.remove( ChunkCoord(a_X, a_Z) );
if( m_pState->GenerateQueue.size() >= MAX_SEMAPHORES )
if (m_pState->GenerateQueue.size() >= QUEUE_WARNING_LIMIT)
{
LOGWARN("WARNING: Can't add chunk (%i, %i) to generation queue: Queue is too big! (%i)", a_X, a_Z, m_pState->GenerateQueue.size() );
m_pState->pCriticalSection->Unlock();
return;
LOGWARN("WARNING: Adding chunk (%i, %i) to generation queue; Queue is too big! (%i)", a_X, a_Z, m_pState->GenerateQueue.size() );
}
m_pState->GenerateQueue.push_back( ChunkCoord(a_X, a_Z) );
int SizeAfter = m_pState->GenerateQueue.size();
m_pState->pCriticalSection->Unlock();
if( SizeBefore < SizeAfter )
m_pState->pSemaphore->Signal();
Lock.Unlock();
m_pState->m_Semaphore.Signal();
}
void cChunkGenerator::GenerateThread( void* a_Params )
{
// Cache some values for easy access (they are all references/pointers)
cChunkGenerator* self = (cChunkGenerator*)a_Params;
sChunkGeneratorState* m_pState = self->m_pState;
ChunkCoordList& GenerateQueue = m_pState->GenerateQueue;
cChunkMap& ChunkMap = *self->m_pChunkMap;
cCriticalSection& CriticalSection = *m_pState->pCriticalSection;
cSemaphore& Semaphore = *m_pState->pSemaphore;
cChunkGenerator * self = (cChunkGenerator*)a_Params;
sChunkGeneratorState * m_pState = self->m_pState;
ChunkCoordList & GenerateQueue = m_pState->GenerateQueue;
cChunkMap & ChunkMap = *self->m_pChunkMap;
cCriticalSection * CriticalSection = &m_pState->m_CriticalSection;
cSemaphore & Semaphore = m_pState->m_Semaphore;
while( !m_pState->bStop )
while (!m_pState->bStop)
{
Semaphore.Wait();
if( m_pState->bStop ) break;
CriticalSection.Lock();
if( GenerateQueue.size() == 0 )
cCSLock Lock(CriticalSection);
if (GenerateQueue.size() == 0)
{
if( !m_pState->bStop ) LOGERROR("ERROR: Semaphore was signaled while GenerateQueue.size == 0");
CriticalSection.Unlock();
continue;
cCSUnlock Unlock(Lock);
Semaphore.Wait();
}
if (m_pState->bStop) break;
ChunkCoord coord = *GenerateQueue.begin(); // Get next coord from queue
GenerateQueue.erase( GenerateQueue.begin() ); // Remove coordinate from queue
m_pState->bCurrentlyGenerating = true;
m_pState->CurrentlyGeneratingCoords = coord;
CriticalSection.Unlock(); // Unlock ASAP
Lock.Unlock(); // Unlock ASAP
ChunkMap.GetWorld()->LockChunks();
if( ChunkMap.GetChunk( coord.first, 0, coord.second ) ) // Make sure it has not been loaded in the meantime. Don't want to generate the same chunk twice
@ -137,36 +144,23 @@ void cChunkGenerator::GenerateThread( void* a_Params )
LOGINFO("cChunkGenerator generating chunk %i %i", coord.first, coord.second );
cChunk* Chunk = new cChunk( coord.first, 0, coord.second, ChunkMap.GetWorld() );
CriticalSection.Lock();
Lock.Lock();
m_pState->pCurrentlyGenerating = Chunk;
CriticalSection.Unlock();
Lock.Unlock();
self->Lock(); // Protect the actual chunk
Chunk->Initialize(); // Generate the chunk
self->Unlock();
ChunkMap.GetWorld()->LockChunks();
ChunkMap.AddChunk( Chunk );
ChunkMap.GetWorld()->UnlockChunks();
CriticalSection.Lock();
Lock.Lock();
m_pState->bCurrentlyGenerating = false;
m_pState->pCurrentlyGenerating = 0;
CriticalSection.Unlock();
}
Lock.Unlock();
} // while (!bStop)
}
cChunk* cChunkGenerator::GetCurrentlyGenerating()
{
return m_pState->pCurrentlyGenerating;
}
void cChunkGenerator::Lock()
{
m_pState->pChunkCriticalSection->Lock();
}
void cChunkGenerator::Unlock()
{
m_pState->pChunkCriticalSection->Unlock();
}

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@ -10,9 +10,6 @@ public:
void GenerateChunk( int a_X, int a_Z );
cChunk* GetCurrentlyGenerating(); // WARNING - Be sure to Lock() before calling, and Unlock() after done with the chunk!
void Lock();
void Unlock();
private:
static void GenerateThread( void* a_Params );

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@ -396,14 +396,15 @@ cChunk* cChunkMap::GetChunk( int a_X, int a_Y, int a_Z )
delete [] Data->m_Compressed; Data->m_Compressed = 0; Data->m_CompressedSize = 0;
return Chunk;
}
}
}
return 0;
}
void cChunkMap::Tick( float a_Dt )
{
/* // OLD

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@ -1,5 +1,6 @@
#include "cCriticalSection.h"
#include "cMCLogger.h"
#include <assert.h>
#ifdef _WIN32
#include <Windows.h>
@ -7,6 +8,13 @@
#include <pthread.h>
#endif
///////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
// cCriticalSection:
cCriticalSection::cCriticalSection()
{
#ifdef _WIN32
@ -25,6 +33,10 @@ cCriticalSection::cCriticalSection()
#endif
}
cCriticalSection::~cCriticalSection()
{
#ifdef _WIN32
@ -41,6 +53,10 @@ cCriticalSection::~cCriticalSection()
#endif
}
void cCriticalSection::Lock()
{
#ifdef _WIN32
@ -50,6 +66,10 @@ void cCriticalSection::Lock()
#endif
}
void cCriticalSection::Unlock()
{
#ifdef _WIN32
@ -58,3 +78,80 @@ void cCriticalSection::Unlock()
pthread_mutex_unlock( (pthread_mutex_t*)m_CriticalSectionPtr );
#endif
}
///////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
// cCSLock
cCSLock::cCSLock(cCriticalSection * a_CS) :
m_CS(a_CS),
m_IsLocked(false)
{
Lock();
}
cCSLock::~cCSLock()
{
Unlock();
}
void cCSLock::Lock(void)
{
#ifdef _DEBUG
assert(!m_IsLocked);
m_IsLocked = true;
#endif // _DEBUG
m_CS->Lock();
}
void cCSLock::Unlock(void)
{
#ifdef _DEBUG
assert(m_IsLocked);
m_IsLocked = false;
#endif // _DEBUG
m_CS->Unlock();
}
///////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
// cCSUnlock:
cCSUnlock::cCSUnlock(cCSLock & a_Lock) :
m_Lock(a_Lock)
{
m_Lock.Unlock();
}
cCSUnlock::~cCSUnlock()
{
m_Lock.Lock();
}

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@ -13,4 +13,43 @@ private:
#ifndef _WIN32
void* m_Attributes;
#endif
};
};
/// RAII for cCriticalSection - locks the CS on creation, unlocks on destruction
class cCSLock
{
cCriticalSection * m_CS;
#ifdef _DEBUG
// Unlike a cCriticalSection, this object should be used from a single thread, therefore access to m_IsLocked is not threadsafe
bool m_IsLocked;
#endif // _DEBUG
public:
cCSLock(cCriticalSection * a_CS);
~cCSLock();
// Temporarily unlock or re-lock:
void Lock(void);
void Unlock(void);
} ;
/// Temporary RAII unlock for a cCSLock. Useful for unlock-wait-relock scenarios
class cCSUnlock
{
cCSLock & m_Lock;
public:
cCSUnlock(cCSLock & a_Lock);
~cCSUnlock();
} ;