Work on volume memory management.

This commit is contained in:
David Williams 2009-04-10 08:56:37 +00:00
parent 19ed8246ff
commit df68b1fe7a
5 changed files with 53 additions and 40 deletions

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@ -66,6 +66,8 @@ int main(int argc, char *argv[])
createCubeInVolume(volData, Vector3DUint16(midPos+1, minPos, midPos+1), Vector3DUint16(maxPos, midPos-1, maxPos), 0);
createCubeInVolume(volData, Vector3DUint16(minPos, midPos+1, midPos+1), Vector3DUint16(midPos-1, maxPos, maxPos), 0);
volData.idle(0);
QApplication app(argc, argv);
OpenGLWidget openGLWidget(0);

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@ -34,7 +34,6 @@ namespace PolyVox
{
public:
POLYVOX_SHARED_PTR< BlockData<VoxelType> > m_pBlockData;
bool m_bIsPotentiallySharable;
};
}

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@ -152,14 +152,12 @@ namespace PolyVox
template <typename VoxelType>
bool BlockData<VoxelType>::isHomogeneous(void)
{
VoxelType currentVoxel = m_tData;
VoxelType firstVal = *currentVoxel;
const VoxelType tFirstVoxel = m_tData[0];
const uint32_t uNoOfVoxels = m_uSideLength * m_uSideLength * m_uSideLength;
uint32_t uNoOfVoxels = m_uSideLength * m_uSideLength * m_uSideLength;
for(uint32_t ct = 1; ct < uNoOfVoxels; ++ct)
{
++currentVoxel;
if(*currentVoxel != firstVal)
if(m_tData[ct] != tFirstVoxel)
{
return false;
}

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@ -29,6 +29,8 @@ Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
#include "PolyVoxImpl/CPlusPlusZeroXSupport.h"
#include <map>
#include <vector>
#pragma endregion
namespace PolyVox
@ -60,8 +62,15 @@ namespace PolyVox
private:
POLYVOX_SHARED_PTR< BlockData<VoxelType> > getHomogenousBlockData(VoxelType tHomogenousValue) const;
Block<VoxelType>* m_pBlocks;
static std::map<VoxelType, POLYVOX_WEAK_PTR< BlockData<VoxelType> > > m_pHomogenousBlockData;
std::vector< Block<VoxelType> > m_pBlocks;
std::vector<bool> m_vecBlockIsPotentiallyHomogenous;
//Note: We were once storing weak_ptr's in this map, so that the blocks would be deleted once they
//were not being referenced by anyone else. However, this made it difficult to know when a block was
//shared. A call to shared_ptr::unique() from within setVoxel was not sufficient as weak_ptr's did
//not contribute to the reference count. Instead we store shared_ptr's here, and check if they
//are used by anyone else (i.e are non-unique) when we tidy the volume.
static std::map<VoxelType, POLYVOX_SHARED_PTR< BlockData<VoxelType> > > m_pHomogenousBlockData;
uint32_t m_uNoOfBlocksInVolume;
uint16_t m_uSideLengthInBlocks;
@ -74,7 +83,7 @@ namespace PolyVox
};
//Required for the static member
template <class VoxelType> std::map<VoxelType, POLYVOX_WEAK_PTR< BlockData<VoxelType> > > Volume<VoxelType>::m_pHomogenousBlockData;
template <class VoxelType> std::map<VoxelType, POLYVOX_SHARED_PTR< BlockData<VoxelType> > > Volume<VoxelType>::m_pHomogenousBlockData;
//Some handy typedefs

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@ -28,6 +28,7 @@ Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
#include <cassert>
#include <cstring> //For memcpy
#include <list>
#include <stdexcept> //For invalid_argument
#pragma endregion
@ -72,11 +73,12 @@ namespace PolyVox
m_uNoOfBlocksInVolume = m_uSideLengthInBlocks * m_uSideLengthInBlocks * m_uSideLengthInBlocks;
//Create the blocks
m_pBlocks = new Block<VoxelType>[m_uNoOfBlocksInVolume];
m_pBlocks.resize(m_uNoOfBlocksInVolume);
m_vecBlockIsPotentiallyHomogenous.resize(m_uNoOfBlocksInVolume);
for(uint32_t i = 0; i < m_uNoOfBlocksInVolume; ++i)
{
m_pBlocks[i].m_pBlockData = getHomogenousBlockData(0);
m_pBlocks[i].m_bIsPotentiallySharable = false;
m_vecBlockIsPotentiallyHomogenous[i] = false;
}
}
@ -89,7 +91,6 @@ namespace PolyVox
template <typename VoxelType>
Volume<VoxelType>::~Volume()
{
delete[] m_pBlocks;
}
#pragma endregion
@ -162,12 +163,12 @@ namespace PolyVox
const uint16_t yOffset = uYPos - (blockY << m_uBlockSideLengthPower);
const uint16_t zOffset = uZPos - (blockZ << m_uBlockSideLengthPower);
Block<VoxelType>& block = m_pBlocks
[
blockX +
blockY * m_uSideLengthInBlocks +
blockZ * m_uSideLengthInBlocks * m_uSideLengthInBlocks
];
uint32_t uBlockIndex =
blockX +
blockY * m_uSideLengthInBlocks +
blockZ * m_uSideLengthInBlocks * m_uSideLengthInBlocks;
Block<VoxelType>& block = m_pBlocks[uBlockIndex];
//It's quite possible that the user might attempt to set a voxel to it's current value.
//We test for this case firstly because it could help performance, but more importantly
@ -177,15 +178,15 @@ namespace PolyVox
if(block.m_pBlockData.unique())
{
block.m_pBlockData->setVoxelAt(xOffset,yOffset,zOffset, tValue);
//There is a chance that setting this voxel makes the block homogenous and therefore shareable. But checking
//this will take some time, so for now just set a flag.
block.m_bIsPotentiallySharable = true;
//There is a chance that setting this voxel makes the block homogenous and therefore shareable.
//But checking this will take some time, so for now just set a flag.
m_vecBlockIsPotentiallyHomogenous[uBlockIndex] = true;
}
else
{
POLYVOX_SHARED_PTR< BlockData<VoxelType> > pNewBlockData(new BlockData<VoxelType>(*(block.m_pBlockData)));
block.m_pBlockData = pNewBlockData;
block.m_bIsPotentiallySharable = false;
m_vecBlockIsPotentiallyHomogenous[uBlockIndex] = false;
block.m_pBlockData->setVoxelAt(xOffset,yOffset,zOffset, tValue);
}
}
@ -202,32 +203,36 @@ namespace PolyVox
template <typename VoxelType>
void Volume<VoxelType>::idle(uint32_t uAmount)
{
//This function performs two roles. Firstly, it examines all of the blocks which are marked as
//'potentially sharable' to determine whether they really are sharable or not. For those which
//are sharable, it adjusts the pointer and deletes tho old data. Secondly, it determines which
//homogeneous regions are not actually being used (by thier reference count) and frees them.
for(uint32_t i = 0; i < m_uNoOfBlocksInVolume; ++i)
{
Block<VoxelType> block = m_pBlocks[i];
if(block.m_bIsPotentiallySharable)
if(m_vecBlockIsPotentiallyHomogenous[i])
{
bool isSharable = block.m_pBlockData->isHomogeneous();
if(isSharable)
if(m_pBlocks[i].m_pBlockData->isHomogeneous())
{
VoxelType homogeneousValue = block.m_pBlockData->getVoxelAt(0,0,0);
delete block.m_pBlockData;
VoxelType homogeneousValue = m_pBlocks[i].m_pBlockData->getVoxelAt(0,0,0);
block.m_pBlockData = getHomogenousBlockData(homogeneousValue);
m_pBlocks[i].m_pBlockData = getHomogenousBlockData(homogeneousValue);
}
//Either way, we have now determined whether the block was sharable. So it's not *potentially* sharable.
block.m_bIsPotentiallySharable = false;
m_vecBlockIsPotentiallyHomogenous[i] = false;
}
}
//Note - this second step should probably happen immediatly, rather than in this function.
//Use of a shared pointer system would allow this.
//FIXME - Better way to do this? Maybe using for_each()?
std::list< std::map<VoxelType, POLYVOX_SHARED_PTR< BlockData<VoxelType> > >::iterator > itersToDelete;
for(std::map<VoxelType, POLYVOX_SHARED_PTR< BlockData<VoxelType> > >::iterator iter = m_pHomogenousBlockData.begin(); iter != m_pHomogenousBlockData.end(); ++iter)
{
if(iter->second.unique())
{
itersToDelete.push_back(iter);
}
}
for(std::list< std::map<VoxelType, POLYVOX_SHARED_PTR< BlockData<VoxelType> > >::iterator >::iterator listIter = itersToDelete.begin(); listIter != itersToDelete.end(); ++listIter)
{
m_pHomogenousBlockData.erase(*listIter);
}
}
template <typename VoxelType>
@ -257,7 +262,7 @@ namespace PolyVox
template <typename VoxelType>
POLYVOX_SHARED_PTR< BlockData<VoxelType> > Volume<VoxelType>::getHomogenousBlockData(VoxelType tHomogenousValue) const
{
typename std::map<VoxelType, POLYVOX_WEAK_PTR< BlockData<VoxelType> > >::iterator iterResult = m_pHomogenousBlockData.find(tHomogenousValue);
std::map<VoxelType, POLYVOX_SHARED_PTR< BlockData<VoxelType> > >::iterator iterResult = m_pHomogenousBlockData.find(tHomogenousValue);
if(iterResult == m_pHomogenousBlockData.end())
{
Block<VoxelType> block;
@ -271,8 +276,8 @@ namespace PolyVox
else
{
//iterResult->second.m_uReferenceCount++;
POLYVOX_SHARED_PTR< BlockData<VoxelType> > result(iterResult->second);
return result;
//POLYVOX_SHARED_PTR< BlockData<VoxelType> > result(iterResult->second);
return iterResult->second;
}
}
#pragma endregion