Fixed a race condition with incremental defragmentation. The issue here is that VmaBlockVector::DefragmentationEnd() relied on the mutex being previously locked to safely mutate its data, but with incremental defrag this isn't guaranteed to be the case anymore.

This commit is contained in:
Sidney Just 2020-03-27 09:58:25 -07:00
parent 3d1ce4ebb8
commit bb7bdb99ec

View File

@ -6523,6 +6523,7 @@ public:
VkCommandBuffer commandBuffer);
void DefragmentationEnd(
class VmaBlockVectorDefragmentationContext* pCtx,
uint32_t flags,
VmaDefragmentationStats* pStats);
uint32_t ProcessDefragmentations(
@ -13180,22 +13181,36 @@ void VmaBlockVector::Defragment(
void VmaBlockVector::DefragmentationEnd(
class VmaBlockVectorDefragmentationContext* pCtx,
uint32_t flags,
VmaDefragmentationStats* pStats)
{
// Destroy buffers.
for(size_t blockIndex = pCtx->blockContexts.size(); blockIndex--; )
if(flags & VMA_DEFRAGMENTATION_FLAG_INCREMENTAL && m_hAllocator->m_UseMutex)
{
VmaBlockDefragmentationContext& blockCtx = pCtx->blockContexts[blockIndex];
if(blockCtx.hBuffer)
{
(*m_hAllocator->GetVulkanFunctions().vkDestroyBuffer)(
m_hAllocator->m_hDevice, blockCtx.hBuffer, m_hAllocator->GetAllocationCallbacks());
}
VMA_ASSERT(pCtx->mutexLocked == false);
// Incremental defragmentation doesn't hold the lock, so when we enter here we don't actually have any
// lock protecting us. Since we mutate state here, we have to take the lock out now
m_Mutex.LockWrite();
pCtx->mutexLocked = true;
}
if(pCtx->res >= VK_SUCCESS)
// If the mutex isn't locked we didn't do any work and there is nothing to delete.
if(pCtx->mutexLocked || !m_hAllocator->m_UseMutex)
{
FreeEmptyBlocks(pStats);
// Destroy buffers.
for(size_t blockIndex = pCtx->blockContexts.size(); blockIndex--;)
{
VmaBlockDefragmentationContext &blockCtx = pCtx->blockContexts[blockIndex];
if(blockCtx.hBuffer)
{
(*m_hAllocator->GetVulkanFunctions().vkDestroyBuffer)(m_hAllocator->m_hDevice, blockCtx.hBuffer, m_hAllocator->GetAllocationCallbacks());
}
}
if(pCtx->res >= VK_SUCCESS)
{
FreeEmptyBlocks(pStats);
}
}
if(pCtx->mutexLocked)
@ -14117,7 +14132,7 @@ VmaDefragmentationContext_T::~VmaDefragmentationContext_T()
for(size_t i = m_CustomPoolContexts.size(); i--; )
{
VmaBlockVectorDefragmentationContext* pBlockVectorCtx = m_CustomPoolContexts[i];
pBlockVectorCtx->GetBlockVector()->DefragmentationEnd(pBlockVectorCtx, m_pStats);
pBlockVectorCtx->GetBlockVector()->DefragmentationEnd(pBlockVectorCtx, m_Flags, m_pStats);
vma_delete(m_hAllocator, pBlockVectorCtx);
}
for(size_t i = m_hAllocator->m_MemProps.memoryTypeCount; i--; )
@ -14125,7 +14140,7 @@ VmaDefragmentationContext_T::~VmaDefragmentationContext_T()
VmaBlockVectorDefragmentationContext* pBlockVectorCtx = m_DefaultPoolContexts[i];
if(pBlockVectorCtx)
{
pBlockVectorCtx->GetBlockVector()->DefragmentationEnd(pBlockVectorCtx, m_pStats);
pBlockVectorCtx->GetBlockVector()->DefragmentationEnd(pBlockVectorCtx, m_Flags, m_pStats);
vma_delete(m_hAllocator, pBlockVectorCtx);
}
}