FEX-Emu/FEX
1
0
Fork 0
mirror of https://github.com/FEX-Emu/FEX.git synced 2025-01-08 22:52:51 +00:00
Code Issues Actions 6 Packages Projects Releases Wiki Activity

FixedSizePooledAllocation: Fix a race when unclaiming disowned buffers

Browse Source 
A disowned buffer could be unclaimed or claimed by a different thread in
the time between the !IsFree check and locking the allocation mutex.
Fix this and prevent such errors in the future by always checking
ownership with the allocator locked before attempting to unclaim
buffers.
This commit is contained in:
Billy Laws 2024-07-19 23:22:50 +00:00
parent e4b7a65a49
commit 1f878ce4cd
1 changed files with 8 additions and 10 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

18
FEXCore/include/FEXCore/Utils/ThreadPoolAllocator.h
View File

@ -120,16 +120,16 @@ public:
}
/**
* @brief Immediately release the buffer back to the allocator
* @brief Immediately release the buffer back to the allocator, given it has not been reclaimed
*
* @param Buffer - The iterator that was previously given with ClaimBuffer
*
* Once this is called on a buffer then the pool allocator has full ownership of the buffer
*/
void UnclaimBuffer(ContainerType::iterator Buffer) {
std::unique_lock lk {AllocationMutex};
(*Buffer)->CurrentClientOwnedFlag->store(ClientFlags::FLAG_FREE);
UnclaimBufferImpl(Buffer);
void UnclaimBuffer(ContainerType::iterator Buffer, BufferOwnedFlag* ClientFlag) {
// Transition the buffer to free, unclaiming if it wasn't free prior.
if (ClientFlag->exchange(ClientFlags::FLAG_FREE) != ClientFlags::FLAG_FREE) {
std::unique_lock lk {AllocationMutex};
UnclaimBufferImpl(Buffer);
}
}
/**
@ -485,9 +485,7 @@ public:
* Only use in that edge case! Otherwise use `DelayedDisownBuffer`
*/
void UnclaimBuffer() {
if (!FEXCore::Utils::IntrusivePooledAllocator::IsClientBufferFree(ClientOwnedFlag)) {
ThreadAllocator.UnclaimBuffer(Info);
}
ThreadAllocator.UnclaimBuffer(Info, &ClientOwnedFlag);
}
private: