extra safety

Author: Agrael1

include/vk_mem_alloc.h

@@ -6093,7 +6093,7 @@ class VmaWin32Handle
 
 public:
     // Strengthened
-    VkResult GetHandle(VkDevice device, VkDeviceMemory memory, decltype(&vkGetMemoryWin32HandleKHR) pvkGetMemoryWin32HandleKHR, HANDLE hTargetProcess, HANDLE* pHandle) noexcept
+    VkResult GetHandle(VkDevice device, VkDeviceMemory memory, decltype(&vkGetMemoryWin32HandleKHR) pvkGetMemoryWin32HandleKHR, HANDLE hTargetProcess, bool useMutex, HANDLE* pHandle) noexcept
     {
         *pHandle = VMA_NULL;
         // We only care about atomicity of handle retrieval, not about memory order.
@@ -6108,8 +6108,15 @@ class VmaWin32Handle
 
         HANDLE hCreatedHandle = VMA_NULL;
 
+        VkResult res = VK_SUCCESS;
         // If failed, try to create it.
-        VkResult res = Create(device, memory, pvkGetMemoryWin32HandleKHR, &hCreatedHandle);
+        {
+            VmaMutexLockWrite lock(m_Mutex, useMutex);
+            if (m_hHandle.load(std::memory_order_relaxed) == VMA_NULL)
+            {
+                VkResult res = Create(device, memory, pvkGetMemoryWin32HandleKHR, &hCreatedHandle);
+            }
+        }
         if (res == VK_SUCCESS)
         {
             // Successfully created handle, try to set it.
@@ -6164,6 +6171,7 @@ class VmaWin32Handle
     }
 private:
     std::atomic<HANDLE> m_hHandle;
+    VMA_RW_MUTEX m_Mutex; // Protects access m_Handle
 };
 #else 
 class VmaWin32Handle
@@ -10802,7 +10810,7 @@ VkResult VmaDeviceMemoryBlock::BindImageMemory(
 VkResult VmaDeviceMemoryBlock::CreateWin32Handle(const VmaAllocator hAllocator, decltype(&vkGetMemoryWin32HandleKHR) pvkGetMemoryWin32HandleKHR, HANDLE hTargetProcess, HANDLE* pHandle) noexcept
 {
     VMA_ASSERT(pHandle);
-    return m_Handle.GetHandle(hAllocator->m_hDevice, m_hMemory, &vkGetMemoryWin32HandleKHR, hTargetProcess, pHandle);
+    return m_Handle.GetHandle(hAllocator->m_hDevice, m_hMemory, &vkGetMemoryWin32HandleKHR, hTargetProcess, hAllocator->m_UseMutex, pHandle);
 }
 #endif // VK_USE_PLATFORM_WIN32_KHR
 #endif // _VMA_DEVICE_MEMORY_BLOCK_FUNCTIONS
@@ -11115,7 +11123,7 @@ VkResult VmaAllocation_T::GetWin32Handle(VmaAllocator hAllocator, HANDLE hTarget
     case ALLOCATION_TYPE_BLOCK:
         return m_BlockAllocation.m_Block->CreateWin32Handle(hAllocator, pvkGetMemoryWin32HandleKHR, hTargetProcess, pHandle);
     case ALLOCATION_TYPE_DEDICATED:
-        return m_DedicatedAllocation.m_Handle.GetHandle(hAllocator->m_hDevice, m_DedicatedAllocation.m_hMemory, pvkGetMemoryWin32HandleKHR, hTargetProcess, pHandle);
+        return m_DedicatedAllocation.m_Handle.GetHandle(hAllocator->m_hDevice, m_DedicatedAllocation.m_hMemory, pvkGetMemoryWin32HandleKHR, hTargetProcess, hAllocator->m_UseMutex, pHandle);
     default:
         VMA_ASSERT(0);
         return VK_ERROR_FEATURE_NOT_PRESENT;