From fafe4813650613cf5bc14eef6190efb93178f654 Mon Sep 17 00:00:00 2001
From: ubuntu1804 <hoenking.wh@hotmail.com>
Date: Mon, 10 Nov 2025 22:31:35 +0800
Subject: [PATCH] Use fence to wait for buffer copy

Create a VkFence for the copy command, submit with that fence, wait with
vkWaitForFences instead of vkQueueWaitIdle, and destroy the fence after
completion. Ensure fence is destroyed and the command buffer is freed on
error paths.
---
 src/vulkanrenderer.cpp | 27 ++++++++++++++++++++++++---
 1 file changed, 24 insertions(+), 3 deletions(-)

diff --git a/src/vulkanrenderer.cpp b/src/vulkanrenderer.cpp
index 44a2b3d..b4b6257 100644
--- a/src/vulkanrenderer.cpp
+++ b/src/vulkanrenderer.cpp
@@ -1918,24 +1918,45 @@ bool VulkanRenderer::copyBuffer(VkBuffer srcBuffer, VkBuffer dstBuffer, uint64_t
         return false;
     }
 
+    // Create a fence for synchronization
+    VkFenceCreateInfo fenceInfo = {};
+    fenceInfo.sType = VK_STRUCTURE_TYPE_FENCE_CREATE_INFO;
+    fenceInfo.flags = 0;
+
+    VkFence fence;
+    result = vkCreateFence(m_device, &fenceInfo, nullptr, &fence);
+    if (result != VK_SUCCESS) {
+        logError("Failed to create fence for buffer copy");
+        vkFreeCommandBuffers(m_device, m_transferCommandPool, 1, &commandBuffer);
+        return false;
+    }
+
     // Submit and wait
     VkSubmitInfo submitInfo = {};
     submitInfo.sType = VK_STRUCTURE_TYPE_SUBMIT_INFO;
     submitInfo.commandBufferCount = 1;
     submitInfo.pCommandBuffers = &commandBuffer;
 
-    result = vkQueueSubmit(m_graphicsQueue, 1, &submitInfo, VK_NULL_HANDLE);
+    result = vkQueueSubmit(m_graphicsQueue, 1, &submitInfo, fence);
     if (result != VK_SUCCESS) {
         logError("Failed to submit copy command");
+        vkDestroyFence(m_device, fence, nullptr);
         vkFreeCommandBuffers(m_device, m_transferCommandPool, 1, &commandBuffer);
         return false;
     }
 
-    result = vkQueueWaitIdle(m_graphicsQueue);
+    // Wait for the fence instead of the entire queue
+    result = vkWaitForFences(m_device, 1, &fence, VK_TRUE, UINT64_MAX);
     if (result != VK_SUCCESS) {
-        logError("Failed to wait for queue idle after copy");
+        logError("Failed to wait for fence after copy");
+        vkDestroyFence(m_device, fence, nullptr);
+        vkFreeCommandBuffers(m_device, m_transferCommandPool, 1, &commandBuffer);
+        return false;
     }
 
+    // Cleanup fence
+    vkDestroyFence(m_device, fence, nullptr);
+
     // Free command buffer
     vkFreeCommandBuffers(m_device, m_transferCommandPool, 1, &commandBuffer);