Version/Branch of Dear ImGui:
git commit 9a5da23, but the code is the same on master
Back-ends:
imgui_impl_metal.cpp + custom platform backend
Compiler, OS:
macOS + Clang 14
Full config/build information:
No response
Details:
My Issue/Question:
I'm using multiple ImGui contexts within a single application, with a thread_local GImGui pointer, as described in imgui.cpp:
struct ImGuiContext;
extern thread_local ImGuiContext* GImGui_tls;
#define GImGui GImGui_tls
I'm observing a significant memory leak with the Metal backend. I've traced it down to the buffers allocated in dequeueReusableBufferOfLength:device:. The asynchronous callback responsible for releasing the buffers is running on a thread without any ImGui context active, therefore the buffers are never released.
I suggest the following changes to fix the problem.
diff --git a/3rdparty/imgui/imgui_impl_metal.mm b/3rdparty/imgui/imgui_impl_metal.mm
index 23870f37..1206187a 100644
--- a/3rdparty/imgui/imgui_impl_metal.mm
+++ b/3rdparty/imgui/imgui_impl_metal.mm
@@ -310,17 +310,14 @@ void ImGui_ImplMetal_RenderDrawData(ImDrawData* drawData, id<MTLCommandBuffer> c
indexBufferOffset += (size_t)cmd_list->IdxBuffer.Size * sizeof(ImDrawIdx);
}
+ __block MetalContext* SharedMetalContext = bd->SharedMetalContext;
[commandBuffer addCompletedHandler:^(id<MTLCommandBuffer>)
{
dispatch_async(dispatch_get_main_queue(), ^{
- ImGui_ImplMetal_Data* bd = ImGui_ImplMetal_GetBackendData();
- if (bd != nullptr)
+ @synchronized(SharedMetalContext.bufferCache)
{
- @synchronized(bd->SharedMetalContext.bufferCache)
- {
- [bd->SharedMetalContext.bufferCache addObject:vertexBuffer];
- [bd->SharedMetalContext.bufferCache addObject:indexBuffer];
- }
+ [SharedMetalContext.bufferCache addObject:vertexBuffer];
+ [SharedMetalContext.bufferCache addObject:indexBuffer];
}
});
}];
Screenshots/Video:
No response
Minimal, Complete and Verifiable Example code:
No response
Version/Branch of Dear ImGui:
git commit 9a5da23, but the code is the same on master
Back-ends:
imgui_impl_metal.cpp + custom platform backend
Compiler, OS:
macOS + Clang 14
Full config/build information:
No response
Details:
My Issue/Question:
I'm using multiple ImGui contexts within a single application, with a thread_local GImGui pointer, as described in imgui.cpp:
I'm observing a significant memory leak with the Metal backend. I've traced it down to the buffers allocated in
dequeueReusableBufferOfLength:device:. The asynchronous callback responsible for releasing the buffers is running on a thread without any ImGui context active, therefore the buffers are never released.I suggest the following changes to fix the problem.
Screenshots/Video:
No response
Minimal, Complete and Verifiable Example code:
No response