From 134c2019b1cdd1e8154c2b5601a2e410a28d047c Mon Sep 17 00:00:00 2001
From: dweiller <4678790+dweiller@users.noreplay.github.com>
Date: Thu, 23 Jun 2022 14:10:32 +1000
Subject: [PATCH] gpu: remove Queue.WorkDownCallback lifetime footgun

The previous implementation required the specific Queue struct that
submit() was called on to be valid when the callback is triggered. By
storing a pointer instead, the Queue does not need to be valid, only the
callback itself.
---
 gpu/src/NativeInstance.zig | 2 +-
 gpu/src/Queue.zig          | 5 ++++-
 2 files changed, 5 insertions(+), 2 deletions(-)

diff --git a/gpu/src/NativeInstance.zig b/gpu/src/NativeInstance.zig
index 28b74be8..d8f1ed7d 100644
--- a/gpu/src/NativeInstance.zig
+++ b/gpu/src/NativeInstance.zig
@@ -902,7 +902,7 @@ const queue_vtable = Queue.VTable{
                     wgpu_queue,
                     signal_value,
                     cCallback,
-                    &queue.on_submitted_work_done,
+                    queue.on_submitted_work_done,
                 );
             }
 
diff --git a/gpu/src/Queue.zig b/gpu/src/Queue.zig
index 206be857..2e5b5a9c 100644
--- a/gpu/src/Queue.zig
+++ b/gpu/src/Queue.zig
@@ -8,7 +8,10 @@ const Texture = @import("Texture.zig");
 
 const Queue = @This();
 
-on_submitted_work_done: ?WorkDoneCallback = null,
+/// Callback to executed when all work has been done
+/// This field must be set before calling `submit()` on the commands the callback waits for.
+/// Note that the address stored must be valid when the callback is executed.
+on_submitted_work_done: ?*WorkDoneCallback = null,
 
 /// The type erased pointer to the Queue implementation
 /// Equal to c.WGPUQueue for NativeInstance.