From f64eae77341c04d3632aa9e99eb69e6272eb589d Mon Sep 17 00:00:00 2001
From: RedMindZ <tavtaor11@gmail.com>
Date: Mon, 21 Apr 2025 18:08:57 +0300
Subject: [PATCH] Fixed a deadlock caused by locking the device's snatchable
 lock **after** locking the queue's pending writes (#7582)

---
 wgpu-core/src/device/queue.rs | 11 ++++++++---
 1 file changed, 8 insertions(+), 3 deletions(-)

diff --git a/wgpu-core/src/device/queue.rs b/wgpu-core/src/device/queue.rs
index 585c1a7b5..7e868b909 100644
--- a/wgpu-core/src/device/queue.rs
+++ b/wgpu-core/src/device/queue.rs
@@ -476,6 +476,8 @@ impl Queue {
             return Ok(());
         };
 
+        let snatch_guard = self.device.snatchable_lock.read();
+
         // Platform validation requires that the staging buffer always be
         // freed, even if an error occurs. All paths from here must call
         // `device.pending_writes.consume`.
@@ -489,6 +491,7 @@ impl Queue {
         };
 
         let result = self.write_staging_buffer_impl(
+            &snatch_guard,
             &mut pending_writes,
             &staging_buffer,
             buffer,
@@ -522,6 +525,7 @@ impl Queue {
 
         let buffer = buffer.get()?;
 
+        let snatch_guard = self.device.snatchable_lock.read();
         let mut pending_writes = self.pending_writes.lock();
 
         // At this point, we have taken ownership of the staging_buffer from the
@@ -531,6 +535,7 @@ impl Queue {
         let staging_buffer = staging_buffer.flush();
 
         let result = self.write_staging_buffer_impl(
+            &snatch_guard,
             &mut pending_writes,
             &staging_buffer,
             buffer,
@@ -583,6 +588,7 @@ impl Queue {
 
     fn write_staging_buffer_impl(
         &self,
+        snatch_guard: &SnatchGuard,
         pending_writes: &mut PendingWrites,
         staging_buffer: &FlushedStagingBuffer,
         buffer: Arc<Buffer>,
@@ -595,8 +601,7 @@ impl Queue {
                 .set_single(&buffer, wgt::BufferUses::COPY_DST)
         };
 
-        let snatch_guard = self.device.snatchable_lock.read();
-        let dst_raw = buffer.try_raw(&snatch_guard)?;
+        let dst_raw = buffer.try_raw(snatch_guard)?;
 
         self.same_device_as(buffer.as_ref())?;
 
@@ -614,7 +619,7 @@ impl Queue {
                 to: wgt::BufferUses::COPY_SRC,
             },
         })
-        .chain(transition.map(|pending| pending.into_hal(&buffer, &snatch_guard)))
+        .chain(transition.map(|pending| pending.into_hal(&buffer, snatch_guard)))
         .collect::<Vec<_>>();
         let encoder = pending_writes.activate();
         unsafe {