fix(hal): Clear query state on reused encoders

(cherry picked from commit 8042314)

Author: andyleiserson

wgpu-hal/src/dx12/command.rs

@@ -419,9 +419,12 @@ impl crate::CommandEncoder for super::CommandEncoder {
             list.set_name(label)?;
         }
 
-        self.list = Some(list);
+        // Ensure clean state even if the last encoding did not complete normally.
         self.temp.clear();
         self.pass.clear();
+        self.end_of_pass_timer_query = None;
+
+        self.list = Some(list);
         Ok(())
     }
     unsafe fn discard_encoding(&mut self) {

wgpu-hal/src/dx12/mod.rs

@@ -964,6 +964,8 @@ impl PassState {
     }
 }
 
+// Any state in this struct that may be dirty after an abandoned encoding must
+// be reset for reused encoders in `begin_encoding`.
 pub struct CommandEncoder {
     allocator: Direct3D12::ID3D12CommandAllocator,
     device: Direct3D12::ID3D12Device,

wgpu-hal/src/metal/command.rs

@@ -490,6 +490,11 @@ impl crate::CommandEncoder for super::CommandEncoder {
             cmd_buf_ref.to_owned()
         });
 
+        // Queries should either be closed out, or cleared in `discard_encoding`.
+        // This assertion is here mainly to facilitate comparison with the other
+        // backends, which clear in `begin_encoding` rather than `discard_encoding`.
+        debug_assert!(self.state.pending_timer_queries.is_empty());
+
         self.raw_cmd_buf = Some(raw);
 
         Ok(())
@@ -506,6 +511,7 @@ impl crate::CommandEncoder for super::CommandEncoder {
         if let Some(encoder) = self.state.compute.take() {
             encoder.endEncoding();
         }
+        self.state.pending_timer_queries.clear();
         let had_command_buffer = self.raw_cmd_buf.is_some();
         // Clear the Option first so the underlying `metal::CommandBuffer` is
         // dropped before we update the counter.

wgpu-hal/src/metal/mod.rs

@@ -1080,6 +1080,8 @@ struct Temp {
     binding_sizes: Vec<u32>,
 }
 
+// Any state in this struct that may be dirty after an abandoned encoding must
+// be reset in `discard_encoding` for possible encoder reuse.
 struct CommandState {
     blit: Option<Retained<ProtocolObject<dyn MTLBlitCommandEncoder>>>,
     acceleration_structure_builder:
@@ -1119,6 +1121,8 @@ struct CommandState {
     pending_timer_queries: Vec<(QuerySet, u32)>,
 }
 
+// Any state in this struct that may be dirty after an abandoned encoding must
+// be reset in `discard_encoding` for possible encoder reuse.
 pub struct CommandEncoder {
     shared: Arc<AdapterShared>,
     queue_shared: Arc<QueueShared>,

wgpu-hal/src/vulkan/command.rs

@@ -138,8 +138,9 @@ impl crate::CommandEncoder for super::CommandEncoder {
         // previous name assigned to this.
         unsafe { self.device.set_object_name(raw, label.unwrap_or_default()) };
 
-        // Reset this in case the last renderpass was never ended.
+        // Reset some state in case the last renderpass was never ended.
         self.rpass_debug_marker_active = false;
+        self.end_of_pass_timer_query = None;
 
         let vk_info = vk::CommandBufferBeginInfo::default()
             .flags(vk::CommandBufferUsageFlags::ONE_TIME_SUBMIT);

wgpu-hal/src/vulkan/mod.rs

@@ -984,6 +984,8 @@ struct TempTextureViewKey {
     depth_slice: u32,
 }
 
+// Any state in this struct that may be dirty after an abandoned encoding must
+// be reset for reused encoders in `begin_encoding`.
 pub struct CommandEncoder {
     raw: vk::CommandPool,
     device: Arc<DeviceShared>,