move CommandEncoderStatus on the CommandBuffer and change its var…

…iants to hold `CommandBufferMutable`

This makes the code more straightforward, we were previously holding invalidity state in 2 places: `CommandBuffer::data` could hold `None` and in `CommandEncoderStatus::Error`.

This commit also implements `Drop` for `CommandEncoder` which makes the destruction/reclamation code automatic. We were previously not reclaiming all command encoders (`CommandBufferMutable::destroy` didn't call `release_encoder`) even though all encoders are coming from a pool.

wgpu-core/src/command/clear.rs

@@ -91,8 +91,8 @@ impl Global {
         let cmd_buf = hub
             .command_buffers
             .get(command_encoder_id.into_command_buffer_id());
-        let mut cmd_buf_data = cmd_buf.try_get()?;
-        cmd_buf_data.check_recording()?;
+        let mut cmd_buf_data = cmd_buf.data.lock();
+        let cmd_buf_data = cmd_buf_data.record()?;
 
         #[cfg(feature = "trace")]
         if let Some(ref mut list) = cmd_buf_data.commands {
@@ -174,8 +174,8 @@ impl Global {
         let cmd_buf = hub
             .command_buffers
             .get(command_encoder_id.into_command_buffer_id());
-        let mut cmd_buf_data = cmd_buf.try_get()?;
-        cmd_buf_data.check_recording()?;
+        let mut cmd_buf_data = cmd_buf.data.lock();
+        let cmd_buf_data = cmd_buf_data.record()?;
 
         #[cfg(feature = "trace")]
         if let Some(ref mut list) = cmd_buf_data.commands {

wgpu-core/src/command/compute.rs

@@ -8,8 +8,8 @@ use crate::{
         end_pipeline_statistics_query,
         memory_init::{fixup_discarded_surfaces, SurfacesInDiscardState},
         validate_and_begin_pipeline_statistics_query, ArcPassTimestampWrites, BasePass,
-        BindGroupStateChange, CommandBuffer, CommandEncoderError, CommandEncoderStatus, MapPassErr,
-        PassErrorScope, PassTimestampWrites, QueryUseError, StateChange,
+        BindGroupStateChange, CommandBuffer, CommandEncoderError, MapPassErr, PassErrorScope,
+        PassTimestampWrites, QueryUseError, StateChange,
     },
     device::{Device, DeviceError, MissingDownlevelFlags, MissingFeatures},
     global::Global,
@@ -30,8 +30,7 @@ use wgt::{BufferAddress, DynamicOffset};
 
 use super::{bind::BinderError, memory_init::CommandBufferTextureMemoryActions};
 use crate::ray_tracing::TlasAction;
-use std::sync::Arc;
-use std::{fmt, mem::size_of, str};
+use std::{fmt, mem::size_of, str, sync::Arc};
 
 pub struct ComputePass {
     /// All pass data & records is stored here.
@@ -282,7 +281,9 @@ impl Global {
     /// If creation fails, an invalid pass is returned.
     /// Any operation on an invalid pass will return an error.
     ///
-    /// If successful, puts the encoder into the [`CommandEncoderStatus::Locked`] state.
+    /// If successful, puts the encoder into the [`Locked`] state.
+    ///
+    /// [`Locked`]: crate::command::CommandEncoderStatus::Locked
     pub fn command_encoder_create_compute_pass(
         &self,
         encoder_id: id::CommandEncoderId,
@@ -299,11 +300,7 @@ impl Global {
 
         let cmd_buf = hub.command_buffers.get(encoder_id.into_command_buffer_id());
 
-        match cmd_buf
-            .try_get()
-            .map_err(|e| e.into())
-            .and_then(|mut cmd_buf_data| cmd_buf_data.lock_encoder())
-        {
+        match cmd_buf.data.lock().lock_encoder() {
             Ok(_) => {}
             Err(e) => return make_err(e, arc_desc),
         };
@@ -340,7 +337,8 @@ impl Global {
                 .hub
                 .command_buffers
                 .get(encoder_id.into_command_buffer_id());
-            let mut cmd_buf_data = cmd_buf.try_get().map_pass_err(pass_scope)?;
+            let mut cmd_buf_data = cmd_buf.data.lock();
+            let cmd_buf_data = cmd_buf_data.get_inner().map_pass_err(pass_scope)?;
 
             if let Some(ref mut list) = cmd_buf_data.commands {
                 list.push(crate::device::trace::Command::RunComputePass {
@@ -408,19 +406,16 @@ impl Global {
         let device = &cmd_buf.device;
         device.check_is_valid().map_pass_err(pass_scope)?;
 
-        let mut cmd_buf_data = cmd_buf.try_get().map_pass_err(pass_scope)?;
-        cmd_buf_data.unlock_encoder().map_pass_err(pass_scope)?;
-        let cmd_buf_data = &mut *cmd_buf_data;
+        let mut cmd_buf_data = cmd_buf.data.lock();
+        let mut cmd_buf_data_guard = cmd_buf_data.unlock_encoder().map_pass_err(pass_scope)?;
+        let cmd_buf_data = &mut *cmd_buf_data_guard;
 
         let encoder = &mut cmd_buf_data.encoder;
-        let status = &mut cmd_buf_data.status;
 
         // We automatically keep extending command buffers over time, and because
         // we want to insert a command buffer _before_ what we're about to record,
         // we need to make sure to close the previous one.
         encoder.close(&cmd_buf.device).map_pass_err(pass_scope)?;
-        // will be reset to true if recording is done without errors
-        *status = CommandEncoderStatus::Error;
         let raw_encoder = encoder.open(&cmd_buf.device).map_pass_err(pass_scope)?;
 
         let mut state = State {
@@ -590,10 +585,6 @@ impl Global {
             state.raw_encoder.end_compute_pass();
         }
 
-        // We've successfully recorded the compute pass, bring the
-        // command buffer out of the error state.
-        *status = CommandEncoderStatus::Recording;
-
         let State {
             snatch_guard,
             tracker,
@@ -626,6 +617,7 @@ impl Global {
         encoder
             .close_and_swap(&cmd_buf.device)
             .map_pass_err(pass_scope)?;
+        cmd_buf_data_guard.mark_successful();
 
         Ok(())
     }