move LifetimeTracker into the Queue

The `Device` should not contain any `Arc`s to resources as that creates cycles (since all resources hold strong references to the `Device`).
Note that `LifetimeTracker` internally has `Arc`s to resources.

wgpu-core/src/device/global.rs

@@ -219,9 +219,11 @@ impl Global {
         device.check_is_valid()?;
         buffer.check_usage(wgt::BufferUsages::MAP_WRITE)?;
 
-        let last_submission = device
+        let last_submission = device.get_queue().and_then(|queue| {
+            queue
                 .lock_life()
-            .get_buffer_latest_submission_index(&buffer);
+                .get_buffer_latest_submission_index(&buffer)
+        });
 
         if let Some(last_submission) = last_submission {
             device.wait_for_submit(last_submission)?;

wgpu-core/src/device/queue.rs

@@ -14,7 +14,7 @@ use crate::{
     hal_label,
     id::{self, QueueId},
     init_tracker::{has_copy_partial_init_tracker_coverage, TextureInitRange},
-    lock::{rank, Mutex, RwLockWriteGuard},
+    lock::{rank, Mutex, MutexGuard, RwLockWriteGuard},
     resource::{
         Buffer, BufferAccessError, BufferMapState, DestroyedBuffer, DestroyedResourceError,
         DestroyedTexture, Fallible, FlushedStagingBuffer, InvalidResourceError, Labeled,
@@ -37,12 +37,13 @@ use std::{
 };
 use thiserror::Error;
 
-use super::Device;
+use super::{life::LifetimeTracker, Device};
 
 pub struct Queue {
     raw: ManuallyDrop<Box<dyn hal::DynQueue>>,
     pub(crate) device: Arc<Device>,
     pub(crate) pending_writes: Mutex<ManuallyDrop<PendingWrites>>,
+    life_tracker: Mutex<LifetimeTracker>,
 }
 
 impl Queue {
@@ -94,12 +95,18 @@ impl Queue {
             raw: ManuallyDrop::new(raw),
             device,
             pending_writes,
+            life_tracker: Mutex::new(rank::QUEUE_LIFE_TRACKER, LifetimeTracker::new()),
         })
     }
 
     pub(crate) fn raw(&self) -> &dyn hal::DynQueue {
         self.raw.as_ref()
     }
+
+    #[track_caller]
+    pub(crate) fn lock_life<'a>(&'a self) -> MutexGuard<'a, LifetimeTracker> {
+        self.life_tracker.lock()
+    }
 }
 
 crate::impl_resource_type!(Queue);
@@ -1292,7 +1299,7 @@ impl Queue {
             profiling::scope!("cleanup");
 
             // this will register the new submission to the life time tracker
-            self.device.lock_life().track_submission(
+            self.lock_life().track_submission(
                 submit_index,
                 pending_writes.temp_resources.drain(..),
                 active_executions,
@@ -1341,7 +1348,7 @@ impl Queue {
     ) -> Option<SubmissionIndex> {
         api_log!("Queue::on_submitted_work_done");
         //TODO: flush pending writes
-        self.device.lock_life().add_work_done_closure(closure)
+        self.lock_life().add_work_done_closure(closure)
     }
 }
 

wgpu-core/src/device/resource.rs

@@ -4,10 +4,9 @@ use crate::{
     binding_model::{self, BindGroup, BindGroupLayout, BindGroupLayoutEntryError},
     command, conv,
     device::{
-        bgl, create_validator,
+        bgl, create_validator, life::WaitIdleError, map_buffer, AttachmentData,
-        life::{LifetimeTracker, WaitIdleError},
+        DeviceLostInvocation, HostMap, MissingDownlevelFlags, MissingFeatures, RenderPassContext,
-        map_buffer, AttachmentData, DeviceLostInvocation, HostMap, MissingDownlevelFlags,
+        CLEANUP_WAIT_MS,
-        MissingFeatures, RenderPassContext, CLEANUP_WAIT_MS,
     },
     hal_label,
     init_tracker::{
@@ -15,7 +14,7 @@ use crate::{
         TextureInitTrackerAction,
     },
     instance::Adapter,
-    lock::{rank, Mutex, MutexGuard, RwLock},
+    lock::{rank, Mutex, RwLock},
     pipeline,
     pool::ResourcePool,
     resource::{
@@ -114,7 +113,6 @@ pub struct Device {
     /// Stores the state of buffers and textures.
     pub(crate) trackers: Mutex<DeviceTracker>,
     pub(crate) tracker_indices: TrackerIndexAllocators,
-    life_tracker: Mutex<LifetimeTracker>,
     /// Pool of bind group layouts, allowing deduplication.
     pub(crate) bgl_pool: ResourcePool<bgl::EntryMap, BindGroupLayout>,
     pub(crate) alignments: hal::Alignments,
@@ -266,7 +264,6 @@ impl Device {
             device_lost_closure: Mutex::new(rank::DEVICE_LOST_CLOSURE, None),
             trackers: Mutex::new(rank::DEVICE_TRACKERS, DeviceTracker::new()),
             tracker_indices: TrackerIndexAllocators::new(),
-            life_tracker: Mutex::new(rank::DEVICE_LIFE_TRACKER, LifetimeTracker::new()),
             bgl_pool: ResourcePool::new(),
             #[cfg(feature = "trace")]
             trace: Mutex::new(
@@ -332,11 +329,6 @@ impl Device {
         assert!(self.queue_to_drop.set(queue).is_ok());
     }
 
-    #[track_caller]
-    pub(crate) fn lock_life<'a>(&'a self) -> MutexGuard<'a, LifetimeTracker> {
-        self.life_tracker.lock()
-    }
-
     /// Run some destroy operations that were deferred.
     ///
     /// Destroying the resources requires taking a write lock on the device's snatch lock,
@@ -449,7 +441,9 @@ impl Device {
             .map_err(|e| self.handle_hal_error(e))?;
         }
 
-        let mut life_tracker = self.lock_life();
+        let (submission_closures, mapping_closures, queue_empty) =
+            if let Some(queue) = self.get_queue() {
+                let mut life_tracker = queue.lock_life();
                 let submission_closures =
                     life_tracker.triage_submissions(submission_index, &self.command_allocator);
 
@@ -457,6 +451,11 @@ impl Device {
 
                 let queue_empty = life_tracker.queue_empty();
 
+                (submission_closures, mapping_closures, queue_empty)
+            } else {
+                (SmallVec::new(), Vec::new(), true)
+            };
+
         // Detect if we have been destroyed and now need to lose the device.
         // If we are invalid (set at start of destroy) and our queue is empty,
         // and we have a DeviceLostClosure, return the closure to be called by
@@ -481,7 +480,6 @@ impl Device {
         }
 
         // Don't hold the locks while calling release_gpu_resources.
-        drop(life_tracker);
         drop(fence);
         drop(snatch_guard);
 
@@ -3562,7 +3560,8 @@ impl Device {
             unsafe { self.raw().wait(fence.as_ref(), submission_index, !0) }
                 .map_err(|e| self.handle_hal_error(e))?;
             drop(fence);
-            let closures = self
+            if let Some(queue) = self.get_queue() {
+                let closures = queue
                     .lock_life()
                     .triage_submissions(submission_index, &self.command_allocator);
                 assert!(
@@ -3570,6 +3569,7 @@ impl Device {
                     "wait_for_submit is not expected to work with closures"
                 );
             }
+        }
         Ok(())
     }
 

wgpu-core/src/lock/rank.rs

@@ -118,9 +118,9 @@ define_lock_ranks! {
     rank QUEUE_PENDING_WRITES "Queue::pending_writes" followed by {
         COMMAND_ALLOCATOR_FREE_ENCODERS,
         SHARED_TRACKER_INDEX_ALLOCATOR_INNER,
-        DEVICE_LIFE_TRACKER,
+        QUEUE_LIFE_TRACKER,
     }
-    rank DEVICE_LIFE_TRACKER "Device::life_tracker" followed by {
+    rank QUEUE_LIFE_TRACKER "Queue::life_tracker" followed by {
         COMMAND_ALLOCATOR_FREE_ENCODERS,
         DEVICE_TRACE,
     }

wgpu-core/src/resource.rs

@@ -634,7 +634,12 @@ impl Buffer {
             .buffers
             .set_single(self, internal_use);
 
-        let submit_index = device.lock_life().map(self).unwrap_or(0); // '0' means no wait is necessary
+        let submit_index = if let Some(queue) = device.get_queue() {
+            queue.lock_life().map(self).unwrap_or(0) // '0' means no wait is necessary
+        } else {
+            // TODO: map immediately
+            0
+        };
 
         Ok(submit_index)
     }
@@ -783,15 +788,14 @@ impl Buffer {
             let mut pending_writes = queue.pending_writes.lock();
             if pending_writes.contains_buffer(self) {
                 pending_writes.consume_temp(temp);
-                return Ok(());
+            } else {
-            }
+                let mut life_lock = queue.lock_life();
-        }
-
-        let mut life_lock = device.lock_life();
                 let last_submit_index = life_lock.get_buffer_latest_submission_index(self);
                 if let Some(last_submit_index) = last_submit_index {
                     life_lock.schedule_resource_destruction(temp, last_submit_index);
                 }
+            }
+        }
 
         Ok(())
     }
@@ -1252,15 +1256,14 @@ impl Texture {
             let mut pending_writes = queue.pending_writes.lock();
             if pending_writes.contains_texture(self) {
                 pending_writes.consume_temp(temp);
-                return Ok(());
+            } else {
-            }
+                let mut life_lock = queue.lock_life();
-        }
-
-        let mut life_lock = device.lock_life();
                 let last_submit_index = life_lock.get_texture_latest_submission_index(self);
                 if let Some(last_submit_index) = last_submit_index {
                     life_lock.schedule_resource_destruction(temp, last_submit_index);
                 }
+            }
+        }
 
         Ok(())
     }
@@ -1971,15 +1974,14 @@ impl Blas {
             let mut pending_writes = queue.pending_writes.lock();
             if pending_writes.contains_blas(self) {
                 pending_writes.consume_temp(temp);
-                return Ok(());
+            } else {
-            }
+                let mut life_lock = queue.lock_life();
-        }
-
-        let mut life_lock = device.lock_life();
                 let last_submit_index = life_lock.get_blas_latest_submission_index(self);
                 if let Some(last_submit_index) = last_submit_index {
                     life_lock.schedule_resource_destruction(temp, last_submit_index);
                 }
+            }
+        }
 
         Ok(())
     }
@@ -2061,15 +2063,14 @@ impl Tlas {
             let mut pending_writes = queue.pending_writes.lock();
             if pending_writes.contains_tlas(self) {
                 pending_writes.consume_temp(temp);
-                return Ok(());
+            } else {
-            }
+                let mut life_lock = queue.lock_life();
-        }
-
-        let mut life_lock = device.lock_life();
                 let last_submit_index = life_lock.get_tlas_latest_submission_index(self);
                 if let Some(last_submit_index) = last_submit_index {
                     life_lock.schedule_resource_destruction(temp, last_submit_index);
                 }
+            }
+        }
 
         Ok(())
     }