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use std::{
collections::HashMap,
sync::{
atomic::{AtomicU32, Ordering},
Arc,
},
};
use parking_lot::{Mutex, RwLock};
use crate::{
CreationError, EndFrameError, GpuProfilerQuery, GpuProfilerSettings, GpuTimerQueryResult,
ManualOwningScope, OwningScope, ProfilerCommandRecorder, Scope, SettingsError,
};
/// Profiler instance.
///
/// You can have an arbitrary number of independent profiler instances per application/adapter.
/// Manages all the necessary [`wgpu::QuerySet`] and [`wgpu::Buffer`] behind the scenes.
///
/// Any query creation method may allocate a new [`wgpu::QuerySet`] and [`wgpu::Buffer`] internally if necessary.
///
/// After the first call that passes [`wgpu::Device`], the same device must be used with all subsequent
/// calls to [`GpuProfiler`] and all passed references to wgpu objects must originate from that device.
pub struct GpuProfiler {
unused_pools: Vec<QueryPool>,
active_frame: ActiveFrame,
pending_frames: Vec<PendingFrame>,
num_open_queries: AtomicU32,
next_query_handle: AtomicU32,
size_for_new_query_pools: u32,
settings: GpuProfilerSettings,
#[cfg(feature = "tracy")]
tracy_context: Option<tracy_client::GpuContext>,
}
// Public interface
impl GpuProfiler {
/// Combination of all timer query features [`GpuProfiler`] can leverage.
pub const ALL_WGPU_TIMER_FEATURES: wgpu::Features = wgpu::Features::TIMESTAMP_QUERY
.union(wgpu::Features::TIMESTAMP_QUERY_INSIDE_ENCODERS)
.union(wgpu::Features::TIMESTAMP_QUERY_INSIDE_PASSES);
/// Combination of all timer query features [`GpuProfiler`] can leverage.
#[deprecated(since = "0.9.0", note = "Use ALL_WGPU_TIMER_FEATURES instead")]
pub const REQUIRED_WGPU_FEATURES: wgpu::Features = GpuProfiler::ALL_WGPU_TIMER_FEATURES;
/// Creates a new Profiler object.
///
/// There is nothing preventing the use of several independent profiler objects.
pub fn new(settings: GpuProfilerSettings) -> Result<Self, CreationError> {
settings.validate()?;
let (closed_scope_sender, closed_scope_receiver) = std::sync::mpsc::channel();
Ok(GpuProfiler {
unused_pools: Vec::new(),
pending_frames: Vec::with_capacity(settings.max_num_pending_frames),
active_frame: ActiveFrame {
query_pools: RwLock::new(PendingFramePools::default()),
closed_query_sender: closed_scope_sender,
closed_query_receiver: Mutex::new(closed_scope_receiver),
},
num_open_queries: AtomicU32::new(0),
next_query_handle: AtomicU32::new(0),
size_for_new_query_pools: QueryPool::MIN_CAPACITY,
settings,
#[cfg(feature = "tracy")]
tracy_context: None,
})
}
/// Creates a new profiler and connects to a running Tracy client.
#[cfg(feature = "tracy")]
pub fn new_with_tracy_client(
settings: GpuProfilerSettings,
backend: wgpu::Backend,
device: &wgpu::Device,
queue: &wgpu::Queue,
) -> Result<Self, CreationError> {
let mut profiler = Self::new(settings)?;
profiler.tracy_context = Some(crate::tracy::create_tracy_gpu_client(
backend, device, queue,
)?);
Ok(profiler)
}
/// Changes the settings of an existing profiler.
///
/// If timer scopes are disabled by setting [`GpuProfilerSettings::enable_timer_queries`] to false,
/// any timer queries that are in flight will still be processed,
/// but unused query sets and buffers will be deallocated during [`Self::process_finished_frame`].
/// Similarly, any opened debugging scope will still be closed if debug groups are disabled by setting
/// [`GpuProfilerSettings::enable_debug_groups`] to false.
pub fn change_settings(&mut self, settings: GpuProfilerSettings) -> Result<(), SettingsError> {
settings.validate()?;
if !settings.enable_timer_queries {
self.unused_pools.clear();
}
self.settings = settings;
Ok(())
}
/// Starts a new auto-closing profiler scope.
///
/// To nest scopes inside this scope, call [`Scope::scope`] on the returned scope.
///
/// If an [`wgpu::CommandEncoder`] is passed but the [`wgpu::Device`]
/// does not support [`wgpu::Features::TIMESTAMP_QUERY_INSIDE_ENCODERS`], no gpu timer will
/// be queried and the scope will not show up in the final results.
/// If an [`wgpu::ComputePass`] or [`wgpu::RenderPass`] is passed but the [`wgpu::Device`]
/// does not support [`wgpu::Features::TIMESTAMP_QUERY_INSIDE_PASSES`], no scope will be opened.
///
/// If [`GpuProfilerSettings::enable_debug_groups`] is true, a debug group will be pushed on the encoder or pass.
///
/// Scope is automatically closed on drop.
#[must_use]
#[track_caller]
#[inline]
pub fn scope<'a, Recorder: ProfilerCommandRecorder>(
&'a self,
label: impl Into<String>,
encoder_or_pass: &'a mut Recorder,
device: &wgpu::Device,
) -> Scope<'a, Recorder> {
let scope = self.begin_query(label, encoder_or_pass, device);
Scope {
profiler: self,
recorder: encoder_or_pass,
scope: Some(scope),
}
}
/// Starts a new auto-closing profiler scope that takes ownership of the passed encoder or rendering/compute pass.
///
/// To nest scopes inside this scope, call [`OwningScope::scope`] on the returned scope.
///
/// If an [`wgpu::CommandEncoder`] is passed but the [`wgpu::Device`]
/// does not support [`wgpu::Features::TIMESTAMP_QUERY_INSIDE_ENCODERS`], no gpu timer will be queried
/// and the scope will not show up in the final results.
/// If an [`wgpu::ComputePass`] or [`wgpu::RenderPass`] is passed but the [`wgpu::Device`]
/// does not support [`wgpu::Features::TIMESTAMP_QUERY_INSIDE_PASSES`], no scope will be opened.
///
/// If [`GpuProfilerSettings::enable_debug_groups`] is true, a debug group will be pushed on the encoder or pass.
///
/// Scope is automatically closed on drop.
#[must_use]
#[track_caller]
#[inline]
pub fn owning_scope<'a, Recorder: ProfilerCommandRecorder>(
&'a self,
label: impl Into<String>,
mut encoder_or_pass: Recorder,
device: &wgpu::Device,
) -> OwningScope<'a, Recorder> {
let scope = self.begin_query(label, &mut encoder_or_pass, device);
OwningScope {
profiler: self,
recorder: encoder_or_pass,
scope: Some(scope),
}
}
/// Starts a new **manually closed** profiler scope that takes ownership of the passed encoder or rendering/compute pass.
///
/// Does NOT call [`GpuProfiler::end_query()`] on drop.
/// This construct is just for completeness in cases where working with scopes is preferred but one can't rely on the Drop call in the right place.
/// This is useful when the owned value needs to be recovered after the end of the scope.
/// In particular, to submit a [`wgpu::CommandEncoder`] to a queue, ownership of the encoder is necessary.
///
/// To nest scopes inside this scope, call [`ManualOwningScope::scope`] on the returned scope.
///
/// If an [`wgpu::CommandEncoder`] is passed but the [`wgpu::Device`]
/// does not support [`wgpu::Features::TIMESTAMP_QUERY_INSIDE_ENCODERS`], no gpu timer will be queried and the scope will
/// not show up in the final results.
/// If an [`wgpu::ComputePass`] or [`wgpu::RenderPass`] is passed but the [`wgpu::Device`]
/// does not support [`wgpu::Features::TIMESTAMP_QUERY_INSIDE_PASSES`], no scope will be opened.
///
/// If [`GpuProfilerSettings::enable_debug_groups`] is true, a debug group will be pushed on the encoder or pass.
#[must_use]
#[track_caller]
#[inline]
pub fn manual_owning_scope<'a, Recorder: ProfilerCommandRecorder>(
&'a self,
label: impl Into<String>,
mut encoder_or_pass: Recorder,
device: &wgpu::Device,
) -> ManualOwningScope<'a, Recorder> {
let scope = self.begin_query(label, &mut encoder_or_pass, device);
ManualOwningScope {
profiler: self,
recorder: encoder_or_pass,
scope: Some(scope),
}
}
/// Starts a new profiler query on the given encoder or rendering/compute pass (if enabled).
///
/// The returned query *must* be closed by calling [`GpuProfiler::end_query`] with the same encoder/pass,
/// even if timer queries are disabled.
/// To do this automatically, use [`GpuProfiler::scope`]/[`GpuProfiler::owning_scope`] instead.
///
/// If an [`wgpu::CommandEncoder`] is passed but the [`wgpu::Device`]
/// does not support [`wgpu::Features::TIMESTAMP_QUERY_INSIDE_ENCODERS`], no gpu timer will be queried and the scope will
/// not show up in the final results.
/// If an [`wgpu::ComputePass`] or [`wgpu::RenderPass`] is passed but the [`wgpu::Device`]
/// does not support [`wgpu::Features::TIMESTAMP_QUERY_INSIDE_PASSES`], no timer queries will be allocated.
///
/// If [`GpuProfilerSettings::enable_debug_groups`] is true, a debug group will be pushed on the encoder or pass.
#[track_caller]
#[must_use]
pub fn begin_query<Recorder: ProfilerCommandRecorder>(
&self,
label: impl Into<String>,
encoder_or_pass: &mut Recorder,
device: &wgpu::Device,
) -> GpuProfilerQuery {
let is_for_pass_timestamp_writes = false;
let mut query = self.begin_query_internal(
label.into(),
is_for_pass_timestamp_writes,
encoder_or_pass,
device,
);
if let Some(timer_query) = &mut query.timer_query_pair {
encoder_or_pass
.write_timestamp(&timer_query.pool.query_set, timer_query.start_query_idx);
timer_query.usage_state = QueryPairUsageState::OnlyStartWritten;
};
if self.settings.enable_debug_groups {
encoder_or_pass.push_debug_group(&query.label);
query.has_debug_group = true;
}
query
}
/// Starts a new profiler query to be used for render/compute pass timestamp writes.
///
/// The returned query *must* be closed by calling [`GpuProfiler::end_query`], even if timer queries are disabled.
/// To do this automatically, use [`Scope::scoped_render_pass`]/[`Scope::scoped_compute_pass`] instead.
///
/// Call [`GpuProfilerQuery::render_pass_timestamp_writes`] or [`GpuProfilerQuery::compute_pass_timestamp_writes`]
/// to acquire the corresponding [`wgpu::RenderPassTimestampWrites`]/[`wgpu::ComputePassTimestampWrites`] object.
///
/// If the [`wgpu::Device`] does not support [`wgpu::Features::TIMESTAMP_QUERY`], no gpu timer will be reserved.
///
/// Unlike [`GpuProfiler::begin_query`] this will not create a debug scope,
/// in order to not force passing of the same encoder/pass to [`GpuProfiler::end_query`].
/// (this is needed to relax resource tracking requirements a bit, making it easier to implement the automatic scopes)
pub fn begin_pass_query(
&self,
label: impl Into<String>,
encoder: &mut wgpu::CommandEncoder,
device: &wgpu::Device,
) -> GpuProfilerQuery {
let is_for_pass_timestamp_writes = true;
let mut query =
self.begin_query_internal(label.into(), is_for_pass_timestamp_writes, encoder, device);
if let Some(timer_query) = &mut query.timer_query_pair {
timer_query.usage_state = QueryPairUsageState::ReservedForPassTimestampWrites;
}
query
}
/// Ends passed query.
///
/// If the passed query was opened with [`GpuProfiler::begin_query`], the passed encoder or pass must be the same
/// as when the query was opened.
pub fn end_query<Recorder: ProfilerCommandRecorder>(
&self,
encoder_or_pass: &mut Recorder,
mut query: GpuProfilerQuery,
) {
if let Some(timer_query) = &mut query.timer_query_pair {
match timer_query.usage_state {
QueryPairUsageState::Reserved => {
unreachable!("Query pair has been reserved but isn't used for anything!")
}
QueryPairUsageState::ReservedForPassTimestampWrites => {
// No need to do a timestamp write, this is handled by wgpu.
}
QueryPairUsageState::OnlyStartWritten => {
encoder_or_pass.write_timestamp(
&timer_query.pool.query_set,
timer_query.start_query_idx + 1,
);
timer_query.usage_state = QueryPairUsageState::BothStartAndEndWritten;
}
QueryPairUsageState::BothStartAndEndWritten => {
unreachable!("Query pair has already been used!")
}
}
}
#[cfg(feature = "tracy")]
if let Some(ref mut tracy_scope) = query.tracy_scope {
tracy_scope.end_zone();
}
if query.has_debug_group {
encoder_or_pass.pop_debug_group();
}
let send_result = self.active_frame.closed_query_sender.send(query);
// The only way we can fail sending the query is if the receiver has been dropped.
// Since it sits on `active_frame` as well, there's no way for this to happen!
debug_assert!(send_result.is_ok());
// Count queries even if we haven't processed this one, makes experiences more consistent
// if there's a lack of support for some queries.
self.num_open_queries.fetch_sub(1, Ordering::Release);
}
/// Puts query resolve commands in the encoder for all unresolved, pending queries of the active profiler frame.
///
/// Note that you do *not* need to do this for every encoder, it is sufficient do do this once per frame as long
/// as you submit the corresponding command buffer after all others that may have opened queries in the same frame.
/// (It does not matter if the passed encoder itself has previously opened queries or not.)
/// If you were to make this part of a command buffer that is enqueued before any other that has
/// opened queries in the same profiling frame, no failure will occur but some timing results may be invalid.
///
/// It is advised to call this only once at the end of a profiling frame, but it is safe to do so several times.
///
///
/// Implementation note:
/// This method could be made `&self`, taking the internal lock on the query pools.
/// However, the intended use is to call this once at the end of a frame, so we instead
/// encourage this explicit sync point and avoid the lock.
pub fn resolve_queries(&mut self, encoder: &mut wgpu::CommandEncoder) {
let query_pools = self.active_frame.query_pools.get_mut();
for query_pool in query_pools.used_pools.iter_mut() {
// We sync with the last update of num_used_query (which has Release semantics)
// mostly to be on the safe side - it happened inside a lock which gives it release semantics anyways
// but the concern is that if we don't acquire here, we may miss on other side prior effects of the query begin.
let num_used_queries = query_pool.num_used_queries.load(Ordering::Acquire);
let num_resolved_queries = query_pool.num_resolved_queries.load(Ordering::Acquire);
if num_resolved_queries == num_used_queries {
continue;
}
debug_assert!(query_pool.capacity >= num_used_queries);
debug_assert!(num_resolved_queries < num_used_queries);
// Resolve into offset 0 of the resolve buffer - this way we don't have to worry about
// the offset restrictions on resolve buffers (`wgpu::QUERY_RESOLVE_BUFFER_ALIGNMENT`)
// and we copy it anyways.
encoder.resolve_query_set(
&query_pool.query_set,
num_resolved_queries..num_used_queries,
&query_pool.resolve_buffer,
0,
);
// Copy the newly resolved queries into the read buffer, making sure
// that we don't override any of the results that are already there.
let destination_offset = (num_resolved_queries * wgpu::QUERY_SIZE) as u64;
let copy_size = ((num_used_queries - num_resolved_queries) * wgpu::QUERY_SIZE) as u64;
encoder.copy_buffer_to_buffer(
&query_pool.resolve_buffer,
0,
&query_pool.read_buffer,
destination_offset,
copy_size,
);
query_pool
.num_resolved_queries
.store(num_used_queries, Ordering::Release);
}
}
/// Marks the end of a frame.
///
/// Needs to be called **after** submitting any encoder used in the current profiler frame.
///
/// Fails if there are still open queries or unresolved queries.
pub fn end_frame(&mut self) -> Result<(), EndFrameError> {
let num_open_queries = self.num_open_queries.load(Ordering::Acquire);
if num_open_queries != 0 {
return Err(EndFrameError::UnclosedQueries(num_open_queries));
}
let query_pools = self.active_frame.query_pools.get_mut();
let mut new_pending_frame = PendingFrame {
query_pools: std::mem::take(&mut query_pools.used_pools),
closed_query_by_parent_handle: HashMap::new(),
mapped_buffers: Arc::new(AtomicU32::new(0)),
};
for query in self.active_frame.closed_query_receiver.get_mut().try_iter() {
new_pending_frame
.closed_query_by_parent_handle
.entry(query.parent_handle)
.or_default()
.push(query);
}
// All loads of pool.num_used_queries are Relaxed since we assume,
// that we already acquired the state during `resolve_queries` and no further otherwise unobserved
// modifications happened since then.
let num_unresolved_queries = new_pending_frame
.query_pools
.iter()
.map(|pool| {
pool.num_used_queries.load(Ordering::Relaxed)
- pool.num_resolved_queries.load(Ordering::Relaxed)
})
.sum();
if num_unresolved_queries != 0 {
return Err(EndFrameError::UnresolvedQueries(num_unresolved_queries));
}
// Next time we create a new query pool, we want it to be at least as big to hold all queries of this frame.
self.size_for_new_query_pools = self
.size_for_new_query_pools
.max(
new_pending_frame
.query_pools
.iter()
.map(|pool| pool.num_used_queries.load(Ordering::Relaxed))
.sum(),
)
.min(QUERY_SET_MAX_QUERIES);
// Make sure we don't overflow.
if self.pending_frames.len() == self.settings.max_num_pending_frames {
// Drop previous (!) frame.
// Dropping the oldest frame could get us into an endless cycle where we're never able to complete
// any pending frames as the ones closest to completion would be evicted.
if let Some(dropped_frame) = self.pending_frames.pop() {
// Drop queries first since they still have references to the query pools that we want to reuse.
drop(dropped_frame.closed_query_by_parent_handle);
// Mark the frame as dropped. We'll give back the query pools once the mapping is done.
// Any previously issued map_async call that haven't finished yet, will invoke their callback with mapping abort.
self.reset_and_cache_unused_query_pools(dropped_frame.query_pools);
}
}
// Map all buffers.
for pool in new_pending_frame.query_pools.iter_mut() {
let mapped_buffers = new_pending_frame.mapped_buffers.clone();
pool.read_buffer
.slice(0..(pool.num_used_queries.load(Ordering::Relaxed) * wgpu::QUERY_SIZE) as u64)
.map_async(wgpu::MapMode::Read, move |mapping_result| {
// Mapping should not fail unless it was cancelled due to the frame being dropped.
match mapping_result {
Err(_) => {
// We only want to ignore the error iff the mapping has been aborted by us (due to a dropped frame, see above).
// In any other case, we need should panic as this would imply something went seriously sideways.
//
// As of writing, this is not yet possible in wgpu, see https://github.com/gfx-rs/wgpu/pull/2939
}
Ok(()) => {
mapped_buffers.fetch_add(1, std::sync::atomic::Ordering::Release);
}
}
});
}
// Enqueue
self.pending_frames.push(new_pending_frame);
assert!(self.pending_frames.len() <= self.settings.max_num_pending_frames);
Ok(())
}
/// Checks if all timer queries for the oldest pending finished frame are done and returns that snapshot if any.
///
/// `timestamp_period`:
/// The timestamp period of the device. Pass the result of [`wgpu::Queue::get_timestamp_period()`].
/// Note that some implementations (Chrome as of writing) may converge to a timestamp period while the application is running,
/// so caching this value is usually not recommended.
pub fn process_finished_frame(
&mut self,
timestamp_period: f32,
) -> Option<Vec<GpuTimerQueryResult>> {
let frame = self.pending_frames.first_mut()?;
// We only process if all mappings succeed.
if frame
.mapped_buffers
.load(std::sync::atomic::Ordering::Acquire)
!= frame.query_pools.len() as u32
{
return None;
}
let PendingFrame {
query_pools,
mut closed_query_by_parent_handle,
mapped_buffers: _,
} = self.pending_frames.remove(0);
let results = {
let timestamp_to_sec = timestamp_period as f64 / 1000.0 / 1000.0 / 1000.0;
Self::process_timings_recursive(
timestamp_to_sec,
&mut closed_query_by_parent_handle,
ROOT_QUERY_HANDLE,
)
};
// Ensure that closed queries no longer hold references to the query pools.
// `process_timings_recursive` should have handled this already.
debug_assert!(closed_query_by_parent_handle.is_empty());
drop(closed_query_by_parent_handle); // But just in case, we make sure to drop it here even if above debug assertion fails.
self.reset_and_cache_unused_query_pools(query_pools);
Some(results)
}
}
// --------------------------------------------------------------------------------
// Internals
// --------------------------------------------------------------------------------
const QUERY_SET_MAX_QUERIES: u32 = wgpu::QUERY_SET_MAX_QUERIES;
/// Returns true if a timestamp query is supported.
fn timestamp_query_support<Recorder: ProfilerCommandRecorder>(
is_for_pass_timestamp_writes: bool,
encoder_or_pass: &mut Recorder,
features: wgpu::Features,
) -> bool {
let required_feature = if is_for_pass_timestamp_writes {
wgpu::Features::TIMESTAMP_QUERY
} else if encoder_or_pass.is_pass() {
wgpu::Features::TIMESTAMP_QUERY_INSIDE_PASSES
} else {
wgpu::Features::TIMESTAMP_QUERY_INSIDE_ENCODERS
};
features.contains(required_feature)
}
impl GpuProfiler {
fn next_scope_tree_handle(&self) -> GpuTimerQueryTreeHandle {
// Relaxed is fine, we just want a number that nobody uses this frame already.
let mut handle = self.next_query_handle.fetch_add(1, Ordering::Relaxed);
// We don't ever expect to run out of handles during a single frame, but who knows how long the app runs.
while handle == ROOT_QUERY_HANDLE {
handle = self.next_query_handle.fetch_add(1, Ordering::Relaxed);
}
handle
}
fn reset_and_cache_unused_query_pools(&mut self, mut discarded_pools: Vec<Arc<QueryPool>>) {
let capacity_threshold = self.size_for_new_query_pools / 2;
for pool in discarded_pools.drain(..) {
// If the pool is truly unused now, it's ref count should be 1!
// If we use it anywhere else we have an implementation bug.
let mut pool = Arc::into_inner(pool).expect("Pool still in use");
pool.reset();
// If a pool was less than half of the size of the max frame, then we don't keep it.
// This way we're going to need less pools in upcoming frames and thus have less overhead in the long run.
// If timer queries were disabled, we also don't keep any pools.
if self.settings.enable_timer_queries && pool.capacity >= capacity_threshold {
self.active_frame
.query_pools
.get_mut()
.unused_pools
.push(pool);
}
}
}
fn try_reserve_query_pair(pool: &Arc<QueryPool>) -> Option<ReservedTimerQueryPair> {
let mut num_used_queries = pool.num_used_queries.load(Ordering::Relaxed);
loop {
if pool.capacity < num_used_queries + 2 {
// This pool is out of capacity, we failed the operation.
return None;
}
match pool.num_used_queries.compare_exchange_weak(
num_used_queries,
num_used_queries + 2,
// Write to num_used_queries with release semantics to be on the safe side.
// (It doesn't look like there's other side effects that we need to publish.)
Ordering::Release,
// No barrier for the failure case.
// The only thing we have to acquire is the pool's capacity which is constant and
// was definitely acquired by the RWLock prior to this call.
Ordering::Relaxed,
) {
Ok(_) => {
// We successfully acquired two queries!
return Some(ReservedTimerQueryPair {
pool: pool.clone(),
start_query_idx: num_used_queries,
usage_state: QueryPairUsageState::Reserved,
});
}
Err(updated) => {
// Someone else acquired queries in the meantime, try again.
num_used_queries = updated;
}
}
}
}
// Reserves two query objects.
// Our query pools always have an even number of queries, so we know the next query is the next in the same pool.
fn reserve_query_pair(&self, device: &wgpu::Device) -> ReservedTimerQueryPair {
// First, try to allocate from current top pool.
// Requires taking a read lock on the current query pool.
{
let query_pools = self.active_frame.query_pools.read();
if let Some(pair) = query_pools
.used_pools
.last()
.and_then(Self::try_reserve_query_pair)
{
return pair;
}
}
// If this didn't work, we may need to add a new pool.
// Requires taking a write lock on the current query pool.
{
let mut query_pools = self.active_frame.query_pools.write();
// It could be that by now, another thread has already added a new pool!
// This is a bit unfortunate because it means we unnecessarily took a write lock, but it seems hard to get around this.
if let Some(pair) = query_pools
.used_pools
.last()
.and_then(Self::try_reserve_query_pair)
{
return pair;
}
// Now we know for certain that the last pool is exhausted, so add a new one!
let new_pool = if let Some(reused_pool) = query_pools.unused_pools.pop() {
// First check if there's an unused pool we can take.
Arc::new(reused_pool)
} else {
// If we can't, create a new pool that is as big as all previous pools combined.
Arc::new(QueryPool::new(
query_pools
.used_pools
.iter()
.map(|pool| pool.capacity)
.sum::<u32>()
.max(self.size_for_new_query_pools)
.min(QUERY_SET_MAX_QUERIES),
device,
))
};
let pair = Self::try_reserve_query_pair(&new_pool)
.expect("Freshly reserved pool doesn't have enough capacity");
query_pools.used_pools.push(new_pool);
pair
}
}
#[track_caller]
#[must_use]
fn begin_query_internal<Recorder: ProfilerCommandRecorder>(
&self,
label: String,
is_for_pass_timestamp_writes: bool,
encoder_or_pass: &mut Recorder,
device: &wgpu::Device,
) -> GpuProfilerQuery {
// Give opening/closing queries acquire/release semantics:
// This way, we won't get any nasty surprises when observing zero open queries.
self.num_open_queries.fetch_add(1, Ordering::Acquire);
let query = if self.settings.enable_timer_queries
&& timestamp_query_support(
is_for_pass_timestamp_writes,
encoder_or_pass,
device.features(),
) {
Some(self.reserve_query_pair(device))
} else {
None
};
let _tracy_scope = if self.settings.enable_timer_queries {
#[cfg(feature = "tracy")]
{
let location = std::panic::Location::caller();
self.tracy_context.as_ref().and_then(|c| {
c.span_alloc(&label, "", location.file(), location.line())
.ok()
})
}
#[cfg(not(feature = "tracy"))]
Option::<()>::None
} else {
None
};
let pid = if cfg!(target_arch = "wasm32") {
0
} else {
std::process::id()
};
GpuProfilerQuery {
label,
pid,
tid: std::thread::current().id(),
timer_query_pair: query,
handle: self.next_scope_tree_handle(),
parent_handle: ROOT_QUERY_HANDLE,
has_debug_group: false,
#[cfg(feature = "tracy")]
tracy_scope: _tracy_scope,
}
}
fn process_timings_recursive(
timestamp_to_sec: f64,
closed_scope_by_parent_handle: &mut HashMap<GpuTimerQueryTreeHandle, Vec<GpuProfilerQuery>>,
parent_handle: GpuTimerQueryTreeHandle,
) -> Vec<GpuTimerQueryResult> {
let Some(queries_with_same_parent) = closed_scope_by_parent_handle.remove(&parent_handle)
else {
return Vec::new();
};
queries_with_same_parent
.into_iter()
.map(|mut scope| {
// Note that inactive queries may still have nested queries, it's therefore important we process all of them.
// In particular, this happens if only `wgpu::Features::TIMESTAMP_QUERY`` is enabled and `timestamp_writes`
// on passes are nested inside inactive encoder timer queries.
let time = scope.timer_query_pair.take().map(|query| {
// Read timestamp from buffer.
// By design timestamps for start/end are consecutive.
let offset = (query.start_query_idx * wgpu::QUERY_SIZE) as u64;
let buffer_slice = &query
.pool
.read_buffer
.slice(offset..(offset + (wgpu::QUERY_SIZE * 2) as u64))
.get_mapped_range();
let start_raw = u64::from_le_bytes(
buffer_slice[0..wgpu::QUERY_SIZE as usize]
.try_into()
.unwrap(),
);
let end_raw = u64::from_le_bytes(
buffer_slice[wgpu::QUERY_SIZE as usize..(wgpu::QUERY_SIZE as usize) * 2]
.try_into()
.unwrap(),
);
#[cfg(feature = "tracy")]
if let Some(tracy_scope) = scope.tracy_scope.take() {
tracy_scope.upload_timestamp(start_raw as i64, end_raw as i64);
}
(start_raw as f64 * timestamp_to_sec)..(end_raw as f64 * timestamp_to_sec)
});
let nested_queries = Self::process_timings_recursive(
timestamp_to_sec,
closed_scope_by_parent_handle,
scope.handle,
);
GpuTimerQueryResult {
label: std::mem::take(&mut scope.label),
time,
nested_queries,
pid: scope.pid,
tid: scope.tid,
}
})
.collect::<Vec<_>>()
}
}
#[derive(PartialEq, Eq)]
pub enum QueryPairUsageState {
/// Transitional state used upon creation.
Reserved,
/// Don't do manual timestamp writes, wgpu is expected to do them for us.
ReservedForPassTimestampWrites,
/// Start query has been used, end query is still available.
OnlyStartWritten,
/// Both start & end query have been used.
BothStartAndEndWritten,
}
pub struct ReservedTimerQueryPair {
/// [`QueryPool`] on which both start & end queries of the scope are done.
///
/// By putting an arc here instead of an index into a vec, we don't need
/// need to take any locks upon closing a profiling scope.
pub pool: Arc<QueryPool>,
/// Query index at which the scope begins.
/// The query after this is reserved for the end of the scope.
pub start_query_idx: u32,
/// Current use of the query pair.
pub usage_state: QueryPairUsageState,
}
/// A pool of queries, consisting of a single queryset & buffer for query results.
#[derive(Debug)]
pub struct QueryPool {
pub query_set: wgpu::QuerySet,
resolve_buffer: wgpu::Buffer,
read_buffer: wgpu::Buffer,
capacity: u32,
num_used_queries: AtomicU32,
num_resolved_queries: AtomicU32,
}
impl QueryPool {
const MIN_CAPACITY: u32 = 32;
fn new(capacity: u32, device: &wgpu::Device) -> Self {
QueryPool {
query_set: device.create_query_set(&wgpu::QuerySetDescriptor {
label: Some("GpuProfiler - Query Set"),
ty: wgpu::QueryType::Timestamp,
count: capacity,
}),
resolve_buffer: device.create_buffer(&wgpu::BufferDescriptor {
label: Some("GpuProfiler - Query Resolve Buffer"),
size: (wgpu::QUERY_SIZE * capacity) as u64,
usage: wgpu::BufferUsages::QUERY_RESOLVE | wgpu::BufferUsages::COPY_SRC,
mapped_at_creation: false,
}),
read_buffer: device.create_buffer(&wgpu::BufferDescriptor {
label: Some("GpuProfiler - Query Read Buffer"),
size: (wgpu::QUERY_SIZE * capacity) as u64,
usage: wgpu::BufferUsages::COPY_DST | wgpu::BufferUsages::MAP_READ,
mapped_at_creation: false,
}),
capacity,
num_used_queries: AtomicU32::new(0),
num_resolved_queries: AtomicU32::new(0),
}
}
fn reset(&mut self) {
self.num_used_queries = AtomicU32::new(0);
self.num_resolved_queries = AtomicU32::new(0);
self.read_buffer.unmap();
}
}
#[derive(Default)]
struct PendingFramePools {
/// List of all pools used in this frame.
/// The last pool is the one new profiling queries will try to make timer queries into.
used_pools: Vec<Arc<QueryPool>>,
/// List of unused pools recycled from previous frames.
unused_pools: Vec<QueryPool>,
}
/// Internal handle to building a tree of profiling queries.
pub type GpuTimerQueryTreeHandle = u32;
/// Handle for the root scope.
pub const ROOT_QUERY_HANDLE: GpuTimerQueryTreeHandle = u32::MAX;
struct ActiveFrame {
query_pools: RwLock<PendingFramePools>,
/// Closed queries get send to this channel.
///
/// Note that channel is still overkill for what we want here:
/// We're in a multi producer situation, *but* the single consumer is known to be only
/// active in a mut context, i.e. while we're consuming we know that we're not producing.
/// We have to wrap it in a Mutex because the channel is not Sync, but we actually never lock it
/// since we only ever access it in a `mut` context.
closed_query_sender: std::sync::mpsc::Sender<GpuProfilerQuery>,
closed_query_receiver: Mutex<std::sync::mpsc::Receiver<GpuProfilerQuery>>,
}
struct PendingFrame {
query_pools: Vec<Arc<QueryPool>>,
closed_query_by_parent_handle: HashMap<GpuTimerQueryTreeHandle, Vec<GpuProfilerQuery>>,
/// Keeps track of the number of buffers in the query pool that have been mapped successfully.
mapped_buffers: std::sync::Arc<std::sync::atomic::AtomicU32>,
}