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[core] Add lock::observing module, for analyzing lock acquisition.

Browse Source 
Add a new module `lock::observing`, enabled by the `observe-locks`
feature, that records all nested lock acquisitions in trace files.

Add a new utility to the workspace, `lock-analyzer`, that reads the
files written by the `observe-locks` feature and writes out a new
`define_lock_ranks!` macro invocation that covers all observed lock
usage, along with comments giving the held and acquired source
locations.
This commit is contained in:
Jim Blandy 2024-04-22 10:59:21 -07:00 committed by Erich Gubler
parent 3f6f1d766c
commit bbdbafdf8a
10 changed files with 796 additions and 21 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

9
Cargo.lock generated
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@ -1766,6 +1766,15 @@ version = "0.4.1"
source = "registry+https://github.com/rust-lang/crates.io-index"
checksum = "b4ce301924b7887e9d637144fdade93f9dfff9b60981d4ac161db09720d39aa5"
[[package]]
name = "lock-analyzer"
version = "22.0.0"
dependencies = [
"anyhow",
"ron",
"serde",
]
[[package]]
name = "lock_api"
version = "0.4.12"

2
Cargo.toml
View File

@ -7,6 +7,7 @@ members = [
# default members
"benches",
"examples",
"lock-analyzer",
"naga-cli",
"naga",
"naga/fuzz",
@ -24,6 +25,7 @@ exclude = []
default-members = [
"benches",
"examples",
"lock-analyzer",
"naga-cli",
"naga",
"naga/fuzz",

18
lock-analyzer/Cargo.toml Normal file
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@ -0,0 +1,18 @@
[package]
name = "lock-analyzer"
edition.workspace = true
rust-version.workspace = true
keywords.workspace = true
license.workspace = true
homepage.workspace = true
repository.workspace = true
version.workspace = true
authors.workspace = true
[dependencies]
ron.workspace = true
anyhow.workspace = true
[dependencies.serde]
workspace = true
features = ["serde_derive"]

254
lock-analyzer/src/main.rs Normal file
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@ -0,0 +1,254 @@
//! Analyzer for data produced by `wgpu-core`'s `observe_locks` feature.
//!
//! When `wgpu-core`'s `observe_locks` feature is enabled, if the
//! `WGPU_CORE_LOCK_OBSERVE_DIR` environment variable is set to the
//! path of an existing directory, then every thread that acquires a
//! lock in `wgpu-core` will write its own log file to that directory.
//! You can then run this program to read those files and summarize
//! the results.
//!
//! This program also consults the `WGPU_CORE_LOCK_OBSERVE_DIR`
//! environment variable to find the log files written by `wgpu-core`.
//!
//! See `wgpu_core/src/lock/observing.rs` for a general explanation of
//! this analysis.
use std::sync::Arc;
use std::{
collections::{btree_map::Entry, BTreeMap, BTreeSet, HashMap},
fmt,
path::PathBuf,
};
use anyhow::{Context, Result};
fn main() -> Result<()> {
let mut ranks: BTreeMap<u32, Rank> = BTreeMap::default();
let Ok(dir) = std::env::var("WGPU_CORE_LOCK_OBSERVE_DIR") else {
eprintln!(concat!(
"Please set the `WGPU_CORE_LOCK_OBSERVE_DIR` environment variable\n",
"to the path of the directory containing the files written by\n",
"`wgpu-core`'s `observe_locks` feature."
));
anyhow::bail!("`WGPU_CORE_LOCK_OBSERVE_DIR` environment variable is not set");
};
let entries =
std::fs::read_dir(&dir).with_context(|| format!("failed to read directory {dir}"))?;
for entry in entries {
let entry = entry.with_context(|| format!("failed to read directory entry from {dir}"))?;
let name = PathBuf::from(&entry.file_name());
let Some(extension) = name.extension() else {
eprintln!("Ignoring {}", name.display());
continue;
};
if extension != "ron" {
eprintln!("Ignoring {}", name.display());
continue;
}
let contents = std::fs::read(entry.path())
.with_context(|| format!("failed to read lock observations from {}", name.display()))?;
// The addresses of `&'static Location<'static>` values could
// vary from run to run.
let mut locations: HashMap<u64, Arc<Location>> = HashMap::default();
for line in contents.split(|&b| b == b'\n') {
if line.is_empty() {
continue;
}
let action = ron::de::from_bytes::<Action>(line)
.with_context(|| format!("Error parsing action from {}", name.display()))?;
match action {
Action::Location {
address,
file,
line,
column,
} => {
let file = match file.split_once("src/") {
Some((_, after)) => after.to_string(),
None => file,
};
assert!(locations
.insert(address, Arc::new(Location { file, line, column }))
.is_none());
}
Action::Rank {
bit,
member_name,
const_name,
} => match ranks.entry(bit) {
Entry::Occupied(occupied) => {
let rank = occupied.get();
assert_eq!(rank.member_name, member_name);
assert_eq!(rank.const_name, const_name);
}
Entry::Vacant(vacant) => {
vacant.insert(Rank {
member_name,
const_name,
acquisitions: BTreeMap::default(),
});
}
},
Action::Acquisition {
older_rank,
older_location,
newer_rank,
newer_location,
} => {
let older_location = locations[&older_location].clone();
let newer_location = locations[&newer_location].clone();
ranks
.get_mut(&older_rank)
.unwrap()
.acquisitions
.entry(newer_rank)
.or_default()
.entry(older_location)
.or_default()
.insert(newer_location);
}
}
}
}
for older_rank in ranks.values() {
if older_rank.is_leaf() {
// We'll print leaf locks separately, below.
continue;
}
println!(
" rank {} {:?} followed by {{",
older_rank.const_name, older_rank.member_name
);
let mut acquired_any_leaf_locks = false;
let mut first_newer = true;
for (newer_rank, locations) in &older_rank.acquisitions {
// List acquisitions of leaf locks at the end.
if ranks[newer_rank].is_leaf() {
acquired_any_leaf_locks = true;
continue;
}
if !first_newer {
println!();
}
for (older_location, newer_locations) in locations {
if newer_locations.len() == 1 {
for newer_loc in newer_locations {
println!(" // holding {older_location} while locking {newer_loc}");
}
} else {
println!(" // holding {older_location} while locking:");
for newer_loc in newer_locations {
println!(" // {newer_loc}");
}
}
}
println!(" {},", ranks[newer_rank].const_name);
first_newer = false;
}
if acquired_any_leaf_locks {
// We checked that older_rank isn't a leaf lock, so we
// must have printed something above.
if !first_newer {
println!();
}
println!(" // leaf lock acquisitions:");
for newer_rank in older_rank.acquisitions.keys() {
if !ranks[newer_rank].is_leaf() {
continue;
}
println!(" {},", ranks[newer_rank].const_name);
}
}
println!(" }};");
println!();
}
for older_rank in ranks.values() {
if !older_rank.is_leaf() {
continue;
}
println!(
" rank {} {:?} followed by {{ }};",
older_rank.const_name, older_rank.member_name
);
}
Ok(())
}
#[derive(Debug, serde::Deserialize)]
#[serde(deny_unknown_fields)]
enum Action {
/// A location that we will refer to in later actions.
Location {
address: LocationAddress,
file: String,
line: u32,
column: u32,
},
/// A lock rank that we will refer to in later actions.
Rank {
bit: u32,
member_name: String,
const_name: String,
},
/// An attempt to acquire a lock while holding another lock.
Acquisition {
/// The number of the already acquired lock's rank.
older_rank: u32,
/// The source position at which we acquired it. Specifically,
/// its `Location`'s address, as an integer.
older_location: LocationAddress,
/// The number of the rank of the lock we are acquiring.
newer_rank: u32,
/// The source position at which we are acquiring it.
/// Specifically, its `Location`'s address, as an integer.
newer_location: LocationAddress,
},
}
/// The memory address at which the `Location` was stored in the
/// observed process.
///
/// This is not `usize` because it does not represent an address in
/// this `lock-analyzer` process. We might generate logs on a 64-bit
/// machine and analyze them on a 32-bit machine. The `u64` type is a
/// reasonable universal type for addresses on any machine.
type LocationAddress = u64;
struct Rank {
member_name: String,
const_name: String,
acquisitions: BTreeMap<u32, LocationSet>,
}
impl Rank {
fn is_leaf(&self) -> bool {
self.acquisitions.is_empty()
}
}
type LocationSet = BTreeMap<Arc<Location>, BTreeSet<Arc<Location>>>;
#[derive(Eq, Ord, PartialEq, PartialOrd)]
struct Location {
file: String,
line: u32,
column: u32,
}
impl fmt::Display for Location {
fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
write!(f, "{}:{}", self.file, self.line)
}
}

3
wgpu-core/Cargo.toml
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@ -57,6 +57,9 @@ serde = ["dep:serde", "wgt/serde", "arrayvec/serde"]
## Enable API tracing.
trace = ["dep:ron", "serde", "naga/serialize"]
## Enable lock order observation.
observe_locks = ["dep:ron", "serde/serde_derive"]
## Enable API replaying
replay = ["serde", "naga/deserialize"]

1
wgpu-core/src/device/resource.rs
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@ -341,6 +341,7 @@ 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()
}

25
wgpu-core/src/lock/mod.rs
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@ -9,17 +9,22 @@
//! checks to ensure that each thread acquires locks only in a
//! specific order, to prevent deadlocks.
//!
//! - The [`observing`] module defines lock types that record
//! `wgpu-core`'s lock acquisition activity to disk, for later
//! analysis by the `lock-analyzer` binary.
//!
//! - The [`vanilla`] module defines lock types that are
//! uninstrumented, no-overhead wrappers around the standard lock
//! types.
//!
//! (We plan to add more wrappers in the future.)
//!
//! If the `wgpu_validate_locks` config is set (for example, with
//! `RUSTFLAGS='--cfg wgpu_validate_locks'`), `wgpu-core` uses the
//! [`ranked`] module's locks. We hope to make this the default for
//! debug builds soon.
//!
//! If the `observe_locks` feature is enabled, `wgpu-core` uses the
//! [`observing`] module's locks.
//!
//! Otherwise, `wgpu-core` uses the [`vanilla`] module's locks.
//!
//! [`Mutex`]: parking_lot::Mutex
@ -31,11 +36,19 @@ pub mod rank;
#[cfg_attr(not(wgpu_validate_locks), allow(dead_code))]
mod ranked;
#[cfg_attr(wgpu_validate_locks, allow(dead_code))]
#[cfg(feature = "observe_locks")]
mod observing;
#[cfg_attr(any(wgpu_validate_locks, feature = "observe_locks"), allow(dead_code))]
mod vanilla;
#[cfg(wgpu_validate_locks)]
pub use ranked::{Mutex, MutexGuard, RwLock, RwLockReadGuard, RwLockWriteGuard};
use ranked as chosen;
#[cfg(not(wgpu_validate_locks))]
pub use vanilla::{Mutex, MutexGuard, RwLock, RwLockReadGuard, RwLockWriteGuard};
#[cfg(feature = "observe_locks")]
use observing as chosen;
#[cfg(not(any(wgpu_validate_locks, feature = "observe_locks")))]
use vanilla as chosen;
pub use chosen::{Mutex, MutexGuard, RwLock, RwLockReadGuard, RwLockWriteGuard};

475
wgpu-core/src/lock/observing.rs Normal file
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@ -0,0 +1,475 @@
//! Lock types that observe lock acquisition order.
//!
//! This module's [`Mutex`] type is instrumented to observe the
//! nesting of `wgpu-core` lock acquisitions. Whenever `wgpu-core`
//! acquires one lock while it is already holding another, we note
//! that nesting pair. This tells us what the [`LockRank::followers`]
//! set for each lock would need to include to accommodate
//! `wgpu-core`'s observed behavior.
//!
//! When `wgpu-core`'s `observe_locks` feature is enabled, if the
//! `WGPU_CORE_LOCK_OBSERVE_DIR` environment variable is set to the
//! path of an existing directory, then every thread that acquires a
//! lock in `wgpu-core` will write its own log file to that directory.
//! You can then run the `wgpu` workspace's `lock-analyzer` binary to
//! read those files and summarize the results. The output from
//! `lock-analyzer` has the same form as the lock ranks given in
//! [`lock/rank.rs`].
//!
//! If the `WGPU_CORE_LOCK_OBSERVE_DIR` environment variable is not
//! set, then no instrumentation takes place, and the locks behave
//! normally.
//!
//! To make sure we capture all acquisitions regardless of when the
//! program exits, each thread writes events directly to its log file
//! as they occur. A `write` system call is generally just a copy from
//! userspace into the kernel's buffer, so hopefully this approach
//! will still have tolerable performance.
//!
//! [`lock/rank.rs`]: ../../../src/wgpu_core/lock/rank.rs.html
use crate::FastHashSet;
use super::rank::{LockRank, LockRankSet};
use std::{
cell::RefCell,
fs::File,
panic::Location,
path::{Path, PathBuf},
};
/// A `Mutex` instrumented for lock acquisition order observation.
///
/// This is just a wrapper around a [`parking_lot::Mutex`], along with
/// its rank in the `wgpu_core` lock ordering.
///
/// For details, see [the module documentation][self].
pub struct Mutex<T> {
inner: parking_lot::Mutex<T>,
rank: LockRank,
}
/// A guard produced by locking [`Mutex`].
///
/// This is just a wrapper around a [`parking_lot::MutexGuard`], along
/// with the state needed to track lock acquisition.
///
/// For details, see [the module documentation][self].
pub struct MutexGuard<'a, T> {
inner: parking_lot::MutexGuard<'a, T>,
_state: LockStateGuard,
}
impl<T> Mutex<T> {
pub fn new(rank: LockRank, value: T) -> Mutex<T> {
Mutex {
inner: parking_lot::Mutex::new(value),
rank,
}
}
#[track_caller]
pub fn lock(&self) -> MutexGuard<T> {
let saved = acquire(self.rank, Location::caller());
MutexGuard {
inner: self.inner.lock(),
_state: LockStateGuard { saved },
}
}
}
impl<'a, T> std::ops::Deref for MutexGuard<'a, T> {
type Target = T;
fn deref(&self) -> &Self::Target {
self.inner.deref()
}
}
impl<'a, T> std::ops::DerefMut for MutexGuard<'a, T> {
fn deref_mut(&mut self) -> &mut Self::Target {
self.inner.deref_mut()
}
}
impl<T: std::fmt::Debug> std::fmt::Debug for Mutex<T> {
fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
self.inner.fmt(f)
}
}
/// An `RwLock` instrumented for lock acquisition order observation.
///
/// This is just a wrapper around a [`parking_lot::RwLock`], along with
/// its rank in the `wgpu_core` lock ordering.
///
/// For details, see [the module documentation][self].
pub struct RwLock<T> {
inner: parking_lot::RwLock<T>,
rank: LockRank,
}
/// A read guard produced by locking [`RwLock`] for reading.
///
/// This is just a wrapper around a [`parking_lot::RwLockReadGuard`], along with
/// the state needed to track lock acquisition.
///
/// For details, see [the module documentation][self].
pub struct RwLockReadGuard<'a, T> {
inner: parking_lot::RwLockReadGuard<'a, T>,
_state: LockStateGuard,
}
/// A write guard produced by locking [`RwLock`] for writing.
///
/// This is just a wrapper around a [`parking_lot::RwLockWriteGuard`], along
/// with the state needed to track lock acquisition.
///
/// For details, see [the module documentation][self].
pub struct RwLockWriteGuard<'a, T> {
inner: parking_lot::RwLockWriteGuard<'a, T>,
_state: LockStateGuard,
}
impl<T> RwLock<T> {
pub fn new(rank: LockRank, value: T) -> RwLock<T> {
RwLock {
inner: parking_lot::RwLock::new(value),
rank,
}
}
#[track_caller]
pub fn read(&self) -> RwLockReadGuard<T> {
let saved = acquire(self.rank, Location::caller());
RwLockReadGuard {
inner: self.inner.read(),
_state: LockStateGuard { saved },
}
}
#[track_caller]
pub fn write(&self) -> RwLockWriteGuard<T> {
let saved = acquire(self.rank, Location::caller());
RwLockWriteGuard {
inner: self.inner.write(),
_state: LockStateGuard { saved },
}
}
}
impl<'a, T> RwLockWriteGuard<'a, T> {
pub fn downgrade(this: Self) -> RwLockReadGuard<'a, T> {
RwLockReadGuard {
inner: parking_lot::RwLockWriteGuard::downgrade(this.inner),
_state: this._state,
}
}
}
impl<T: std::fmt::Debug> std::fmt::Debug for RwLock<T> {
fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
self.inner.fmt(f)
}
}
impl<'a, T> std::ops::Deref for RwLockReadGuard<'a, T> {
type Target = T;
fn deref(&self) -> &Self::Target {
self.inner.deref()
}
}
impl<'a, T> std::ops::Deref for RwLockWriteGuard<'a, T> {
type Target = T;
fn deref(&self) -> &Self::Target {
self.inner.deref()
}
}
impl<'a, T> std::ops::DerefMut for RwLockWriteGuard<'a, T> {
fn deref_mut(&mut self) -> &mut Self::Target {
self.inner.deref_mut()
}
}
/// A container that restores a prior per-thread lock state when dropped.
///
/// This type serves two purposes:
///
/// - Operations like `RwLockWriteGuard::downgrade` would like to be able to
/// destructure lock guards and reassemble their pieces into new guards, but
/// if the guard type itself implements `Drop`, we can't destructure it
/// without unsafe code or pointless `Option`s whose state is almost always
/// statically known.
///
/// - We can just implement `Drop` for this type once, and then use it in lock
/// guards, rather than implementing `Drop` separately for each guard type.
struct LockStateGuard {
/// The youngest lock that was already held when we acquired this
/// one, if any.
saved: Option<HeldLock>,
}
impl Drop for LockStateGuard {
fn drop(&mut self) {
release(self.saved)
}
}
/// Check and record the acquisition of a lock with `new_rank`.
///
/// Log the acquisition of a lock with `new_rank`, and
/// update the per-thread state accordingly.
///
/// Return the `Option<HeldLock>` state that must be restored when this lock is
/// released.
fn acquire(new_rank: LockRank, location: &'static Location<'static>) -> Option<HeldLock> {
LOCK_STATE.with_borrow_mut(|state| match *state {
ThreadState::Disabled => None,
ThreadState::Initial => {
let Ok(dir) = std::env::var("WGPU_CORE_LOCK_OBSERVE_DIR") else {
*state = ThreadState::Disabled;
return None;
};
// Create the observation log file.
let mut log = ObservationLog::create(dir)
.expect("Failed to open lock observation file (does the dir exist?)");
// Log the full set of lock ranks, so that the analysis can even see
// locks that are only acquired in isolation.
for rank in LockRankSet::all().iter() {
log.write_rank(rank);
}
// Update our state to reflect that we are logging acquisitions, and
// that we have acquired this lock.
*state = ThreadState::Enabled {
held_lock: Some(HeldLock {
rank: new_rank,
location,
}),
log,
};
// Since this is the first acquisition on this thread, we know that
// there is no prior lock held, and thus nothing to log yet.
None
}
ThreadState::Enabled {
ref mut held_lock,
ref mut log,
} => {
if let Some(ref held_lock) = held_lock {
log.write_acquisition(held_lock, new_rank, location);
}
std::mem::replace(
held_lock,
Some(HeldLock {
rank: new_rank,
location,
}),
)
}
})
}
/// Record the release of a lock whose saved state was `saved`.
fn release(saved: Option<HeldLock>) {
LOCK_STATE.with_borrow_mut(|state| {
if let ThreadState::Enabled {
ref mut held_lock, ..
} = *state
{
*held_lock = saved;
}
});
}
thread_local! {
static LOCK_STATE: RefCell<ThreadState> = const { RefCell::new(ThreadState::Initial) };
}
/// Thread-local state for lock observation.
enum ThreadState {
/// This thread hasn't yet checked the environment variable.
Initial,
/// This thread checked the environment variable, and it was
/// unset, so this thread is not observing lock acquisitions.
Disabled,
/// Lock observation is enabled for this thread.
Enabled {
held_lock: Option<HeldLock>,
log: ObservationLog,
},
}
/// Information about a currently held lock.
#[derive(Debug, Copy, Clone)]
struct HeldLock {
/// The lock's rank.
rank: LockRank,
/// Where we acquired the lock.
location: &'static Location<'static>,
}
/// A log to which we can write observations of lock activity.
struct ObservationLog {
/// The file to which we are logging lock observations.
log_file: File,
/// [`Location`]s we've seen so far.
///
/// This is a hashset of raw pointers because raw pointers have
/// the [`Eq`] and [`Hash`] relations we want: the pointer value, not
/// the contents. There's no unsafe code in this module.
locations_seen: FastHashSet<*const Location<'static>>,
/// Buffer for serializing events, retained for allocation reuse.
buffer: Vec<u8>,
}
#[allow(trivial_casts)]
impl ObservationLog {
/// Create an observation log in `dir` for the current pid and thread.
fn create(dir: impl AsRef<Path>) -> Result<Self, std::io::Error> {
let mut path = PathBuf::from(dir.as_ref());
path.push(format!(
"locks-{}.{:?}.ron",
std::process::id(),
std::thread::current().id()
));
let log_file = File::create(&path)?;
Ok(ObservationLog {
log_file,
locations_seen: FastHashSet::default(),
buffer: Vec::new(),
})
}
/// Record the acquisition of one lock while holding another.
///
/// Log that we acquired a lock of `new_rank` at `new_location` while still
/// holding other locks, the most recently acquired of which has
/// `older_rank`.
fn write_acquisition(
&mut self,
older_lock: &HeldLock,
new_rank: LockRank,
new_location: &'static Location<'static>,
) {
self.write_location(older_lock.location);
self.write_location(new_location);
self.write_action(&Action::Acquisition {
older_rank: older_lock.rank.bit.number(),
older_location: older_lock.location as *const _ as usize,
newer_rank: new_rank.bit.number(),
newer_location: new_location as *const _ as usize,
});
}
fn write_location(&mut self, location: &'static Location<'static>) {
if self.locations_seen.insert(location) {
self.write_action(&Action::Location {
address: location as *const _ as usize,
file: location.file(),
line: location.line(),
column: location.column(),
});
}
}
fn write_rank(&mut self, rank: LockRankSet) {
self.write_action(&Action::Rank {
bit: rank.number(),
member_name: rank.member_name(),
const_name: rank.const_name(),
});
}
fn write_action(&mut self, action: &Action) {
use std::io::Write;
self.buffer.clear();
ron::ser::to_writer(&mut self.buffer, &action)
.expect("error serializing `lock::observing::Action`");
self.buffer.push(b'\n');
self.log_file
.write_all(&self.buffer)
.expect("error writing `lock::observing::Action`");
}
}
/// An action logged by a thread that is observing lock acquisition order.
///
/// Each thread's log file is a sequence of these enums, serialized
/// using the [`ron`] crate, one action per line.
///
/// Lock observation cannot assume that there will be any convenient
/// finalization point before the program exits, so in practice,
/// actions must be written immediately when they occur. This means we
/// can't, say, accumulate tables and write them out when they're
/// complete. The `lock-analyzer` binary is then responsible for
/// consolidating the data into a single table of observed transitions.
#[derive(serde::Serialize)]
enum Action {
/// A location that we will refer to in later actions.
///
/// We write one of these events the first time we see a
/// particular `Location`. Treating this as a separate action
/// simply lets us avoid repeating the content over and over
/// again in every [`Acquisition`] action.
///
/// [`Acquisition`]: Action::Acquisition
Location {
address: usize,
file: &'static str,
line: u32,
column: u32,
},
/// A lock rank that we will refer to in later actions.
///
/// We write out one these events for every lock rank at the
/// beginning of each thread's log file. Treating this as a
/// separate action simply lets us avoid repeating the names over
/// and over again in every [`Acquisition`] action.
///
/// [`Acquisition`]: Action::Acquisition
Rank {
bit: u32,
member_name: &'static str,
const_name: &'static str,
},
/// An attempt to acquire a lock while holding another lock.
Acquisition {
/// The number of the already acquired lock's rank.
older_rank: u32,
/// The source position at which we acquired it. Specifically,
/// its `Location`'s address, as an integer.
older_location: usize,
/// The number of the rank of the lock we are acquiring.
newer_rank: u32,
/// The source position at which we are acquiring it.
/// Specifically, its `Location`'s address, as an integer.
newer_location: usize,
},
}
impl LockRankSet {
/// Return the number of this rank's first member.
fn number(self) -> u32 {
self.bits().trailing_zeros()
}
}

10
wgpu-core/src/lock/rank.rs
View File

@ -71,6 +71,16 @@ macro_rules! define_lock_ranks {
_ => "<unrecognized LockRankSet bit>",
}
}
#[cfg_attr(not(feature = "observe_locks"), allow(dead_code))]
pub fn const_name(self) -> &'static str {
match self {
$(
LockRankSet:: $name => stringify!($name),
)*
_ => "<unrecognized LockRankSet bit>",
}
}
}
$(

20
wgpu-core/src/lock/ranked.rs
View File

@ -63,9 +63,7 @@ use std::{cell::Cell, panic::Location};
/// This is just a wrapper around a [`parking_lot::Mutex`], along with
/// its rank in the `wgpu_core` lock ordering.
///
/// For details, see [the module documentation][mod].
///
/// [mod]: crate::lock::ranked
/// For details, see [the module documentation][self].
pub struct Mutex<T> {
inner: parking_lot::Mutex<T>,
rank: LockRank,
@ -76,9 +74,7 @@ pub struct Mutex<T> {
/// This is just a wrapper around a [`parking_lot::MutexGuard`], along
/// with the state needed to track lock acquisition.
///
/// For details, see [the module documentation][mod].
///
/// [mod]: crate::lock::ranked
/// For details, see [the module documentation][self].
pub struct MutexGuard<'a, T> {
inner: parking_lot::MutexGuard<'a, T>,
saved: LockStateGuard,
@ -220,9 +216,7 @@ impl<T: std::fmt::Debug> std::fmt::Debug for Mutex<T> {
/// This is just a wrapper around a [`parking_lot::RwLock`], along with
/// its rank in the `wgpu_core` lock ordering.
///
/// For details, see [the module documentation][mod].
///
/// [mod]: crate::lock::ranked
/// For details, see [the module documentation][self].
pub struct RwLock<T> {
inner: parking_lot::RwLock<T>,
rank: LockRank,
@ -233,9 +227,7 @@ pub struct RwLock<T> {
/// This is just a wrapper around a [`parking_lot::RwLockReadGuard`], along with
/// the state needed to track lock acquisition.
///
/// For details, see [the module documentation][mod].
///
/// [mod]: crate::lock::ranked
/// For details, see [the module documentation][self].
pub struct RwLockReadGuard<'a, T> {
inner: parking_lot::RwLockReadGuard<'a, T>,
saved: LockStateGuard,
@ -246,9 +238,7 @@ pub struct RwLockReadGuard<'a, T> {
/// This is just a wrapper around a [`parking_lot::RwLockWriteGuard`], along
/// with the state needed to track lock acquisition.
///
/// For details, see [the module documentation][mod].
///
/// [mod]: crate::lock::ranked
/// For details, see [the module documentation][self].
pub struct RwLockWriteGuard<'a, T> {
inner: parking_lot::RwLockWriteGuard<'a, T>,
saved: LockStateGuard,