Replace std synchronization primitives with parking_lot (#210)

* Replace std::sync::Mutex with parking_lot::Mutex
* Replace std::sync::RwLock with parking_lot::RwLock

Author: lachlansneff

crates/bevy_asset/Cargo.toml

@@ -27,4 +27,5 @@ crossbeam-channel = "0.4.2"
 anyhow = "1.0"
 thiserror = "1.0"
 log = { version = "0.4", features = ["release_max_level_info"] }
-notify = { version = "5.0.0-pre.2", optional = true }
+notify = { version = "5.0.0-pre.2", optional = true }
+parking_lot = "0.10.2"

crates/bevy_asset/src/asset_server.rs

@@ -5,11 +5,12 @@ use crate::{
 use anyhow::Result;
 use bevy_ecs::{Res, Resource, Resources};
 use crossbeam_channel::TryRecvError;
+use parking_lot::RwLock;
 use std::{
     collections::{HashMap, HashSet},
     env, fs, io,
     path::{Path, PathBuf},
-    sync::{Arc, RwLock},
+    sync::Arc,
     thread,
 };
 use thiserror::Error;
@@ -107,7 +108,7 @@ impl AssetServer {
     where
         T: AssetLoadRequestHandler,
     {
-        let mut asset_handlers = self.asset_handlers.write().unwrap();
+        let mut asset_handlers = self.asset_handlers.write();
         let handler_index = asset_handlers.len();
         for extension in asset_handler.extensions().iter() {
             self.extension_to_handler_index
@@ -140,14 +141,13 @@ impl AssetServer {
         let root_path = self.get_root_path()?;
         let asset_folder = root_path.join(path);
         let handle_ids = self.load_assets_in_folder_recursive(&asset_folder)?;
-        self.asset_folders.write().unwrap().push(asset_folder);
+        self.asset_folders.write().push(asset_folder);
         Ok(handle_ids)
     }
 
     pub fn get_handle<T, P: AsRef<Path>>(&self, path: P) -> Option<Handle<T>> {
         self.asset_info_paths
             .read()
-            .unwrap()
             .get(path.as_ref())
             .map(|handle_id| Handle::from(*handle_id))
     }
@@ -170,11 +170,11 @@ impl AssetServer {
 
     #[cfg(feature = "filesystem_watcher")]
     pub fn watch_for_changes(&self) -> Result<(), AssetServerError> {
-        let mut filesystem_watcher = self.filesystem_watcher.write().unwrap();
+        let mut filesystem_watcher = self.filesystem_watcher.write();
 
         let _ = filesystem_watcher.get_or_insert_with(FilesystemWatcher::default);
         // watch current files
-        let asset_info_paths = self.asset_info_paths.read().unwrap();
+        let asset_info_paths = self.asset_info_paths.read();
         for asset_path in asset_info_paths.keys() {
             Self::watch_path_for_changes(&mut filesystem_watcher, asset_path)?;
         }
@@ -187,9 +187,7 @@ impl AssetServer {
         use notify::event::{Event, EventKind, ModifyKind};
         let mut changed = HashSet::new();
 
-        while let Some(filesystem_watcher) =
-            asset_server.filesystem_watcher.read().unwrap().as_ref()
-        {
+        while let Some(filesystem_watcher) = asset_server.filesystem_watcher.read().as_ref() {
             let result = match filesystem_watcher.receiver.try_recv() {
                 Ok(result) => result,
                 Err(TryRecvError::Empty) => {
@@ -280,8 +278,8 @@ impl AssetServer {
             ) {
                 let mut new_version = 0;
                 let handle_id = {
-                    let mut asset_info = self.asset_info.write().unwrap();
-                    let mut asset_info_paths = self.asset_info_paths.write().unwrap();
+                    let mut asset_info = self.asset_info.write();
+                    let mut asset_info_paths = self.asset_info_paths.write();
                     if let Some(asset_info) = asset_info_paths
                         .get(path)
                         .and_then(|handle_id| asset_info.get_mut(&handle_id))
@@ -319,7 +317,7 @@ impl AssetServer {
                 // TODO: watching each asset explicitly is a simpler implementation, its possible it would be more efficient to watch
                 // folders instead (when possible)
                 #[cfg(feature = "filesystem_watcher")]
-                Self::watch_path_for_changes(&mut self.filesystem_watcher.write().unwrap(), path)?;
+                Self::watch_path_for_changes(&mut self.filesystem_watcher.write(), path)?;
                 Ok(handle_id)
             } else {
                 Err(AssetServerError::MissingAssetHandler)
@@ -330,7 +328,7 @@ impl AssetServer {
     }
 
     pub fn set_load_state(&self, handle_id: HandleId, load_state: LoadState) {
-        if let Some(asset_info) = self.asset_info.write().unwrap().get_mut(&handle_id) {
+        if let Some(asset_info) = self.asset_info.write().get_mut(&handle_id) {
             if load_state.get_version() >= asset_info.load_state.get_version() {
                 asset_info.load_state = load_state;
             }
@@ -340,7 +338,6 @@ impl AssetServer {
     pub fn get_load_state_untyped(&self, handle_id: HandleId) -> Option<LoadState> {
         self.asset_info
             .read()
-            .unwrap()
             .get(&handle_id)
             .map(|asset_info| asset_info.load_state.clone())
     }
@@ -367,7 +364,7 @@ impl AssetServer {
 
     fn send_request_to_loader_thread(&self, load_request: LoadRequest) {
         // NOTE: This lock makes the call to Arc::strong_count safe. Removing (or reordering) it could result in undefined behavior
-        let mut loader_threads = self.loader_threads.write().unwrap();
+        let mut loader_threads = self.loader_threads.write();
         if loader_threads.len() < self.max_loader_threads {
             let loader_thread = LoaderThread {
                 requests: Arc::new(RwLock::new(vec![load_request])),
@@ -378,9 +375,9 @@ impl AssetServer {
         } else {
             let most_free_thread = loader_threads
                 .iter()
-                .min_by_key(|l| l.requests.read().unwrap().len())
+                .min_by_key(|l| l.requests.read().len())
                 .unwrap();
-            let mut requests = most_free_thread.requests.write().unwrap();
+            let mut requests = most_free_thread.requests.write();
             requests.push(load_request);
             // if most free thread only has one reference, the thread as spun down. if so, we need to spin it back up!
             if Arc::strong_count(&most_free_thread.requests) == 1 {
@@ -399,7 +396,7 @@ impl AssetServer {
         thread::spawn(move || {
             loop {
                 let request = {
-                    let mut current_requests = requests.write().unwrap();
+                    let mut current_requests = requests.write();
                     if current_requests.len() == 0 {
                         // if there are no requests, spin down the thread
                         break;
@@ -408,7 +405,7 @@ impl AssetServer {
                     current_requests.pop().unwrap()
                 };
 
-                let handlers = request_handlers.read().unwrap();
+                let handlers = request_handlers.read();
                 let request_handler = &handlers[request.handler_index];
                 request_handler.handle_request(&request);
             }

crates/bevy_audio/Cargo.toml

@@ -18,6 +18,7 @@ bevy_ecs = {path = "../bevy_ecs", version = "0.1"}
 # other
 anyhow = "1.0"
 rodio = {version = "0.11", default-features = false}
+parking_lot = "0.10.2"
 
 [features]
 mp3 = ["rodio/mp3"]

crates/bevy_audio/src/audio_output.rs

@@ -1,8 +1,9 @@
 use crate::AudioSource;
 use bevy_asset::{Assets, Handle};
 use bevy_ecs::Res;
+use parking_lot::RwLock;
 use rodio::{Decoder, Device, Sink};
-use std::{collections::VecDeque, io::Cursor, sync::RwLock};
+use std::{collections::VecDeque, io::Cursor};
 
 /// Used to play audio on the current "audio device"
 pub struct AudioOutput {
@@ -27,11 +28,11 @@ impl AudioOutput {
     }
 
     pub fn play(&self, audio_source: Handle<AudioSource>) {
-        self.queue.write().unwrap().push_front(audio_source);
+        self.queue.write().push_front(audio_source);
     }
 
     pub fn try_play_queued(&self, audio_sources: &Assets<AudioSource>) {
-        let mut queue = self.queue.write().unwrap();
+        let mut queue = self.queue.write();
         let len = queue.len();
         let mut i = 0;
         while i < len {

crates/bevy_diagnostic/Cargo.toml

@@ -20,3 +20,4 @@ bevy_ecs = { path = "../bevy_ecs", version = "0.1" }
 
 # other
 uuid = { version = "0.8", features = ["v4", "serde"] }
+parking_lot = "0.10"

crates/bevy_diagnostic/src/system_profiler.rs

@@ -1,11 +1,7 @@
 use crate::{Diagnostic, DiagnosticId, Diagnostics};
 use bevy_ecs::{Profiler, Res, ResMut};
-use std::{
-    borrow::Cow,
-    collections::HashMap,
-    sync::{Arc, RwLock},
-    time::Instant,
-};
+use parking_lot::RwLock;
+use std::{borrow::Cow, collections::HashMap, sync::Arc, time::Instant};
 
 #[derive(Debug)]
 struct SystemRunInfo {
@@ -28,7 +24,7 @@ pub struct SystemProfiler {
 
 impl Profiler for SystemProfiler {
     fn start(&self, scope: Cow<'static, str>) {
-        let mut system_profiles = self.system_profiles.write().unwrap();
+        let mut system_profiles = self.system_profiles.write();
         let profiles = system_profiles
             .entry(scope.clone())
             .or_insert_with(SystemProfiles::default);
@@ -38,7 +34,7 @@ impl Profiler for SystemProfiler {
 
     fn stop(&self, scope: Cow<'static, str>) {
         let now = Instant::now();
-        let mut system_profiles = self.system_profiles.write().unwrap();
+        let mut system_profiles = self.system_profiles.write();
         let profiles = system_profiles.get_mut(&scope).unwrap();
         if let Some(current_start) = profiles.current_start.take() {
             profiles.history.push(SystemRunInfo {
@@ -54,7 +50,7 @@ pub fn profiler_diagnostic_system(
     system_profiler: Res<Box<dyn Profiler>>,
 ) {
     let system_profiler = system_profiler.downcast_ref::<SystemProfiler>().unwrap();
-    let mut system_profiles = system_profiler.system_profiles.write().unwrap();
+    let mut system_profiles = system_profiler.system_profiles.write();
     for (scope, profiles) in system_profiles.iter_mut() {
         if diagnostics.get(profiles.diagnostic_id).is_none() {
             diagnostics.add(Diagnostic::new(profiles.diagnostic_id, &scope, 20))

crates/bevy_ecs/Cargo.toml

@@ -20,3 +20,4 @@ rayon = "1.3"
 crossbeam-channel = "0.4.2"
 fixedbitset = "0.3.0"
 downcast-rs = "1.1.1"
+parking_lot = "0.10"