storage: Move shared functionality to base (#39419)

Part of #39418. See that PR for a full description.

Moves:
- `read_json_from_file`
- `write_json_to_file`
- `IpcSendResult`
- `IpcSend`

Renames:
- `CoreResourceThreadPool` to `ThreadPool` (shorter and more
descriptive, as we use it for more than the core resource thread now)

Signed-off-by: Ashwin Naren <arihant2math@gmail.com>

Cargo.lock

@@ -766,10 +766,13 @@ dependencies = [
  "crossbeam-channel",
  "ipc-channel",
  "libc",
+ "log",
  "mach2",
  "malloc_size_of_derive",
  "parking_lot",
+ "rayon",
  "serde",
+ "serde_json",
  "servo_config",
  "servo_malloc_size_of",
  "time",

components/constellation/constellation.rs

@@ -104,7 +104,7 @@ use base::id::{
     BrowsingContextGroupId, BrowsingContextId, HistoryStateId, MessagePortId, MessagePortRouterId,
     PipelineId, PipelineNamespace, PipelineNamespaceId, PipelineNamespaceRequest, WebViewId,
 };
-use base::{Epoch, generic_channel};
+use base::{Epoch, IpcSend, generic_channel};
 #[cfg(feature = "bluetooth")]
 use bluetooth_traits::BluetoothRequest;
 use canvas::canvas_paint_thread::CanvasPaintThread;
@@ -153,8 +153,7 @@ use net_traits::pub_domains::reg_host;
 use net_traits::request::Referrer;
 use net_traits::storage_thread::{StorageThreadMsg, StorageType};
 use net_traits::{
-    self, AsyncRuntime, IpcSend, ReferrerPolicy, ResourceThreads, exit_fetch_thread,
+    self, AsyncRuntime, ReferrerPolicy, ResourceThreads, exit_fetch_thread, start_fetch_thread,
-    start_fetch_thread,
 };
 use profile_traits::mem::ProfilerMsg;
 use profile_traits::{mem, time};

components/net/resource_thread.rs

@@ -7,8 +7,7 @@
 use std::borrow::ToOwned;
 use std::collections::HashMap;
 use std::fs::File;
-use std::io::prelude::*;
+use std::io::{self, BufReader};
-use std::io::{self, BufReader, BufWriter};
 use std::path::{Path, PathBuf};
 use std::sync::{Arc, Mutex, RwLock, Weak};
 use std::thread;
@@ -22,7 +21,7 @@ use devtools_traits::DevtoolsControlMsg;
 use embedder_traits::EmbedderProxy;
 use hyper_serde::Serde;
 use ipc_channel::ipc::{self, IpcReceiver, IpcReceiverSet, IpcSender};
-use log::{debug, trace, warn};
+use log::{debug, warn};
 use net_traits::blob_url_store::parse_blob_url;
 use net_traits::filemanager_thread::FileTokenCheck;
 use net_traits::indexeddb_thread::IndexedDBThreadMsg;
@@ -198,9 +197,9 @@ fn create_http_states(
     let http_cache = HttpCache::default();
     let mut cookie_jar = CookieStorage::new(150);
     if let Some(config_dir) = config_dir {
-        read_json_from_file(&mut auth_cache, config_dir, "auth_cache.json");
+        base::read_json_from_file(&mut auth_cache, config_dir, "auth_cache.json");
-        read_json_from_file(&mut hsts_list, config_dir, "hsts_list.json");
+        base::read_json_from_file(&mut hsts_list, config_dir, "hsts_list.json");
-        read_json_from_file(&mut cookie_jar, config_dir, "cookie_jar.json");
+        base::read_json_from_file(&mut cookie_jar, config_dir, "cookie_jar.json");
     }
 
     let override_manager = CertificateErrorOverrideManager::new();
@@ -532,16 +531,16 @@ impl ResourceChannelManager {
                 if let Some(ref config_dir) = self.config_dir {
                     match http_state.auth_cache.read() {
                         Ok(auth_cache) => {
-                            write_json_to_file(&*auth_cache, config_dir, "auth_cache.json")
+                            base::write_json_to_file(&*auth_cache, config_dir, "auth_cache.json")
                         },
                         Err(_) => warn!("Error writing auth cache to disk"),
                     }
                     match http_state.cookie_jar.read() {
-                        Ok(jar) => write_json_to_file(&*jar, config_dir, "cookie_jar.json"),
+                        Ok(jar) => base::write_json_to_file(&*jar, config_dir, "cookie_jar.json"),
                         Err(_) => warn!("Error writing cookie jar to disk"),
                     }
                     match http_state.hsts_list.read() {
-                        Ok(hsts) => write_json_to_file(&*hsts, config_dir, "hsts_list.json"),
+                        Ok(hsts) => base::write_json_to_file(&*hsts, config_dir, "hsts_list.json"),
                         Err(_) => warn!("Error writing hsts list to disk"),
                     }
                 }
@@ -554,49 +553,6 @@ impl ResourceChannelManager {
     }
 }
 
-pub fn read_json_from_file<T>(data: &mut T, config_dir: &Path, filename: &str)
-where
-    T: for<'de> Deserialize<'de>,
-{
-    let path = config_dir.join(filename);
-    let display = path.display();
-
-    let mut file = match File::open(&path) {
-        Err(why) => {
-            warn!("couldn't open {}: {}", display, why);
-            return;
-        },
-        Ok(file) => file,
-    };
-
-    let mut string_buffer: String = String::new();
-    match file.read_to_string(&mut string_buffer) {
-        Err(why) => panic!("couldn't read from {}: {}", display, why),
-        Ok(_) => trace!("successfully read from {}", display),
-    }
-
-    match serde_json::from_str(&string_buffer) {
-        Ok(decoded_buffer) => *data = decoded_buffer,
-        Err(why) => warn!("Could not decode buffer{}", why),
-    }
-}
-
-pub fn write_json_to_file<T>(data: &T, config_dir: &Path, filename: &str)
-where
-    T: Serialize,
-{
-    let path = config_dir.join(filename);
-    let display = path.display();
-
-    let mut file = match File::create(&path) {
-        Err(why) => panic!("couldn't create {}: {}", display, why),
-        Ok(file) => file,
-    };
-    let mut writer = BufWriter::new(&mut file);
-    serde_json::to_writer_pretty(&mut writer, data).expect("Could not serialize to file");
-    trace!("successfully wrote to {display}");
-}
-
 #[derive(Clone, Debug, Deserialize, Serialize)]
 pub struct AuthCacheEntry {
     pub user_name: String,

components/net/storage_thread.rs

@@ -18,8 +18,6 @@ use profile_traits::path;
 use rustc_hash::FxHashMap;
 use servo_url::ServoUrl;
 
-use crate::resource_thread;
-
 const QUOTA_SIZE_LIMIT: usize = 5 * 1024 * 1024;
 
 pub trait StorageThreadFactory {
@@ -62,7 +60,7 @@ impl StorageManager {
     fn new(port: GenericReceiver<StorageThreadMsg>, config_dir: Option<PathBuf>) -> StorageManager {
         let mut local_data = HashMap::new();
         if let Some(ref config_dir) = config_dir {
-            resource_thread::read_json_from_file(&mut local_data, config_dir, "local_data.json");
+            base::read_json_from_file(&mut local_data, config_dir, "local_data.json");
         }
         StorageManager {
             port,
@@ -142,7 +140,7 @@ impl StorageManager {
 
     fn save_state(&self) {
         if let Some(ref config_dir) = self.config_dir {
-            resource_thread::write_json_to_file(&self.local_data, config_dir, "local_data.json");
+            base::write_json_to_file(&self.local_data, config_dir, "local_data.json");
         }
     }
 

components/script/dom/cookiestore.rs

@@ -6,6 +6,7 @@ use std::borrow::Cow;
 use std::collections::VecDeque;
 use std::rc::Rc;
 
+use base::IpcSend;
 use base::id::CookieStoreId;
 use cookie::{Cookie, SameSite};
 use dom_struct::dom_struct;
@@ -16,7 +17,7 @@ use ipc_channel::router::ROUTER;
 use itertools::Itertools;
 use js::jsval::NullValue;
 use net_traits::CookieSource::NonHTTP;
-use net_traits::{CookieAsyncResponse, CookieData, CoreResourceMsg, IpcSend};
+use net_traits::{CookieAsyncResponse, CookieData, CoreResourceMsg};
 use script_bindings::script_runtime::CanGc;
 use servo_url::ServoUrl;
 

components/script/dom/dedicatedworkerglobalscope.rs

@@ -6,6 +6,7 @@ use std::sync::Arc;
 use std::sync::atomic::AtomicBool;
 use std::thread::{self, JoinHandle};
 
+use base::IpcSend;
 use base::id::{BrowsingContextId, PipelineId, WebViewId};
 use constellation_traits::{WorkerGlobalScopeInit, WorkerScriptLoadOrigin};
 use crossbeam_channel::{Receiver, Sender, unbounded};
@@ -18,13 +19,13 @@ use ipc_channel::router::ROUTER;
 use js::jsapi::{Heap, JS_AddInterruptCallback, JSContext, JSObject};
 use js::jsval::UndefinedValue;
 use js::rust::{CustomAutoRooter, CustomAutoRooterGuard, HandleValue};
+use net_traits::Metadata;
 use net_traits::image_cache::ImageCache;
 use net_traits::policy_container::PolicyContainer;
 use net_traits::request::{
     CredentialsMode, Destination, InsecureRequestsPolicy, ParserMetadata, Referrer, RequestBuilder,
     RequestMode,
 };
-use net_traits::{IpcSend, Metadata};
 use servo_rand::random;
 use servo_url::{ImmutableOrigin, ServoUrl};
 use style::thread_state::{self, ThreadState};

components/script/dom/document.rs

@@ -14,7 +14,7 @@ use std::time::Duration;
 
 use base::cross_process_instant::CrossProcessInstant;
 use base::id::WebViewId;
-use base::{Epoch, generic_channel};
+use base::{Epoch, IpcSend, generic_channel};
 use canvas_traits::canvas::CanvasId;
 use canvas_traits::webgl::{WebGLContextId, WebGLMsg};
 use chrono::Local;
@@ -41,7 +41,7 @@ use net_traits::policy_container::PolicyContainer;
 use net_traits::pub_domains::is_pub_domain;
 use net_traits::request::{InsecureRequestsPolicy, RequestBuilder};
 use net_traits::response::HttpsState;
-use net_traits::{FetchResponseListener, IpcSend, ReferrerPolicy};
+use net_traits::{FetchResponseListener, ReferrerPolicy};
 use percent_encoding::percent_decode;
 use profile_traits::ipc as profile_ipc;
 use profile_traits::time::TimerMetadataFrameType;

components/script/dom/globalscope.rs

@@ -14,6 +14,7 @@ use std::thread::JoinHandle;
 use std::time::{Duration, Instant, SystemTime, UNIX_EPOCH};
 use std::{mem, ptr};
 
+use base::IpcSend;
 use base::id::{
     BlobId, BroadcastChannelRouterId, MessagePortId, MessagePortRouterId, PipelineId,
     ServiceWorkerId, ServiceWorkerRegistrationId, WebViewId,
@@ -52,8 +53,8 @@ use net_traits::policy_container::PolicyContainer;
 use net_traits::request::{InsecureRequestsPolicy, Referrer, RequestBuilder};
 use net_traits::response::HttpsState;
 use net_traits::{
-    CoreResourceMsg, CoreResourceThread, FetchResponseListener, IpcSend, ReferrerPolicy,
+    CoreResourceMsg, CoreResourceThread, FetchResponseListener, ReferrerPolicy, ResourceThreads,
-    ResourceThreads, fetch_async,
+    fetch_async,
 };
 use profile_traits::{ipc as profile_ipc, mem as profile_mem, time as profile_time};
 use rustc_hash::{FxBuildHasher, FxHashMap};

components/script/dom/history.rs

@@ -5,6 +5,7 @@
 use std::cell::Cell;
 use std::cmp::Ordering;
 
+use base::IpcSend;
 use base::id::HistoryStateId;
 use constellation_traits::{
     ScriptToConstellationMessage, StructuredSerializedData, TraversalDirection,
@@ -13,7 +14,7 @@ use dom_struct::dom_struct;
 use js::jsapi::Heap;
 use js::jsval::{JSVal, NullValue, UndefinedValue};
 use js::rust::{HandleValue, MutableHandleValue};
-use net_traits::{CoreResourceMsg, IpcSend};
+use net_traits::CoreResourceMsg;
 use profile_traits::ipc;
 use profile_traits::ipc::channel;
 use servo_url::ServoUrl;

components/script/dom/html/htmlinputelement.rs

@@ -11,7 +11,7 @@ use std::ptr::NonNull;
 use std::str::FromStr;
 use std::{f64, ptr};
 
-use base::generic_channel;
+use base::{IpcSend, generic_channel};
 use dom_struct::dom_struct;
 use embedder_traits::{
     EmbedderMsg, FilterPattern, FormControl as EmbedderFormControl, InputMethodType, RgbColor,
@@ -26,9 +26,9 @@ use js::jsapi::{
 use js::jsval::UndefinedValue;
 use js::rust::wrappers::{CheckRegExpSyntax, ExecuteRegExpNoStatics, ObjectIsRegExp};
 use js::rust::{HandleObject, MutableHandleObject};
+use net_traits::CoreResourceMsg;
 use net_traits::blob_url_store::get_blob_origin;
 use net_traits::filemanager_thread::{FileManagerResult, FileManagerThreadMsg};
-use net_traits::{CoreResourceMsg, IpcSend};
 use script_bindings::codegen::GenericBindings::CharacterDataBinding::CharacterDataMethods;
 use script_bindings::codegen::GenericBindings::DocumentBinding::DocumentMethods;
 use servo_config::pref;

components/script/dom/idbdatabase.rs

@@ -4,9 +4,9 @@
 
 use std::cell::Cell;
 
+use base::IpcSend;
 use dom_struct::dom_struct;
 use ipc_channel::ipc::IpcSender;
-use net_traits::IpcSend;
 use net_traits::indexeddb_thread::{IndexedDBThreadMsg, KeyPath, SyncOperation};
 use profile_traits::ipc;
 use stylo_atoms::Atom;

components/script/dom/idbobjectstore.rs

@@ -2,11 +2,11 @@
  * License, v. 2.0. If a copy of the MPL was not distributed with this
  * file, You can obtain one at https://mozilla.org/MPL/2.0/. */
 
+use base::IpcSend;
 use dom_struct::dom_struct;
 use js::gc::MutableHandleValue;
 use js::jsval::NullValue;
 use js::rust::HandleValue;
-use net_traits::IpcSend;
 use net_traits::indexeddb_thread::{
     AsyncOperation, AsyncReadOnlyOperation, AsyncReadWriteOperation, IndexedDBKeyType,
     IndexedDBThreadMsg, SyncOperation,

components/script/dom/idbopendbrequest.rs

@@ -2,11 +2,11 @@
  * License, v. 2.0. If a copy of the MPL was not distributed with this
  * file, You can obtain one at https://mozilla.org/MPL/2.0/. */
 
+use base::IpcSend;
 use dom_struct::dom_struct;
 use ipc_channel::router::ROUTER;
 use js::jsval::UndefinedValue;
 use js::rust::HandleValue;
-use net_traits::IpcSend;
 use net_traits::indexeddb_thread::{BackendResult, IndexedDBThreadMsg, SyncOperation};
 use profile_traits::ipc;
 use script_bindings::conversions::SafeToJSValConvertible;

components/script/dom/idbrequest.rs

@@ -5,12 +5,12 @@
 use std::cell::Cell;
 use std::iter::repeat_n;
 
+use base::IpcSend;
 use dom_struct::dom_struct;
 use ipc_channel::router::ROUTER;
 use js::jsapi::Heap;
 use js::jsval::{DoubleValue, JSVal, ObjectValue, UndefinedValue};
 use js::rust::HandleValue;
-use net_traits::IpcSend;
 use net_traits::indexeddb_thread::{
     AsyncOperation, AsyncReadOnlyOperation, BackendError, BackendResult, IndexedDBKeyType,
     IndexedDBRecord, IndexedDBThreadMsg, IndexedDBTxnMode, PutItemResult,

components/script/dom/idbtransaction.rs

@@ -5,9 +5,9 @@
 use std::cell::Cell;
 use std::collections::HashMap;
 
+use base::IpcSend;
 use dom_struct::dom_struct;
 use ipc_channel::ipc::IpcSender;
-use net_traits::IpcSend;
 use net_traits::indexeddb_thread::{IndexedDBThreadMsg, KeyPath, SyncOperation};
 use profile_traits::ipc;
 use script_bindings::codegen::GenericUnionTypes::StringOrStringSequence;

components/script/dom/serviceworkerglobalscope.rs

@@ -7,6 +7,7 @@ use std::sync::atomic::AtomicBool;
 use std::thread::{self, JoinHandle};
 use std::time::{Duration, Instant};
 
+use base::IpcSend;
 use base::generic_channel::GenericSender;
 use base::id::PipelineId;
 use constellation_traits::{
@@ -20,10 +21,10 @@ use ipc_channel::ipc::IpcReceiver;
 use ipc_channel::router::ROUTER;
 use js::jsapi::{JS_AddInterruptCallback, JSContext};
 use js::jsval::UndefinedValue;
+use net_traits::CustomResponseMediator;
 use net_traits::request::{
     CredentialsMode, Destination, InsecureRequestsPolicy, ParserMetadata, Referrer, RequestBuilder,
 };
-use net_traits::{CustomResponseMediator, IpcSend};
 use servo_config::pref;
 use servo_rand::random;
 use servo_url::ServoUrl;

components/script/dom/servoparser/prefetch.rs

@@ -5,6 +5,7 @@
 use std::cell::{Cell, RefCell};
 use std::ops::Deref;
 
+use base::IpcSend;
 use base::id::{PipelineId, WebViewId};
 use html5ever::buffer_queue::BufferQueue;
 use html5ever::tokenizer::states::RawKind;
@@ -18,7 +19,7 @@ use net_traits::policy_container::PolicyContainer;
 use net_traits::request::{
     CorsSettings, CredentialsMode, Destination, InsecureRequestsPolicy, ParserMetadata, Referrer,
 };
-use net_traits::{CoreResourceMsg, FetchChannels, IpcSend, ReferrerPolicy, ResourceThreads};
+use net_traits::{CoreResourceMsg, FetchChannels, ReferrerPolicy, ResourceThreads};
 use servo_url::{ImmutableOrigin, ServoUrl};
 
 use crate::dom::bindings::reflector::DomGlobal;

components/script/dom/url.rs

@@ -4,11 +4,12 @@
 
 use std::default::Default;
 
+use base::IpcSend;
 use dom_struct::dom_struct;
 use js::rust::HandleObject;
+use net_traits::CoreResourceMsg;
 use net_traits::blob_url_store::{get_blob_origin, parse_blob_url};
 use net_traits::filemanager_thread::FileManagerThreadMsg;
-use net_traits::{CoreResourceMsg, IpcSend};
 use profile_traits::ipc;
 use servo_url::ServoUrl;
 use uuid::Uuid;

components/script/dom/workerglobalscope.rs

@@ -9,6 +9,7 @@ use std::sync::Arc;
 use std::sync::atomic::{AtomicBool, Ordering};
 use std::time::Duration;
 
+use base::IpcSend;
 use base::cross_process_instant::CrossProcessInstant;
 use base::id::{PipelineId, PipelineNamespace};
 use constellation_traits::WorkerGlobalScopeInit;
@@ -21,12 +22,12 @@ use ipc_channel::ipc::IpcSender;
 use js::jsval::UndefinedValue;
 use js::panic::maybe_resume_unwind;
 use js::rust::{HandleValue, MutableHandleValue, ParentRuntime};
+use net_traits::ReferrerPolicy;
 use net_traits::policy_container::PolicyContainer;
 use net_traits::request::{
     CredentialsMode, Destination, InsecureRequestsPolicy, ParserMetadata,
     RequestBuilder as NetRequestInit,
 };
-use net_traits::{IpcSend, ReferrerPolicy};
 use profile_traits::mem::{ProcessReports, perform_memory_report};
 use servo_url::{MutableOrigin, ServoUrl};
 use timers::TimerScheduler;

components/script/dom/worklet.rs

@@ -18,12 +18,12 @@ use std::sync::Arc;
 use std::sync::atomic::{AtomicIsize, Ordering};
 use std::thread;
 
+use base::IpcSend;
 use base::id::PipelineId;
 use crossbeam_channel::{Receiver, Sender, unbounded};
 use dom_struct::dom_struct;
 use js::jsapi::{GCReason, JS_GC, JS_GetGCParameter, JSGCParamKey, JSTracer};
 use malloc_size_of::malloc_size_of_is_0;
-use net_traits::IpcSend;
 use net_traits::request::{Destination, RequestBuilder, RequestMode};
 use rustc_hash::FxHashMap;
 use servo_url::{ImmutableOrigin, ServoUrl};

components/script/webdriver_handlers.rs

@@ -6,6 +6,7 @@ use std::collections::{HashMap, HashSet};
 use std::ffi::CString;
 use std::ptr::NonNull;
 
+use base::IpcSend;
 use base::generic_channel::GenericSender;
 use base::id::{BrowsingContextId, PipelineId};
 use cookie::Cookie;
@@ -27,7 +28,6 @@ use net_traits::CookieSource::{HTTP, NonHTTP};
 use net_traits::CoreResourceMsg::{
     DeleteCookie, DeleteCookies, GetCookiesDataForUrl, SetCookieForUrl,
 };
-use net_traits::IpcSend;
 use script_bindings::codegen::GenericBindings::ShadowRootBinding::ShadowRootMethods;
 use script_bindings::conversions::is_array_like;
 use script_bindings::num::Finite;

components/shared/base/Cargo.toml

@@ -19,10 +19,13 @@ ipc-channel = { workspace = true }
 malloc_size_of = { workspace = true }
 malloc_size_of_derive = { workspace = true }
 parking_lot = { workspace = true }
+rayon = { workspace = true }
 serde = { workspace = true }
+serde_json = { workspace = true }
 servo_config = { path = "../../config" }
 time = { workspace = true }
 webrender_api = { workspace = true }
+log = { workspace = true }
 
 [target.'cfg(any(target_os = "macos", target_os = "ios"))'.dependencies]
 mach2 = { workspace = true }

components/shared/base/lib.rs

@@ -14,12 +14,62 @@ pub mod generic_channel;
 pub mod id;
 pub mod print_tree;
 pub mod text;
+pub mod threadpool;
 mod unicode_block;
 
+use std::fs::File;
+use std::io::{BufWriter, Read};
+use std::path::Path;
+
+use ipc_channel::ipc::{IpcError, IpcSender};
+use log::{trace, warn};
 use malloc_size_of_derive::MallocSizeOf;
 use serde::{Deserialize, Serialize};
 use webrender_api::Epoch as WebRenderEpoch;
 
+pub fn read_json_from_file<T>(data: &mut T, config_dir: &Path, filename: &str)
+where
+    T: for<'de> Deserialize<'de>,
+{
+    let path = config_dir.join(filename);
+    let display = path.display();
+
+    let mut file = match File::open(&path) {
+        Err(why) => {
+            warn!("couldn't open {}: {}", display, why);
+            return;
+        },
+        Ok(file) => file,
+    };
+
+    let mut string_buffer: String = String::new();
+    match file.read_to_string(&mut string_buffer) {
+        Err(why) => panic!("couldn't read from {}: {}", display, why),
+        Ok(_) => trace!("successfully read from {}", display),
+    }
+
+    match serde_json::from_str(&string_buffer) {
+        Ok(decoded_buffer) => *data = decoded_buffer,
+        Err(why) => warn!("Could not decode buffer{}", why),
+    }
+}
+
+pub fn write_json_to_file<T>(data: &T, config_dir: &Path, filename: &str)
+where
+    T: Serialize,
+{
+    let path = config_dir.join(filename);
+    let display = path.display();
+
+    let mut file = match File::create(&path) {
+        Err(why) => panic!("couldn't create {}: {}", display, why),
+        Ok(file) => file,
+    };
+    let mut writer = BufWriter::new(&mut file);
+    serde_json::to_writer_pretty(&mut writer, data).expect("Could not serialize to file");
+    trace!("successfully wrote to {display}");
+}
+
 /// A struct for denoting the age of messages; prevents race conditions.
 #[derive(
     Clone, Copy, Debug, Deserialize, Eq, Hash, Ord, PartialEq, PartialOrd, Serialize, MallocSizeOf,
@@ -50,3 +100,18 @@ impl WebRenderEpochToU16 for WebRenderEpoch {
         (self.0 % u16::MAX as u32) as u16
     }
 }
+
+pub type IpcSendResult = Result<(), IpcError>;
+
+/// Abstraction of the ability to send a particular type of message,
+/// used by net_traits::ResourceThreads to ease the use its IpcSender sub-fields
+/// XXX: If this trait will be used more in future, some auto derive might be appealing
+pub trait IpcSend<T>
+where
+    T: serde::Serialize + for<'de> serde::Deserialize<'de>,
+{
+    /// send message T
+    fn send(&self, _: T) -> IpcSendResult;
+    /// get underlying sender
+    fn sender(&self) -> IpcSender<T>;
+}

components/shared/base/threadpool.rs

@@ -0,0 +1,139 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at https://mozilla.org/MPL/2.0/. */
+
+use std::sync::{Arc, Mutex};
+use std::thread;
+use std::time::Duration;
+
+use log::debug;
+
+/// The state of the thread-pool used by CoreResource.
+struct ThreadPoolState {
+    /// The number of active workers.
+    active_workers: u32,
+    /// Whether the pool can spawn additional work.
+    active: bool,
+}
+
+impl ThreadPoolState {
+    pub fn new() -> ThreadPoolState {
+        ThreadPoolState {
+            active_workers: 0,
+            active: true,
+        }
+    }
+
+    /// Is the pool still able to spawn new work?
+    pub fn is_active(&self) -> bool {
+        self.active
+    }
+
+    /// How many workers are currently active?
+    pub fn active_workers(&self) -> u32 {
+        self.active_workers
+    }
+
+    /// Prevent additional work from being spawned.
+    pub fn switch_to_inactive(&mut self) {
+        self.active = false;
+    }
+
+    /// Add to the count of active workers.
+    pub fn increment_active(&mut self) {
+        self.active_workers += 1;
+    }
+
+    /// Substract from the count of active workers.
+    pub fn decrement_active(&mut self) {
+        self.active_workers -= 1;
+    }
+}
+
+/// Threadpool used by Fetch and file operations.
+pub struct ThreadPool {
+    pool: rayon::ThreadPool,
+    state: Arc<Mutex<ThreadPoolState>>,
+}
+
+impl ThreadPool {
+    pub fn new(num_threads: usize, pool_name: String) -> Self {
+        debug!("Creating new ThreadPool with {num_threads} threads!");
+        let pool = rayon::ThreadPoolBuilder::new()
+            .thread_name(move |i| format!("{pool_name}#{i}"))
+            .num_threads(num_threads)
+            .build()
+            .unwrap();
+        let state = Arc::new(Mutex::new(ThreadPoolState::new()));
+        Self { pool, state }
+    }
+
+    /// Spawn work on the thread-pool, if still active.
+    ///
+    /// There is no need to give feedback to the caller,
+    /// because if we do not perform work,
+    /// it is because the system as a whole is exiting.
+    pub fn spawn<OP>(&self, work: OP)
+    where
+        OP: FnOnce() + Send + 'static,
+    {
+        {
+            let mut state = self.state.lock().unwrap();
+            if state.is_active() {
+                state.increment_active();
+            } else {
+                // Don't spawn any work.
+                return;
+            }
+        }
+
+        let state = self.state.clone();
+
+        self.pool.spawn(move || {
+            {
+                let mut state = state.lock().unwrap();
+                if !state.is_active() {
+                    // Decrement number of active workers and return,
+                    // without doing any work.
+                    return state.decrement_active();
+                }
+            }
+            // Perform work.
+            work();
+            {
+                // Decrement number of active workers.
+                let mut state = state.lock().unwrap();
+                state.decrement_active();
+            }
+        });
+    }
+
+    /// Prevent further work from being spawned,
+    /// and wait until all workers are done,
+    /// or a timeout of roughly one second has been reached.
+    pub fn exit(&self) {
+        {
+            let mut state = self.state.lock().unwrap();
+            state.switch_to_inactive();
+        }
+        let mut rounds = 0;
+        loop {
+            rounds += 1;
+            {
+                let state = self.state.lock().unwrap();
+                let still_active = state.active_workers();
+
+                if still_active == 0 || rounds == 10 {
+                    if still_active > 0 {
+                        debug!(
+                            "Exiting ThreadPool with {:?} still working(should be zero)",
+                            still_active
+                        );
+                    }
+                    break;
+                }
+            }
+            thread::sleep(Duration::from_millis(100));
+        }
+    }
+}

components/shared/net/lib.rs

@@ -11,6 +11,7 @@ use std::thread::{self, JoinHandle};
 use base::cross_process_instant::CrossProcessInstant;
 use base::generic_channel::{GenericSend, GenericSender, SendResult};
 use base::id::{CookieStoreId, HistoryStateId};
+use base::{IpcSend, IpcSendResult};
 use content_security_policy::{self as csp};
 use cookie::Cookie;
 use crossbeam_channel::{Receiver, Sender, unbounded};
@@ -18,8 +19,7 @@ use headers::{ContentType, HeaderMapExt, ReferrerPolicy as ReferrerPolicyHeader}
 use http::{Error as HttpError, HeaderMap, HeaderValue, StatusCode, header};
 use hyper_serde::Serde;
 use hyper_util::client::legacy::Error as HyperError;
-use ipc_channel::Error as IpcError;
+use ipc_channel::ipc::{self, IpcError, IpcReceiver, IpcSender};
-use ipc_channel::ipc::{self, IpcReceiver, IpcSender};
 use ipc_channel::router::ROUTER;
 use malloc_size_of::malloc_size_of_is_0;
 use malloc_size_of_derive::MallocSizeOf;
@@ -415,21 +415,6 @@ pub trait AsyncRuntime: Send {
 /// Handle to a resource thread
 pub type CoreResourceThread = IpcSender<CoreResourceMsg>;
 
-pub type IpcSendResult = Result<(), IpcError>;
-
-/// Abstraction of the ability to send a particular type of message,
-/// used by net_traits::ResourceThreads to ease the use its IpcSender sub-fields
-/// XXX: If this trait will be used more in future, some auto derive might be appealing
-pub trait IpcSend<T>
-where
-    T: serde::Serialize + for<'de> serde::Deserialize<'de>,
-{
-    /// send message T
-    fn send(&self, _: T) -> IpcSendResult;
-    /// get underlying sender
-    fn sender(&self) -> IpcSender<T>;
-}
-
 // FIXME: Originally we will construct an Arc<ResourceThread> from ResourceThread
 // in script_thread to avoid some performance pitfall. Now we decide to deal with
 // the "Arc" hack implicitly in future.
@@ -462,7 +447,7 @@ impl ResourceThreads {
 
 impl IpcSend<CoreResourceMsg> for ResourceThreads {
     fn send(&self, msg: CoreResourceMsg) -> IpcSendResult {
-        self.core_thread.send(msg)
+        self.core_thread.send(msg).map_err(IpcError::Bincode)
     }
 
     fn sender(&self) -> IpcSender<CoreResourceMsg> {
@@ -472,7 +457,7 @@ impl IpcSend<CoreResourceMsg> for ResourceThreads {
 
 impl IpcSend<IndexedDBThreadMsg> for ResourceThreads {
     fn send(&self, msg: IndexedDBThreadMsg) -> IpcSendResult {
-        self.idb_thread.send(msg)
+        self.idb_thread.send(msg).map_err(IpcError::Bincode)
     }
 
     fn sender(&self) -> IpcSender<IndexedDBThreadMsg> {