net: Start reducing number of IPCs channels used for fetch with a `FetchThread` (#33863)

Instead of creating a `ROUTER` for each fetch, create a fetch thread
which handles all incoming and outcoming fetch requests. Now messages
involving fetches carry a "request id" which indicates which fetch is
being addressed by the message. This greatly reduces the number of file
descriptors used by fetch.

In addition, the interface for kicking off fetches is simplified when
using the `Listener` with `Document`s and the `GlobalScope`.

This does not fix all leaked file descriptors / mach ports, but greatly
eliminates the number used. Now tests can be run without limiting
procesess on modern macOS systems.

Followup work:

1. There are more instances where fetch is done using the old method.
   Some of these require more changes in order to be converted to the
   `FetchThread` approach.
2. Eliminate usage of IPC channels when doing redirects.
3. Also eliminate the IPC channel used for cancel handling.
4. This change opens up the possiblity of controlling the priority of
   fetch requests.

Fixes #29834.

Signed-off-by: Martin Robinson <mrobinson@igalia.com>

5 files changed, 97 insertions, 245 deletions

diff --git a/components/net/tests/data_loader.rs b/components/net/tests/data_loader.rs
index 198fe19709c..034e75bbd82 100644
--- a/components/net/tests/data_loader.rs
+++ b/components/net/tests/data_loader.rs
@@ -7,8 +7,8 @@ use std::ops::Deref;
 use headers::{ContentType, HeaderMapExt};
 use hyper_serde::Serde;
 use mime::{self, Mime};
-use net_traits::request::{Origin, Referrer, Request};
-use net_traits::response::{HttpsState, ResponseBody};
+use net_traits::request::Referrer;
+use net_traits::response::ResponseBody;
 use net_traits::{FetchMetadata, FilteredMetadata, NetworkError};
 use servo_url::ServoUrl;
 
@@ -21,15 +21,13 @@ fn assert_parse(
     charset: Option<&str>,
     data: Option<&[u8]>,
 ) {
+    use net_traits::request::RequestBuilder;
+
     let url = ServoUrl::parse(url).unwrap();
-    let origin = Origin::Origin(url.origin());
-    let mut request = Request::new(
-        url,
-        Some(origin),
-        Referrer::NoReferrer,
-        None,
-        HttpsState::None,
-    );
+    let mut request = RequestBuilder::new(url.clone(), Referrer::NoReferrer)
+        .origin(url.origin())
+        .pipeline_id(None)
+        .build();
 
     let response = fetch(&mut request, None);
 
diff --git a/components/net/tests/fetch.rs b/components/net/tests/fetch.rs
index bc0d19a5b9a..81321770a4e 100644
--- a/components/net/tests/fetch.rs
+++ b/components/net/tests/fetch.rs
@@ -33,15 +33,15 @@ use net::test::HttpState;
 use net_traits::filemanager_thread::FileTokenCheck;
 use net_traits::http_status::HttpStatus;
 use net_traits::request::{
-    Destination, Origin, RedirectMode, Referrer, Request, RequestBuilder, RequestMode,
+    Destination, RedirectMode, Referrer, Request, RequestBuilder, RequestMode,
 };
-use net_traits::response::{CacheState, HttpsState, Response, ResponseBody, ResponseType};
+use net_traits::response::{CacheState, Response, ResponseBody, ResponseType};
 use net_traits::{
     FetchTaskTarget, IncludeSubdomains, NetworkError, ReferrerPolicy, ResourceFetchTiming,
     ResourceTimingType,
 };
 use servo_arc::Arc as ServoArc;
-use servo_url::{ImmutableOrigin, ServoUrl};
+use servo_url::ServoUrl;
 use tokio_test::block_on;
 use uuid::Uuid;
 
@@ -61,14 +61,9 @@ fn test_fetch_response_is_not_network_error() {
     };
     let (server, url) = make_server(handler);
 
-    let origin = Origin::Origin(url.origin());
-    let mut request = Request::new(
-        url,
-        Some(origin),
-        Referrer::NoReferrer,
-        None,
-        HttpsState::None,
-    );
+    let mut request = RequestBuilder::new(url.clone(), Referrer::NoReferrer)
+        .origin(url.origin())
+        .build();
     let fetch_response = fetch(&mut request, None);
     let _ = server.close();
 
@@ -80,14 +75,9 @@ fn test_fetch_response_is_not_network_error() {
 #[test]
 fn test_fetch_on_bad_port_is_network_error() {
     let url = ServoUrl::parse("http://www.example.org:6667").unwrap();
-    let origin = Origin::Origin(url.origin());
-    let mut request = Request::new(
-        url,
-        Some(origin),
-        Referrer::NoReferrer,
-        None,
-        HttpsState::None,
-    );
+    let mut request = RequestBuilder::new(url.clone(), Referrer::NoReferrer)
+        .origin(url.origin())
+        .build();
     let fetch_response = fetch(&mut request, None);
     assert!(fetch_response.is_network_error());
     let fetch_error = fetch_response.get_network_error().unwrap();
@@ -105,14 +95,9 @@ fn test_fetch_response_body_matches_const_message() {
     };
     let (server, url) = make_server(handler);
 
-    let origin = Origin::Origin(url.origin());
-    let mut request = Request::new(
-        url,
-        Some(origin),
-        Referrer::NoReferrer,
-        None,
-        HttpsState::None,
-    );
+    let mut request = RequestBuilder::new(url.clone(), Referrer::NoReferrer)
+        .origin(url.origin())
+        .build();
     let fetch_response = fetch(&mut request, None);
     let _ = server.close();
 
@@ -130,14 +115,9 @@ fn test_fetch_response_body_matches_const_message() {
 #[test]
 fn test_fetch_aboutblank() {
     let url = ServoUrl::parse("about:blank").unwrap();
-    let origin = Origin::Origin(url.origin());
-    let mut request = Request::new(
-        url,
-        Some(origin),
-        Referrer::NoReferrer,
-        None,
-        HttpsState::None,
-    );
+    let mut request = RequestBuilder::new(url.clone(), Referrer::NoReferrer)
+        .origin(url.origin())
+        .build();
 
     let fetch_response = fetch(&mut request, None);
     // We should see an opaque-filtered response.
@@ -168,12 +148,12 @@ fn test_fetch_blob() {
     impl FetchTaskTarget for FetchResponseCollector {
         fn process_request_body(&mut self, _: &Request) {}
         fn process_request_eof(&mut self, _: &Request) {}
-        fn process_response(&mut self, _: &Response) {}
-        fn process_response_chunk(&mut self, chunk: Vec<u8>) {
+        fn process_response(&mut self, _: &Request, _: &Response) {}
+        fn process_response_chunk(&mut self, _: &Request, chunk: Vec<u8>) {
             self.buffer.extend_from_slice(chunk.as_slice());
         }
         /// Fired when the response is fully fetched
-        fn process_response_eof(&mut self, response: &Response) {
+        fn process_response_eof(&mut self, _: &Request, response: &Response) {
             assert_eq!(self.buffer, self.expected);
             let _ = self.sender.send(response.clone());
         }
@@ -200,13 +180,9 @@ fn test_fetch_blob() {
     );
     let url = ServoUrl::parse(&format!("blob:{}{}", origin.as_str(), id.simple())).unwrap();
 
-    let mut request = Request::new(
-        url,
-        Some(Origin::Origin(origin.origin())),
-        Referrer::NoReferrer,
-        None,
-        HttpsState::None,
-    );
+    let mut request = RequestBuilder::new(url.clone(), Referrer::NoReferrer)
+        .origin(origin.origin())
+        .build();
 
     let (sender, receiver) = unbounded();
 
@@ -246,14 +222,9 @@ fn test_file() {
         .unwrap();
     let url = ServoUrl::from_file_path(path.clone()).unwrap();
 
-    let origin = Origin::Origin(url.origin());
-    let mut request = Request::new(
-        url,
-        Some(origin),
-        Referrer::NoReferrer,
-        None,
-        HttpsState::None,
-    );
+    let mut request = RequestBuilder::new(url.clone(), Referrer::NoReferrer)
+        .origin(url.origin())
+        .build();
 
     let pool = CoreResourceThreadPool::new(1);
     let pool_handle = Arc::new(pool);
@@ -294,14 +265,9 @@ fn test_file() {
 #[test]
 fn test_fetch_ftp() {
     let url = ServoUrl::parse("ftp://not-supported").unwrap();
-    let origin = Origin::Origin(url.origin());
-    let mut request = Request::new(
-        url,
-        Some(origin),
-        Referrer::NoReferrer,
-        None,
-        HttpsState::None,
-    );
+    let mut request = RequestBuilder::new(url.clone(), Referrer::NoReferrer)
+        .origin(url.origin())
+        .build();
     let fetch_response = fetch(&mut request, None);
     assert!(fetch_response.is_network_error());
 }
@@ -309,14 +275,9 @@ fn test_fetch_ftp() {
 #[test]
 fn test_fetch_bogus_scheme() {
     let url = ServoUrl::parse("bogus://whatever").unwrap();
-    let origin = Origin::Origin(url.origin());
-    let mut request = Request::new(
-        url,
-        Some(origin),
-        Referrer::NoReferrer,
-        None,
-        HttpsState::None,
-    );
+    let mut request = RequestBuilder::new(url.clone(), Referrer::NoReferrer)
+        .origin(url.origin())
+        .build();
     let fetch_response = fetch(&mut request, None);
     assert!(fetch_response.is_network_error());
 }
@@ -360,15 +321,7 @@ fn test_cors_preflight_fetch() {
     let (server, url) = make_server(handler);
 
     let target_url = url.clone().join("a.html").unwrap();
-
-    let origin = Origin::Origin(ImmutableOrigin::new_opaque());
-    let mut request = Request::new(
-        url.clone(),
-        Some(origin),
-        Referrer::ReferrerUrl(target_url),
-        None,
-        HttpsState::None,
-    );
+    let mut request = RequestBuilder::new(url, Referrer::ReferrerUrl(target_url)).build();
     request.referrer_policy = Some(ReferrerPolicy::Origin);
     request.use_cors_preflight = true;
     request.mode = RequestMode::CorsMode;
@@ -418,14 +371,7 @@ fn test_cors_preflight_cache_fetch() {
     };
     let (server, url) = make_server(handler);
 
-    let origin = Origin::Origin(ImmutableOrigin::new_opaque());
-    let mut request = Request::new(
-        url.clone(),
-        Some(origin.clone()),
-        Referrer::NoReferrer,
-        None,
-        HttpsState::None,
-    );
+    let mut request = RequestBuilder::new(url, Referrer::NoReferrer).build();
     request.use_cors_preflight = true;
     request.mode = RequestMode::CorsMode;
     let mut wrapped_request0 = request.clone();
@@ -485,14 +431,7 @@ fn test_cors_preflight_fetch_network_error() {
     };
     let (server, url) = make_server(handler);
 
-    let origin = Origin::Origin(ImmutableOrigin::new_opaque());
-    let mut request = Request::new(
-        url,
-        Some(origin),
-        Referrer::NoReferrer,
-        None,
-        HttpsState::None,
-    );
+    let mut request = RequestBuilder::new(url, Referrer::NoReferrer).build();
     request.method = Method::from_bytes(b"CHICKEN").unwrap();
     request.use_cors_preflight = true;
     request.mode = RequestMode::CorsMode;
@@ -519,14 +458,9 @@ fn test_fetch_response_is_basic_filtered() {
     };
     let (server, url) = make_server(handler);
 
-    let origin = Origin::Origin(url.origin());
-    let mut request = Request::new(
-        url,
-        Some(origin),
-        Referrer::NoReferrer,
-        None,
-        HttpsState::None,
-    );
+    let mut request = RequestBuilder::new(url.clone(), Referrer::NoReferrer)
+        .origin(url.origin())
+        .build();
     let fetch_response = fetch(&mut request, None);
     let _ = server.close();
 
@@ -587,14 +521,7 @@ fn test_fetch_response_is_cors_filtered() {
     let (server, url) = make_server(handler);
 
     // an origin mis-match will stop it from defaulting to a basic filtered response
-    let origin = Origin::Origin(ImmutableOrigin::new_opaque());
-    let mut request = Request::new(
-        url,
-        Some(origin),
-        Referrer::NoReferrer,
-        None,
-        HttpsState::None,
-    );
+    let mut request = RequestBuilder::new(url, Referrer::NoReferrer).build();
     request.mode = RequestMode::CorsMode;
     let fetch_response = fetch(&mut request, None);
     let _ = server.close();
@@ -626,14 +553,7 @@ fn test_fetch_response_is_opaque_filtered() {
     let (server, url) = make_server(handler);
 
     // an origin mis-match will fall through to an Opaque filtered response
-    let origin = Origin::Origin(ImmutableOrigin::new_opaque());
-    let mut request = Request::new(
-        url,
-        Some(origin),
-        Referrer::NoReferrer,
-        None,
-        HttpsState::None,
-    );
+    let mut request = RequestBuilder::new(url, Referrer::NoReferrer).build();
     let fetch_response = fetch(&mut request, None);
     let _ = server.close();
 
@@ -679,14 +599,9 @@ fn test_fetch_response_is_opaque_redirect_filtered() {
 
     let (server, url) = make_server(handler);
 
-    let origin = Origin::Origin(url.origin());
-    let mut request = Request::new(
-        url,
-        Some(origin),
-        Referrer::NoReferrer,
-        None,
-        HttpsState::None,
-    );
+    let mut request = RequestBuilder::new(url.clone(), Referrer::NoReferrer)
+        .origin(url.origin())
+        .build();
     request.redirect_mode = RedirectMode::Manual;
     let fetch_response = fetch(&mut request, None);
     let _ = server.close();
@@ -718,14 +633,9 @@ fn test_fetch_with_local_urls_only() {
     let (server, server_url) = make_server(handler);
 
     let do_fetch = |url: ServoUrl| {
-        let origin = Origin::Origin(url.origin());
-        let mut request = Request::new(
-            url,
-            Some(origin),
-            Referrer::NoReferrer,
-            None,
-            HttpsState::None,
-        );
+        let mut request = RequestBuilder::new(url.clone(), Referrer::NoReferrer)
+            .origin(url.origin())
+            .build();
 
         // Set the flag.
         request.local_urls_only = true;
@@ -786,14 +696,9 @@ fn test_fetch_with_hsts() {
             HstsEntry::new("localhost".to_owned(), IncludeSubdomains::NotIncluded, None).unwrap(),
         );
     }
-    let origin = Origin::Origin(url.origin());
-    let mut request = Request::new(
-        url,
-        Some(origin),
-        Referrer::NoReferrer,
-        None,
-        HttpsState::None,
-    );
+    let mut request = RequestBuilder::new(url.clone(), Referrer::NoReferrer)
+        .origin(url.origin())
+        .build();
     // Set the flag.
     request.local_urls_only = false;
     let response = fetch_with_context(&mut request, &mut context);
@@ -935,14 +840,9 @@ fn test_fetch_with_sri_network_error() {
     };
     let (server, url) = make_server(handler);
 
-    let origin = Origin::Origin(url.origin());
-    let mut request = Request::new(
-        url,
-        Some(origin),
-        Referrer::NoReferrer,
-        None,
-        HttpsState::None,
-    );
+    let mut request = RequestBuilder::new(url.clone(), Referrer::NoReferrer)
+        .origin(url.origin())
+        .build();
     // To calulate hash use :
     // echo -n "alert('Hello, Network Error');" | openssl dgst -sha384 -binary | openssl base64 -A
     request.integrity_metadata =
@@ -964,14 +864,9 @@ fn test_fetch_with_sri_sucess() {
     };
     let (server, url) = make_server(handler);
 
-    let origin = Origin::Origin(url.origin());
-    let mut request = Request::new(
-        url,
-        Some(origin),
-        Referrer::NoReferrer,
-        None,
-        HttpsState::None,
-    );
+    let mut request = RequestBuilder::new(url.clone(), Referrer::NoReferrer)
+        .origin(url.origin())
+        .build();
     // To calulate hash use :
     // echo -n "alert('Hello, Network Error');" | openssl dgst -sha384 -binary | openssl base64 -A
     request.integrity_metadata =
@@ -1009,15 +904,10 @@ fn test_fetch_blocked_nosniff() {
 
         let (server, url) = make_server(handler);
 
-        let origin = Origin::Origin(url.origin());
-        let mut request = Request::new(
-            url,
-            Some(origin),
-            Referrer::NoReferrer,
-            None,
-            HttpsState::None,
-        );
-        request.destination = destination;
+        let mut request = RequestBuilder::new(url.clone(), Referrer::NoReferrer)
+            .origin(url.origin())
+            .destination(destination)
+            .build();
         let fetch_response = fetch(&mut request, None);
         let _ = server.close();
 
@@ -1059,14 +949,9 @@ fn setup_server_and_fetch(message: &'static [u8], redirect_cap: u32) -> Response
 
     let (server, url) = make_server(handler);
 
-    let origin = Origin::Origin(url.origin());
-    let mut request = Request::new(
-        url,
-        Some(origin),
-        Referrer::NoReferrer,
-        None,
-        HttpsState::None,
-    );
+    let mut request = RequestBuilder::new(url.clone(), Referrer::NoReferrer)
+        .origin(url.origin())
+        .build();
     let fetch_response = fetch(&mut request, None);
     let _ = server.close();
     fetch_response
@@ -1152,15 +1037,10 @@ fn test_fetch_redirect_updates_method_runner(
 
     let (server, url) = make_server(handler);
 
-    let origin = Origin::Origin(url.origin());
-    let mut request = Request::new(
-        url,
-        Some(origin),
-        Referrer::NoReferrer,
-        None,
-        HttpsState::None,
-    );
-    request.method = method;
+    let mut request = RequestBuilder::new(url.clone(), Referrer::NoReferrer)
+        .origin(url.origin())
+        .method(method)
+        .build();
 
     let _ = fetch(&mut request, None);
     let _ = server.close();
@@ -1240,15 +1120,9 @@ fn test_fetch_async_returns_complete_response() {
     };
     let (server, url) = make_server(handler);
 
-    let origin = Origin::Origin(url.origin());
-    let mut request = Request::new(
-        url,
-        Some(origin),
-        Referrer::NoReferrer,
-        None,
-        HttpsState::None,
-    );
-
+    let mut request = RequestBuilder::new(url.clone(), Referrer::NoReferrer)
+        .origin(url.origin())
+        .build();
     let fetch_response = fetch(&mut request, None);
 
     let _ = server.close();
@@ -1264,15 +1138,7 @@ fn test_opaque_filtered_fetch_async_returns_complete_response() {
     let (server, url) = make_server(handler);
 
     // an origin mis-match will fall through to an Opaque filtered response
-    let origin = Origin::Origin(ImmutableOrigin::new_opaque());
-    let mut request = Request::new(
-        url,
-        Some(origin),
-        Referrer::NoReferrer,
-        None,
-        HttpsState::None,
-    );
-
+    let mut request = RequestBuilder::new(url, Referrer::NoReferrer).build();
     let fetch_response = fetch(&mut request, None);
 
     let _ = server.close();
@@ -1304,16 +1170,10 @@ fn test_opaque_redirect_filtered_fetch_async_returns_complete_response() {
     };
 
     let (server, url) = make_server(handler);
-
-    let origin = Origin::Origin(url.origin());
-    let mut request = Request::new(
-        url,
-        Some(origin),
-        Referrer::NoReferrer,
-        None,
-        HttpsState::None,
-    );
-    request.redirect_mode = RedirectMode::Manual;
+    let mut request = RequestBuilder::new(url.clone(), Referrer::NoReferrer)
+        .origin(url.origin())
+        .redirect_mode(RedirectMode::Manual)
+        .build();
 
     let fetch_response = fetch(&mut request, None);
 
@@ -1333,14 +1193,11 @@ fn test_fetch_with_devtools() {
 
     let (server, url) = make_server(handler);
 
-    let origin = Origin::Origin(url.origin());
-    let mut request = Request::new(
-        url.clone(),
-        Some(origin),
-        Referrer::NoReferrer,
-        Some(TEST_PIPELINE_ID),
-        HttpsState::None,
-    );
+    let mut request = RequestBuilder::new(url.clone(), Referrer::NoReferrer)
+        .origin(url.origin())
+        .redirect_mode(RedirectMode::Manual)
+        .pipeline_id(Some(TEST_PIPELINE_ID))
+        .build();
 
     let (devtools_chan, devtools_port) = unbounded();
 
diff --git a/components/net/tests/http_cache.rs b/components/net/tests/http_cache.rs
index 9900295c891..478e452213b 100644
--- a/components/net/tests/http_cache.rs
+++ b/components/net/tests/http_cache.rs
@@ -6,8 +6,8 @@ use base::id::TEST_PIPELINE_ID;
 use http::header::{HeaderValue, EXPIRES};
 use http::StatusCode;
 use net::http_cache::HttpCache;
-use net_traits::request::{Origin, Referrer, Request};
-use net_traits::response::{HttpsState, Response, ResponseBody};
+use net_traits::request::{Referrer, RequestBuilder};
+use net_traits::response::{Response, ResponseBody};
 use net_traits::{ResourceFetchTiming, ResourceTimingType};
 use servo_url::ServoUrl;
 use tokio::sync::mpsc::unbounded_channel as unbounded;
@@ -20,13 +20,10 @@ fn test_refreshing_resource_sets_done_chan_the_appropriate_value() {
         ResponseBody::Done(vec![]),
     ];
     let url = ServoUrl::parse("https://servo.org").unwrap();
-    let request = Request::new(
-        url.clone(),
-        Some(Origin::Origin(url.clone().origin())),
-        Referrer::NoReferrer,
-        Some(TEST_PIPELINE_ID),
-        HttpsState::None,
-    );
+    let request = RequestBuilder::new(url.clone(), Referrer::NoReferrer)
+        .pipeline_id(Some(TEST_PIPELINE_ID))
+        .origin(url.origin())
+        .build();
     let timing = ResourceFetchTiming::new(ResourceTimingType::Navigation);
     let mut response = Response::new(url.clone(), timing);
     // Expires header makes the response cacheable.
diff --git a/components/net/tests/http_loader.rs b/components/net/tests/http_loader.rs
index fac0101baba..bfa87f5df20 100644
--- a/components/net/tests/http_loader.rs
+++ b/components/net/tests/http_loader.rs
@@ -1426,12 +1426,12 @@ fn test_fetch_compressed_response_update_count() {
     impl FetchTaskTarget for FetchResponseCollector {
         fn process_request_body(&mut self, _: &Request) {}
         fn process_request_eof(&mut self, _: &Request) {}
-        fn process_response(&mut self, _: &Response) {}
-        fn process_response_chunk(&mut self, _: Vec<u8>) {
+        fn process_response(&mut self, _: &Request, _: &Response) {}
+        fn process_response_chunk(&mut self, _: &Request, _: Vec<u8>) {
             self.update_count += 1;
         }
         /// Fired when the response is fully fetched
-        fn process_response_eof(&mut self, _: &Response) {
+        fn process_response_eof(&mut self, _: &Request, _: &Response) {
             let _ = self.sender.send(self.update_count);
         }
     }
diff --git a/components/net/tests/main.rs b/components/net/tests/main.rs
index ae86c749d10..010898c2f83 100644
--- a/components/net/tests/main.rs
+++ b/components/net/tests/main.rs
@@ -121,10 +121,10 @@ fn new_fetch_context(
 impl FetchTaskTarget for FetchResponseCollector {
     fn process_request_body(&mut self, _: &Request) {}
     fn process_request_eof(&mut self, _: &Request) {}
-    fn process_response(&mut self, _: &Response) {}
-    fn process_response_chunk(&mut self, _: Vec<u8>) {}
+    fn process_response(&mut self, _: &Request, _: &Response) {}
+    fn process_response_chunk(&mut self, _: &Request, _: Vec<u8>) {}
     /// Fired when the response is fully fetched
-    fn process_response_eof(&mut self, response: &Response) {
+    fn process_response_eof(&mut self, _: &Request, response: &Response) {
         let _ = self.sender.send(response.clone());
     }
 }