From 5cdd8d442ef5a573f4af07e68dce7720ca603aba Mon Sep 17 00:00:00 2001 From: Aleksey Kladov Date: Sun, 28 Jun 2020 23:42:44 +0200 Subject: Cleanup cargo process handling in flycheck --- crates/flycheck/src/lib.rs | 121 +++++++++++++++++++++++---------------------- 1 file changed, 61 insertions(+), 60 deletions(-) (limited to 'crates/flycheck/src') diff --git a/crates/flycheck/src/lib.rs b/crates/flycheck/src/lib.rs index ab1d71b98..1023d3040 100644 --- a/crates/flycheck/src/lib.rs +++ b/crates/flycheck/src/lib.rs @@ -85,7 +85,7 @@ pub enum Message { pub enum Progress { DidStart, DidCheckCrate(String), - DidFinish, + DidFinish(io::Result<()>), DidCancel, } @@ -100,7 +100,7 @@ struct FlycheckActor { /// doesn't provide a way to read sub-process output without blocking, so we /// have to wrap sub-processes output handling in a thread and pass messages /// back over a channel. - check_process: Option, + cargo_handle: Option, } enum Event { @@ -114,10 +114,10 @@ impl FlycheckActor { config: FlycheckConfig, workspace_root: PathBuf, ) -> FlycheckActor { - FlycheckActor { sender, config, workspace_root, check_process: None } + FlycheckActor { sender, config, workspace_root, cargo_handle: None } } fn next_event(&self, inbox: &Receiver) -> Option { - let check_chan = self.check_process.as_ref().map(|cargo| &cargo.receiver); + let check_chan = self.cargo_handle.as_ref().map(|cargo| &cargo.receiver); select! { recv(inbox) -> msg => msg.ok().map(Event::Restart), recv(check_chan.unwrap_or(&never())) -> msg => Some(Event::CheckEvent(msg.ok())), @@ -128,15 +128,22 @@ impl FlycheckActor { match event { Event::Restart(Restart) => { while let Ok(Restart) = inbox.recv_timeout(Duration::from_millis(50)) {} + self.cancel_check_process(); - self.check_process = Some(self.start_check_process()); - self.send(Message::Progress(Progress::DidStart)); + + let mut command = self.check_command(); + command.stdout(Stdio::piped()).stderr(Stdio::null()).stdin(Stdio::null()); + if let Ok(child) = command.spawn().map(JodChild) { + self.cargo_handle = Some(CargoHandle::spawn(child)); + self.send(Message::Progress(Progress::DidStart)); + } } Event::CheckEvent(None) => { // Watcher finished, replace it with a never channel to // avoid busy-waiting. - assert!(self.check_process.take().is_some()); - self.send(Message::Progress(Progress::DidFinish)); + let cargo_handle = self.cargo_handle.take().unwrap(); + let res = cargo_handle.join(); + self.send(Message::Progress(Progress::DidFinish(res))); } Event::CheckEvent(Some(message)) => match message { cargo_metadata::Message::CompilerArtifact(msg) => { @@ -161,11 +168,11 @@ impl FlycheckActor { self.cancel_check_process(); } fn cancel_check_process(&mut self) { - if self.check_process.take().is_some() { + if self.cargo_handle.take().is_some() { self.send(Message::Progress(Progress::DidCancel)); } } - fn start_check_process(&self) -> CargoHandle { + fn check_command(&self) -> Command { let mut cmd = match &self.config { FlycheckConfig::CargoCommand { command, @@ -197,8 +204,7 @@ impl FlycheckActor { } }; cmd.current_dir(&self.workspace_root); - - CargoHandle::spawn(cmd) + cmd } fn send(&self, check_task: Message) { @@ -207,49 +213,62 @@ impl FlycheckActor { } struct CargoHandle { - receiver: Receiver, + child: JodChild, #[allow(unused)] - thread: jod_thread::JoinHandle, + thread: jod_thread::JoinHandle>, + receiver: Receiver, } impl CargoHandle { - fn spawn(command: Command) -> CargoHandle { + fn spawn(mut child: JodChild) -> CargoHandle { + let child_stdout = child.stdout.take().unwrap(); let (sender, receiver) = unbounded(); - let actor = CargoActor::new(command, sender); - let thread = jod_thread::spawn(move || { - let _ = actor.run(); - }); - CargoHandle { receiver, thread } + let actor = CargoActor::new(child_stdout, sender); + let thread = jod_thread::spawn(move || actor.run()); + CargoHandle { child, thread, receiver } + } + fn join(mut self) -> io::Result<()> { + // It is okay to ignore the result, as it only errors if the process is already dead + let _ = self.child.kill(); + let exit_status = self.child.wait()?; + let read_at_least_one_message = self.thread.join()?; + if !exit_status.success() && !read_at_least_one_message { + // FIXME: Read the stderr to display the reason, see `read2()` reference in PR comment: + // https://github.com/rust-analyzer/rust-analyzer/pull/3632#discussion_r395605298 + return Err(io::Error::new( + io::ErrorKind::Other, + format!( + "Cargo watcher failed,the command produced no valid metadata (exit code: {:?})", + exit_status + ), + )); + } + Ok(()) } } struct CargoActor { - command: Command, + child_stdout: process::ChildStdout, sender: Sender, } impl CargoActor { - fn new(command: Command, sender: Sender) -> CargoActor { - CargoActor { command, sender } + fn new( + child_stdout: process::ChildStdout, + sender: Sender, + ) -> CargoActor { + CargoActor { child_stdout, sender } } - fn run(mut self) -> io::Result<()> { - let child = self - .command - .stdout(Stdio::piped()) - .stderr(Stdio::null()) - .stdin(Stdio::null()) - .spawn()?; - let mut child = ChildKiller(child); - + fn run(self) -> io::Result { // We manually read a line at a time, instead of using serde's // stream deserializers, because the deserializer cannot recover // from an error, resulting in it getting stuck, because we try to - // be resillient against failures. + // be resilient against failures. // // Because cargo only outputs one JSON object per line, we can // simply skip a line if it doesn't parse, which just ignores any // erroneus output. - let stdout = BufReader::new(child.stdout.take().unwrap()); + let stdout = BufReader::new(self.child_stdout); let mut read_at_least_one_message = false; for message in cargo_metadata::Message::parse_stream(stdout) { let message = match message { @@ -264,50 +283,32 @@ impl CargoActor { // Skip certain kinds of messages to only spend time on what's useful match &message { - cargo_metadata::Message::CompilerArtifact(artifact) if artifact.fresh => continue, + cargo_metadata::Message::CompilerArtifact(artifact) if artifact.fresh => (), cargo_metadata::Message::BuildScriptExecuted(_) - | cargo_metadata::Message::Unknown => continue, - _ => { - // if the send channel was closed, we want to shutdown - if self.sender.send(message).is_err() { - break; - } - } + | cargo_metadata::Message::Unknown => (), + _ => self.sender.send(message).unwrap(), } } - - // It is okay to ignore the result, as it only errors if the process is already dead - let _ = child.kill(); - - let exit_status = child.wait()?; - if !exit_status.success() && !read_at_least_one_message { - // FIXME: Read the stderr to display the reason, see `read2()` reference in PR comment: - // https://github.com/rust-analyzer/rust-analyzer/pull/3632#discussion_r395605298 - - // FIXME: make the `message_send` to be `Sender>` - // to display user-caused misconfiguration errors instead of just logging them here - log::error!("Cargo watcher failed,the command produced no valid metadata (exit code: {:?}): {:?}", exit_status, self.command); - } - Ok(()) + Ok(read_at_least_one_message) } } -struct ChildKiller(process::Child); +struct JodChild(process::Child); -impl ops::Deref for ChildKiller { +impl ops::Deref for JodChild { type Target = process::Child; fn deref(&self) -> &process::Child { &self.0 } } -impl ops::DerefMut for ChildKiller { +impl ops::DerefMut for JodChild { fn deref_mut(&mut self) -> &mut process::Child { &mut self.0 } } -impl Drop for ChildKiller { +impl Drop for JodChild { fn drop(&mut self) { let _ = self.0.kill(); } -- cgit v1.2.3