move thread worker to a separate crate

crates/ra_lsp_server/src/lib.rs

@@ -5,7 +5,6 @@ mod path_map;
 mod project_model;
 pub mod req;
 mod server_world;
-pub mod thread_watcher;
 mod vfs;
 
 pub type Result<T> = ::std::result::Result<T, ::failure::Error>;

crates/ra_lsp_server/src/main_loop.rs

@@ -10,6 +10,7 @@ use gen_lsp_server::{
 use languageserver_types::NumberOrString;
 use ra_analysis::{Canceled, FileId, LibraryData};
 use rayon;
+use thread_worker::Worker;
 use threadpool::ThreadPool;
 use rustc_hash::FxHashSet;
 use serde::{de::DeserializeOwned, Serialize};
@@ -21,7 +22,6 @@ use crate::{
     project_model::{workspace_loader, CargoWorkspace},
     req,
     server_world::{ServerWorld, ServerWorldState},
-    thread_watcher::Worker,
     vfs::{self, FileEvent},
     Result,
 };
@@ -92,8 +92,8 @@ pub fn main_loop(
     let ws_res = ws_watcher.stop();
 
     main_res?;
-    fs_res?;
-    ws_res?;
+    fs_res.map_err(|_| format_err!("fs watcher died"))?;
+    ws_res.map_err(|_| format_err!("ws watcher died"))?;
 
     Ok(())
 }

crates/ra_lsp_server/src/project_model.rs

@@ -4,11 +4,9 @@ use cargo_metadata::{metadata_run, CargoOpt};
 use ra_syntax::SmolStr;
 use rustc_hash::{FxHashMap, FxHashSet};
 use failure::{format_err, bail};
+use thread_worker::{WorkerHandle, Worker};
 
-use crate::{
-    Result,
-    thread_watcher::{ThreadWatcher, Worker},
-};
+use crate::Result;
 
 /// `CargoWorksapce` represents the logical structure of, well, a Cargo
 /// workspace. It pretty closely mirrors `cargo metadata` output.
@@ -199,8 +197,8 @@ impl TargetKind {
     }
 }
 
-pub fn workspace_loader() -> (Worker<PathBuf, Result<CargoWorkspace>>, ThreadWatcher) {
-    Worker::<PathBuf, Result<CargoWorkspace>>::spawn(
+pub fn workspace_loader() -> (Worker<PathBuf, Result<CargoWorkspace>>, WorkerHandle) {
+    thread_worker::spawn::<PathBuf, Result<CargoWorkspace>, _>(
         "workspace loader",
         1,
         |input_receiver, output_sender| {

crates/ra_lsp_server/src/thread_watcher.rs

@@ -1,81 +0,0 @@
-use std::thread;
-
-use crossbeam_channel::{bounded, unbounded, Receiver, Sender};
-use drop_bomb::DropBomb;
-use failure::format_err;
-
-use crate::Result;
-
-pub struct Worker<I, O> {
-    pub inp: Sender<I>,
-    pub out: Receiver<O>,
-}
-
-impl<I, O> Worker<I, O> {
-    pub fn spawn<F>(name: &'static str, buf: usize, f: F) -> (Self, ThreadWatcher)
-    where
-        F: FnOnce(Receiver<I>, Sender<O>) + Send + 'static,
-        I: Send + 'static,
-        O: Send + 'static,
-    {
-        let (worker, inp_r, out_s) = worker_chan(buf);
-        let watcher = ThreadWatcher::spawn(name, move || f(inp_r, out_s));
-        (worker, watcher)
-    }
-
-    pub fn stop(self) -> Receiver<O> {
-        self.out
-    }
-
-    pub fn send(&self, item: I) {
-        self.inp.send(item)
-    }
-}
-
-pub struct ThreadWatcher {
-    name: &'static str,
-    thread: thread::JoinHandle<()>,
-    bomb: DropBomb,
-}
-
-impl ThreadWatcher {
-    fn spawn(name: &'static str, f: impl FnOnce() + Send + 'static) -> ThreadWatcher {
-        let thread = thread::spawn(f);
-        ThreadWatcher {
-            name,
-            thread,
-            bomb: DropBomb::new(format!("ThreadWatcher {} was not stopped", name)),
-        }
-    }
-
-    pub fn stop(mut self) -> Result<()> {
-        log::info!("waiting for {} to finish ...", self.name);
-        let name = self.name;
-        self.bomb.defuse();
-        let res = self
-            .thread
-            .join()
-            .map_err(|_| format_err!("ThreadWatcher {} died", name));
-        match &res {
-            Ok(()) => log::info!("... {} terminated with ok", name),
-            Err(_) => log::error!("... {} terminated with err", name),
-        }
-        res
-    }
-}
-
-/// Sets up worker channels in a deadlock-avoind way.
-/// If one sets both input and output buffers to a fixed size,
-/// a worker might get stuck.
-fn worker_chan<I, O>(buf: usize) -> (Worker<I, O>, Receiver<I>, Sender<O>) {
-    let (input_sender, input_receiver) = bounded::<I>(buf);
-    let (output_sender, output_receiver) = unbounded::<O>();
-    (
-        Worker {
-            inp: input_sender,
-            out: output_receiver,
-        },
-        input_receiver,
-        output_sender,
-    )
-}

crates/ra_lsp_server/src/vfs.rs

@@ -4,8 +4,7 @@ use std::{
 };
 
 use walkdir::WalkDir;
-
-use crate::thread_watcher::{ThreadWatcher, Worker};
+use thread_worker::{WorkerHandle, Worker};
 
 #[derive(Debug)]
 pub struct FileEvent {
@@ -18,8 +17,8 @@ pub enum FileEventKind {
     Add(String),
 }
 
-pub fn roots_loader() -> (Worker<PathBuf, (PathBuf, Vec<FileEvent>)>, ThreadWatcher) {
-    Worker::<PathBuf, (PathBuf, Vec<FileEvent>)>::spawn(
+pub fn roots_loader() -> (Worker<PathBuf, (PathBuf, Vec<FileEvent>)>, WorkerHandle) {
+    thread_worker::spawn::<PathBuf, (PathBuf, Vec<FileEvent>), _>(
         "roots loader",
         128,
         |input_receiver, output_sender| {