replace scoped_pool (#685)

Cargo.toml

@@ -50,10 +50,10 @@ owned-read = "0.4"
 failure = "0.1"
 htmlescape = "0.3.1"
 fail = "0.3"
-scoped-pool = "1.0"
 murmurhash32 = "0.2"
 chrono = "0.4"
 smallvec = "1.0"
+rayon = "1"
 
 [target.'cfg(windows)'.dependencies]
 winapi = "0.3"
@@ -64,6 +64,10 @@ maplit = "1"
 matches = "0.1.8"
 time = "0.1.42"
 
+[dev-dependencies.fail]
+version = "0.3"
+features = ["failpoints"]
+
 [profile.release]
 opt-level = 3
 debug = false
@@ -87,10 +91,6 @@ members = ["query-grammar"]
 [badges]
 travis-ci = { repository = "tantivy-search/tantivy" }
 
-[dev-dependencies.fail]
-version = "0.3"
-features = ["failpoints"]
-
 # Following the "fail" crate best practises, we isolate
 # tests that define specific behavior in fail check points
 # in a different binary.

src/core/executor.rs

@@ -1,6 +1,6 @@
 use crate::Result;
 use crossbeam::channel;
-use scoped_pool::{Pool, ThreadConfig};
+use rayon::{ThreadPool, ThreadPoolBuilder};
 
 /// Search executor whether search request are single thread or multithread.
 ///
@@ -11,7 +11,7 @@ use scoped_pool::{Pool, ThreadConfig};
 /// used by the client. Second, we may stop using rayon in the future.
 pub enum Executor {
     SingleThread,
-    ThreadPool(Pool),
+    ThreadPool(ThreadPool),
 }
 
 impl Executor {
@@ -21,10 +21,12 @@ impl Executor {
     }
 
     // Creates an Executor that dispatches the tasks in a thread pool.
-    pub fn multi_thread(num_threads: usize, prefix: &'static str) -> Executor {
-        let thread_config = ThreadConfig::new().prefix(prefix);
-        let pool = Pool::with_thread_config(num_threads, thread_config);
-        Executor::ThreadPool(pool)
+    pub fn multi_thread(num_threads: usize, prefix: &'static str) -> Result<Executor> {
+        let pool = ThreadPoolBuilder::new()
+            .num_threads(num_threads)
+            .thread_name(move |num| format!("{}{}", prefix, num))
+            .build()?;
+        Ok(Executor::ThreadPool(pool))
     }
 
     // Perform a map in the thread pool.
@@ -48,9 +50,9 @@ impl Executor {
                 let num_fruits = args_with_indices.len();
                 let fruit_receiver = {
                     let (fruit_sender, fruit_receiver) = channel::unbounded();
-                    pool.scoped(|scope| {
+                    pool.scope(|scope| {
                         for arg_with_idx in args_with_indices {
-                            scope.execute(|| {
+                            scope.spawn(|_| {
                                 let (idx, arg) = arg_with_idx;
                                 let fruit = f(arg);
                                 if let Err(err) = fruit_sender.send((idx, fruit)) {
@@ -103,6 +105,7 @@ mod tests {
     #[should_panic] //< unfortunately the panic message is not propagated
     fn test_panic_propagates_multi_thread() {
         let _result: Vec<usize> = Executor::multi_thread(1, "search-test")
+            .unwrap()
             .map(
                 |_| {
                     panic!("panic should propagate");
@@ -126,6 +129,7 @@ mod tests {
     #[test]
     fn test_map_multithread() {
         let result: Vec<usize> = Executor::multi_thread(3, "search-test")
+            .unwrap()
             .map(|i| Ok(i * 2), 0..10)
             .unwrap();
         assert_eq!(result.len(), 10);

src/core/index.rs

@@ -73,15 +73,16 @@ impl Index {
 
     /// Replace the default single thread search executor pool
     /// by a thread pool with a given number of threads.
-    pub fn set_multithread_executor(&mut self, num_threads: usize) {
-        self.executor = Arc::new(Executor::multi_thread(num_threads, "thrd-tantivy-search-"));
+    pub fn set_multithread_executor(&mut self, num_threads: usize) -> Result<()> {
+        self.executor = Arc::new(Executor::multi_thread(num_threads, "thrd-tantivy-search-")?);
+        Ok(())
     }
 
     /// Replace the default single thread search executor pool
     /// by a thread pool with a given number of threads.
-    pub fn set_default_multithread_executor(&mut self) {
+    pub fn set_default_multithread_executor(&mut self) -> Result<()> {
         let default_num_threads = num_cpus::get();
-        self.set_multithread_executor(default_num_threads);
+        self.set_multithread_executor(default_num_threads)
     }
 
     /// Creates a new index using the `RAMDirectory`.

src/error.rs

@@ -170,3 +170,9 @@ impl From<serde_json::Error> for TantivyError {
         TantivyError::IOError(io_err.into())
     }
 }
+
+impl From<rayon::ThreadPoolBuildError> for TantivyError {
+    fn from(error: rayon::ThreadPoolBuildError) -> TantivyError {
+        TantivyError::SystemError(error.to_string())
+    }
+}