1 use rayon_core::ThreadPoolBuilder;
2 use std::sync::{Arc, Condvar, Mutex};
3 use std::thread::{self, JoinHandle};
4
5 #[test]
6 #[cfg_attr(any(target_os = "emscripten", target_family = "wasm"), ignore)]
use_current_thread_basic()7 fn use_current_thread_basic() {
8 static JOIN_HANDLES: Mutex<Vec<JoinHandle<()>>> = Mutex::new(Vec::new());
9 let pool = ThreadPoolBuilder::new()
10 .num_threads(2)
11 .use_current_thread()
12 .spawn_handler(|builder| {
13 let handle = thread::Builder::new().spawn(|| builder.run())?;
14 JOIN_HANDLES.lock().unwrap().push(handle);
15 Ok(())
16 })
17 .build()
18 .unwrap();
19 assert_eq!(rayon_core::current_thread_index(), Some(0));
20 assert_eq!(
21 JOIN_HANDLES.lock().unwrap().len(),
22 1,
23 "Should only spawn one extra thread"
24 );
25
26 let another_pool = ThreadPoolBuilder::new()
27 .num_threads(2)
28 .use_current_thread()
29 .build();
30 assert!(
31 another_pool.is_err(),
32 "Should error if the thread is already part of a pool"
33 );
34
35 let pair = Arc::new((Mutex::new(false), Condvar::new()));
36 let pair2 = Arc::clone(&pair);
37 pool.spawn(move || {
38 assert_ne!(rayon_core::current_thread_index(), Some(0));
39 // This should execute even if the current thread is blocked, since we have two threads in
40 // the pool.
41 let &(ref started, ref condvar) = &*pair2;
42 *started.lock().unwrap() = true;
43 condvar.notify_one();
44 });
45
46 let _guard = pair
47 .1
48 .wait_while(pair.0.lock().unwrap(), |ran| !*ran)
49 .unwrap();
50 std::mem::drop(pool); // Drop the pool.
51
52 // Wait until all threads have actually exited. This is not really needed, other than to
53 // reduce noise of leak-checking tools.
54 for handle in std::mem::take(&mut *JOIN_HANDLES.lock().unwrap()) {
55 let _ = handle.join();
56 }
57 }
58