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use rayon_core::ThreadPoolBuilder;
use std::sync::{Arc, Condvar, Mutex};
use std::thread::{self, JoinHandle};
#[test]
#[cfg_attr(any(target_os = "emscripten", target_family = "wasm"), ignore)]
fn use_current_thread_basic() {
static JOIN_HANDLES: Mutex<Vec<JoinHandle<()>>> = Mutex::new(Vec::new());
let pool = ThreadPoolBuilder::new()
.num_threads(2)
.use_current_thread()
.spawn_handler(|builder| {
let handle = thread::Builder::new().spawn(|| builder.run())?;
JOIN_HANDLES.lock().unwrap().push(handle);
Ok(())
})
.build()
.unwrap();
assert_eq!(rayon_core::current_thread_index(), Some(0));
assert_eq!(
JOIN_HANDLES.lock().unwrap().len(),
1,
"Should only spawn one extra thread"
);
let another_pool = ThreadPoolBuilder::new()
.num_threads(2)
.use_current_thread()
.build();
assert!(
another_pool.is_err(),
"Should error if the thread is already part of a pool"
);
let pair = Arc::new((Mutex::new(false), Condvar::new()));
let pair2 = Arc::clone(&pair);
pool.spawn(move || {
assert_ne!(rayon_core::current_thread_index(), Some(0));
// This should execute even if the current thread is blocked, since we have two threads in
// the pool.
let &(ref started, ref condvar) = &*pair2;
*started.lock().unwrap() = true;
condvar.notify_one();
});
let _guard = pair
.1
.wait_while(pair.0.lock().unwrap(), |ran| !*ran)
.unwrap();
std::mem::drop(pool); // Drop the pool.
// Wait until all threads have actually exited. This is not really needed, other than to
// reduce noise of leak-checking tools.
for handle in std::mem::take(&mut *JOIN_HANDLES.lock().unwrap()) {
let _ = handle.join();
}
}