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authorValentin Popov <valentin@popov.link>2024-01-08 00:21:28 +0300
committerValentin Popov <valentin@popov.link>2024-01-08 00:21:28 +0300
commit1b6a04ca5504955c571d1c97504fb45ea0befee4 (patch)
tree7579f518b23313e8a9748a88ab6173d5e030b227 /vendor/rayon-core/src/spawn/mod.rs
parent5ecd8cf2cba827454317368b68571df0d13d7842 (diff)
downloadfparkan-1b6a04ca5504955c571d1c97504fb45ea0befee4.tar.xz
fparkan-1b6a04ca5504955c571d1c97504fb45ea0befee4.zip
Initial vendor packages
Signed-off-by: Valentin Popov <valentin@popov.link>
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+use crate::job::*;
+use crate::registry::Registry;
+use crate::unwind;
+use std::mem;
+use std::sync::Arc;
+
+/// Fires off a task into the Rayon threadpool in the "static" or
+/// "global" scope. Just like a standard thread, this task is not
+/// tied to the current stack frame, and hence it cannot hold any
+/// references other than those with `'static` lifetime. If you want
+/// to spawn a task that references stack data, use [the `scope()`
+/// function][scope] to create a scope.
+///
+/// [scope]: fn.scope.html
+///
+/// Since tasks spawned with this function cannot hold references into
+/// the enclosing stack frame, you almost certainly want to use a
+/// `move` closure as their argument (otherwise, the closure will
+/// typically hold references to any variables from the enclosing
+/// function that you happen to use).
+///
+/// This API assumes that the closure is executed purely for its
+/// side-effects (i.e., it might send messages, modify data protected
+/// by a mutex, or some such thing).
+///
+/// There is no guaranteed order of execution for spawns, given that
+/// other threads may steal tasks at any time. However, they are
+/// generally prioritized in a LIFO order on the thread from which
+/// they were spawned. Other threads always steal from the other end of
+/// the deque, like FIFO order. The idea is that "recent" tasks are
+/// most likely to be fresh in the local CPU's cache, while other
+/// threads can steal older "stale" tasks. For an alternate approach,
+/// consider [`spawn_fifo()`] instead.
+///
+/// [`spawn_fifo()`]: fn.spawn_fifo.html
+///
+/// # Panic handling
+///
+/// If this closure should panic, the resulting panic will be
+/// propagated to the panic handler registered in the `ThreadPoolBuilder`,
+/// if any. See [`ThreadPoolBuilder::panic_handler()`][ph] for more
+/// details.
+///
+/// [ph]: struct.ThreadPoolBuilder.html#method.panic_handler
+///
+/// # Examples
+///
+/// This code creates a Rayon task that increments a global counter.
+///
+/// ```rust
+/// # use rayon_core as rayon;
+/// use std::sync::atomic::{AtomicUsize, Ordering, ATOMIC_USIZE_INIT};
+///
+/// static GLOBAL_COUNTER: AtomicUsize = ATOMIC_USIZE_INIT;
+///
+/// rayon::spawn(move || {
+/// GLOBAL_COUNTER.fetch_add(1, Ordering::SeqCst);
+/// });
+/// ```
+pub fn spawn<F>(func: F)
+where
+ F: FnOnce() + Send + 'static,
+{
+ // We assert that current registry has not terminated.
+ unsafe { spawn_in(func, &Registry::current()) }
+}
+
+/// Spawns an asynchronous job in `registry.`
+///
+/// Unsafe because `registry` must not yet have terminated.
+pub(super) unsafe fn spawn_in<F>(func: F, registry: &Arc<Registry>)
+where
+ F: FnOnce() + Send + 'static,
+{
+ // We assert that this does not hold any references (we know
+ // this because of the `'static` bound in the interface);
+ // moreover, we assert that the code below is not supposed to
+ // be able to panic, and hence the data won't leak but will be
+ // enqueued into some deque for later execution.
+ let abort_guard = unwind::AbortIfPanic; // just in case we are wrong, and code CAN panic
+ let job_ref = spawn_job(func, registry);
+ registry.inject_or_push(job_ref);
+ mem::forget(abort_guard);
+}
+
+unsafe fn spawn_job<F>(func: F, registry: &Arc<Registry>) -> JobRef
+where
+ F: FnOnce() + Send + 'static,
+{
+ // Ensure that registry cannot terminate until this job has
+ // executed. This ref is decremented at the (*) below.
+ registry.increment_terminate_count();
+
+ HeapJob::new({
+ let registry = Arc::clone(registry);
+ move || {
+ registry.catch_unwind(func);
+ registry.terminate(); // (*) permit registry to terminate now
+ }
+ })
+ .into_static_job_ref()
+}
+
+/// Fires off a task into the Rayon threadpool in the "static" or
+/// "global" scope. Just like a standard thread, this task is not
+/// tied to the current stack frame, and hence it cannot hold any
+/// references other than those with `'static` lifetime. If you want
+/// to spawn a task that references stack data, use [the `scope_fifo()`
+/// function](fn.scope_fifo.html) to create a scope.
+///
+/// The behavior is essentially the same as [the `spawn`
+/// function](fn.spawn.html), except that calls from the same thread
+/// will be prioritized in FIFO order. This is similar to the now-
+/// deprecated [`breadth_first`] option, except the effect is isolated
+/// to relative `spawn_fifo` calls, not all threadpool tasks.
+///
+/// For more details on this design, see Rayon [RFC #1].
+///
+/// [`breadth_first`]: struct.ThreadPoolBuilder.html#method.breadth_first
+/// [RFC #1]: https://github.com/rayon-rs/rfcs/blob/master/accepted/rfc0001-scope-scheduling.md
+///
+/// # Panic handling
+///
+/// If this closure should panic, the resulting panic will be
+/// propagated to the panic handler registered in the `ThreadPoolBuilder`,
+/// if any. See [`ThreadPoolBuilder::panic_handler()`][ph] for more
+/// details.
+///
+/// [ph]: struct.ThreadPoolBuilder.html#method.panic_handler
+pub fn spawn_fifo<F>(func: F)
+where
+ F: FnOnce() + Send + 'static,
+{
+ // We assert that current registry has not terminated.
+ unsafe { spawn_fifo_in(func, &Registry::current()) }
+}
+
+/// Spawns an asynchronous FIFO job in `registry.`
+///
+/// Unsafe because `registry` must not yet have terminated.
+pub(super) unsafe fn spawn_fifo_in<F>(func: F, registry: &Arc<Registry>)
+where
+ F: FnOnce() + Send + 'static,
+{
+ // We assert that this does not hold any references (we know
+ // this because of the `'static` bound in the interface);
+ // moreover, we assert that the code below is not supposed to
+ // be able to panic, and hence the data won't leak but will be
+ // enqueued into some deque for later execution.
+ let abort_guard = unwind::AbortIfPanic; // just in case we are wrong, and code CAN panic
+ let job_ref = spawn_job(func, registry);
+
+ // If we're in the pool, use our thread's private fifo for this thread to execute
+ // in a locally-FIFO order. Otherwise, just use the pool's global injector.
+ match registry.current_thread() {
+ Some(worker) => worker.push_fifo(job_ref),
+ None => registry.inject(job_ref),
+ }
+ mem::forget(abort_guard);
+}
+
+#[cfg(test)]
+mod test;