Struct ThreadPool 

pub struct ThreadPool { /* private fields */ }

A work-stealing pool of worker threads.

Dropping the pool signals shutdown and joins every worker, so no task outlives it.

Implementations

impl ThreadPool

pub fn new(threads: usize) -> Result<Self>

Build a pool with threads workers.

threads is clamped to at least one. Use ThreadPool::default_threads for the machine’s parallelism.

Errors

Returns PixelsError::Io if the operating system refuses to spawn a worker thread.

pub fn default_threads() -> usize

The parallelism to use when the caller has no preference.

Falls back to one thread where the platform cannot report it, which yields a correct if serial engine rather than a failure.

pub fn with_default_threads() -> Result<Self>

A pool sized to ThreadPool::default_threads.

Errors

As ThreadPool::new.

pub fn on_worker_thread() -> bool

Whether the calling thread is a worker of any pool.

A run blocks its caller until its tiles are done, so a run started from inside a task would hold a worker of the pool it is waiting on. Callers that would otherwise use a shared pool check this first.

pub const fn threads(&self) -> usize

How many workers this pool runs.

pub fn spawn(&self, task: impl FnOnce() + Send + 'static)

Queue task for execution.

Returns immediately. Panics inside task are contained by the worker and do not propagate here.

pub fn run_all<F>(&self, tasks: Vec<F>) -> Result<()>

where F: FnOnce() -> Result<()> + Send + 'static,

Run tasks on the pool and return once every one has finished.

Why 'static

Tasks must be 'static because they run on long-lived worker threads that outlive this call. Erasing a shorter lifetime is what rayon uses unsafe for, and ADR-0008 keeps unsafe_code = "forbid" in our crates. This costs the scheduler nothing: tiles are already Arc<TileBuf> and graph nodes Arc<Node>, so a task moves cheap handles rather than borrowing.

The calling thread blocks. Calling run_all from inside a pool task is not supported and can deadlock; the scheduler submits one flat batch per wave instead of nesting.

Errors

Returns the failing task’s error, choosing the lowest-indexed failure when several fail. Which worker happens to fail first is a race; which task index is lowest is not, so the reported error is deterministic (SPEC §Guarantees 2).

Trait Implementations

impl Debug for ThreadPool

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.

impl Drop for ThreadPool

fn drop(&mut self)

Executes the destructor for this type.

fn pin_drop(self: Pin<&mut Self>)

🔬This is a nightly-only experimental API. (pin_ergonomics)

Execute the destructor for this type, but different to Drop::drop, it requires self to be pinned.