Struct WorkerPool 

pub struct WorkerPool { /* private fields */ }

Fixed-size thread pool with bounded FIFO task queue.

zshrs-original — replaces C zsh’s per-task fork() + wait() pattern (Src/exec.c zfork() / Src/jobs.c child management) with a persistent thread pool. Uses crossbeam-channel for lock-free multi-consumer dispatch — each worker calls recv() directly, no mutex.

Implementations

impl WorkerPool

pub fn new(size: usize) -> Self

Create a pool with size worker threads and bounded channel. Channel capacity = 4 × size (provides backpressure without starving). zshrs-original — no C counterpart. Replaces the “spawn-on-demand” semantics of zfork() (Src/exec.c) with pre-spawned threads ready to receive work over a bounded channel.

pub fn default_size() -> Self

Create a pool sized to the machine’s parallelism, clamped to [2, 18]. zshrs-original — no C counterpart. C zsh has no concept of a “pool size” because it forks on demand (one child per background task, see Src/jobs.c).

pub fn submit<F>(&self, f: F)

where F: FnOnce() + Send + 'static,

Submit a task to the pool. Blocks if the queue is full (backpressure). Panics if the pool has been shut down. zshrs-original — replaces the fork() + execve() / fork() + run-shell-fn dispatch pairs in Src/exec.c.

pub fn submit_with_result<F, R>(&self, f: F) -> Receiver<R>

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

Submit a task and get a receiver for its result. zshrs-original — closest C analog is the pipe-based command-substitution result capture in Src/exec.c (getoutput() reading the child’s stdout pipe), but using a typed Rust channel sidesteps the marshalling.

pub fn cancel(&self)

Signal all workers to drop pending tasks. Already-running tasks will finish, but queued tasks are skipped. Reset with reset_cancel(). zshrs-original — closest C analog is the SIGINT/SIGQUIT signal-storm dispatch C zsh fires at its background children in Src/signals.c (killjb() / killpg()), but here we set a flag instead of sending a signal across a fork boundary.

pub fn reset_cancel(&self)

Clear the cancellation flag — pool resumes normal execution. zshrs-original — no C counterpart.

pub fn size(&self) -> usize

Number of worker threads. zshrs-original — no C counterpart.

pub fn queue_depth(&self) -> usize

Approximate number of tasks waiting in the queue. zshrs-original — no C counterpart; closest equivalent is the jobtab length walk Src/jobs.c uses for jobs -l output.

pub fn completed(&self) -> usize

Total tasks completed since pool creation. zshrs-original — no C counterpart.

Trait Implementations

impl Drop for WorkerPool

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.