[−][src]Crate blocking_permit

This crate provides:

A specialized, custom thread pool, DispatchPool, for offloading blocking or otherwise long running operations from a main or reactor thread(s). Once registered, it is used via dispatch_rx() (to await a return value) or dispatch() for background tasks (fire and forget).
A BlockingPermit, obtained via blocking_permit_future() for limiting the number of concurrent blocking operations via a re-exported Semaphore type selected by one of the (non-default) features futures-intrusive, or tokio-semaphore (or tokio-omnibus).
A Cleaver for splitting Stream buffers into more manageable sizes.
A YieldStream for yielding between Stream items.

Optional Features

The following features may be enabled at build time. All are disabled by default, unless otherwise noted.

futures-channel : Use this oneshot channel implementation (Default enabled, but overridden by tokio-oneshot or tokio-omnibus.)

tokio-oneshot : Use tokio's oneshot channel implementation (Overrides futures-channel default.).

futures-intrusive : Include BlockingPermit and re-export Semaphore from the futures-intrusive crate. (Works with all prominent runtimes.)

tokio-semaphore : Include BlockingPermit and re-export tokio's Semaphore type. (Overrides futures-intrusive.)

tokio-threaded : Add block_in_place support, exposed via BlockingPermit::run.

tokio-omnibus : A simpler way to include all above and, we expect, any future added tokio-* features in this crate.

cleaver : Include the Cleaver wrapper stream.

yield-stream : Include the YieldStream wrapper.

Attempt to dispatch a blocking operation, or otherwise obtain a permit and run on thread, returning the result of the closure.

BlockingPermit	A scoped permit for blocking operations. When dropped (out of scope or manually), the permit is released.
BlockingPermitFuture	A future which resolves to a `BlockingPermit`.
Canceled	Error type returned as output from the `BlockingPermitFuture` or `Dispatched` futures if they are canceled.
Cleaver	A `Stream` adapter that splits buffers from a source to a given, maximum length.
DispatchPool	A specialized thread pool and queue for dispatching blocking (synchronous, long running) operations.
DispatchPoolBuilder	A builder for `DispatchPool` supporting an extenstive set of configuration options.
Dispatched	A future type created by `dispatch_rx`.
SyncBlockingPermitFuture	A `Sync` wrapper available via `BlockingPermitFuture::make_sync`.
YieldStream	A `Stream` adapter that yields after every `Poll::Ready(Some(_))` result from its source.

Value returned by dispatch_rx.

Semaphorish	Extension trait for uniform construction of the re-exported `Semaphore` types.
Splittable	Trait for buffer types that may be split at a maximum length.

blocking_permit_future	Request a permit to perform a blocking operation on the current thread.
deregister_dispatch_pool	Deregister and return any `DispatchPool` on the current thread.
dispatch	Dispatch a blocking operation closure to a pool, if registered.
dispatch_rx	Dispatch a blocking operation closure to a registered pool, returning a future for awaiting the result.
is_dispatch_pool_registered	Return true if a DispatchPool is registered to the current thread.
register_dispatch_pool	Register a `DispatchPool` on the calling thread.

An async-aware semaphore for constraining the number of concurrent blocking operations.