from typing import AsyncGenerator, ContextManager, TypeVar

import anyio
from anyio import CapacityLimiter
from starlette.concurrency import iterate_in_threadpool as iterate_in_threadpool  # noqa
from starlette.concurrency import run_in_threadpool as run_in_threadpool  # noqa
from starlette.concurrency import (  # noqa
    run_until_first_complete as run_until_first_complete,
)

_T = TypeVar("_T")


@asynccontextmanager

Concurrency
===========

This document describes the concurrency considerations for http/2 connections and the connection pool within OkHttp.

## HTTP/2 Connections

The HttpURLConnection API is a blocking API. You make a blocking write to send a request, and a blocking read to receive the response.

#### Blocking APIs

Committer's Guides
------------------

 * [Concurrency][concurrency]
 * [Debug Logging][debug_logging]
 * [Releasing][releasing]

 [cla]: https://spreadsheets.google.com/spreadsheet/viewform?formkey=dDViT2xzUHAwRkI3X3k5Z0lQM091OGc6MQ&ndplr=1
 [concurrency]: https://square.github.io/okhttp/concurrency/
 [debug_logging]: https://square.github.io/okhttp/debug_logging/

Committer's Guides
------------------

 * [Concurrency][concurrency]
 * [Debug Logging][debug_logging]
 * [Releasing][releasing]

 [cla]: https://spreadsheets.google.com/spreadsheet/viewform?formkey=dDViT2xzUHAwRkI3X3k5Z0lQM091OGc6MQ&ndplr=1
 [concurrency]: https://square.github.io/okhttp/concurrency/
 [debug_logging]: https://square.github.io/okhttp/debug_logging/

	go func() {
		defer xioutil.SafeClose(ch)

		concurrency := opts.concurrencyStart

		if opts.autotune {
			// if we have less drives than concurrency then choose
			// only the concurrency to be number of drives to start
			// with - since default '32' might be big and may not
			// complete in total time of 10s.
			if globalEndpoints.NEndpoints() < concurrency {
				concurrency = globalEndpoints.NEndpoints()
			}

  // methods is identical, save for method being invoked.

  /** Invokes {@code latch.}{@link CountDownLatch#await() await()} uninterruptibly. */
  @J2ktIncompatible
  @GwtIncompatible // concurrency
  public static void awaitUninterruptibly(CountDownLatch latch) {
    boolean interrupted = false;
    try {
      while (true) {
        try {
          latch.await();
          return;

  // methods is identical, save for method being invoked.

  /** Invokes {@code latch.}{@link CountDownLatch#await() await()} uninterruptibly. */
  @J2ktIncompatible
  @GwtIncompatible // concurrency
  public static void awaitUninterruptibly(CountDownLatch latch) {
    boolean interrupted = false;
    try {
      while (true) {
        try {
          latch.await();
          return;

### Concurrency and Burgers

This idea of **asynchronous** code described above is also sometimes called **"concurrency"**. It is different from **"parallelism"**.

**Concurrency** and **parallelism** both relate to "different things happening more or less at the same time".

But the details between *concurrency* and *parallelism* are quite different.

        # Redirect all contributing pages to contribute/*
        'contributing.md': 'contribute/contributing.md'
        'code_of_conduct.md': 'contribute/code_of_conduct.md'
        'concurrency.md': 'contribute/concurrency.md'
        'debug_logging.md': 'contribute/debug_logging.md'

nav:
  - 'Overview':
    - 'Overview': index.md
    - 'Stack Overflow': https://stackoverflow.com/questions/tagged/okhttp?sort=active

  // priority level that may be exeucting at a given time.  ACS must
  // be a positive number. The server's concurrency limit (SCL) is
  // divided among the concurrency-controlled priority levels in
  // proportion to their assured concurrency shares. This produces
  // the assured concurrency value (ACV) --- the number of requests
  // that may be executing at a time --- for each such priority
  // level:
  //