*/
  internal var interceptorScopedExchange: Exchange? = null
    private set

  // These properties are guarded by [lock]. They are typically only accessed by the thread executing
  // the call, but they may be accessed by other threads for duplex requests.

  /** True if this call still has a request body open. */
  private var requestBodyOpen = false

  /** True if this call still has a response body open. */

Framing rules make it impractical to implement http/2 correctly on a single blocking thread. The flow-control features introduce feedback between reads and writes, requiring writes to acknowledge reads and reads to throttle writes.

In OkHttp we expose a blocking API over a framed protocol. This document explains the code and policy that makes that work.

 *  New: Share threads more aggressively between OkHttp's HTTP/2 connections, connection pool,
    web sockets, and cache. OkHttp has a new internal task runner abstraction for managed task
    scheduling. In your debugger you will see new thread names and more use of daemon threads.

 *  Fix: Don't drop callbacks on unexpected exceptions. When an interceptor throws an unchecked

  /**
   * When we need a new thread to run tasks, we call [Backend.execute]. A few microseconds later we
   * expect a newly-started thread to call [Runnable.run]. We shouldn't request new threads until
   * the already-requested ones are in service, otherwise we might create more threads than we need.
   *
   * We use [executeCallCount] and [runCallCount] to defend against starting more threads than we

 * deterministic.
 *
 * This class ensures that at most one thread is running at a time. This is initially the JUnit test
 * thread, which yields its execution privilege while calling [runTasks], [runNextTask], or
 * [advanceUntil]. These functions don't return until the task threads are all idle.
 *
 * Task threads release their execution privilege in these ways:
 *

    assertThat(realTaskRunner.activeQueues()).isNotEmpty()
    Thread.sleep(100)
    val threads = arrayOfNulls<Thread>(Thread.activeCount() * 2)
    Thread.enumerate(threads)
    for (t in threads) {
      if (t != null && t.name == "OkHttp TaskRunner") {
        t.interrupt()
      }
    }
    Thread.sleep(100)
    assertThat(realTaskRunner.activeQueues()).isEmpty()
  }

  private var nextTcpConnectAtNanos = Long.MIN_VALUE

  /**
   * Plans currently being connected, and that will later be added to [connectResults]. This is
   * mutated by the call thread only. If is accessed by background connect threads.
   */
  private val tcpConnectsInFlight = CopyOnWriteArrayList<Plan>()

  /**
   * Results are posted here as they occur. The find job is done when either one plan completes

import okhttp3.internal.okHttpName

/**
 * A set of tasks that are executed in sequential order.
 *
 * Work within queues is not concurrent. This is equivalent to each queue having a dedicated thread
 * for its work; in practice a set of queues may share a set of threads to save resources.
 */
class TaskQueue internal constructor(
  internal val taskRunner: TaskRunner,
  internal val name: String,
) {
  val lock: ReentrantLock = ReentrantLock()

 * Support asynchronous disconnects by breaking the socket only. This should
   prevent flakiness from multiple threads concurrently accessing a stream.

## Version 1.5.3

_2014-03-29_

 * Fix bug where the Content-Length header was not always dropped when
   following a redirect from a POST to a GET.
 * Implement basic support for `Thread.interrupt()`. OkHttp now checks
   for an interruption before doing a blocking call. If it is interrupted,

release has many critical bug fixes and is safe to run in production. We're eager to stabilize our
new APIs so we can get out of alpha.

 *  New: Support Java 21's virtual threads (‘OpenJDK Project Loom’). We changed OkHttp's internals
    to use `Lock` and `Condition` instead of `synchronized` for best resource utilization.