import okhttp3.internal.platform.Platform
import okio.IOException

class RealConnectionPool(
  private val taskRunner: TaskRunner,
  /**
   * The maximum number of idle connections across all addresses.
   * Connections needed to satisfy a [ConnectionPool.AddressPolicy] are not considered idle.
   */
  private val maxIdleConnections: Int,
  keepAliveDuration: Long,
  timeUnit: TimeUnit,
  internal val connectionListener: ConnectionListener,

      encodings[ 0x13] = encoding // Device Control 3 (oft. XOFF)
      encodings[ 0x14] = encoding // Device Control 4
      encodings[ 0x15] = encoding // Negative Acknowledgment
      encodings[ 0x16] = encoding // Synchronous idle
      encodings[ 0x17] = encoding // End of Transmission Block
      encodings[ 0x18] = encoding // Cancel
      encodings[ 0x19] = encoding // End of Medium
      encodings[ 0x1a] = encoding // Substitute

  /** Returns the number of idle connections in the pool. */
  fun idleConnectionCount(): Int = delegate.idleConnectionCount()

  /** Returns total number of connections in the pool. */
  fun connectionCount(): Int = delegate.connectionCount()

  internal val connectionListener: ConnectionListener
    get() = delegate.connectionListener

  /** Close and remove all idle connections in the pool. */
  fun evictAll() {

    if (http2Connection != null) {
      return http2Connection.isHealthy(nowNs)
    }

    val idleDurationNs = lock.withLock { nowNs - idleAtNs }
    if (idleDurationNs >= IDLE_CONNECTION_HEALTHY_NS && doExtensiveChecks) {
      return socket.isHealthy(source)
    }

    return true
  }

  /** Refuse incoming streams. */
  @Throws(IOException::class)

 * used. HTTP/1.x connections can carry either zero or one streams. HTTP/2 connections can carry any
 * number of streams, dynamically configured with `SETTINGS_MAX_CONCURRENT_STREAMS`. A connection
 * currently carrying zero streams is an idle stream. We keep it alive because reusing an existing
 * connection is typically faster than establishing a new one.
 *
 * When a single logical call requires multiple streams due to redirects or authorization

      if (!inputExhausted) {
        responseBodyComplete()
      }
      closed = true
    }
  }

  companion object {
    private const val NO_CHUNK_YET = -1L

    private const val STATE_IDLE = 0 // Idle connections are ready to write request headers.
    private const val STATE_OPEN_REQUEST_BODY = 1
    private const val STATE_WRITING_REQUEST_BODY = 2
    private const val STATE_READ_RESPONSE_HEADERS = 3

          return -1L
        }
      },
      delayNanos,
    )
  }

  /** Returns a latch that reaches 0 when the queue is next idle. */
  fun idleLatch(): CountDownLatch {
    taskRunner.lock.withLock {
      // If the queue is already idle, that's easy.
      if (activeTask == null && futureTasks.isEmpty()) {
        return CountDownLatch(0)
      }

Blocking APIs may be inefficient because you hold a thread idle while waiting on the network. Threads are expensive because they have both a memory overhead and a context-switching overhead.

#### Framed protocols

- OkHttp is a small and light dependency.  Don't introduce new dependencies or major new functionality.
- OkHttp targets the intersection of RFC correct *and* widely implemented.  Incorrect implementations that are very widely implemented e.g. a bug in Apache, Nginx, Google, Firefox should also be handled.

Before your code can be accepted into the project you must also sign the

  }

  @Test
  fun idleCallbackInvokedWhenIdle() {
    val idle = AtomicBoolean()
    dispatcher.idleCallback = Runnable { idle.set(true) }
    client.newCall(newRequest("http://a/1")).enqueue(callback)
    client.newCall(newRequest("http://a/2")).enqueue(callback)
    executor.finishJob("http://a/1")
    assertThat(idle.get()).isFalse()
    val ready = CountDownLatch(1)
    val proceed = CountDownLatch(1)