*
 * The task runner is also responsible for releasing held threads when the library is unloaded.
 * This is for the benefit of container environments that implement code unloading.
 *
 * Most applications should share a process-wide [TaskRunner] and use queues for per-client work.
 */
class TaskRunner(
  val backend: Backend,
  internal val logger: Logger = TaskRunner.logger,
) {

import okhttp3.internal.platform.Platform
import okhttp3.internal.threadName
import okio.AsyncTimeout
import okio.Timeout

/**
 * Bridge between OkHttp's application and network layers. This class exposes high-level application
 * layer primitives: connections, requests, responses, and streams.
 *
 * This class supports [asynchronous canceling][cancel]. This is intended to have the smallest

 */
class RealConnection(
  val taskRunner: TaskRunner,
  val connectionPool: RealConnectionPool,
  override val route: Route,
  /** The low-level TCP socket. */
  private var rawSocket: Socket?,
  /**
   * The application layer socket. Either an [SSLSocket] layered over [rawSocket], or [rawSocket]
   * itself if this connection does not use SSL.
   */
  private var socket: Socket?,
  private var handshake: Handshake?,

  @Volatile private var canceled = false

  // These properties are initialized by connect() and never reassigned.

  /** The low-level TCP socket. */
  private var rawSocket: Socket? = null

  /**
   * The application layer socket. Either an [SSLSocket] layered over [rawSocket], or [rawSocket]
   * itself if this connection does not use SSL.
   */
  internal var socket: Socket? = null
  private var handshake: Handshake? = null

   * never mutated once it has been assigned.
   */
  var peerSettings = DEFAULT_SETTINGS

  /** The bytes consumed and acknowledged by the application. */
  val readBytes: WindowCounter = WindowCounter(streamId = 0)

  /** The total number of bytes produced by the application. */
  var writeBytesTotal = 0L
    private set

  /** The total number of bytes permitted to be produced according to `WINDOW_UPDATE` frames. */

  }

  /**
   * Prunes any leaked calls and then returns the number of remaining live calls on [connection].
   * Calls are leaked if the connection is tracking them but the application code has abandoned
   * them. Leak detection is imprecise and relies on garbage collection.
   */
  private fun pruneAndGetAllocationCount(
    connection: RealConnection,
    now: Long,
  ): Int {

  // performed while the lock is held.

  /** The bytes consumed and acknowledged by the stream. */
  val readBytes: WindowCounter = WindowCounter(id)

  /** The total number of bytes produced by the application. */
  var writeBytesTotal = 0L
    internal set

  /** The total number of bytes permitted to be produced by incoming `WINDOW_UPDATE` frame. */