internal val connectionSpecIndex: Int,
  internal val isTlsFallback: Boolean,
) : RoutePlanner.Plan,
  ExchangeCodec.Carrier {
  /** True if this connect was canceled; typically because it lost a race. */
  @Volatile private var canceled = false

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

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

  /**

  /**
   * This test is for a case where two Service.Listener callbacks for the same service would call
   * transitionService in the wrong order due to a race. Due to the fact that it is a race this test
   * isn't guaranteed to expose the issue, but it is at least likely to become flaky if the race
   * sneaks back in, and in this case flaky means something is definitely wrong.
   *

      "plan 1 TLS connected",
    )

    taskFaker.assertNoMoreTasks()
  }

  /**
   * This test performs two races:
   *
   *  * The first race is between plan0 and plan1, with a 250 ms head start for plan0.
   *  * The second race is between plan2 and plan3, with a 250 ms head start for plan2.
   *
   * We get plan0 and plan1 from the route planner.

   * - Both request discover no existing connection. They both make a connection.
   * - The first request "wins the race".
   * - The second request discovers it "lost the race" and closes the connection it just opened.
   * - The second request uses the coalesced connection from request1.
   * - The coalesced connection is violently closed after servicing the first request.

    void setNext(@Nullable Waiter next) {
      putNext(this, next);
    }

    void unpark() {
      // This is racy with removeWaiter. The consequence of the race is that we may spuriously call
      // unpark even though the thread has already removed itself from the list. But even if we did
      // use a CAS, that race would still exist (it would just be ever so slightly smaller).
      Thread w = thread;
      if (w != null) {

 *  Fix: Don't lose HTTP/2 flow control bytes when incoming data races with a stream close. If this
    happened enough then eventually the connection would stall.

 *  Fix: Acknowledge and apply inbound HTTP/2 settings atomically. Previously we had a race where we
    could use new flow control capacity before acknowledging it, causing strict HTTP/2 servers to
    fail the call.

    void setNext(@Nullable Waiter next) {
      putNext(this, next);
    }

    void unpark() {
      // This is racy with removeWaiter. The consequence of the race is that we may spuriously call
      // unpark even though the thread has already removed itself from the list. But even if we did
      // use a CAS, that race would still exist (it would just be ever so slightly smaller).
      Thread w = thread;
      if (w != null) {

    the previous alpha due to an unexpected race.


## Version 5.0.0-alpha.5

_2022-02-21_

 *  Fix: Don't include [Assertk][assertk] in OkHttp's production dependencies. This regression was
    introduced in the 5.0.0-alpha.4 release.
 *  Fix: Don't ask `Dns` implementations to resolve strings that are already IP addresses.
 *  Fix: Change fast fallback to race TCP handshakes only. To avoid wasted work, OkHttp will not

        //
        // Note that there is a race condition here which can result in missing
        // a cyclic edge: it's possible for two threads to simultaneous find
        // "safe" edges which together form a cycle. Preventing this race
        // condition efficiently without _introducing_ deadlock is probably
        // tricky. For now, just accept the race condition---missing a warning

    testClient?.let {
      val connectionPool = it.connectionPool

      connectionPool.evictAll()
      if (connectionPool.connectionCount() > 0) {
        // Minimise test flakiness due to possible race conditions with connections closing.
        // Some number of tests will report here, but not fail due to this delay.
        println("Delaying to avoid flakes")
        Thread.sleep(500L)