* When making TLS connections with multiple [connection specs](https://square.github.io/okhttp/4.x/okhttp/okhttp3/-connection-spec/), these are attempted in sequence until the TLS handshake succeeds.

### [Connections](https://square.github.io/okhttp/4.x/okhttp/okhttp3/-connection/)

When you request a URL with OkHttp, here's what it does:

      }
    }
    return null
  }

  fun put(connection: RealConnection) {
    connection.assertThreadHoldsLock()

    connections.add(connection)
//    connection.queueEvent { connectionListener.connectEnd(connection) }
    scheduleCloser()
  }

  /**
   * Notify this pool that [connection] has become idle. Returns true if the connection has been
   * removed from the pool and should be closed.

 * avoiding these options entirely, this class allows a connection to be attempted with modern
 * options and then retried without them should the attempt fail.
 *
 * ## Connection Reuse
 *
 * Each connection can carry a varying number of streams, depending on the underlying protocol being
 * used. HTTP/1.x connections can carry either zero or one streams. HTTP/2 connections can carry any

        }
        throw new TransportException("All connection attempts failed");
    }


    /**
     * 
     * @param trans
     * @return whether (non-exclusive) connection is in the pool
     */
    public boolean contains ( SmbTransport trans ) {
        synchronized ( this.connections ) {
            cleanup();
            return this.connections.contains(trans);
        }
    }

 * **ExchangeFinder** chooses which connection carries each exchange. Where possible it will use the same connection for all exchanges in a single call. It prefers reusing pooled connections over establishing new connections.      

#### Per-Connection Locks

    GraphConnections<N, V> connectionsU = nodeConnections.get(nodeU);
    return (connectionsU != null) && connectionsU.successors().contains(nodeV);
  }

  @CheckForNull
  private final V edgeValueOrDefaultInternal(N nodeU, N nodeV, @CheckForNull V defaultValue) {
    GraphConnections<N, V> connectionsU = nodeConnections.get(nodeU);
    V value = (connectionsU == null) ? null : connectionsU.value(nodeV);

    }

    GraphConnections<N, V> connectionsU = nodeConnections.get(nodeU);
    if (connectionsU == null) {
      connectionsU = addNodeInternal(nodeU);
    }
    V previousValue = connectionsU.addSuccessor(nodeV, value);
    GraphConnections<N, V> connectionsV = nodeConnections.get(nodeV);
    if (connectionsV == null) {
      connectionsV = addNodeInternal(nodeV);
    }

import okhttp3.internal.concurrent.TaskRunner
import okhttp3.internal.connection.FastFallbackExchangeFinder
import okhttp3.internal.connection.ForceConnectRoutePlanner
import okhttp3.internal.connection.RealConnectionPool
import okhttp3.internal.connection.RealRoutePlanner
import okhttp3.internal.connection.RouteDatabase

/**
 * Manages reuse of HTTP and HTTP/2 connections for reduced network latency. HTTP requests that

    }

    if (connectionsU == null) {
      connectionsU = addNodeInternal(nodeU);
    }
    connectionsU.addOutEdge(edge, nodeV);
    NetworkConnections<N, E> connectionsV = nodeConnections.get(nodeV);
    if (connectionsV == null) {
      connectionsV = addNodeInternal(nodeV);
    }
    connectionsV.addInEdge(edge, nodeU, isSelfLoop);
    edgeToReferenceNode.put(edge, nodeU);

import okhttp3.internal.indexOf
import okhttp3.internal.intersect

/**
 * Specifies configuration for the socket connection that HTTP traffic travels through. For `https:`
 * URLs, this includes the TLS version and cipher suites to use when negotiating a secure
 * connection.
 *
 * The TLS versions configured in a connection spec are only be used if they are also enabled in the