address may also share the same underlying TCP socket connection. Sharing a connection has substantial performance benefits: lower latency, higher throughput (due to [TCP slow start](https://www.igvita.com/2011/10/20/faster-web-vs-tcp-slow-start/)) and conserved battery. OkHttp uses a [ConnectionPool](https://square.github.io/okhttp/4.x/okhttp/okhttp3/-connection-pool/) that automatically reuses HTTP/1.x connections and multiplexes HTTP/2 connections.

In OkHttp some fields of the address come...

 * 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

 * **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

  }

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

    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.
   */

import okhttp3.internal.connection.ConnectionListener
import okhttp3.internal.connection.RealConnectionPool

/**
 * Manages reuse of HTTP and HTTP/2 connections for reduced network latency. HTTP requests that
 * share the same [Address] may share a [Connection]. This class implements the policy
 * of which connections to keep open for future use.
 *

    }

    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);

 *
 *  4. If there's no existing connection, make a list of routes (which may require blocking DNS
 *     lookups) and attempt new connections to them. When failures occur, retries iterate the
 *     list of available routes.
 *
 * If the pool gains an eligible connection while DNS, TCP, or TLS work is in flight, this finder
 * will prefer pooled connections. Only pooled HTTP/2 connections are used for such de-duplication.
 *

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

_2016-01-01_

 *  Fix: Don't do a health check on newly-created connections. This is
    unnecessary work that could put the client in an inconsistent state if the
    health check fails.


## Version 2.7.0

_2015-12-13_

 *  **Rewritten connection management.** Previously OkHttp's connection pool
    managed both idle and active connections for HTTP/2, but only idle
    connections for HTTP/1.x. With this update the connection pool manages both

 * limitations under the License.
 */
package okhttp3.internal.connection

/**
 * A policy for how the pool should treat a specific address.
 */
class AddressPolicy(
  /**
   * How many concurrent calls should be possible to make at any time.
   * The pool will routinely try to pre-emptively open connections to satisfy this minimum.
   * Connections will still be closed if they idle beyond the keep-alive but will be replaced.