//
    //  2. EVICTABLE: Connections not required by any address policy. This matches connections that
    //     don't participate in any policy, plus connections whose policies won't be violated if the
    //     connection is closed. We only close these if the idle connection limit is exceeded.
    //
    // Also count the evictable connections to find out if we must close an EVICTABLE connection

        boolean inUse = false;

        List<SmbTransportImpl> toClose;
        synchronized ( this.connections ) {
            cleanup();
            log.debug("Closing pool");
            toClose = new LinkedList<>(this.connections);
            toClose.addAll(this.nonPooledConnections);
            this.connections.clear();
            this.nonPooledConnections.clear();
        }

Realistically, that means the best we can do is:
* Ensure that, at any point in time, any _new_ connections will succeed. There is no period where new connections are dropped.
* Provide some period of time for the old Ztunnel to continue processing any established connections.

If this period of time ("drain period") is longer than any connections, there is zero impact on applications at all.

#### Per-Connection Locks

Each connection has its own lock. The connections in the pool are all in a `ConcurrentLinkedQueue`. Due to data races, iterators of this queue may return removed connections. Callers must check the connection's `noNewExchanges` property before using connections from the pool.

    }

    fun allEnabledCipherSuites() =
      apply {
        require(tls) { "no cipher suites for cleartext connections" }
        this.cipherSuites = null
      }

    fun cipherSuites(vararg cipherSuites: CipherSuite): Builder =
      apply {
        require(tls) { "no cipher suites for cleartext connections" }
        val strings = cipherSuites.map { it.javaName }.toTypedArray()
        return cipherSuites(*strings)

 * HTTP request/response exchanges. Connections may be direct to the origin server or via a proxy.
 *
 * Typically instances of this class are created, connected and exercised automatically by the HTTP
 * client. Applications may use this class to monitor HTTP connections as members of a
 * [connection pool][ConnectionPool].
 *

var globalLockGrid atomic.Pointer[grid.Manager]

// globalGridStart is a channel that will block startup of grid connections until closed.
var globalGridStart = make(chan struct{})

// globalLockGridStart is a channel that will block startup of lock grid connections until closed.
var globalLockGridStart = make(chan struct{})

func initGlobalGrid(ctx context.Context, eps EndpointServerPools) error {

plugins:
  - search
  - redirects:
      redirect_maps:
        # Redirect all feature pages to features/*
        'caching.md': 'features/caching.md'
        'calls.md': 'features/calls.md'
        'connections.md': 'features/connections.md'
        'events.md': 'features/events.md'
        'https.md': 'features/events.md'
        'interceptors.md': 'features/interceptors.md'
        'r8_proguard.md': 'features/r8_proguard.md'

      panels.timeSeries.base('CPU Usage', queries.cpuUsage, 'CPU usage of each running instance'),
    ]),
    row.new('Network')
    + row.withPanels([
      panels.timeSeries.connections('Connections', queries.connections, 'Connections opened and closed per instance'),
      panels.timeSeries.bytesRate('Bytes Transmitted', queries.bytes, 'Bytes sent and received per instance'),

  /** 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() {