Method Close

clientconn.go:1191–1239

Close tears down the ClientConn and all underlying connections.

()

// Close tears down the ClientConn and all underlying connections.
func (cc *ClientConn) Close() error {
	defer func() {
		cc.cancel()
		<-cc.csMgr.pubSub.Done()
	}()

	// Prevent calls to enter/exit idle immediately, and ensure we are not
	// currently entering/exiting idle mode.
	cc.idlenessMgr.Close()

	cc.mu.Lock()
	if cc.conns == nil {
		cc.mu.Unlock()
		return ErrClientConnClosing
	}

	conns := cc.conns
	cc.conns = nil
	cc.csMgr.updateState(connectivity.Shutdown)

	// We can safely unlock and continue to access all fields now as
	// cc.conns==nil, preventing any further operations on cc.
	cc.mu.Unlock()

	cc.resolverWrapper.close()
	// The order of closing matters here since the balancer wrapper assumes the
	// picker is closed before it is closed.
	cc.pickerWrapper.close()
	cc.balancerWrapper.close()

	<-cc.resolverWrapper.serializer.Done()
	<-cc.balancerWrapper.serializer.Done()
	var wg sync.WaitGroup
	for ac := range conns {
		wg.Add(1)
		go func(ac *addrConn) {
			defer wg.Done()
			ac.tearDown(ErrClientConnClosing)
		}(ac)
	}
	wg.Wait()
	cc.addTraceEvent("deleted")
	// TraceEvent needs to be called before RemoveEntry, as TraceEvent may add
	// trace reference to the entity being deleted, and thus prevent it from being
	// deleted right away.
	channelz.RemoveEntry(cc.channelz.ID)

	return nil
}

// addrConn is a network connection to a given address.
type addrConn struct {