func (c *clientSession) fanoutRequest(fanoutFn func(int) *fanout, cancelCh chan struct{}) interface{} {
defer c.mutex.RUnlock()
c.mutex.RLock()
rpcClients := c.peerClients
numClients := len(rpcClients)
f := fanoutFn(numClients)
var wg sync.WaitGroup
wg.Add(numClients)
doneCh := make(chan struct{})
go func() {
select {
case <-cancelCh:
f.respCh.Close()
case <-doneCh:
f.respCh.Close()
}
}()
go func() {
defer close(doneCh)
wg.Wait()
}()
for _, r := range rpcClients {
go func(p *peerClient) {
// requestCh might be closed because of session being terminated
// let go of the wait
defer common.RecoverAndDo(func() { wg.Done() })
p.requestCh <- func() {
defer wg.Done()
defer common.NoopRecoverLog() // respCh might be closed because of session being terminated
resp, err := f.reqFn(p)
if err != nil {
log.Warn(err)
} else {
c.listener.HandleEvent(
common.Event{
Term: resp.Term(),
EventType: common.ResponseReceived,
})
f.respCh.Send(reflect.ValueOf(resp))
}
}
}(r)
}
return f.respCh.Interface()
}
func (c *clientSession) removeGrpcClient(id string) {
defer c.mutex.Unlock()
defer common.NoopRecoverLog() // session is terminating and already closed requestCh and this was invoked concurrently
c.mutex.Lock()
if peerClient := c.peerClients[id]; peerClient != nil {
close(peerClient.requestCh)
delete(c.peerClients, id)
}
}
func (c *clientSession) watchForTerminate() {
defer c.mutex.RUnlock()
defer common.NoopRecoverLog() // requestCh might be closed by an unhealthy connection in removeGrpcClient
<-c.terminateCh
c.mutex.RLock()
log.Debug("Terminating session")
for _, r := range c.peerClients {
close(r.requestCh)
}
c.client.removeSession(c)
}