rpc-go/client/request-state.go

package client

import (
	"sync"
	"sync/atomic"
	"time"
)

type requestState struct {
	id          uint64
	method      string
	params      []interface{}
	result      interface{}
	clientError *Error
	doneChan    chan *requestState

	canceled atomic.Value
}

func (rs *requestState) done() {
	select {
	case rs.doneChan <- rs:
	default:
	}
}

func (rs *requestState) cancel() {
	rs.canceled.Store(true)
}

func (rs *requestState) isCanceled() bool {
	v := rs.canceled.Load()
	if nil == v {
		return false
	}
	vv := v.(bool)

	return vv
}

func (rs *requestState) setError(err error) {
	if nil == err {
		return
	}
	rs.clientError = newError(rs.method, rs.params, err)
}

var requestStatePool sync.Pool

func retainRequestState() *requestState {
	v := requestStatePool.Get()
	if v == nil {
		return &requestState{}
	}
	return v.(*requestState)
}

func releaseRequestState(rs *requestState) {
	rs.id = 0
	rs.method = ""
	rs.params = nil
	rs.result = nil
	rs.clientError = nil
	rs.doneChan = nil
	rs.canceled.Store(false)

	requestStatePool.Put(rs)
}

var timerPool sync.Pool

func retainTimer(timeout time.Duration) *time.Timer {
	tv := timerPool.Get()
	if tv == nil {
		return time.NewTimer(timeout)
	}

	t := tv.(*time.Timer)
	if t.Reset(timeout) {
		panic("Client: Active timer trapped into retainTimer()")
	}
	return t
}

func releaseTimer(t *time.Timer) {
	if !t.Stop() {
		// Collect possibly added time from the channel
		// if timer has been stopped and nobody collected its' value.
		select {
		case <-t.C:
		default:
		}
	}

	timerPool.Put(t)
}