nightingale/vendor/github.com/uber/tchannel-go/idle_sweep.go

124 lines
3.7 KiB
Go

// Copyright (c) 2017 Uber Technologies, Inc.
// Permission is hereby granted, free of charge, to any person obtaining a copy
// of this software and associated documentation files (the "Software"), to deal
// in the Software without restriction, including without limitation the rights
// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
// copies of the Software, and to permit persons to whom the Software is
// furnished to do so, subject to the following conditions:
//
// The above copyright notice and this permission notice shall be included in
// all copies or substantial portions of the Software.
//
// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
// THE SOFTWARE.
package tchannel
import "time"
// idleSweep controls a periodic task that looks for idle connections and clears
// them from the peer list.
// NOTE: This struct is not thread-safe on its own. Calls to Start() and Stop()
// should be guarded by locking ch.mutable
type idleSweep struct {
ch *Channel
maxIdleTime time.Duration
idleCheckInterval time.Duration
stopCh chan struct{}
started bool
}
// startIdleSweep starts a poller that checks for idle connections at given
// intervals.
func startIdleSweep(ch *Channel, opts *ChannelOptions) *idleSweep {
is := &idleSweep{
ch: ch,
maxIdleTime: opts.MaxIdleTime,
idleCheckInterval: opts.IdleCheckInterval,
}
is.start()
return is
}
// Start runs the goroutine responsible for checking idle connections.
func (is *idleSweep) start() {
if is.started || is.idleCheckInterval <= 0 {
return
}
is.ch.log.WithFields(
LogField{"idleCheckInterval", is.idleCheckInterval},
LogField{"maxIdleTime", is.maxIdleTime},
).Info("Starting idle connections poller.")
is.started = true
is.stopCh = make(chan struct{})
go is.pollerLoop()
}
// Stop kills the poller checking for idle connections.
func (is *idleSweep) Stop() {
if !is.started {
return
}
is.started = false
is.ch.log.Info("Stopping idle connections poller.")
close(is.stopCh)
}
func (is *idleSweep) pollerLoop() {
ticker := is.ch.timeTicker(is.idleCheckInterval)
for {
select {
case <-ticker.C:
is.checkIdleConnections()
case <-is.stopCh:
ticker.Stop()
return
}
}
}
func (is *idleSweep) checkIdleConnections() {
now := is.ch.timeNow()
// Acquire the read lock and examine which connections are idle.
idleConnections := make([]*Connection, 0, 10)
is.ch.mutable.RLock()
for _, conn := range is.ch.mutable.conns {
if idleTime := now.Sub(conn.getLastActivityTime()); idleTime >= is.maxIdleTime {
idleConnections = append(idleConnections, conn)
}
}
is.ch.mutable.RUnlock()
for _, conn := range idleConnections {
// It's possible that the connection is already closed when we get here.
if !conn.IsActive() {
continue
}
// We shouldn't get to a state where we have pending calls, but the connection
// is idle. This either means the max-idle time is too low, or there's a stuck call.
if conn.hasPendingCalls() {
conn.log.Error("Skip closing idle Connection as it has pending calls.")
continue
}
is.ch.log.WithFields(
LogField{"remotePeer", conn.remotePeerInfo},
LogField{"lastActivityTime", conn.getLastActivityTime()},
).Info("Closing idle inbound connection.")
conn.close(LogField{"reason", "Idle connection closed"})
}
}