gr1ffon/quic-go
1
0
Fork 0
forked from quic-go/quic-go
Code Pull Requests Activity

rewrite flow control auto-tuning

Browse Source
This commit is contained in:
Marten Seemann
2017-12-21 15:29:47 +07:00
parent ac05343b00
commit f7526b9883
5 changed files with 118 additions and 78 deletions
Download Patch File Download Diff File Expand all files Collapse all files

31
internal/flowcontrol/base_flow_controller.go
View File

@@ -22,8 +22,10 @@ type baseFlowController struct {
receiveWindow protocol.ByteCount
receiveWindowSize protocol.ByteCount
maxReceiveWindowSize protocol.ByteCount
lastWindowUpdateTime time.Time
rttStats *congestion.RTTStats
epochStartTime time.Time
epochStartOffset protocol.ByteCount
rttStats *congestion.RTTStats
}
func (c *baseFlowController) AddBytesSent(n protocol.ByteCount) {
@@ -53,7 +55,7 @@ func (c *baseFlowController) AddBytesRead(n protocol.ByteCount) {
// pretend we sent a WindowUpdate when reading the first byte
// this way auto-tuning of the window size already works for the first WindowUpdate
if c.bytesRead == 0 {
c.lastWindowUpdateTime = time.Now()
c.startNewAutoTuningEpoch()
}
c.bytesRead += n
}
@@ -69,7 +71,6 @@ func (c *baseFlowController) getWindowUpdate() protocol.ByteCount {
c.maybeAdjustWindowSize()
c.receiveWindow = c.bytesRead + c.receiveWindowSize
c.lastWindowUpdateTime = time.Now()
return c.receiveWindow
}
@@ -85,23 +86,29 @@ func (c *baseFlowController) IsNewlyBlocked() (bool, protocol.ByteCount) {
}
// maybeAdjustWindowSize increases the receiveWindowSize if we're sending updates too often.
// For details about auto-tuning, see https://docs.google.com/document/d/1F2YfdDXKpy20WVKJueEf4abn_LVZHhMUMS5gX6Pgjl4/edit#heading=h.hcm2y5x4qmqt.
// For details about auto-tuning, see https://docs.google.com/document/d/1SExkMmGiz8VYzV3s9E35JQlJ73vhzCekKkDi85F1qCE/edit?usp=sharing.
func (c *baseFlowController) maybeAdjustWindowSize() {
if c.lastWindowUpdateTime.IsZero() {
bytesReadInEpoch := c.bytesRead - c.epochStartOffset
// don't do anything if less than half the window has been consumed
if bytesReadInEpoch <= c.receiveWindowSize/2 {
return
}
rtt := c.rttStats.SmoothedRTT()
if rtt == 0 {
return
}
timeSinceLastWindowUpdate := time.Since(c.lastWindowUpdateTime)
// interval between the updates is sufficiently large, no need to increase the window size
if timeSinceLastWindowUpdate >= 4*protocol.WindowUpdateThreshold*rtt {
return
fraction := float64(bytesReadInEpoch) / float64(c.receiveWindowSize)
if time.Since(c.epochStartTime) < time.Duration(4*fraction*float64(rtt)) {
// window is consumed too fast, try to increase the window size
c.receiveWindowSize = utils.MinByteCount(2*c.receiveWindowSize, c.maxReceiveWindowSize)
}
c.receiveWindowSize = utils.MinByteCount(2*c.receiveWindowSize, c.maxReceiveWindowSize)
c.startNewAutoTuningEpoch()
}
func (c *baseFlowController) startNewAutoTuningEpoch() {
c.epochStartTime = time.Now()
c.epochStartOffset = c.bytesRead
}
func (c *baseFlowController) checkFlowControlViolation() bool {