base backpressure decisions on queue size in bytes, instead of packet counts

This commit is contained in:
Arceliar 2018-07-05 23:07:01 -05:00
parent d0e6a9ad41
commit a7c8be4d69

View File

@ -595,7 +595,7 @@ type switch_packetInfo struct {
// Used to keep track of buffered packets // Used to keep track of buffered packets
type switch_buffer struct { type switch_buffer struct {
packets []switch_packetInfo // Currently buffered packets, which may be dropped if it grows too large packets []switch_packetInfo // Currently buffered packets, which may be dropped if it grows too large
count uint64 // Total queue size, including dropped packets size uint64 // Total queue size in bytes
} }
func (b *switch_buffer) dropTimedOut() { func (b *switch_buffer) dropTimedOut() {
@ -603,8 +603,10 @@ func (b *switch_buffer) dropTimedOut() {
const timeout = 25 * time.Millisecond const timeout = 25 * time.Millisecond
now := time.Now() now := time.Now()
for len(b.packets) > 0 && now.Sub(b.packets[0].time) > timeout { for len(b.packets) > 0 && now.Sub(b.packets[0].time) > timeout {
util_putBytes(b.packets[0].bytes) var packet switch_packetInfo
b.packets = b.packets[1:] packet, b.packets = b.packets[0], b.packets[1:]
b.size -= uint64(len(packet.bytes))
util_putBytes(packet.bytes)
} }
} }
@ -629,9 +631,9 @@ func (t *switchTable) handleIdle(port switchPort, buffs map[string]switch_buffer
buffs[streamID] = buf buffs[streamID] = buf
packet := buf.packets[0] packet := buf.packets[0]
coords := switch_getPacketCoords(packet.bytes) coords := switch_getPacketCoords(packet.bytes)
if (bestSize == 0 || buf.count < bestSize) && t.portIsCloser(coords, port) { if (bestSize == 0 || buf.size < bestSize) && t.portIsCloser(coords, port) {
best = streamID best = streamID
bestSize = buf.count bestSize = buf.size
} }
} }
if bestSize != 0 { if bestSize != 0 {
@ -639,7 +641,7 @@ func (t *switchTable) handleIdle(port switchPort, buffs map[string]switch_buffer
var packet switch_packetInfo var packet switch_packetInfo
// TODO decide if this should be LIFO or FIFO // TODO decide if this should be LIFO or FIFO
packet, buf.packets = buf.packets[0], buf.packets[1:] packet, buf.packets = buf.packets[0], buf.packets[1:]
buf.count-- buf.size -= uint64(len(packet.bytes))
if len(buf.packets) == 0 { if len(buf.packets) == 0 {
delete(buffs, best) delete(buffs, best)
} else { } else {
@ -658,16 +660,16 @@ func (t *switchTable) doWorker() {
idle := make(map[switchPort]struct{}) // this is to deduplicate things idle := make(map[switchPort]struct{}) // this is to deduplicate things
for { for {
select { select {
case packet := <-t.packetIn: case bytes := <-t.packetIn:
// Try to send it somewhere (or drop it if it's corrupt or at a dead end) // Try to send it somewhere (or drop it if it's corrupt or at a dead end)
if !t.handleIn(packet, idle) { if !t.handleIn(bytes, idle) {
// There's nobody free to take it right now, so queue it for later // There's nobody free to take it right now, so queue it for later
streamID := switch_getPacketStreamID(packet) packet := switch_packetInfo{bytes, time.Now()}
streamID := switch_getPacketStreamID(packet.bytes)
buf := buffs[streamID] buf := buffs[streamID]
buf.dropTimedOut() buf.dropTimedOut()
pinfo := switch_packetInfo{packet, time.Now()} buf.packets = append(buf.packets, packet)
buf.packets = append(buf.packets, pinfo) buf.size += uint64(len(packet.bytes))
buf.count++
buffs[streamID] = buf buffs[streamID] = buf
} }
case port := <-t.idleIn: case port := <-t.idleIn: