les: implement request distributor, fix blocking issues (#3660)

* les: implement request distributor, fix blocking issues
* core: moved header validation before chain mutex lock
This commit is contained in:
Felföldi Zsolt
2017-03-22 20:44:22 +01:00
committed by Felix Lange
parent 1c1dc0e0fc
commit 525116dbff
19 changed files with 875 additions and 320 deletions

View File

@ -94,14 +94,12 @@ func (peer *ClientNode) RequestProcessed(cost uint64) (bv, realCost uint64) {
}
type ServerNode struct {
bufEstimate uint64
lastTime mclock.AbsTime
params *ServerParams
sumCost uint64 // sum of req costs sent to this server
pending map[uint64]uint64 // value = sumCost after sending the given req
assignedRequest uint64 // when != 0, only the request with the given ID can be sent to this peer
assignToken chan struct{} // send to this channel before assigning, read from it after deassigning
lock sync.RWMutex
bufEstimate uint64
lastTime mclock.AbsTime
params *ServerParams
sumCost uint64 // sum of req costs sent to this server
pending map[uint64]uint64 // value = sumCost after sending the given req
lock sync.RWMutex
}
func NewServerNode(params *ServerParams) *ServerNode {
@ -110,7 +108,6 @@ func NewServerNode(params *ServerParams) *ServerNode {
lastTime: mclock.Now(),
params: params,
pending: make(map[uint64]uint64),
assignToken: make(chan struct{}, 1),
}
}
@ -127,94 +124,37 @@ func (peer *ServerNode) recalcBLE(time mclock.AbsTime) {
}
// safetyMargin is added to the flow control waiting time when estimated buffer value is low
const safetyMargin = time.Millisecond * 200
const safetyMargin = time.Millisecond
func (peer *ServerNode) canSend(maxCost uint64) time.Duration {
func (peer *ServerNode) canSend(maxCost uint64) (time.Duration, float64) {
peer.recalcBLE(mclock.Now())
maxCost += uint64(safetyMargin) * peer.params.MinRecharge / uint64(fcTimeConst)
if maxCost > peer.params.BufLimit {
maxCost = peer.params.BufLimit
}
if peer.bufEstimate >= maxCost {
return 0
return 0, float64(peer.bufEstimate-maxCost) / float64(peer.params.BufLimit)
}
return time.Duration((maxCost - peer.bufEstimate) * uint64(fcTimeConst) / peer.params.MinRecharge)
return time.Duration((maxCost - peer.bufEstimate) * uint64(fcTimeConst) / peer.params.MinRecharge), 0
}
// CanSend returns the minimum waiting time required before sending a request
// with the given maximum estimated cost
func (peer *ServerNode) CanSend(maxCost uint64) time.Duration {
// with the given maximum estimated cost. Second return value is the relative
// estimated buffer level after sending the request (divided by BufLimit).
func (peer *ServerNode) CanSend(maxCost uint64) (time.Duration, float64) {
peer.lock.RLock()
defer peer.lock.RUnlock()
return peer.canSend(maxCost)
}
// AssignRequest tries to assign the server node to the given request, guaranteeing
// that once it returns true, no request will be sent to the node before this one
func (peer *ServerNode) AssignRequest(reqID uint64) bool {
select {
case peer.assignToken <- struct{}{}:
default:
return false
}
peer.lock.Lock()
peer.assignedRequest = reqID
peer.lock.Unlock()
return true
}
// MustAssignRequest waits until the node can be assigned to the given request.
// It is always guaranteed that assignments are released in a short amount of time.
func (peer *ServerNode) MustAssignRequest(reqID uint64) {
peer.assignToken <- struct{}{}
peer.lock.Lock()
peer.assignedRequest = reqID
peer.lock.Unlock()
}
// DeassignRequest releases a request assignment in case the planned request
// is not being sent.
func (peer *ServerNode) DeassignRequest(reqID uint64) {
peer.lock.Lock()
if peer.assignedRequest == reqID {
peer.assignedRequest = 0
<-peer.assignToken
}
peer.lock.Unlock()
}
// IsAssigned returns true if the server node has already been assigned to a request
// (note that this function returning false does not guarantee that you can assign a request
// immediately afterwards, its only purpose is to help peer selection)
func (peer *ServerNode) IsAssigned() bool {
peer.lock.RLock()
locked := peer.assignedRequest != 0
peer.lock.RUnlock()
return locked
}
// blocks until request can be sent
func (peer *ServerNode) SendRequest(reqID, maxCost uint64) {
// QueueRequest should be called when the request has been assigned to the given
// server node, before putting it in the send queue. It is mandatory that requests
// are sent in the same order as the QueueRequest calls are made.
func (peer *ServerNode) QueueRequest(reqID, maxCost uint64) {
peer.lock.Lock()
defer peer.lock.Unlock()
if peer.assignedRequest != reqID {
peer.lock.Unlock()
peer.MustAssignRequest(reqID)
peer.lock.Lock()
}
peer.recalcBLE(mclock.Now())
wait := peer.canSend(maxCost)
for wait > 0 {
peer.lock.Unlock()
time.Sleep(wait)
peer.lock.Lock()
peer.recalcBLE(mclock.Now())
wait = peer.canSend(maxCost)
}
peer.assignedRequest = 0
<-peer.assignToken
peer.bufEstimate -= maxCost
peer.sumCost += maxCost
if reqID >= 0 {
@ -222,6 +162,8 @@ func (peer *ServerNode) SendRequest(reqID, maxCost uint64) {
}
}
// GotReply adjusts estimated buffer value according to the value included in
// the latest request reply.
func (peer *ServerNode) GotReply(reqID, bv uint64) {
peer.lock.Lock()
@ -235,6 +177,10 @@ func (peer *ServerNode) GotReply(reqID, bv uint64) {
return
}
delete(peer.pending, reqID)
peer.bufEstimate = bv - (peer.sumCost - sc)
cc := peer.sumCost - sc
peer.bufEstimate = 0
if bv > cc {
peer.bufEstimate = bv - cc
}
peer.lastTime = mclock.Now()
}