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-rw-r--r--OpenSim/Region/ClientStack/LindenUDP/LLUDPClient.cs54
-rw-r--r--OpenSim/Region/ClientStack/LindenUDP/LLUDPServer.cs4
2 files changed, 42 insertions, 16 deletions
diff --git a/OpenSim/Region/ClientStack/LindenUDP/LLUDPClient.cs b/OpenSim/Region/ClientStack/LindenUDP/LLUDPClient.cs
index d2cd6d9..0948e1c 100644
--- a/OpenSim/Region/ClientStack/LindenUDP/LLUDPClient.cs
+++ b/OpenSim/Region/ClientStack/LindenUDP/LLUDPClient.cs
@@ -144,6 +144,9 @@ namespace OpenSim.Region.ClientStack.LindenUDP
144 private readonly OutgoingPacket[] m_nextPackets = new OutgoingPacket[THROTTLE_CATEGORY_COUNT]; 144 private readonly OutgoingPacket[] m_nextPackets = new OutgoingPacket[THROTTLE_CATEGORY_COUNT];
145 /// <summary>A reference to the LLUDPServer that is managing this client</summary> 145 /// <summary>A reference to the LLUDPServer that is managing this client</summary>
146 private readonly LLUDPServer m_udpServer; 146 private readonly LLUDPServer m_udpServer;
147 /// <summary>Locks access to the variables used while calculating round-trip
148 /// packet times and the retransmission timeout</summary>
149 private readonly object m_roundTripCalcLock = new object();
147 150
148 /// <summary> 151 /// <summary>
149 /// Default constructor 152 /// Default constructor
@@ -484,29 +487,52 @@ namespace OpenSim.Region.ClientStack.LindenUDP
484 const float BETA = 0.25f; 487 const float BETA = 0.25f;
485 const float K = 4.0f; 488 const float K = 4.0f;
486 489
487 if (RTTVAR == 0.0f) 490 lock (m_roundTripCalcLock)
488 { 491 {
489 // First RTT measurement 492 if (RTTVAR == 0.0f)
490 SRTT = r; 493 {
491 RTTVAR = r * 0.5f; 494 // First RTT measurement
492 } 495 SRTT = r;
493 else 496 RTTVAR = r * 0.5f;
494 { 497 }
495 // Subsequence RTT measurement 498 else
496 RTTVAR = (1.0f - BETA) * RTTVAR + BETA * Math.Abs(SRTT - r); 499 {
497 SRTT = (1.0f - ALPHA) * SRTT + ALPHA * r; 500 // Subsequence RTT measurement
498 } 501 RTTVAR = (1.0f - BETA) * RTTVAR + BETA * Math.Abs(SRTT - r);
502 SRTT = (1.0f - ALPHA) * SRTT + ALPHA * r;
503 }
499 504
500 RTO = (int)(SRTT + Math.Max(m_udpServer.TickCountResolution, K * RTTVAR)); 505 int rto = (int)(SRTT + Math.Max(m_udpServer.TickCountResolution, K * RTTVAR));
501 506
502 // Clamp the retransmission timeout to manageable values 507 // Clamp the retransmission timeout to manageable values
503 RTO = Utils.Clamp(RTO, 3000, 60000); 508 rto = Utils.Clamp(RTO, 3000, 60000);
509
510 RTO = rto;
511 }
504 512
505 //m_log.Debug("[LLUDPCLIENT]: Setting agent " + this.Agent.FullName + "'s RTO to " + RTO + "ms with an RTTVAR of " + 513 //m_log.Debug("[LLUDPCLIENT]: Setting agent " + this.Agent.FullName + "'s RTO to " + RTO + "ms with an RTTVAR of " +
506 // RTTVAR + " based on new RTT of " + r + "ms"); 514 // RTTVAR + " based on new RTT of " + r + "ms");
507 } 515 }
508 516
509 /// <summary> 517 /// <summary>
518 /// Exponential backoff of the retransmission timeout, per section 5.5
519 /// of RFC 2988
520 /// </summary>
521 public void BackoffRTO()
522 {
523 lock (m_roundTripCalcLock)
524 {
525 // Reset SRTT and RTTVAR, we assume they are bogus since things
526 // didn't work out and we're backing off the timeout
527 SRTT = 0.0f;
528 RTTVAR = 0.0f;
529
530 // Double the retransmission timeout
531 RTO = Math.Min(RTO * 2, 60000);
532 }
533 }
534
535 /// <summary>
510 /// Does an early check to see if this queue empty callback is already 536 /// Does an early check to see if this queue empty callback is already
511 /// running, then asynchronously firing the event 537 /// running, then asynchronously firing the event
512 /// </summary> 538 /// </summary>
diff --git a/OpenSim/Region/ClientStack/LindenUDP/LLUDPServer.cs b/OpenSim/Region/ClientStack/LindenUDP/LLUDPServer.cs
index 1dd58bf..82ae640 100644
--- a/OpenSim/Region/ClientStack/LindenUDP/LLUDPServer.cs
+++ b/OpenSim/Region/ClientStack/LindenUDP/LLUDPServer.cs
@@ -431,8 +431,8 @@ namespace OpenSim.Region.ClientStack.LindenUDP
431 { 431 {
432 m_log.Debug("[LLUDPSERVER]: Resending " + expiredPackets.Count + " packets to " + udpClient.AgentID + ", RTO=" + udpClient.RTO); 432 m_log.Debug("[LLUDPSERVER]: Resending " + expiredPackets.Count + " packets to " + udpClient.AgentID + ", RTO=" + udpClient.RTO);
433 433
434 // Backoff the RTO 434 // Exponential backoff of the retransmission timeout
435 udpClient.RTO = Math.Min(udpClient.RTO * 2, 60000); 435 udpClient.BackoffRTO();
436 436
437 // Resend packets 437 // Resend packets
438 for (int i = 0; i < expiredPackets.Count; i++) 438 for (int i = 0; i < expiredPackets.Count; i++)