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[core] Minor refactoring around ACK processing (#1928)
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@mbakholdina
mbakholdina committed Apr 13, 2021
1 parent 65d5483 commit 9e6c90f
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Showing 2 changed files with 52 additions and 52 deletions.
38 changes: 20 additions & 18 deletions srtcore/core.cpp
View file
Expand Up @@ -221,15 +221,18 @@ void CUDT::construct()
m_pSndLossList = NULL;
m_pRcvLossList = NULL;
m_iReorderTolerance = 0;
m_iConsecEarlyDelivery = 0; // how many times so far the packet considered lost has been received before TTL expires
// How many times so far the packet considered lost has been received
// before TTL expires.
m_iConsecEarlyDelivery = 0;
m_iConsecOrderedDelivery = 0;

m_pSndQueue = NULL;
m_pRcvQueue = NULL;
m_pSNode = NULL;
m_pRNode = NULL;

m_iSndHsRetryCnt = SRT_MAX_HSRETRY + 1; // Will be reset to 0 for HSv5, this value is important for HSv4
// Will be reset to 0 for HSv5, this value is important for HSv4.
m_iSndHsRetryCnt = SRT_MAX_HSRETRY + 1;

// Initial status
m_bOpened = false;
Expand All @@ -239,12 +242,12 @@ void CUDT::construct()
m_bClosing = false;
m_bShutdown = false;
m_bBroken = false;
// XXX m_iBrokenCounter should be still set to some default!
// TODO: m_iBrokenCounter should be still set to some default.
m_bPeerHealth = true;
m_RejectReason = SRT_REJ_UNKNOWN;
m_tsLastReqTime = steady_clock::time_point();
m_SrtHsSide = HSD_DRAW;
m_uPeerSrtVersion = 0; // not defined until connected.
m_uPeerSrtVersion = 0; // Not defined until connected.
m_iTsbPdDelay_ms = 0;
m_iPeerTsbPdDelay_ms = 0;
m_bPeerTsbPd = false;
Expand All @@ -254,10 +257,10 @@ void CUDT::construct()
m_bGroupTsbPd = false;
m_bPeerTLPktDrop = false;

// Initilize mutex and condition variables
// Initilize mutex and condition variables.
initSynch();

// XXX: Unblock, when the callback is implemented
// TODO: Uncomment when the callback is implemented.
// m_cbPacketArrival.set(this, &CUDT::defaultPacketArrival);
}

Expand Down Expand Up @@ -5433,17 +5436,18 @@ void CUDT::acceptAndRespond(const sockaddr_any& agent, const sockaddr_any& peer,
// And of course, it is connected.
m_bConnected = true;

// register this socket for receiving data packets
// Register this socket for receiving data packets.
m_pRNode->m_bOnList = true;
m_pRcvQueue->setNewEntry(this);

// Save the handshake in m_ConnRes in case when needs repeating.
m_ConnRes = w_hs;

// send the response to the peer, see listen() for more discussions about this
// XXX Here create CONCLUSION RESPONSE with:
// Send the response to the peer, see listen() for more discussions
// about this.
// TODO: Here create CONCLUSION RESPONSE with:
// - just the UDT handshake, if HS_VERSION_UDT4,
// - if higher, the UDT handshake, the SRT HSRSP, the SRT KMRSP
// - if higher, the UDT handshake, the SRT HSRSP, the SRT KMRSP.
size_t size = m_iMaxSRTPayloadSize;
// Allocate the maximum possible memory for an SRT payload.
// This is a maximum you can send once.
Expand Down Expand Up @@ -7711,8 +7715,8 @@ int CUDT::sendCtrlAck(CPacket& ctrlpkt, int size)
if (m_uPeerSrtVersion == SrtVersion(1, 0, 2))
{
data[ACKD_RCVRATE] = rcvRate; // bytes/sec
data[ACKD_XMRATE] = data[ACKD_BANDWIDTH] * m_iMaxSRTPayloadSize; // bytes/sec
ctrlsz = ACKD_FIELD_SIZE * ACKD_TOTAL_SIZE_VER102;
data[ACKD_XMRATE_VER102_ONLY] = data[ACKD_BANDWIDTH] * m_iMaxSRTPayloadSize; // bytes/sec
ctrlsz = ACKD_FIELD_SIZE * ACKD_TOTAL_SIZE_VER102_ONLY;
}
else if (m_uPeerSrtVersion >= SrtVersion(1, 0, 3))
{
Expand Down Expand Up @@ -8001,10 +8005,10 @@ void CUDT::processCtrlAck(const CPacket &ctrlpkt, const steady_clock::time_point
* Additional UDT fields, not always attached:
* ACKD_RCVSPEED
* ACKD_BANDWIDTH
* SRT extension version 1.0.2 (bstats):
* SRT extension since v1.0.1:
* ACKD_RCVRATE
* SRT extension version 1.0.4:
* ACKD_XMRATE
* SRT extension in v1.0.2 only:
* ACKD_XMRATE_VER102_ONLY
*/

if (acksize > ACKD_TOTAL_SIZE_SMALL)
Expand All @@ -8014,7 +8018,7 @@ void CUDT::processCtrlAck(const CPacket &ctrlpkt, const steady_clock::time_point
int bandwidth = ackdata[ACKD_BANDWIDTH];
int bytesps;

/* SRT v1.0.2 Bytes-based stats: bandwidth (pcData[ACKD_XMRATE]) and delivery rate (pcData[ACKD_RCVRATE]) in
/* SRT v1.0.2 Bytes-based stats: bandwidth (pcData[ACKD_XMRATE_VER102_ONLY]) and delivery rate (pcData[ACKD_RCVRATE]) in
* bytes/sec instead of pkts/sec */
/* SRT v1.0.3 Bytes-based stats: only delivery rate (pcData[ACKD_RCVRATE]) in bytes/sec instead of pkts/sec */
if (acksize > ACKD_TOTAL_SIZE_UDTBASE)
Expand All @@ -8025,8 +8029,6 @@ void CUDT::processCtrlAck(const CPacket &ctrlpkt, const steady_clock::time_point
m_iBandwidth = avg_iir<8>(m_iBandwidth, bandwidth);
m_iDeliveryRate = avg_iir<8>(m_iDeliveryRate, pktps);
m_iByteDeliveryRate = avg_iir<8>(m_iByteDeliveryRate, bytesps);
// XXX not sure if ACKD_XMRATE is of any use. This is simply
// calculated as ACKD_BANDWIDTH * m_iMaxSRTPayloadSize.

// Update Estimated Bandwidth and packet delivery rate
// m_iRcvRate = m_iDeliveryRate;
Expand Down
66 changes: 32 additions & 34 deletions srtcore/core.h
View file
Expand Up @@ -76,7 +76,7 @@ modified by
#include <haicrypt.h>


// XXX Utility function - to be moved to utilities.h?
// TODO: Utility function - to be moved to utilities.h?
template <class T>
inline T CountIIR(T base, T newval, double factor)
{
Expand All @@ -87,32 +87,30 @@ inline T CountIIR(T base, T newval, double factor)
return base+T(diff*factor);
}

// XXX Probably a better rework for that can be done - this can be
// turned into a serializable structure, just like it's for CHandShake.
// TODO: Probably a better rework for that can be done - this can be
// turned into a serializable structure, just like it's done for CHandShake.
enum AckDataItem
{
ACKD_RCVLASTACK = 0,
ACKD_RTT = 1,
ACKD_RTTVAR = 2,
ACKD_BUFFERLEFT = 3,
ACKD_TOTAL_SIZE_SMALL = 4,

// Extra fields existing in UDT (not always sent)

ACKD_RCVSPEED = 4, // length would be 16
ACKD_BANDWIDTH = 5,
ACKD_TOTAL_SIZE_UDTBASE = 6, // length = 24
// Extra stats for SRT

ACKD_RCVRATE = 6,
ACKD_TOTAL_SIZE_VER101 = 7, // length = 28
ACKD_XMRATE = 7, // XXX This is a weird compat stuff. Version 1.1.3 defines it as ACKD_BANDWIDTH*m_iMaxSRTPayloadSize when set. Never got.
// XXX NOTE: field number 7 may be used for something in future, need to confirm destruction of all !compat 1.0.2 version

ACKD_TOTAL_SIZE_VER102 = 8, // 32
// FEATURE BLOCKED. Probably not to be restored.
// ACKD_ACKBITMAP = 8,
ACKD_TOTAL_SIZE = ACKD_TOTAL_SIZE_VER102 // length = 32 (or more)
ACKD_RCVLASTACK = 0,
ACKD_RTT = 1,
ACKD_RTTVAR = 2,
ACKD_BUFFERLEFT = 3,
ACKD_TOTAL_SIZE_SMALL = 4, // Size of the Small ACK, packet length = 16.

// Extra fields for Full ACK.
ACKD_RCVSPEED = 4,
ACKD_BANDWIDTH = 5,
ACKD_TOTAL_SIZE_UDTBASE = 6, // Packet length = 24.

// Extra stats since SRT v1.0.1.
ACKD_RCVRATE = 6,
ACKD_TOTAL_SIZE_VER101 = 7, // Packet length = 28.

// Only in SRT v1.0.2.
ACKD_XMRATE_VER102_ONLY = 7,
ACKD_TOTAL_SIZE_VER102_ONLY = 8, // Packet length = 32.

ACKD_TOTAL_SIZE = ACKD_TOTAL_SIZE_VER102_ONLY // The maximum known ACK length is 32 bytes.
};
const size_t ACKD_FIELD_SIZE = sizeof(int32_t);

Expand Down Expand Up @@ -267,14 +265,15 @@ class CUDT

// Parameters
//
// Note: use notation with X*1000*1000*... instead of million zeros in a row
static const int COMM_RESPONSE_MAX_EXP = 16;
static const int SRT_TLPKTDROP_MINTHRESHOLD_MS = 1000;
static const uint64_t COMM_KEEPALIVE_PERIOD_US = 1*1000*1000;
static const int32_t COMM_SYN_INTERVAL_US = 10*1000;
static const int COMM_CLOSE_BROKEN_LISTENER_TIMEOUT_MS = 3000;
static const uint16_t MAX_WEIGHT = 32767;
static const size_t ACK_WND_SIZE = 1024;
// NOTE: Use notation with X*1000*1000*... instead of
// million zeros in a row.
static const int COMM_RESPONSE_MAX_EXP = 16;
static const int SRT_TLPKTDROP_MINTHRESHOLD_MS = 1000;
static const uint64_t COMM_KEEPALIVE_PERIOD_US = 1*1000*1000;
static const int32_t COMM_SYN_INTERVAL_US = 10*1000;
static const int COMM_CLOSE_BROKEN_LISTENER_TIMEOUT_MS = 3000;
static const uint16_t MAX_WEIGHT = 32767;
static const size_t ACK_WND_SIZE = 1024;

int handshakeVersion()
{
Expand Down Expand Up @@ -745,7 +744,6 @@ class CUDT
int m_iDeliveryRate; // Packet arrival rate at the receiver side
int m_iByteDeliveryRate; // Byte arrival rate at the receiver side


CHandShake m_ConnReq; // Connection request
CHandShake m_ConnRes; // Connection response
CHandShake::RendezvousState m_RdvState; // HSv5 rendezvous state
Expand Down

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