Use per-message send buffer, rather than per connection

src/main.cpp

@@ -3104,7 +3104,7 @@ bool static ProcessMessage(CNode* pfrom, string strCommand, CDataStream& vRecv)
 
         // Change version
         pfrom->PushMessage("verack");
-        pfrom->vSend.SetVersion(min(pfrom->nVersion, PROTOCOL_VERSION));
+        pfrom->ssSend.SetVersion(min(pfrom->nVersion, PROTOCOL_VERSION));
 
         if (!pfrom->fInbound)
         {
@@ -3722,9 +3722,9 @@ bool ProcessMessages(CNode* pfrom)
     bool fOk = true;
 
     std::deque<CNetMessage>::iterator it = pfrom->vRecvMsg.begin();
-    while (it != pfrom->vRecvMsg.end()) {
+    while (!pfrom->fDisconnect && it != pfrom->vRecvMsg.end()) {
         // Don't bother if send buffer is too full to respond anyway
-        if (pfrom->vSend.size() >= SendBufferSize())
+        if (pfrom->nSendSize >= SendBufferSize())
             break;
 
         // get next message
@@ -3811,7 +3811,10 @@ bool ProcessMessages(CNode* pfrom)
             printf("ProcessMessage(%s, %u bytes) FAILED\n", strCommand.c_str(), nMessageSize);
     }
 
-    pfrom->vRecvMsg.erase(pfrom->vRecvMsg.begin(), it);
+    // In case the connection got shut down, its receive buffer was wiped
+    if (!pfrom->fDisconnect)
+        pfrom->vRecvMsg.erase(pfrom->vRecvMsg.begin(), it);
+
     return fOk;
 }
 
@@ -3826,7 +3829,7 @@ bool SendMessages(CNode* pto, bool fSendTrickle)
 
         // Keep-alive ping. We send a nonce of zero because we don't use it anywhere
         // right now.
-        if (pto->nLastSend && GetTime() - pto->nLastSend > 30 * 60 && pto->vSend.empty()) {
+        if (pto->nLastSend && GetTime() - pto->nLastSend > 30 * 60 && pto->vSendMsg.empty()) {
             uint64 nonce = 0;
             if (pto->nVersion > BIP0031_VERSION)
                 pto->PushMessage("ping", nonce);

src/net.cpp

@@ -715,26 +715,43 @@ int CNetMessage::readData(const char *pch, unsigned int nBytes)
 // requires LOCK(cs_vSend)
 void SocketSendData(CNode *pnode)
 {
-    CDataStream& vSend = pnode->vSend;
-    if (vSend.empty())
-        return;
-
-    int nBytes = send(pnode->hSocket, &vSend[0], vSend.size(), MSG_NOSIGNAL | MSG_DONTWAIT);
-    if (nBytes > 0)
-    {
-        vSend.erase(vSend.begin(), vSend.begin() + nBytes);
-        pnode->nLastSend = GetTime();
-    }
-    else if (nBytes < 0)
-    {
-        // error
-        int nErr = WSAGetLastError();
-        if (nErr != WSAEWOULDBLOCK && nErr != WSAEMSGSIZE && nErr != WSAEINTR && nErr != WSAEINPROGRESS)
-        {
-            printf("socket send error %d\n", nErr);
-            pnode->CloseSocketDisconnect();
+    std::deque<CSerializeData>::iterator it = pnode->vSendMsg.begin();
+
+    while (it != pnode->vSendMsg.end()) {
+        const CSerializeData &data = *it;
+        assert(data.size() > pnode->nSendOffset);
+        int nBytes = send(pnode->hSocket, &data[pnode->nSendOffset], data.size() - pnode->nSendOffset, MSG_NOSIGNAL | MSG_DONTWAIT);
+        if (nBytes > 0) {
+            pnode->nLastSend = GetTime();
+            pnode->nSendOffset += nBytes;
+            if (pnode->nSendOffset == data.size()) {
+                pnode->nSendOffset = 0;
+                pnode->nSendSize -= data.size();
+                it++;
+            } else {
+                // could not send full message; stop sending more
+                break;
+            }
+        } else {
+            if (nBytes < 0) {
+                // error
+                int nErr = WSAGetLastError();
+                if (nErr != WSAEWOULDBLOCK && nErr != WSAEMSGSIZE && nErr != WSAEINTR && nErr != WSAEINPROGRESS)
+                {
+                    printf("socket send error %d\n", nErr);
+                    pnode->CloseSocketDisconnect();
+                }
+            }
+            // couldn't send anything at all
+            break;
         }
     }
+
+    if (it == pnode->vSendMsg.end()) {
+        assert(pnode->nSendOffset == 0);
+        assert(pnode->nSendSize == 0);
+    }
+    pnode->vSendMsg.erase(pnode->vSendMsg.begin(), it);
 }
 
 void ThreadSocketHandler(void* parg)
@@ -776,7 +793,7 @@ void ThreadSocketHandler2(void* parg)
             BOOST_FOREACH(CNode* pnode, vNodesCopy)
             {
                 if (pnode->fDisconnect ||
-                    (pnode->GetRefCount() <= 0 && pnode->vRecvMsg.empty() && pnode->vSend.empty()))
+                    (pnode->GetRefCount() <= 0 && pnode->vRecvMsg.empty() && pnode->nSendSize == 0 && pnode->ssSend.empty()))
                 {
                     // remove from vNodes
                     vNodes.erase(remove(vNodes.begin(), vNodes.end(), pnode), vNodes.end());
@@ -863,7 +880,7 @@ void ThreadSocketHandler2(void* parg)
                     TRY_LOCK(pnode->cs_vSend, lockSend);
                     if (lockSend) {
                         // do not read, if draining write queue
-                        if (!pnode->vSend.empty())
+                        if (!pnode->vSendMsg.empty())
                             FD_SET(pnode->hSocket, &fdsetSend);
                         else
                             FD_SET(pnode->hSocket, &fdsetRecv);
@@ -1032,7 +1049,7 @@ void ThreadSocketHandler2(void* parg)
             //
             // Inactivity checking
             //
-            if (pnode->vSend.empty())
+            if (pnode->vSendMsg.empty())
                 pnode->nLastSendEmpty = GetTime();
             if (GetTime() - pnode->nTimeConnected > 60)
             {

src/net.h

@@ -173,7 +173,10 @@ public:
     // socket
     uint64 nServices;
     SOCKET hSocket;
-    CDataStream vSend;
+    CDataStream ssSend;
+    size_t nSendSize; // total size of all vSendMsg entries
+    size_t nSendOffset; // offset inside the first vSendMsg already sent
+    std::deque<CSerializeData> vSendMsg;
     CCriticalSection cs_vSend;
 
     std::deque<CNetMessage> vRecvMsg;
@@ -184,8 +187,6 @@ public:
     int64 nLastRecv;
     int64 nLastSendEmpty;
     int64 nTimeConnected;
-    int nHeaderStart;
-    unsigned int nMessageStart;
     CAddress addr;
     std::string addrName;
     CService addrLocal;
@@ -233,7 +234,7 @@ public:
     CCriticalSection cs_inventory;
     std::multimap<int64, CInv> mapAskFor;
 
-    CNode(SOCKET hSocketIn, CAddress addrIn, std::string addrNameIn = "", bool fInboundIn=false) : vSend(SER_NETWORK, MIN_PROTO_VERSION)
+    CNode(SOCKET hSocketIn, CAddress addrIn, std::string addrNameIn = "", bool fInboundIn=false) : ssSend(SER_NETWORK, MIN_PROTO_VERSION)
     {
         nServices = 0;
         hSocket = hSocketIn;
@@ -242,8 +243,6 @@ public:
         nLastRecv = 0;
         nLastSendEmpty = GetTime();
         nTimeConnected = GetTime();
-        nHeaderStart = -1;
-        nMessageStart = -1;
         addr = addrIn;
         addrName = addrNameIn == "" ? addr.ToStringIPPort() : addrNameIn;
         nVersion = 0;
@@ -256,6 +255,8 @@ public:
         fDisconnect = false;
         nRefCount = 0;
         nReleaseTime = 0;
+        nSendSize = 0;
+        nSendOffset = 0;
         hashContinue = 0;
         pindexLastGetBlocksBegin = 0;
         hashLastGetBlocksEnd = 0;
@@ -387,11 +388,8 @@ public:
     void BeginMessage(const char* pszCommand) EXCLUSIVE_LOCK_FUNCTION(cs_vSend)
     {
         ENTER_CRITICAL_SECTION(cs_vSend);
-        if (nHeaderStart != -1)
-            AbortMessage();
-        nHeaderStart = vSend.size();
-        vSend << CMessageHeader(pszCommand, 0);
-        nMessageStart = vSend.size();
+        assert(ssSend.size() == 0);
+        ssSend << CMessageHeader(pszCommand, 0);
         if (fDebug)
             printf("sending: %s ", pszCommand);
     }
@@ -399,11 +397,8 @@ public:
     // TODO: Document the precondition of this function.  Is cs_vSend locked?
     void AbortMessage() UNLOCK_FUNCTION(cs_vSend)
     {
-        if (nHeaderStart < 0)
-            return;
-        vSend.resize(nHeaderStart);
-        nHeaderStart = -1;
-        nMessageStart = -1;
+        ssSend.clear();
+
         LEAVE_CRITICAL_SECTION(cs_vSend);
 
         if (fDebug)
@@ -420,30 +415,32 @@ public:
             return;
         }
 
-        if (nHeaderStart < 0)
+        if (ssSend.size() == 0)
             return;
 
         // Set the size
-        unsigned int nSize = vSend.size() - nMessageStart;
-        memcpy((char*)&vSend[nHeaderStart] + CMessageHeader::MESSAGE_SIZE_OFFSET, &nSize, sizeof(nSize));
+        unsigned int nSize = ssSend.size() - CMessageHeader::HEADER_SIZE;
+        memcpy((char*)&ssSend[CMessageHeader::MESSAGE_SIZE_OFFSET], &nSize, sizeof(nSize));
 
         // Set the checksum
-        uint256 hash = Hash(vSend.begin() + nMessageStart, vSend.end());
+        uint256 hash = Hash(ssSend.begin() + CMessageHeader::HEADER_SIZE, ssSend.end());
         unsigned int nChecksum = 0;
         memcpy(&nChecksum, &hash, sizeof(nChecksum));
-        assert(nMessageStart - nHeaderStart >= CMessageHeader::CHECKSUM_OFFSET + sizeof(nChecksum));
-        memcpy((char*)&vSend[nHeaderStart] + CMessageHeader::CHECKSUM_OFFSET, &nChecksum, sizeof(nChecksum));
+        assert(ssSend.size () >= CMessageHeader::CHECKSUM_OFFSET + sizeof(nChecksum));
+        memcpy((char*)&ssSend[CMessageHeader::CHECKSUM_OFFSET], &nChecksum, sizeof(nChecksum));
 
         if (fDebug) {
             printf("(%d bytes)\n", nSize);
         }
 
+        std::deque<CSerializeData>::iterator it = vSendMsg.insert(vSendMsg.end(), CSerializeData());
+        ssSend.GetAndClear(*it);
+        nSendSize += (*it).size();
+
         // If write queue empty, attempt "optimistic write"
-        if (nHeaderStart == 0)
+        if (it == vSendMsg.begin())
             SocketSendData(this);
 
-        nHeaderStart = -1;
-        nMessageStart = -1;
         LEAVE_CRITICAL_SECTION(cs_vSend);
     }
 
@@ -470,7 +467,7 @@ public:
         try
         {
             BeginMessage(pszCommand);
-            vSend << a1;
+            ssSend << a1;
             EndMessage();
         }
         catch (...)
@@ -486,7 +483,7 @@ public:
         try
         {
             BeginMessage(pszCommand);
-            vSend << a1 << a2;
+            ssSend << a1 << a2;
             EndMessage();
         }
         catch (...)
@@ -502,7 +499,7 @@ public:
         try
         {
             BeginMessage(pszCommand);
-            vSend << a1 << a2 << a3;
+            ssSend << a1 << a2 << a3;
             EndMessage();
         }
         catch (...)
@@ -518,7 +515,7 @@ public:
         try
         {
             BeginMessage(pszCommand);
-            vSend << a1 << a2 << a3 << a4;
+            ssSend << a1 << a2 << a3 << a4;
             EndMessage();
         }
         catch (...)
@@ -534,7 +531,7 @@ public:
         try
         {
             BeginMessage(pszCommand);
-            vSend << a1 << a2 << a3 << a4 << a5;
+            ssSend << a1 << a2 << a3 << a4 << a5;
             EndMessage();
         }
         catch (...)
@@ -550,7 +547,7 @@ public:
         try
         {
             BeginMessage(pszCommand);
-            vSend << a1 << a2 << a3 << a4 << a5 << a6;
+            ssSend << a1 << a2 << a3 << a4 << a5 << a6;
             EndMessage();
         }
         catch (...)
@@ -566,7 +563,7 @@ public:
         try
         {
             BeginMessage(pszCommand);
-            vSend << a1 << a2 << a3 << a4 << a5 << a6 << a7;
+            ssSend << a1 << a2 << a3 << a4 << a5 << a6 << a7;
             EndMessage();
         }
         catch (...)
@@ -582,7 +579,7 @@ public:
         try
         {
             BeginMessage(pszCommand);
-            vSend << a1 << a2 << a3 << a4 << a5 << a6 << a7 << a8;
+            ssSend << a1 << a2 << a3 << a4 << a5 << a6 << a7 << a8;
             EndMessage();
         }
         catch (...)
@@ -598,7 +595,7 @@ public:
         try
         {
             BeginMessage(pszCommand);
-            vSend << a1 << a2 << a3 << a4 << a5 << a6 << a7 << a8 << a9;
+            ssSend << a1 << a2 << a3 << a4 << a5 << a6 << a7 << a8 << a9;
             EndMessage();
         }
         catch (...)

src/protocol.h

@@ -56,7 +56,8 @@ class CMessageHeader
             CHECKSUM_SIZE=sizeof(int),
 
             MESSAGE_SIZE_OFFSET=MESSAGE_START_SIZE+COMMAND_SIZE,
-            CHECKSUM_OFFSET=MESSAGE_SIZE_OFFSET+MESSAGE_SIZE_SIZE
+            CHECKSUM_OFFSET=MESSAGE_SIZE_OFFSET+MESSAGE_SIZE_SIZE,
+            HEADER_SIZE=MESSAGE_START_SIZE+COMMAND_SIZE+MESSAGE_SIZE_SIZE+CHECKSUM_SIZE
         };
         char pchMessageStart[MESSAGE_START_SIZE];
         char pchCommand[COMMAND_SIZE];

src/serialize.h

@@ -789,6 +789,7 @@ struct ser_streamplaceholder
 
 
 
+typedef std::vector<char, zero_after_free_allocator<char> > CSerializeData;
 
 /** Double ended buffer combining vector and stream-like interfaces.
  *
@@ -798,7 +799,7 @@ struct ser_streamplaceholder
 class CDataStream
 {
 protected:
-    typedef std::vector<char, zero_after_free_allocator<char> > vector_type;
+    typedef CSerializeData vector_type;
     vector_type vch;
     unsigned int nReadPos;
     short state;
@@ -1095,6 +1096,11 @@ public:
         ::Unserialize(*this, obj, nType, nVersion);
         return (*this);
     }
+
+    void GetAndClear(CSerializeData &data) {
+        vch.swap(data);
+        CSerializeData().swap(vch);
+    }
 };