Some fixes to CNetMessage processing

* Change CNode::vRecvMsg to be a deque instead of a vector (less copying)
* Make sure to acquire cs_vRecvMsg in CNode::CloseSocketDisconnect (as it
  may be called without that lock).

src/main.cpp

@@ -3708,8 +3708,6 @@ bool static ProcessMessage(CNode* pfrom, string strCommand, CDataStream& vRecv)
 // requires LOCK(cs_vRecvMsg)
 bool ProcessMessages(CNode* pfrom)
 {
-    if (pfrom->vRecvMsg.empty())
-        return true;
     //if (fDebug)
     //    printf("ProcessMessages(%zu messages)\n", pfrom->vRecvMsg.size());
 
@@ -3721,29 +3719,34 @@ bool ProcessMessages(CNode* pfrom)
     //  (4) checksum
     //  (x) data
     //
+    bool fOk = true;
 
-    unsigned int nMsgPos = 0;
-    for (; nMsgPos < pfrom->vRecvMsg.size(); nMsgPos++)
-    {
+    std::deque<CNetMessage>::iterator it = pfrom->vRecvMsg.begin();
+    while (it != pfrom->vRecvMsg.end()) {
         // Don't bother if send buffer is too full to respond anyway
         if (pfrom->vSend.size() >= SendBufferSize())
             break;
 
-        // get next message; end, if an incomplete message is found
-        CNetMessage& msg = pfrom->vRecvMsg[nMsgPos];
+        // get next message
+        CNetMessage& msg = *it;
 
         //if (fDebug)
         //    printf("ProcessMessages(message %u msgsz, %zu bytes, complete:%s)\n",
         //            msg.hdr.nMessageSize, msg.vRecv.size(),
         //            msg.complete() ? "Y" : "N");
 
+        // end, if an incomplete message is found
         if (!msg.complete())
             break;
 
+        // at this point, any failure means we can delete the current message
+        it++;
+
         // Scan for message start
         if (memcmp(msg.hdr.pchMessageStart, pchMessageStart, sizeof(pchMessageStart)) != 0) {
             printf("\n\nPROCESSMESSAGE: INVALID MESSAGESTART\n\n");
-            return false;
+            fOk = false;
+            break;
         }
 
         // Read header
@@ -3779,7 +3782,7 @@ bool ProcessMessages(CNode* pfrom)
                 fRet = ProcessMessage(pfrom, strCommand, vRecv);
             }
             if (fShutdown)
-                return true;
+                break;
         }
         catch (std::ios_base::failure& e)
         {
@@ -3808,11 +3811,8 @@ bool ProcessMessages(CNode* pfrom)
             printf("ProcessMessage(%s, %u bytes) FAILED\n", strCommand.c_str(), nMessageSize);
     }
 
-    // remove processed messages; one incomplete message may remain
-    if (nMsgPos > 0)
-        pfrom->vRecvMsg.erase(pfrom->vRecvMsg.begin(),
-                              pfrom->vRecvMsg.begin() + nMsgPos);
-    return true;
+    pfrom->vRecvMsg.erase(pfrom->vRecvMsg.begin(), it);
+    return fOk;
 }
 
 

src/net.cpp

@@ -536,7 +536,11 @@ void CNode::CloseSocketDisconnect()
         printf("disconnecting node %s\n", addrName.c_str());
         closesocket(hSocket);
         hSocket = INVALID_SOCKET;
-        vRecvMsg.clear();
+
+        // in case this fails, we'll empty the recv buffer when the CNode is deleted
+        TRY_LOCK(cs_vRecvMsg, lockRecv);
+        if (lockRecv)
+            vRecvMsg.clear();
     }
 }
 
@@ -634,7 +638,7 @@ bool CNode::ReceiveMsgBytes(const char *pch, unsigned int nBytes)
     while (nBytes > 0) {
 
         // get current incomplete message, or create a new one
-        if (vRecvMsg.size() == 0 ||
+        if (vRecvMsg.empty() ||
             vRecvMsg.back().complete())
             vRecvMsg.push_back(CNetMessage(SER_NETWORK, nRecvVersion));
 
@@ -1767,6 +1771,9 @@ void ThreadMessageHandler2(void* parg)
             pnodeTrickle = vNodesCopy[GetRand(vNodesCopy.size())];
         BOOST_FOREACH(CNode* pnode, vNodesCopy)
         {
+            if (pnode->fDisconnect)
+                continue;
+
             // Receive messages
             {
                 TRY_LOCK(pnode->cs_vRecvMsg, lockRecv);

src/net.h

@@ -176,7 +176,7 @@ public:
     CDataStream vSend;
     CCriticalSection cs_vSend;
 
-    std::vector<CNetMessage> vRecvMsg;
+    std::deque<CNetMessage> vRecvMsg;
     CCriticalSection cs_vRecvMsg;
     int nRecvVersion;
 
@@ -297,8 +297,8 @@ public:
     unsigned int GetTotalRecvSize()
     {
         unsigned int total = 0;
-        for (unsigned int i = 0; i < vRecvMsg.size(); i++)
-            total += vRecvMsg[i].vRecv.size();
+        BOOST_FOREACH(const CNetMessage &msg, vRecvMsg) 
+            total += msg.vRecv.size() + 24;
         return total;
     }
 
@@ -309,8 +309,8 @@ public:
     void SetRecvVersion(int nVersionIn)
     {
         nRecvVersion = nVersionIn;
-        for (unsigned int i = 0; i < vRecvMsg.size(); i++)
-            vRecvMsg[i].SetVersion(nVersionIn);
+        BOOST_FOREACH(CNetMessage &msg, vRecvMsg)
+            msg.SetVersion(nVersionIn);
     }
 
     CNode* AddRef(int64 nTimeout=0)