process received messages one at a time without sleeping between messages

src/main.cpp

@@ -3141,6 +3141,9 @@ void static ProcessGetData(CNode* pfrom)
 
             // Track requests for our stuff.
             Inventory(inv.hash);
+
+            if (inv.type == MSG_BLOCK || inv.type == MSG_FILTERED_BLOCK)
+                break;
         }
     }
 
@@ -3751,6 +3754,9 @@ bool ProcessMessages(CNode* pfrom)
     if (!pfrom->vRecvGetData.empty())
         ProcessGetData(pfrom);
 
+    // this maintains the order of responses
+    if (!pfrom->vRecvGetData.empty()) return fOk;
+
     std::deque<CNetMessage>::iterator it = pfrom->vRecvMsg.begin();
     while (!pfrom->fDisconnect && it != pfrom->vRecvMsg.end()) {
         // Don't bother if send buffer is too full to respond anyway
@@ -3841,6 +3847,8 @@ bool ProcessMessages(CNode* pfrom)
 
         if (!fRet)
             printf("ProcessMessage(%s, %u bytes) FAILED\n", strCommand.c_str(), nMessageSize);
+
+        break;
     }
 
     // In case the connection got shut down, its receive buffer was wiped

src/net.cpp

@@ -1629,6 +1629,9 @@ void ThreadMessageHandler()
         CNode* pnodeTrickle = NULL;
         if (!vNodesCopy.empty())
             pnodeTrickle = vNodesCopy[GetRand(vNodesCopy.size())];
+
+        bool fSleep = true;
+
         BOOST_FOREACH(CNode* pnode, vNodesCopy)
         {
             if (pnode->fDisconnect)
@@ -1638,8 +1641,18 @@ void ThreadMessageHandler()
             {
                 TRY_LOCK(pnode->cs_vRecvMsg, lockRecv);
                 if (lockRecv)
+                {
                     if (!ProcessMessages(pnode))
                         pnode->CloseSocketDisconnect();
+
+                    if (pnode->nSendSize < SendBufferSize())
+                    {
+                        if (!pnode->vRecvGetData.empty() || (!pnode->vRecvMsg.empty() && pnode->vRecvMsg[0].complete()))
+                        {
+                            fSleep = false;
+                        }
+                    }
+                }
             }
             boost::this_thread::interruption_point();
 
@@ -1658,7 +1671,8 @@ void ThreadMessageHandler()
                 pnode->Release();
         }
 
-        MilliSleep(100);
+        if (fSleep)
+            MilliSleep(100);
     }
 }