624739 - sort idle persistent http connections by pereceived server cwnd

--HG--
extra : rebase_source : 29c50d0c0e99220bb87b5f584188fad49cc33439

netwerk/protocol/http/nsHttpConnection.cpp

@@ -70,6 +70,8 @@ nsHttpConnection::nsHttpConnection()
     , mIdleTimeout(0)
     , mConsiderReusedAfterInterval(0)
     , mConsiderReusedAfterEpoch(0)
+    , mCurrentBytesRead(0)
+    , mMaxBytesRead(0)
     , mKeepAlive(PR_TRUE) // assume to keep-alive by default
     , mKeepAliveMask(PR_TRUE)
     , mSupportsPipelining(PR_FALSE) // assume low-grade server
@@ -161,6 +163,9 @@ nsHttpConnection::Activate(nsAHttpTransaction *trans, PRUint8 caps)
             goto failed_activation;
     }
 
+    // Clear the per activation counter
+    mCurrentBytesRead = 0;
+
     rv = OnOutputStreamReady(mSocketOut);
     
 failed_activation:
@@ -502,6 +507,9 @@ nsHttpConnection::CloseTransaction(nsAHttpTransaction *trans, nsresult reason)
     NS_ASSERTION(trans == mTransaction, "wrong transaction");
     NS_ASSERTION(PR_GetCurrentThread() == gSocketThread, "wrong thread");
 
+    if (mCurrentBytesRead > mMaxBytesRead)
+        mMaxBytesRead = mCurrentBytesRead;
+
     // mask this error code because its not a real error.
     if (reason == NS_BASE_STREAM_CLOSED)
         reason = NS_OK;
@@ -677,13 +685,16 @@ nsHttpConnection::OnSocketReadable()
                 rv = NS_OK;
             again = PR_FALSE;
         }
-        else if (NS_FAILED(mSocketInCondition)) {
-            // continue waiting for the socket if necessary...
-            if (mSocketInCondition == NS_BASE_STREAM_WOULD_BLOCK)
-                rv = mSocketIn->AsyncWait(this, 0, 0, nsnull);
-            else
-                rv = mSocketInCondition;
-            again = PR_FALSE;
+        else {
+            mCurrentBytesRead += n;
+            if (NS_FAILED(mSocketInCondition)) {
+                // continue waiting for the socket if necessary...
+                if (mSocketInCondition == NS_BASE_STREAM_WOULD_BLOCK)
+                    rv = mSocketIn->AsyncWait(this, 0, 0, nsnull);
+                else
+                    rv = mSocketInCondition;
+                again = PR_FALSE;
+            }
         }
         // read more from the socket until error...
     } while (again);

netwerk/protocol/http/nsHttpConnection.h

@@ -138,6 +138,7 @@ public:
     nsresult PushBack(const char *data, PRUint32 length) { NS_NOTREACHED("PushBack"); return NS_ERROR_UNEXPECTED; }
     nsresult ResumeSend();
     nsresult ResumeRecv();
+    PRInt64  MaxBytesRead() {return mMaxBytesRead;}
 
     static NS_METHOD ReadFromStream(nsIInputStream *, void *, const char *,
                                     PRUint32, PRUint32, PRUint32 *);
@@ -180,6 +181,8 @@ private:
     PRUint16                        mIdleTimeout;    // value of keep-alive: timeout=
     PRIntervalTime                  mConsiderReusedAfterInterval;
     PRIntervalTime                  mConsiderReusedAfterEpoch;
+    PRInt64                         mCurrentBytesRead;   // data read per activation
+    PRInt64                         mMaxBytesRead;       // max read in 1 activation
 
     PRPackedBool                    mKeepAlive;
     PRPackedBool                    mKeepAliveMask;

netwerk/protocol/http/nsHttpConnectionMgr.cpp

@@ -1057,12 +1057,24 @@ nsHttpConnectionMgr::OnMsgReclaimConnection(PRInt32, void *param)
 
         if (conn->CanReuse()) {
             LOG(("  adding connection to idle list\n"));
-            // hold onto this connection in the idle list.  we push it to
-            // the end of the list so as to ensure that we'll visit older
-            // connections first before getting to this one.
+            // Keep The idle connection list sorted with the connections that
+            // have moved the largest data pipelines at the front because these
+            // connections have the largest cwnds on the server.
+
+            // The linear search is ok here because the number of idleconns
+            // in a single entry is generally limited to a small number (i.e. 6)
+
+            PRInt32 idx;
+            for (idx = 0; idx < ent->mIdleConns.Length(); idx++) {
+                nsHttpConnection *idleConn = ent->mIdleConns[idx];
+                if (idleConn->MaxBytesRead() < conn->MaxBytesRead())
+                    break;
+            }
+
             NS_ADDREF(conn);
-            ent->mIdleConns.AppendElement(conn);
+            ent->mIdleConns.InsertElementAt(idx, conn);
             mNumIdleConns++;
+
             // If the added connection was first idle connection or has shortest
             // time to live among the idle connections, pruning dead
             // connections needs to be done when it can't be reused anymore.