From 37a09dd732b4ebb898c8abf95a11e1675c0a6abd Mon Sep 17 00:00:00 2001
From: Phil Ringnalda <philringnalda@gmail.com>
Date: Wed, 24 Apr 2013 23:45:40 -0700
Subject: [PATCH] Back out 96a806212cac (bug 865314) for apparently causing
 fairly frequent failures in test_spdy.js

---
 .../protocol/http/ConnectionDiagnostics.cpp   |  4 +--
 netwerk/protocol/http/nsHttpConnectionMgr.cpp | 33 +++++--------------
 netwerk/protocol/http/nsHttpConnectionMgr.h   |  6 ++++
 3 files changed, 16 insertions(+), 27 deletions(-)

diff --git a/netwerk/protocol/http/ConnectionDiagnostics.cpp b/netwerk/protocol/http/ConnectionDiagnostics.cpp
index ae0ef20c06d5..ca3f839b4485 100644
--- a/netwerk/protocol/http/ConnectionDiagnostics.cpp
+++ b/netwerk/protocol/http/ConnectionDiagnostics.cpp
@@ -68,8 +68,8 @@ nsHttpConnectionMgr::PrintDiagnosticsCB(const nsACString &key,
                               ent->mHalfOpens.Length());
   self->mLogData.AppendPrintf("   Coalescing Key = %s\n",
                               ent->mCoalescingKey.get());
-  self->mLogData.AppendPrintf("   Spdy using = %d, preferred = %d\n",
-                              ent->mUsingSpdy, ent->mSpdyPreferred);
+  self->mLogData.AppendPrintf("   Spdy using = %d, tested = %d, preferred = %d\n",
+                              ent->mUsingSpdy, ent->mTestedSpdy, ent->mSpdyPreferred);
   self->mLogData.AppendPrintf("   pipelinestate = %d penalty = %d\n",
                               ent->mPipelineState, ent->mPipeliningPenalty);
   for (i = 0; i < nsAHttpTransaction::CLASS_MAX; ++i) {
diff --git a/netwerk/protocol/http/nsHttpConnectionMgr.cpp b/netwerk/protocol/http/nsHttpConnectionMgr.cpp
index 32d67f157f78..08fccd0f5863 100644
--- a/netwerk/protocol/http/nsHttpConnectionMgr.cpp
+++ b/netwerk/protocol/http/nsHttpConnectionMgr.cpp
@@ -521,6 +521,8 @@ nsHttpConnectionMgr::ReportSpdyConnection(nsHttpConnection *conn,
     if (!ent)
         return;
 
+    ent->mTestedSpdy = true;
+
     if (!usingSpdy)
         return;
 
@@ -562,28 +564,7 @@ nsHttpConnectionMgr::ReportSpdyConnection(nsHttpConnection *conn,
         // normally, but then it will go away and future connections will be
         // coalesced through the preferred entry.
 
-      LOG(("ReportSpdyConnection shutting down connection because "
-	   "of desharding\n"));
-      conn->DontReuse();
-    }
-    else if (ent->mActiveConns.Length() > 1) {
-      // this is a new connection to an established preferred spdy host.
-      // if there is more than 1 live and established spdy connection (e.g.
-      // some could still be handshaking, shutting down, etc..) then close
-      // this one down after any transactions that are on it are complete.
-      // This probably happened due to the parallel connection algorithm
-      // that is used only before the host is known to speak spdy.
-      for (uint32_t index = 0; index < ent->mActiveConns.Length(); ++index) {
-	nsHttpConnection *otherConn = ent->mActiveConns[index];
-	if (otherConn == conn)
-	  continue;
-	if (conn->CanDirectlyActivate()) {
-	  LOG(("ReportSpdyConnection shutting down connection because more "
-	       "than 1 active spdy connection is live to this host\n"));
-	  conn->DontReuse();
-	  break;
-	}
-      }
+        conn->DontReuse();
     }
 
     PostEvent(&nsHttpConnectionMgr::OnMsgProcessAllSpdyPendingQ);
@@ -970,8 +951,9 @@ nsHttpConnectionMgr::PruneDeadConnectionsCB(const nsACString &key,
         ent->mActiveConns.Length() == 0 &&
         ent->mHalfOpens.Length()   == 0 &&
         ent->mPendingQ.Length()    == 0 &&
-        !ent->mUsingSpdy &&
-	self->mCT.Count() > 300) {
+        ((!ent->mTestedSpdy && !ent->mUsingSpdy) ||
+         !gHttpHandler->IsSpdyEnabled() ||
+         self->mCT.Count() > 300)) {
         LOG(("    removing empty connection entry\n"));
         return PL_DHASH_REMOVE;
     }
@@ -1307,7 +1289,7 @@ nsHttpConnectionMgr::RestrictConnections(nsConnectionEntry *ent)
     
     bool doRestrict = ent->mConnInfo->UsingSSL() &&
         gHttpHandler->IsSpdyEnabled() &&
-        ent->mUsingSpdy &&
+        (!ent->mTestedSpdy || ent->mUsingSpdy) &&
         (ent->mHalfOpens.Length() || ent->mActiveConns.Length());
 
     // If there are no restrictions, we are done
@@ -3122,6 +3104,7 @@ nsConnectionEntry::nsConnectionEntry(nsHttpConnectionInfo *ci)
     , mPipeliningPenalty(0)
     , mSpdyCWND(0)
     , mUsingSpdy(false)
+    , mTestedSpdy(false)
     , mSpdyPreferred(false)
     , mPreferIPv4(false)
     , mPreferIPv6(false)
diff --git a/netwerk/protocol/http/nsHttpConnectionMgr.h b/netwerk/protocol/http/nsHttpConnectionMgr.h
index 4fa923c5ec36..97614d600f2a 100644
--- a/netwerk/protocol/http/nsHttpConnectionMgr.h
+++ b/netwerk/protocol/http/nsHttpConnectionMgr.h
@@ -358,6 +358,12 @@ private:
         // connection is currently using spdy.
         bool mUsingSpdy;
 
+        // mTestedSpdy is set after NPN negotiation has occurred and we know
+        // with confidence whether a host speaks spdy or not (which is reflected
+        // in mUsingSpdy). Before mTestedSpdy is set, handshake parallelism is
+        // minimized so that we can multiplex on a single spdy connection.
+        bool mTestedSpdy;
+
         bool mSpdyPreferred;
 
         // Flags to remember our happy-eyeballs decision.