bug 792438 - part 2 block network image loads on head css,js r=honzab…

… sr=bz

modules/libpref/src/init/all.js

@@ -910,6 +910,10 @@ pref("network.http.connection-retry-timeout", 250);
 // to give up if the OS does not give up first
 pref("network.http.connection-timeout", 90);
 
+// The maximum number of current global half open sockets allowable
+// when starting a new speculative connection.
+pref("network.http.speculative-parallel-limit", 6);
+
 // Disable IPv6 for backup connections to workaround problems about broken
 // IPv6 connectivity.
 pref("network.http.fast-fallback-to-IPv4", true);

netwerk/base/public/nsILoadGroup.idl

@@ -8,11 +8,12 @@
 interface nsISimpleEnumerator;
 interface nsIRequestObserver;
 interface nsIInterfaceRequestor;
+interface nsILoadGroupConnectionInfo;
 
 /**
  * A load group maintains a collection of nsIRequest objects. 
  */
-[scriptable, uuid(3de0a31c-feaf-400f-9f1e-4ef71f8b20cc)]
+[scriptable, uuid(19501006-46e3-4634-b97d-26eff894b4d3)]
 interface nsILoadGroup : nsIRequest
 {
     /**
@@ -71,4 +72,36 @@ interface nsILoadGroup : nsIRequest
      * Notification callbacks for the load group.
      */
     attribute nsIInterfaceRequestor notificationCallbacks;
+
+    /**
+     * Connection information for managing things like js/css
+     * connection blocking, and per-tab connection grouping
+     */
+    readonly attribute nsILoadGroupConnectionInfo connectionInfo;
+};
+
+/**
+ * Used to maintain state about the connections of a load group and
+ * how they interact with blocking items like HEAD css/js loads.
+ */
+[uuid(d1f9f18e-3d85-473a-ad58-a2367d7cdb2a)]
+interface nsILoadGroupConnectionInfo : nsISupports
+{
+    /**
+     * Number of active blocking transactions associated with this load group
+     */
+    readonly attribute unsigned long blockingTransactionCount;
+
+    /**
+     * Increase the number of active blocking transactions associated
+     * with this load group by one.
+     */
+    void addBlockingTransaction();
+
+    /**
+     * Decrease the number of active blocking transactions associated
+     * with this load group by one. The return value is the number of remaining
+     * blockers.
+     */
+    unsigned long removeBlockingTransaction();
 };

netwerk/base/src/nsLoadGroup.cpp

@@ -146,30 +146,6 @@ nsLoadGroup::~nsLoadGroup()
 }
 
 
-nsresult nsLoadGroup::Init()
-{
-    static PLDHashTableOps hash_table_ops =
-    {
-        PL_DHashAllocTable,
-        PL_DHashFreeTable,
-        PL_DHashVoidPtrKeyStub,
-        RequestHashMatchEntry,
-        PL_DHashMoveEntryStub,
-        RequestHashClearEntry,
-        PL_DHashFinalizeStub,
-        RequestHashInitEntry
-    };
-
-    if (!PL_DHashTableInit(&mRequests, &hash_table_ops, nullptr,
-                           sizeof(RequestMapEntry), 16)) {
-        mRequests.ops = nullptr;
-
-        return NS_ERROR_OUT_OF_MEMORY;
-    }
-
-    return NS_OK;
-}
-
 ////////////////////////////////////////////////////////////////////////////////
 // nsISupports methods:
 
@@ -791,6 +767,15 @@ nsLoadGroup::SetNotificationCallbacks(nsIInterfaceRequestor *aCallbacks)
     return NS_OK;
 }
 
+NS_IMETHODIMP
+nsLoadGroup::GetConnectionInfo(nsILoadGroupConnectionInfo **aCI)
+{
+    NS_ENSURE_ARG_POINTER(aCI);
+    *aCI = mConnectionInfo;
+    NS_IF_ADDREF(*aCI);
+    return NS_OK;
+}
+
 ////////////////////////////////////////////////////////////////////////////////
 // nsISupportsPriority methods:
 
@@ -1004,3 +989,73 @@ nsresult nsLoadGroup::MergeLoadFlags(nsIRequest *aRequest, nsLoadFlags& outFlags
     outFlags = flags;
     return rv;
 }
+
+// nsLoadGroupConnectionInfo
+
+class nsLoadGroupConnectionInfo MOZ_FINAL : public nsILoadGroupConnectionInfo
+{
+public:
+    NS_DECL_ISUPPORTS
+    NS_DECL_NSILOADGROUPCONNECTIONINFO
+
+    nsLoadGroupConnectionInfo();
+private:
+    int32_t       mBlockingTransactionCount; // signed for PR_ATOMIC_*
+};
+
+NS_IMPL_THREADSAFE_ISUPPORTS1(nsLoadGroupConnectionInfo, nsILoadGroupConnectionInfo)
+
+nsLoadGroupConnectionInfo::nsLoadGroupConnectionInfo()
+    : mBlockingTransactionCount(0)
+{
+}
+
+NS_IMETHODIMP
+nsLoadGroupConnectionInfo::GetBlockingTransactionCount(uint32_t *aBlockingTransactionCount)
+{
+    NS_ENSURE_ARG_POINTER(aBlockingTransactionCount);
+    *aBlockingTransactionCount = static_cast<uint32_t>(mBlockingTransactionCount);
+    return NS_OK;
+}
+
+NS_IMETHODIMP
+nsLoadGroupConnectionInfo::AddBlockingTransaction()
+{
+    PR_ATOMIC_INCREMENT(&mBlockingTransactionCount);
+    return NS_OK;
+}
+
+NS_IMETHODIMP
+nsLoadGroupConnectionInfo::RemoveBlockingTransaction(uint32_t *_retval)
+{
+    NS_ENSURE_ARG_POINTER(_retval);
+    *_retval =
+        static_cast<uint32_t>(PR_ATOMIC_DECREMENT(&mBlockingTransactionCount));
+    return NS_OK;
+}
+
+nsresult nsLoadGroup::Init()
+{
+    static PLDHashTableOps hash_table_ops =
+    {
+        PL_DHashAllocTable,
+        PL_DHashFreeTable,
+        PL_DHashVoidPtrKeyStub,
+        RequestHashMatchEntry,
+        PL_DHashMoveEntryStub,
+        RequestHashClearEntry,
+        PL_DHashFinalizeStub,
+        RequestHashInitEntry
+    };
+
+    if (!PL_DHashTableInit(&mRequests, &hash_table_ops, nullptr,
+                           sizeof(RequestMapEntry), 16)) {
+        mRequests.ops = nullptr;
+
+        return NS_ERROR_OUT_OF_MEMORY;
+    }
+
+    mConnectionInfo = new nsLoadGroupConnectionInfo();
+
+    return NS_OK;
+}

netwerk/base/src/nsLoadGroup.h

@@ -21,6 +21,7 @@
 #include "mozilla/TimeStamp.h"
 
 class  nsISupportsArray;
+class  nsILoadGroupConnectionInfo;
 
 class nsLoadGroup : public nsILoadGroup,
                     public nsISupportsPriority,
@@ -64,6 +65,7 @@ class nsLoadGroup : public nsILoadGroup,
 
     nsCOMPtr<nsILoadGroup>          mLoadGroup; // load groups can contain load groups
     nsCOMPtr<nsIInterfaceRequestor> mCallbacks;
+    nsCOMPtr<nsILoadGroupConnectionInfo> mConnectionInfo;
 
     nsCOMPtr<nsIRequest>            mDefaultLoadRequest;
     PLDHashTable                    mRequests;

netwerk/protocol/http/nsHttp.h

@@ -93,13 +93,19 @@ typedef uint8_t nsHttpVersion;
 // a transaction with this caps flag keeps timing information
 #define NS_HTTP_TIMING_ENABLED       (1<<5)
 
-// (1<<6) is unused
+// a transaction with this flag blocks the initiation of other transactons
+// in the same load group until it is complete
+#define NS_HTTP_LOAD_AS_BLOCKING     (1<<6)
 
 // Disallow the use of the SPDY protocol. This is meant for the contexts
 // such as HTTP upgrade which are nonsensical for SPDY, it is not the
 // SPDY configuration variable.
 #define NS_HTTP_DISALLOW_SPDY        (1<<7)
 
+// a transaction with this flag loads without respect to whether the load
+// group is currently blocking on some resources
+#define NS_HTTP_LOAD_UNBLOCKED       (1<<8)
+
 //-----------------------------------------------------------------------------
 // some default values
 //-----------------------------------------------------------------------------

netwerk/protocol/http/nsHttpChannel.cpp

@@ -681,6 +681,31 @@ nsHttpChannel::ContinueHandleAsyncFallback(nsresult rv)
     return rv;
 }
 
+void
+nsHttpChannel::SetupTransactionLoadGroupInfo()
+{
+    // Find the loadgroup at the end of the chain in order
+    // to make sure all channels derived from the load group
+    // use the same connection scope.
+    nsCOMPtr<nsILoadGroup> rootLoadGroup = mLoadGroup;
+    while (rootLoadGroup) {
+        nsCOMPtr<nsILoadGroup> tmp;
+        rootLoadGroup->GetLoadGroup(getter_AddRefs(tmp));
+        if (tmp)
+            rootLoadGroup.swap(tmp);
+        else
+            break;
+    }
+
+    // Set the load group connection scope on the transaction
+    if (rootLoadGroup) {
+        nsCOMPtr<nsILoadGroupConnectionInfo> ci;
+        rootLoadGroup->GetConnectionInfo(getter_AddRefs(ci));
+        if (ci)
+            mTransaction->SetLoadGroupConnectionInfo(ci);
+    }
+}
+
 nsresult
 nsHttpChannel::SetupTransaction()
 {
@@ -854,6 +879,8 @@ nsHttpChannel::SetupTransaction()
         return rv;
     }
 
+    SetupTransactionLoadGroupInfo();
+
     rv = nsInputStreamPump::Create(getter_AddRefs(mTransactionPump),
                                    responseStream);
     return rv;
@@ -4418,6 +4445,11 @@ nsHttpChannel::BeginConnect()
         (BYPASS_LOCAL_CACHE(mLoadFlags)))
         mCaps |= NS_HTTP_REFRESH_DNS;
 
+    if (mLoadAsBlocking)
+        mCaps |= NS_HTTP_LOAD_AS_BLOCKING;
+    if (mLoadUnblocked)
+        mCaps |= NS_HTTP_LOAD_UNBLOCKED;
+
     // Force-Reload should reset the persistent connection pool for this host
     if (mLoadFlags & LOAD_FRESH_CONNECTION) {
         // just the initial document resets the whole pool

netwerk/protocol/http/nsHttpChannel.h

@@ -160,6 +160,7 @@ class nsHttpChannel : public HttpBaseChannel
     nsresult ContinueConnect();
     void     SpeculativeConnect();
     nsresult SetupTransaction();
+    void     SetupTransactionLoadGroupInfo();
     nsresult CallOnStartRequest();
     nsresult ProcessResponse();
     nsresult ContinueProcessResponse(nsresult);