1 files changed, 30 insertions, 32 deletions

diff --git a/src/mongo/db/repl/bgsync.h b/src/mongo/db/repl/bgsync.h
index eb88040f64c..45f87731200 100644
--- a/src/mongo/db/repl/bgsync.h
+++ b/src/mongo/db/repl/bgsync.h
@@ -39,7 +39,6 @@ namespace repl {
 
     class Member;
     class ReplicationCoordinator;
-    class ReplicationCoordinatorImpl;
 
     // This interface exists to facilitate easier testing;
     // the test infrastructure implements these functions with stubs.
@@ -56,12 +55,6 @@ namespace repl {
         // called by sync thread after it has applied an op
         virtual void consume() = 0;
 
-        // Returns the member we're currently syncing from (or NULL)
-        virtual const Member* getSyncTarget() = 0;
-
-        // Sets the member we're currently syncing from to be NULL
-        virtual void clearSyncTarget() = 0;
-
         // wait up to 1 second for more ops to appear
         virtual void waitForMore() = 0;
     };
@@ -79,21 +72,26 @@ namespace repl {
         // protects creation of s_instance
         static boost::mutex s_mutex;
 
-        // _mutex protects all of the class variables
-        boost::mutex _mutex;
-
         // Production thread
         BlockingQueue<BSONObj> _buffer;
+        OplogReader _syncSourceReader;
+
+        // _mutex protects all of the class variables except _syncSourceReader and _buffer
+        mutable boost::mutex _mutex;
 
         OpTime _lastOpTimeFetched;
-        long long _lastH;
+
+        // hash we use to make sure we are reading the right flow of ops and aren't on
+        // an out-of-date "fork"
+        long long _lastHash;
+
         // if produce thread should be running
         bool _pause;
         bool _appliedBuffer;
         bool _assumingPrimary;
         boost::condition _condvar;
 
-        const Member* _currentSyncTarget;
+        HostAndPort _syncSourceHost;
 
         BackgroundSync();
         BackgroundSync(const BackgroundSync& s);
@@ -107,23 +105,28 @@ namespace repl {
         bool _rollbackIfNeeded(OperationContext* txn, OplogReader& r);
 
         // Evaluate if the current sync target is still good
-        bool shouldChangeSyncTarget();
+        bool shouldChangeSyncSource();
         // check lastOpTimeWritten against the remote's earliest op, filling in remoteOldestOp.
-        bool isStale(OplogReader& r, BSONObj& remoteOldestOp);
-        // stop syncing when this becomes a primary
-        void stop();
+        bool isStale(OpTime lastOpTimeFetched, OplogReader& r, BSONObj& remoteOldestOp);
         // restart syncing
-        void start();
+        void start(OperationContext* txn);
 
         // A pointer to the replication coordinator running the show.
         ReplicationCoordinator* _replCoord;
 
+        // bool for indicating resync need on this node and the mutex that protects it
+        // The resync command sets this flag; the Applier thread observes and clears it.
+        bool _initialSyncRequestedFlag;
+        boost::mutex _initialSyncMutex;
+
     public:
+        // stop syncing (when this node becomes a primary, e.g.)
+        void stop();
         bool isAssumingPrimary();
 
         static BackgroundSync* get();
-        static void shutdown();
-        static void notify();
+        void shutdown();
+        void notify();
 
         virtual ~BackgroundSync() {}
 
@@ -132,11 +135,12 @@ namespace repl {
         // starts the sync target notifying thread
         void notifierThread();
 
+        HostAndPort getSyncTarget();
+
         // Interface implementation
 
         virtual bool peek(BSONObj* op);
         virtual void consume();
-        virtual const Member* getSyncTarget();
         virtual void clearSyncTarget();
         virtual void waitForMore();
 
@@ -147,18 +151,12 @@ namespace repl {
         // primary.
         void stopReplicationAndFlushBuffer();
 
-        /**
-         * Connects an oplog reader to a viable sync source.  Legacy uses getOplogReaderLegacy(),
-         * which sets _currentSyncTarget as a side effect.
-         * connectOplogReader() is used in new replication.
-         * Both functions can affect the TopoCoord's blacklist of sync sources, and may set
-         * our minValid value, durably, if we detect we haven fallen off the back of all sync
-         * sources' oplogs.
-         **/
-        void getOplogReaderLegacy(OperationContext* txn, OplogReader* reader);
-        void connectOplogReader(OperationContext* txn, 
-                                ReplicationCoordinatorImpl* replCoordImpl, 
-                                OplogReader* reader);
+        long long getLastHash() const;
+        void setLastHash(long long oldH);
+        void loadLastHash(OperationContext* txn);
+
+        bool getInitialSyncRequestedFlag();
+        void setInitialSyncRequestedFlag(bool value);
     };