SERVER-13798 add dependency on connection to cursor object tracker in JavaScript scripting engine

3 files changed, 45 insertions, 27 deletions

diff --git a/src/mongo/scripting/engine_v8.h b/src/mongo/scripting/engine_v8.h
index f711911454c..a4262450c97 100644
--- a/src/mongo/scripting/engine_v8.h
+++ b/src/mongo/scripting/engine_v8.h
@@ -17,6 +17,7 @@
 
 #pragma once
 
+#include <boost/shared_ptr.hpp>
 #include <v8.h>
 #include <vector>
 
@@ -60,13 +61,16 @@ namespace mongo {
     class ObjTracker {
     public:
         /** Track an object to be freed when it is no longer referenced in JavaScript.
+         * Return handle to object instance shared pointer.
          * @param  instanceHandle  persistent handle to the weakly referenced object
          * @param  rawData         pointer to the object instance
          */
-        void track(v8::Persistent<v8::Value> instanceHandle, _ObjType* instance) {
+        v8::Local<v8::External> track(v8::Persistent<v8::Value> instanceHandle,
+                                      _ObjType* instance) {
             TrackedPtr* collectionHandle = new TrackedPtr(instance, this);
             _container.insert(collectionHandle);
             instanceHandle.MakeWeak(collectionHandle, deleteOnCollect);
+            return v8::External::New(&(collectionHandle->_objPtr));
         }
         /**
          * Free any remaining objects and their TrackedPtrs.  Invoked when the
@@ -94,7 +98,7 @@ namespace mongo {
             TrackedPtr(_ObjType* instance, ObjTracker<_ObjType>* tracker) :
                 _objPtr(instance),
                 _tracker(tracker) { }
-            scoped_ptr<_ObjType> _objPtr;
+            boost::shared_ptr<_ObjType> _objPtr;
             ObjTracker<_ObjType>* _tracker;
         };
 
@@ -294,9 +298,17 @@ namespace mongo {
         v8::Persistent<v8::Object> getGlobal() { return _global; }
 
         ObjTracker<BSONHolder> bsonHolderTracker;
-        ObjTracker<DBClientWithCommands> dbClientWithCommandsTracker;
         ObjTracker<DBClientBase> dbClientBaseTracker;
-        ObjTracker<DBClientCursor> dbClientCursorTracker;
+        // Track both cursor and connection.
+        // This ensures the connection outlives the cursor.
+        struct DBConnectionAndCursor {
+            boost::shared_ptr<DBClientBase> conn;
+            boost::shared_ptr<DBClientCursor> cursor;
+            DBConnectionAndCursor(boost::shared_ptr<DBClientBase> conn,
+                                  boost::shared_ptr<DBClientCursor> cursor)
+                : conn(conn), cursor(cursor) { }
+        };
+        ObjTracker<DBConnectionAndCursor> dbConnectionAndCursor;
 
         // These are all named after the JS constructor name + FT
         v8::Handle<v8::FunctionTemplate> ObjectIdFT()       const { return _ObjectIdFT; }
diff --git a/src/mongo/scripting/v8_db.cpp b/src/mongo/scripting/v8_db.cpp
index 3f085115322..2bc86b5e32b 100644
--- a/src/mongo/scripting/v8_db.cpp
+++ b/src/mongo/scripting/v8_db.cpp
@@ -143,18 +143,18 @@ namespace mongo {
             return v8AssertionException(errmsg);
         }
 
-        DBClientWithCommands* conn;
+        DBClientBase* conn;
         conn = cs.connect(errmsg);
         if (!conn) {
             return v8AssertionException(errmsg);
         }
 
         v8::Persistent<v8::Object> self = v8::Persistent<v8::Object>::New(args.This());
-        scope->dbClientWithCommandsTracker.track(self, conn);
+        v8::Local<v8::External> connHandle = scope->dbClientBaseTracker.track(self, conn);
 
         ScriptEngine::runConnectCallback(*conn);
 
-        args.This()->SetInternalField(0, v8::External::New(conn));
+        args.This()->SetInternalField(0, connHandle);
         args.This()->ForceSet(scope->v8StringData("slaveOk"), v8::Boolean::New(false));
         args.This()->ForceSet(scope->v8StringData("host"), scope->v8StringData(host));
 
@@ -171,22 +171,23 @@ namespace mongo {
 
         DBClientBase* conn = createDirectClient();
         v8::Persistent<v8::Object> self = v8::Persistent<v8::Object>::New(args.This());
-        scope->dbClientBaseTracker.track(self, conn);
+        v8::Local<v8::External> connHandle = scope->dbClientBaseTracker.track(self, conn);
 
-        args.This()->SetInternalField(0, v8::External::New(conn));
+        args.This()->SetInternalField(0, connHandle);
         args.This()->ForceSet(scope->v8StringData("slaveOk"), v8::Boolean::New(false));
         args.This()->ForceSet(scope->v8StringData("host"), scope->v8StringData("EMBEDDED"));
 
         return v8::Undefined();
     }
 
-    DBClientBase* getConnection(V8Scope* scope, const v8::Arguments& args) {
+    boost::shared_ptr<DBClientBase> getConnection(V8Scope* scope, const v8::Arguments& args) {
         verify(scope->MongoFT()->HasInstance(args.This()));
         verify(args.This()->InternalFieldCount() == 1);
         v8::Local<v8::External> c = v8::External::Cast(*(args.This()->GetInternalField(0)));
-        DBClientBase* conn = (DBClientBase*)(c->Value());
-        massert(16667, "Unable to get db client connection", conn);
-        return conn;
+        boost::shared_ptr<DBClientBase>* conn =
+            static_cast<boost::shared_ptr<DBClientBase>*>(c->Value());
+        massert(16667, "Unable to get db client connection", conn && conn->get());
+        return *conn;
     }
 
     /**
@@ -195,7 +196,7 @@ namespace mongo {
     v8::Handle<v8::Value> mongoFind(V8Scope* scope, const v8::Arguments& args) {
         argumentCheck(args.Length() == 7, "find needs 7 args")
         argumentCheck(args[1]->IsObject(), "needs to be an object")
-        DBClientBase * conn = getConnection(scope, args);
+        boost::shared_ptr<DBClientBase> conn = getConnection(scope, args);
         const string ns = toSTLString(args[0]);
         BSONObj fields;
         BSONObj q = scope->v8ToMongo(args[1]->ToObject());
@@ -204,7 +205,7 @@ namespace mongo {
         if (haveFields)
             fields = scope->v8ToMongo(args[2]->ToObject());
 
-        auto_ptr<mongo::DBClientCursor> cursor;
+        boost::shared_ptr<mongo::DBClientCursor> cursor;
         int nToReturn = args[3]->Int32Value();
         int nToSkip = args[4]->Int32Value();
         int batchSize = args[5]->Int32Value();
@@ -216,9 +217,11 @@ namespace mongo {
         }
 
         v8::Handle<v8::Function> cons = scope->InternalCursorFT()->GetFunction();
-        v8::Persistent<v8::Object> c = v8::Persistent<v8::Object>::New(cons->NewInstance());
+        v8::Handle<v8::Object> c = cons->NewInstance();
         c->SetInternalField(0, v8::External::New(cursor.get()));
-        scope->dbClientCursorTracker.track(c, cursor.release());
+        scope->dbConnectionAndCursor.track(
+            v8::Persistent<v8::Value>::New(c),
+            new V8Scope::DBConnectionAndCursor(conn, cursor));
         return c;
     }
 
@@ -227,19 +230,22 @@ namespace mongo {
         argumentCheck(scope->NumberLongFT()->HasInstance(args[1]), "2nd arg must be a NumberLong")
         argumentCheck(args[2]->IsUndefined() || args[2]->IsNumber(), "3rd arg must be a js Number")
 
-        DBClientBase* conn = getConnection(scope, args);
+        boost::shared_ptr<DBClientBase> conn = getConnection(scope, args);
         const string ns = toSTLString(args[0]);
         long long cursorId = numberLongVal(scope, args[1]->ToObject());
 
-        auto_ptr<mongo::DBClientCursor> cursor(new DBClientCursor(conn, ns, cursorId, 0, 0));
+        boost::shared_ptr<mongo::DBClientCursor> cursor(
+            new DBClientCursor(conn.get(), ns, cursorId, 0, 0));
 
         if (!args[2]->IsUndefined())
             cursor->setBatchSize(args[2]->Int32Value());
 
         v8::Handle<v8::Function> cons = scope->InternalCursorFT()->GetFunction();
-        v8::Persistent<v8::Object> c = v8::Persistent<v8::Object>::New(cons->NewInstance());
+        v8::Handle<v8::Object> c = cons->NewInstance();
         c->SetInternalField(0, v8::External::New(cursor.get()));
-        scope->dbClientCursorTracker.track(c, cursor.release());
+        scope->dbConnectionAndCursor.track(
+            v8::Persistent<v8::Value>::New(c),
+            new V8Scope::DBConnectionAndCursor(conn, cursor));
         return c;
     }
 
@@ -253,7 +259,7 @@ namespace mongo {
             return v8AssertionException("js db in read only mode");
         }
 
-        DBClientBase * conn = getConnection(scope, args);
+        boost::shared_ptr<DBClientBase> conn = getConnection(scope, args);
         const string ns = toSTLString(args[0]);
 
         v8::Handle<v8::Integer> flags = args[2]->ToInteger();
@@ -301,7 +307,7 @@ namespace mongo {
             return v8AssertionException("js db in read only mode");
         }
 
-        DBClientBase * conn = getConnection(scope, args);
+        boost::shared_ptr<DBClientBase> conn = getConnection(scope, args);
         const string ns = toSTLString(args[0]);
 
         v8::Handle<v8::Object> in = args[1]->ToObject();
@@ -327,7 +333,7 @@ namespace mongo {
             return v8AssertionException("js db in read only mode");
         }
 
-        DBClientBase * conn = getConnection(scope, args);
+        boost::shared_ptr<DBClientBase> conn = getConnection(scope, args);
         const string ns = toSTLString(args[0]);
 
         v8::Handle<v8::Object> q = args[1]->ToObject();
@@ -343,7 +349,7 @@ namespace mongo {
     }
 
     v8::Handle<v8::Value> mongoAuth(V8Scope* scope, const v8::Arguments& args) {
-        DBClientWithCommands* conn = getConnection(scope, args);
+        boost::shared_ptr<DBClientBase> conn = getConnection(scope, args);
         if (NULL == conn)
             return v8AssertionException("no connection");
 
@@ -372,7 +378,7 @@ namespace mongo {
 
     v8::Handle<v8::Value> mongoLogout(V8Scope* scope, const v8::Arguments& args) {
         argumentCheck(args.Length() == 1, "logout needs 1 arg")
-        DBClientBase* conn = getConnection(scope, args);
+        boost::shared_ptr<DBClientBase> conn = getConnection(scope, args);
         const string db = toSTLString(args[0]);
         BSONObj ret;
         conn->logout(db, ret);
diff --git a/src/mongo/scripting/v8_db.h b/src/mongo/scripting/v8_db.h
index 9de634b9471..c00cf703df9 100644
--- a/src/mongo/scripting/v8_db.h
+++ b/src/mongo/scripting/v8_db.h
@@ -29,7 +29,7 @@ namespace mongo {
     /**
      * get the DBClientBase connection from JS args
      */
-    mongo::DBClientBase* getConnection(V8Scope* scope, const v8::Arguments& args);
+    boost::shared_ptr<mongo::DBClientBase> getConnection(V8Scope* scope, const v8::Arguments& args);
 
     // Internal Cursor
     v8::Handle<v8::FunctionTemplate> getInternalCursorFunctionTemplate(V8Scope* scope);