SERVER-13498 Get rid of LockStatus

This change removes all usages of LockStatus and pushes the lock
acquisitions to be inside the respective commands. This is a
refactoring on the way to per-document locking.

src/mongo/SConscript

@@ -419,7 +419,6 @@ env.Library("coredb", [
         "db/commands/mr_common.cpp",
         "db/commands/rename_collection_common.cpp",
         "db/commands/server_status.cpp",
-        "db/commands/shutdown.cpp",
         "db/commands/parameters.cpp",
         "db/commands/user_management_commands.cpp",
         "db/commands/write_commands/write_commands_common.cpp",

src/mongo/db/client.cpp

@@ -448,7 +448,7 @@ namespace mongo {
     public:
         void help(stringstream& h) const { h << "internal"; }
         HandshakeCmd() : Command( "handshake" ) {}
-        virtual LockType locktype() const { return NONE; }
+        virtual bool isWriteCommandForConfigServer() const { return false; }
         virtual bool slaveOk() const { return true; }
         virtual bool adminOnly() const { return false; }
         virtual void addRequiredPrivileges(const std::string& dbname,

src/mongo/db/clientcursor.cpp

@@ -336,7 +336,7 @@ namespace mongo {
         virtual void help( stringstream& help ) const {
             help << " example: { cursorInfo : 1 }, deprecated";
         }
-        virtual LockType locktype() const { return NONE; }
+        virtual bool isWriteCommandForConfigServer() const { return false; }
         virtual void addRequiredPrivileges(const std::string& dbname,
                                            const BSONObj& cmdObj,
                                            std::vector<Privilege>* out) {

src/mongo/db/cloner.cpp

@@ -539,7 +539,7 @@ namespace mongo {
         virtual bool slaveOk() const {
             return false;
         }
-        virtual LockType locktype() const { return WRITE; }
+        virtual bool isWriteCommandForConfigServer() const { return true; }
         virtual void help( stringstream &help ) const {
             help << "clone this database from an instance of the db on another host\n";
             help << "{ clone : \"host13\" }";
@@ -579,6 +579,8 @@ namespace mongo {
             }
 
             set<string> clonedColls;
+
+            Lock::DBWrite dbXLock(dbname);
             Client::Context context( dbname );
 
             Cloner cloner;
@@ -599,7 +601,7 @@ namespace mongo {
         virtual bool slaveOk() const {
             return false;
         }
-        virtual LockType locktype() const { return NONE; }
+        virtual bool isWriteCommandForConfigServer() const { return false; }
         CmdCloneCollection() : Command("cloneCollection") { }
 
         virtual std::string parseNs(const std::string& dbname, const BSONObj& cmdObj) const {
@@ -685,7 +687,7 @@ namespace mongo {
         virtual bool slaveOk() const {
             return false;
         }
-        virtual LockType locktype() const { return NONE; }
+        virtual bool isWriteCommandForConfigServer() const { return false; }
         virtual void addRequiredPrivileges(const std::string& dbname,
                                            const BSONObj& cmdObj,
                                            std::vector<Privilege>* out) {} // No auth required
@@ -766,7 +768,7 @@ namespace mongo {
         virtual bool slaveOk() const {
             return false;
         }
-        virtual LockType locktype() const { return NONE; }
+        virtual bool isWriteCommandForConfigServer() const { return false; }
         virtual Status checkAuthForCommand(ClientBasic* client,
                                            const std::string& dbname,
                                            const BSONObj& cmdObj) {

src/mongo/db/commands.cpp

@@ -105,16 +105,16 @@ namespace mongo {
         if( web ) ss << "</a>";
         ss << "</td>\n";
         ss << "<td>";
-        int l = locktype();
-        //if( l == NONE ) ss << "N ";
-        if( l == READ ) ss << "R ";
-        else if( l == WRITE ) ss << "W ";
+        if (isWriteCommandForConfigServer()) { 
+            ss << "W "; 
+        }
+        else { 
+            ss << "R "; 
+        }
         if( slaveOk() )
             ss << "S ";
         if( adminOnly() )
             ss << "A";
-        if( lockGlobally() ) 
-            ss << " lockGlobally ";
         ss << "</td>";
         ss << "<td>";
         if( helpStr != "no help defined" ) {
@@ -197,13 +197,6 @@ namespace mongo {
         return i->second;
     }
 
-    Command::LockType Command::locktype( const string& name ) {
-        Command * c = findCommand( name );
-        if ( ! c )
-            return WRITE;
-        return c->locktype();
-    }
-
     bool Command::appendCommandStatus(BSONObjBuilder& result, const Status& status) {
         appendCommandStatus(result, status.isOK(), status.reason());
         BSONObj tmp = result.asTempObj();
@@ -335,7 +328,7 @@ namespace mongo {
     public:
         PoolFlushCmd() : Command( "connPoolSync" , false , "connpoolsync" ) {}
         virtual void help( stringstream &help ) const { help<<"internal"; }
-        virtual LockType locktype() const { return NONE; }
+        virtual bool isWriteCommandForConfigServer() const { return false; }
         virtual void addRequiredPrivileges(const std::string& dbname,
                                            const BSONObj& cmdObj,
                                            std::vector<Privilege>* out) {
@@ -359,7 +352,7 @@ namespace mongo {
     public:
         PoolStats() : Command( "connPoolStats" ) {}
         virtual void help( stringstream &help ) const { help<<"stats about connection pool"; }
-        virtual LockType locktype() const { return NONE; }
+        virtual bool isWriteCommandForConfigServer() const { return false; }
         virtual void addRequiredPrivileges(const std::string& dbname,
                                            const BSONObj& cmdObj,
                                            std::vector<Privilege>* out) {

src/mongo/db/commands.h

@@ -61,10 +61,6 @@ namespace mutablebson {
         ResourcePattern parseResourcePattern(const std::string& dbname,
                                              const BSONObj& cmdObj) const;
 
-        // warning: isAuthorized uses the lockType() return values, and values are being passed 
-        // around as ints so be careful as it isn't really typesafe and will need cleanup later
-        enum LockType { READ = -1 , NONE = 0 , WRITE = 1 };
-
         const string name;
 
         /* run the given command
@@ -77,17 +73,15 @@ namespace mutablebson {
         */
         virtual bool run(const string& db, BSONObj& cmdObj, int options, string& errmsg, BSONObjBuilder& result, bool fromRepl = false ) = 0;
 
-        /*
-           note: logTheOp() MUST be false if READ
-           if NONE, can't use Client::Context setup
-                    use with caution
+        /**
+         * This designation for the command is only used by the 'help' call and has nothing to do 
+         * with lock acquisition. The reason we need to have it there is because 
+         * SyncClusterConnection uses this to determine whether the command is update and needs to
+         * be sent to all three servers or just one.
+         *
+         * Eventually when SyncClusterConnection is refactored out, we can get rid of it.
          */
-        virtual LockType locktype() const = 0;
-
-        /** if true, lock globally instead of just the one database. by default only the one 
-            database will be locked. 
-        */
-        virtual bool lockGlobally() const { return false; }
+        virtual bool isWriteCommandForConfigServer() const = 0;
 
         /* Return true if only the admin ns has privileges to run this command. */
         virtual bool adminOnly() const {
@@ -203,7 +197,6 @@ namespace mutablebson {
                                          BSONObj& jsobj,
                                          BSONObjBuilder& anObjBuilder,
                                          int queryOptions = 0);
-        static LockType locktype( const string& name );
         static Command * findCommand( const string& name );
         // For mongod and webserver.
         static void execCommand(Command* c,

src/mongo/db/commands/apply_ops.cpp

@@ -46,8 +46,8 @@ namespace mongo {
     class ApplyOpsCmd : public Command {
     public:
         virtual bool slaveOk() const { return false; }
-        virtual LockType locktype() const { return WRITE; }
-        virtual bool lockGlobally() const { return true; } // SERVER-4328 todo : is global ok or does this take a long time? i believe multiple ns used so locking individually requires more analysis
+        virtual bool isWriteCommandForConfigServer() const { return true; }
+
         ApplyOpsCmd() : Command( "applyOps" ) {}
         virtual void help( stringstream &help ) const {
             help << "internal (sharding)\n{ applyOps : [ ] , preCondition : [ { ns : ... , q : ... , res : ... } ] }";
@@ -105,6 +105,9 @@ namespace mongo {
             BSONArrayBuilder ab;
             const bool alwaysUpsert = cmdObj.hasField("alwaysUpsert") ?
                     cmdObj["alwaysUpsert"].trueValue() : true;
+
+            // SERVER-4328 todo : is global ok or does this take a long time? i believe multiple ns used so locking individually requires more analysis
+            Lock::GlobalWrite globalWriteLock;
 
             while ( i.more() ) {
                 BSONElement e = i.next();

src/mongo/db/commands/authentication_commands.cpp

@@ -96,7 +96,7 @@ namespace mongo {
             return true;
         }
         void help(stringstream& h) const { h << "internal"; }
-        virtual LockType locktype() const { return NONE; }
+        virtual bool isWriteCommandForConfigServer() const { return false; }
         virtual void addRequiredPrivileges(const std::string& dbname,
                                            const BSONObj& cmdObj,
                                            std::vector<Privilege>* out) {} // No auth required
@@ -349,7 +349,7 @@ namespace mongo {
                                            const BSONObj& cmdObj,
                                            std::vector<Privilege>* out) {} // No auth required
         void help(stringstream& h) const { h << "de-authenticate"; }
-        virtual LockType locktype() const { return NONE; }
+        virtual bool isWriteCommandForConfigServer() const { return false; }
         CmdLogout() : Command("logout") {}
         bool run(const string& dbname,
                  BSONObj& cmdObj,

src/mongo/db/commands/authentication_commands.h

@@ -46,7 +46,7 @@ namespace mongo {
         virtual bool slaveOk() const {
             return true;
         }
-        virtual LockType locktype() const { return NONE; }
+        virtual bool isWriteCommandForConfigServer() const { return false; }
         virtual void help(stringstream& ss) const { ss << "internal"; }
         virtual void addRequiredPrivileges(const std::string& dbname,
                                            const BSONObj& cmdObj,

src/mongo/db/commands/cleanup_orphaned_cmd.cpp

@@ -167,7 +167,7 @@ namespace mongo {
             return Status::OK();
         }
 
-        virtual LockType locktype() const { return NONE; }
+        virtual bool isWriteCommandForConfigServer() const { return false; }
 
         // Input
         static BSONField<string> nsField;

src/mongo/db/commands/collection_to_capped.cpp

@@ -117,7 +117,7 @@ namespace mongo {
     public:
         CmdCloneCollectionAsCapped() : Command( "cloneCollectionAsCapped" ) {}
         virtual bool slaveOk() const { return false; }
-        virtual LockType locktype() const { return WRITE; }
+        virtual bool isWriteCommandForConfigServer() const { return true; }
         virtual void help( stringstream &help ) const {
             help << "{ cloneCollectionAsCapped:<fromName>, toCollection:<toName>, size:<sizeInBytes> }";
         }
@@ -150,6 +150,9 @@ namespace mongo {
                 return false;
             }
 
+            Lock::DBWrite dbXLock(dbname);
+            Client::Context ctx(dbname);
+
             Status status = cloneCollectionAsCapped( cc().database(), from, to, size, temp, true );
             return appendCommandStatus( result, status );
         }
@@ -164,9 +167,7 @@ namespace mongo {
     public:
         CmdConvertToCapped() : Command( "convertToCapped" ) {}
         virtual bool slaveOk() const { return false; }
-        virtual LockType locktype() const { return WRITE; }
-        // calls renamecollection which does a global lock, so we must too:
-        virtual bool lockGlobally() const { return true; }
+        virtual bool isWriteCommandForConfigServer() const { return true; }
         virtual bool logTheOp() {
             // see CmdRenameCollection::logTheOp as to why this is best
             return true;
@@ -193,6 +194,11 @@ namespace mongo {
         }
 
         bool run(const string& dbname, BSONObj& jsobj, int, string& errmsg, BSONObjBuilder& result, bool fromRepl ) {
+            // calls renamecollection which does a global lock, so we must too:
+            //
+            Lock::GlobalWrite globalWriteLock;
+            Client::Context ctx(dbname);
+
             Database* db = cc().database();
 
             stopIndexBuilds(db, jsobj);

src/mongo/db/commands/compact.cpp

@@ -51,7 +51,7 @@ namespace mongo {
 
     class CompactCmd : public Command {
     public:
-        virtual LockType locktype() const { return NONE; }
+        virtual bool isWriteCommandForConfigServer() const { return false; }
         virtual bool adminOnly() const { return false; }
         virtual bool slaveOk() const { return true; }
         virtual bool maintenanceMode() const { return true; }

src/mongo/db/commands/connection_status.cpp

@@ -38,7 +38,7 @@ namespace mongo {
         CmdConnectionStatus() : Command("connectionStatus") {}
         virtual bool logTheOp() { return false; }
         virtual bool slaveOk() const { return true; }
-        virtual LockType locktype() const { return NONE; }
+        virtual bool isWriteCommandForConfigServer() const { return false; }
         virtual void addRequiredPrivileges(const std::string& dbname,
                                            const BSONObj& cmdObj,
                                            std::vector<Privilege>* out) {} // No auth required

src/mongo/db/commands/cpuprofile.cpp

@@ -58,6 +58,7 @@
 #include "mongo/db/auth/action_type.h"
 #include "mongo/db/auth/authorization_manager.h"
 #include "mongo/db/auth/privilege.h"
+#include "mongo/db/client.h"
 #include "mongo/db/commands.h"
 #include "mongo/db/jsobj.h"
 
@@ -85,7 +86,7 @@ namespace mongo {
             // This is an abuse of the global dbmutex.  We only really need to
             // ensure that only one cpuprofiler command runs at once; it would
             // be fine for it to run concurrently with other operations.
-            virtual LockType locktype() const { return WRITE; }
+            virtual bool isWriteCommandForConfigServer() const { return true; }
         };
 
         /**
@@ -131,6 +132,8 @@ namespace mongo {
                                            string &errmsg,
                                            BSONObjBuilder &result,
                                            bool fromRepl ) {
+            Lock::DBWrite dbXLock(db);
+            Client::Context ctx(db);
 
             std::string profileFilename = cmdObj[commandName]["profileFilename"].String();
             if ( ! ::ProfilerStart( profileFilename.c_str() ) ) {
@@ -146,6 +149,9 @@ namespace mongo {
                                           string &errmsg,
                                           BSONObjBuilder &result,
                                           bool fromRepl ) {
+            Lock::DBWrite dbXLock(db);
+            Client::Context ctx(db);
+
             ::ProfilerStop();
             return true;
         }

src/mongo/db/commands/create_indexes.cpp

@@ -47,7 +47,7 @@ namespace mongo {
     public:
         CmdCreateIndex() : Command( "createIndexes" ){}
 
-        virtual LockType locktype() const { return NONE; }
+        virtual bool isWriteCommandForConfigServer() const { return false; }
         virtual bool logTheOp() { return false; }
         virtual bool slaveOk() const { return false; } // TODO: this could be made true...
 

src/mongo/db/commands/dbhash.cpp

@@ -146,6 +146,9 @@ namespace mongo {
             }
         }
 
+        const string ns = parseNs(dbname, cmdObj);
+        Client::ReadContext ctx(ns);
+
         list<string> colls;
         Database* db = cc().database();
         if ( db )

src/mongo/db/commands/dbhash.h

@@ -46,7 +46,7 @@ namespace mongo {
         DBHashCmd();
 
         virtual bool slaveOk() const { return true; }
-        virtual LockType locktype() const { return READ; }
+        virtual bool isWriteCommandForConfigServer() const { return false; }
         virtual void addRequiredPrivileges(const std::string& dbname,
                                            const BSONObj& cmdObj,
                                            std::vector<Privilege>* out);

src/mongo/db/commands/distinct.cpp

@@ -54,7 +54,7 @@ namespace mongo {
 
         virtual bool slaveOk() const { return false; }
         virtual bool slaveOverrideOk() const { return true; }
-        virtual LockType locktype() const { return READ; }
+        virtual bool isWriteCommandForConfigServer() const { return false; }
 
         virtual void addRequiredPrivileges(const std::string& dbname,
                                            const BSONObj& cmdObj,
@@ -90,6 +90,8 @@ namespace mongo {
             long long nscannedObjects = 0; // full objects looked at
             long long n = 0; // matches
 
+            Client::ReadContext ctx(ns);
+
             Collection* collection = cc().database()->getCollection( ns );
 
             if (!collection) {