SERVER-13961 Add capability to register and discover OperationContexts

This replaces the need to iterate through the list of registered Clients
for diagnostics/reporting purposes. Also moves some of the per-client
information to be under OperationContext.

This is in preparation for removing LockState from TLS.

42 files changed, 353 insertions, 232 deletions

diff --git a/src/mongo/client/clientAndShell.cpp b/src/mongo/client/clientAndShell.cpp
index 66092e70e2e..23ebd04ac63 100644
--- a/src/mongo/client/clientAndShell.cpp
+++ b/src/mongo/client/clientAndShell.cpp
@@ -85,8 +85,4 @@ namespace mongo {
     ClientBasic* ClientBasic::getCurrent() {
         return 0;
     }
-
-    bool ClientBasic::hasCurrent() {
-        return false;
-    }
 }
diff --git a/src/mongo/db/client.cpp b/src/mongo/db/client.cpp
index 2abfc67e358..f427b73052a 100644
--- a/src/mongo/db/client.cpp
+++ b/src/mongo/db/client.cpp
@@ -32,7 +32,7 @@
    to an open socket (or logical connection if pooling on sockets) from a client.
 */
 
-#include "mongo/pch.h"
+#include "mongo/platform/basic.h"
 
 #include "mongo/db/client.h"
 
@@ -67,6 +67,7 @@
 #include "mongo/util/mongoutils/checksum.h"
 #include "mongo/util/mongoutils/str.h"
 
+
 namespace mongo {
 
     mongo::mutex& Client::clientsMutex = *(new mutex("clientsMutex"));
@@ -293,20 +294,6 @@ namespace mongo {
         return "";
     }
 
-    string Client::toString() const {
-        stringstream ss;
-        if ( _curOp )
-            ss << _curOp->info().jsonString();
-        return ss.str();
-    }
-
-    string sayClientState() {
-        Client* c = currentClient.get();
-        if ( !c )
-            return "no client";
-        return c->toString();
-    }
-
     bool Client::gotHandshake( const BSONObj& o ) {
         BSONObjIterator i(o);
 
@@ -332,10 +319,6 @@ namespace mongo {
         return repl::theReplSet->registerSlave(_remoteId, o["member"].Int());
     }
 
-    bool ClientBasic::hasCurrent() {
-        return currentClient.get();
-    }
-
     ClientBasic* ClientBasic::getCurrent() {
         return currentClient.get();
     }
@@ -362,57 +345,7 @@ namespace mongo {
 
     } handshakeCmd;
 
-    int Client::recommendedYieldMicros( int * writers , int * readers, bool needExact ) {
-        int num = 0;
-        int w = 0;
-        int r = 0;
-        {
-            scoped_lock bl(clientsMutex);
-            for ( set<Client*>::iterator i=clients.begin(); i!=clients.end(); ++i ) {
-                Client* c = *i;
-                if ( c->lockState().hasLockPending() ) {
-                    num++;
-                    if ( c->lockState().isWriteLocked() )
-                        w++;
-                    else
-                        r++;
-                }
-                if (num > 100 && !needExact)
-                    break;
-            }
-        }
-
-        if ( writers )
-            *writers = w;
-        if ( readers )
-            *readers = r;
-
-        int time = r * 10; // we have to be nice to readers since they don't have priority
-        time += w; // writers are greedy, so we can be mean tot hem
-
-        time = min( time , 1000000 );
-
-        return time;
-    }
 
-    int Client::getActiveClientCount( int& writers, int& readers ) {
-        writers = 0;
-        readers = 0;
-
-        scoped_lock bl(clientsMutex);
-        for ( set<Client*>::iterator i=clients.begin(); i!=clients.end(); ++i ) {
-            Client* c = *i;
-            if ( ! c->curop()->active() )
-                continue;
-
-            if ( c->lockState().isWriteLocked() )
-                writers++;
-            if ( c->lockState().hasAnyReadLock() )
-                readers++;
-        }
-
-        return writers + readers;
-    }
 
     void OpDebug::reset() {
         extra.reset();
diff --git a/src/mongo/db/client.h b/src/mongo/db/client.h
index 13dcaab77c9..48a8d74dd18 100644
--- a/src/mongo/db/client.h
+++ b/src/mongo/db/client.h
@@ -59,6 +59,7 @@ namespace mongo {
     class AbstractMessagingPort;
     class LockCollectionForReading;
 
+
     TSP_DECLARE(Client, currentClient)
 
     typedef long long ConnectionId;
@@ -69,11 +70,9 @@ namespace mongo {
         // always be in clientsMutex when manipulating this. killop stuff uses these.
         static std::set<Client*>& clients;
         static mongo::mutex& clientsMutex;
-        static int getActiveClientCount( int& writers , int& readers );
-        class Context;
+
         ~Client();
-        static int recommendedYieldMicros( int * writers = 0 , int * readers = 0,
-                                           bool needExact = false );
+
         /** each thread which does db operations has a Client object in TLS.
          *  call this when your thread starts.
         */
@@ -101,11 +100,11 @@ namespace mongo {
 
         bool isGod() const { return _god; } /* this is for map/reduce writes */
         bool setGod(bool newVal) { const bool prev = _god; _god = newVal; return prev; }
-        std::string toString() const;
         bool gotHandshake( const BSONObj& o );
         BSONObj getRemoteID() const { return _remoteId; }
         BSONObj getHandshake() const { return _handshake; }
         ConnectionId getConnectionId() const { return _connectionId; }
+        const std::string& getThreadId() const { return _threadId; }
 
         // XXX(hk): this is per-thread mmapv1 recovery unit stuff, move into that
         // impl of recovery unit
@@ -139,6 +138,8 @@ namespace mongo {
         
     public:
 
+        class Context;
+
         /** "read lock, and set my context, all in one operation" 
          *  This handles (if not recursively locked) opening an unopened database.
          */
diff --git a/src/mongo/db/client_basic.h b/src/mongo/db/client_basic.h
index 0a41400f3df..c8a5f611aac 100644
--- a/src/mongo/db/client_basic.h
+++ b/src/mongo/db/client_basic.h
@@ -72,7 +72,6 @@ namespace mongo {
         AbstractMessagingPort * port() const { return _messagingPort; }
 
         static ClientBasic* getCurrent();
-        static bool hasCurrent();
 
     protected:
         ClientBasic(AbstractMessagingPort* messagingPort);
diff --git a/src/mongo/db/clientlistplugin.cpp b/src/mongo/db/clientlistplugin.cpp
index 7cf07358056..37046a3c05a 100644
--- a/src/mongo/db/clientlistplugin.cpp
+++ b/src/mongo/db/clientlistplugin.cpp
@@ -30,10 +30,59 @@
 
 #include "mongo/db/client.h"
 #include "mongo/db/curop.h"
+#include "mongo/db/global_environment_experiment.h"
+#include "mongo/db/operation_context.h"
 #include "mongo/db/dbwebserver.h"
 #include "mongo/util/mongoutils/html.h"
 
+
 namespace mongo {
+
+    class OperationsDataBuilder : public GlobalEnvironmentExperiment::ProcessOperationContext {
+    public:
+        OperationsDataBuilder(std::stringstream& stringStream)
+            : _stringStream(stringStream) {
+
+        }
+
+        virtual void processOpContext(OperationContext* txn) {
+            using namespace mongoutils::html;
+
+            CurOp& co = *(txn->getCurOp());
+
+            _stringStream << "<tr><td>" << txn->getClient()->desc() << "</td>";
+
+            tablecell(_stringStream, co.opNum());
+            tablecell(_stringStream, co.active());
+            tablecell(_stringStream, txn->lockState()->reportState());
+            if (co.active()) {
+                tablecell(_stringStream, co.elapsedSeconds());
+            }
+            else {
+                tablecell(_stringStream, "");
+            }
+
+            tablecell(_stringStream, co.getOp());
+            tablecell(_stringStream, html::escape(co.getNS()));
+            if (co.haveQuery()) {
+                tablecell(_stringStream, html::escape(co.query().toString()));
+            }
+            else {
+                tablecell(_stringStream, "");
+            }
+
+            tablecell(_stringStream, co.getRemoteString());
+
+            tablecell(_stringStream, co.getMessage());
+            tablecell(_stringStream, co.getProgressMeter().toString());
+
+            _stringStream << "</tr>\n";
+        }
+
+    private:
+        std::stringstream& _stringStream;
+    };
+
 namespace {
     class ClientListPlugin : public WebStatusPlugin {
     public:
@@ -58,35 +107,10 @@ namespace {
                << "<th>progress</th>"
 
                << "</tr>\n";
-            {
-                scoped_lock bl(Client::clientsMutex);
-                for( set<Client*>::iterator i = Client::clients.begin(); i != Client::clients.end(); i++ ) {
-                    Client *c = *i;
-                    CurOp& co = *(c->curop());
-                    ss << "<tr><td>" << c->desc() << "</td>";
-
-                    tablecell( ss , co.opNum() );
-                    tablecell( ss , co.active() );
-                    tablecell( ss , c->lockState().reportState() );
-                    if ( co.active() )
-                        tablecell( ss , co.elapsedSeconds() );
-                    else
-                        tablecell( ss , "" );
-                    tablecell( ss , co.getOp() );
-                    tablecell( ss , html::escape( co.getNS() ) );
-                    if ( co.haveQuery() )
-                        tablecell( ss , html::escape( co.query().toString() ) );
-                    else
-                        tablecell( ss , "" );
-                    tablecell( ss , co.getRemoteString() );
-
-                    tablecell( ss , co.getMessage() );
-                    tablecell( ss , co.getProgressMeter().toString() );
-
-
-                    ss << "</tr>\n";
-                }
-            }
+            
+            OperationsDataBuilder opCtxDataBuilder(ss);
+            getGlobalEnvironment()->forEachOperationContext(&opCtxDataBuilder);
+            
             ss << "</table>\n";
 
         }
diff --git a/src/mongo/db/commands/apply_ops.cpp b/src/mongo/db/commands/apply_ops.cpp
index 733cdfd1dd6..88c8c66f484 100644
--- a/src/mongo/db/commands/apply_ops.cpp
+++ b/src/mongo/db/commands/apply_ops.cpp
@@ -85,6 +85,8 @@ namespace mongo {
             // ns used so locking individually requires more analysis
             Lock::GlobalWrite globalWriteLock(txn->lockState());
 
+            DBDirectClient db(txn);
+
             // Preconditions check reads the database state, so needs to be done locked
             if ( cmdObj["preCondition"].type() == Array ) {
                 BSONObjIterator i( cmdObj["preCondition"].Obj() );
@@ -172,7 +174,6 @@ namespace mongo {
 
             return errors == 0;
         }
-
     } applyOpsCmd;
 
 }
diff --git a/src/mongo/db/commands/drop_indexes.cpp b/src/mongo/db/commands/drop_indexes.cpp
index 9c11baab7f7..c659454d684 100644
--- a/src/mongo/db/commands/drop_indexes.cpp
+++ b/src/mongo/db/commands/drop_indexes.cpp
@@ -214,7 +214,7 @@ namespace mongo {
         }
 
         bool run(OperationContext* txn, const string& dbname , BSONObj& jsobj, int, string& errmsg, BSONObjBuilder& result, bool /*fromRepl*/) {
-            DBDirectClient db;
+            DBDirectClient db(txn);
 
             BSONElement e = jsobj.firstElement();
             string toDeleteNs = dbname + '.' + e.valuestr();
diff --git a/src/mongo/db/commands/mr.cpp b/src/mongo/db/commands/mr.cpp
index 3eca6ce9259..38dbceefe4d 100644
--- a/src/mongo/db/commands/mr.cpp
+++ b/src/mongo/db/commands/mr.cpp
@@ -665,6 +665,7 @@ namespace mongo {
 
         State::State(OperationContext* txn, const Config& c) :
                 _config(c),
+                _db(txn),
                 _useIncremental(true),
                 _txn(txn),
                 _size(0),
diff --git a/src/mongo/db/curop.cpp b/src/mongo/db/curop.cpp
index b5b535b3ba9..178166402d3 100644
--- a/src/mongo/db/curop.cpp
+++ b/src/mongo/db/curop.cpp
@@ -166,67 +166,55 @@ namespace mongo {
         }
     }
 
-    BSONObj CurOp::info() {
-        BSONObjBuilder b;
-        b.append("opid", _opNum);
+    void CurOp::reportState(BSONObjBuilder* builder) {
+        builder->append("opid", _opNum);
         bool a = _active && _start;
-        b.append("active", a);
+        builder->append("active", a);
 
         if( a ) {
-            b.append("secs_running", elapsedSeconds() );
-            b.append("microsecs_running", static_cast<long long int>(elapsedMicros()) );
+            builder->append("secs_running", elapsedSeconds() );
+            builder->append("microsecs_running", static_cast<long long int>(elapsedMicros()) );
         }
 
-        b.append( "op" , opToString( _op ) );
+        builder->append( "op" , opToString( _op ) );
 
-        b.append("ns", _ns);
+        builder->append("ns", _ns);
 
         if (_op == dbInsert) {
-            _query.append(b, "insert");
+            _query.append(*builder, "insert");
         }
         else {
-            _query.append(b , "query");
+            _query.append(*builder, "query");
         }
 
         if ( !debug().planSummary.empty() ) {
-            b.append( "planSummary" , debug().planSummary.toString() );
+            builder->append( "planSummary" , debug().planSummary.toString() );
         }
 
         if( !_remote.empty() ) {
-            b.append("client", _remote.toString());
-        }
-
-        if ( _client ) {
-            b.append( "desc" , _client->desc() );
-            if ( _client->_threadId.size() )
-                b.append( "threadId" , _client->_threadId );
-            if ( _client->_connectionId )
-                b.appendNumber( "connectionId" , _client->_connectionId );
-            _client->_ls.reportState(b);
+            builder->append("client", _remote.toString());
         }
 
         if ( ! _message.empty() ) {
             if ( _progressMeter.isActive() ) {
                 StringBuilder buf;
                 buf << _message.toString() << " " << _progressMeter.toString();
-                b.append( "msg" , buf.str() );
-                BSONObjBuilder sub( b.subobjStart( "progress" ) );
+                builder->append( "msg" , buf.str() );
+                BSONObjBuilder sub( builder->subobjStart( "progress" ) );
                 sub.appendNumber( "done" , (long long)_progressMeter.done() );
                 sub.appendNumber( "total" , (long long)_progressMeter.total() );
                 sub.done();
             }
             else {
-                b.append( "msg" , _message.toString() );
+                builder->append( "msg" , _message.toString() );
             }
         }
 
         if( killPending() )
-            b.append("killPending", true);
-
-        b.append( "numYields" , _numYields );
-        b.append( "lockStats" , _lockStat.report() );
+            builder->append("killPending", true);
 
-        return b.obj();
+        builder->append( "numYields" , _numYields );
+        builder->append( "lockStats" , _lockStat.report() );
     }
 
     BSONObj CurOp::description() {
diff --git a/src/mongo/db/curop.h b/src/mongo/db/curop.h
index 62a92215737..f24da292c98 100644
--- a/src/mongo/db/curop.h
+++ b/src/mongo/db/curop.h
@@ -283,7 +283,7 @@ namespace mongo {
         Command * getCommand() const { return _command; }
         void setCommand(Command* command) { _command = command; }
         
-        BSONObj info();
+        void reportState(BSONObjBuilder* builder);
 
         // Fetches less information than "info()"; used to search for ops with certain criteria
         BSONObj description();
diff --git a/src/mongo/db/d_concurrency.cpp b/src/mongo/db/d_concurrency.cpp
index a8651645303..530dc4d3879 100644
--- a/src/mongo/db/d_concurrency.cpp
+++ b/src/mongo/db/d_concurrency.cpp
@@ -36,9 +36,11 @@
 #include "mongo/db/commands/server_status.h"
 #include "mongo/db/curop.h"
 #include "mongo/db/d_globals.h"
+#include "mongo/db/global_environment_experiment.h"
 #include "mongo/db/lockstat.h"
 #include "mongo/db/namespace_string.h"
 #include "mongo/db/server_parameters.h"
+#include "mongo/db/operation_context.h"
 #include "mongo/server.h"
 #include "mongo/util/assert_util.h"
 #include "mongo/util/concurrency/mapsf.h"
@@ -743,6 +745,40 @@ namespace mongo {
 
     }
 
+    /**
+     * This is passed to the iterator for global environments and aggregates information about the
+     * locks which are currently being held or waited on.
+     */
+    class LockStateAggregator : public GlobalEnvironmentExperiment::ProcessOperationContext {
+    public:
+        LockStateAggregator(bool blockedOnly) 
+            : numWriteLocked(0),
+              numReadLocked(0),
+              _blockedOnly(blockedOnly) {
+
+        }
+
+        virtual void processOpContext(OperationContext* txn) {
+            if (_blockedOnly && !txn->lockState()->hasLockPending()) {
+                return;
+            }
+
+            if (txn->lockState()->isWriteLocked()) {
+                numWriteLocked++;
+            }
+            else {
+                numReadLocked++;
+            }
+        }
+
+        int numWriteLocked;
+        int numReadLocked;
+
+    private:
+        const bool _blockedOnly;
+    };
+
+
     class GlobalLockServerStatusSection : public ServerStatusSection {
     public:
         GlobalLockServerStatusSection() : ServerStatusSection( "globalLock" ){
@@ -757,23 +793,29 @@ namespace mongo {
             t.append( "totalTime" , (long long)(1000 * ( curTimeMillis64() - _started ) ) );
             t.append( "lockTime" , Lock::globalLockStat()->getTimeLocked( 'W' ) );
 
+            // This returns the blocked lock states
             {
                 BSONObjBuilder ttt( t.subobjStart( "currentQueue" ) );
-                int w=0, r=0;
-                Client::recommendedYieldMicros( &w , &r, true );
-                ttt.append( "total" , w + r );
-                ttt.append( "readers" , r );
-                ttt.append( "writers" , w );
+
+                LockStateAggregator blocked(true);
+                getGlobalEnvironment()->forEachOperationContext(&blocked);
+
+                ttt.append("total", blocked.numReadLocked + blocked.numWriteLocked);
+                ttt.append("readers", blocked.numReadLocked);
+                ttt.append("writers", blocked.numWriteLocked);
                 ttt.done();
             }
 
+            // This returns all the active clients (including those holding locks)
             {
                 BSONObjBuilder ttt( t.subobjStart( "activeClients" ) );
-                int w=0, r=0;
-                Client::getActiveClientCount( w , r );
-                ttt.append( "total" , w + r );
-                ttt.append( "readers" , r );
-                ttt.append( "writers" , w );
+
+                LockStateAggregator active(false);
+                getGlobalEnvironment()->forEachOperationContext(&active);
+
+                ttt.append("total", active.numReadLocked + active.numWriteLocked);
+                ttt.append("readers", active.numReadLocked);
+                ttt.append("writers", active.numWriteLocked);
                 ttt.done();
             }
 
diff --git a/src/mongo/db/db.cpp b/src/mongo/db/db.cpp
index bb57f42023e..29a5f1bf85c 100644
--- a/src/mongo/db/db.cpp
+++ b/src/mongo/db/db.cpp
@@ -178,11 +178,6 @@ namespace mongo {
     };
 #endif
 
-    /* if server is really busy, wait a bit */
-    void beNice() {
-        sleepmicros( Client::recommendedYieldMicros() );
-    }
-
     class MyMessageHandler : public MessageHandler {
     public:
         virtual void connected( AbstractMessagingPort* p ) {
@@ -224,7 +219,6 @@ namespace mongo {
                             m.appendData(b.buf(), b.len());
                             b.decouple();
                             DEV log() << "exhaust=true sending more" << endl;
-                            beNice();
                             continue; // this goes back to top loop
                         }
                     }
diff --git a/src/mongo/db/dbcommands.cpp b/src/mongo/db/dbcommands.cpp
index 2e5fadf2c70..8d833cb12b6 100644
--- a/src/mongo/db/dbcommands.cpp
+++ b/src/mongo/db/dbcommands.cpp
@@ -826,7 +826,7 @@ namespace mongo {
                         break; // skipped chunk is probably on another shard
                     }
                     log() << "should have chunk: " << n << " have:" << myn << endl;
-                    dumpChunks( ns , query , sort );
+                    dumpChunks(txn, ns, query, sort);
                     uassert( 10040 ,  "chunks out of order" , n == myn );
                 }
 
@@ -850,8 +850,11 @@ namespace mongo {
             return true;
         }
 
-        void dumpChunks( const string& ns , const BSONObj& query , const BSONObj& sort ) {
-            DBDirectClient client;
+        void dumpChunks(OperationContext* txn,
+                        const string& ns,
+                        const BSONObj& query,
+                        const BSONObj& sort) {
+            DBDirectClient client(txn);
             Query q(query);
             q.sort(sort);
             auto_ptr<DBClientCursor> c = client.query(ns, q);
@@ -1250,8 +1253,7 @@ namespace mongo {
                                            const BSONObj& cmdObj,
                                            std::vector<Privilege>* out) {} // No auth required
         virtual bool run(OperationContext* txn, const string& dbname, BSONObj& cmdObj, int, string& errmsg, BSONObjBuilder& result, bool) {
-            BSONObj info = txn->getCurOp()->info();
-            result << "you" << info[ "client" ];
+            result << "you" << txn->getCurOp()->getRemoteString();
             return true;
         }
     } cmdWhatsMyUri;
diff --git a/src/mongo/db/dbhelpers.cpp b/src/mongo/db/dbhelpers.cpp
index 272e527c6c2..abbeea15a86 100644
--- a/src/mongo/db/dbhelpers.cpp
+++ b/src/mongo/db/dbhelpers.cpp
@@ -446,14 +446,6 @@ namespace mongo {
                 }
                 millisWaitingForReplication += replStatus.duration.total_milliseconds();
             }
-            
-            if (!txn->lockState()->isLocked()) {
-                int micros = ( 2 * Client::recommendedYieldMicros() ) - secondaryThrottleTime.micros();
-                if ( micros > 0 ) {
-                    LOG(1) << "Helpers::removeRangeUnlocked going to sleep for " << micros << " micros" << endl;
-                    sleepmicros( micros );
-                }
-            }
         }
         
         if ( secondaryThrottle )
diff --git a/src/mongo/db/global_environment_d.cpp b/src/mongo/db/global_environment_d.cpp
index dcbc758d5d6..cc0a2577190 100644
--- a/src/mongo/db/global_environment_d.cpp
+++ b/src/mongo/db/global_environment_d.cpp
@@ -38,7 +38,17 @@
 
 namespace mongo {
 
-    GlobalEnvironmentMongoD::GlobalEnvironmentMongoD() : _globalKill(false) { }
+    GlobalEnvironmentMongoD::GlobalEnvironmentMongoD()
+        : _globalKill(false),
+          _registeredOpContextsMutex("RegisteredOpContextsMutex") {
+
+    }
+
+    GlobalEnvironmentMongoD::~GlobalEnvironmentMongoD() {
+        if (!_registeredOpContexts.empty()) {
+            warning() << "Terminating with outstanding operation contexts." << endl;
+        }
+    }
 
     namespace {
         void interruptJs(AtomicUInt* op) {
@@ -97,6 +107,34 @@ namespace mongo {
         _globalKill = false;
     }
 
+    void GlobalEnvironmentMongoD::registerOperationContext(OperationContext* txn) {
+        scoped_lock lock(_registeredOpContextsMutex);
+
+        // It is an error to register twice
+        pair<OperationContextSet::const_iterator, bool> inserted 
+                    = _registeredOpContexts.insert(txn);
+        invariant(inserted.second);
+    }
+
+    void GlobalEnvironmentMongoD::unregisterOperationContext(OperationContext* txn) {
+        scoped_lock lock(_registeredOpContextsMutex);
+
+        // It is an error to unregister twice or to unregister something that's not been registered
+        OperationContextSet::const_iterator it = _registeredOpContexts.find(txn);
+        invariant(it != _registeredOpContexts.end());
+
+        _registeredOpContexts.erase(it);
+    }
+
+    void GlobalEnvironmentMongoD::forEachOperationContext(ProcessOperationContext* procOpCtx) {
+        scoped_lock lock(_registeredOpContextsMutex);
+
+        OperationContextSet::iterator it;
+        for (it = _registeredOpContexts.begin(); it != _registeredOpContexts.end(); it++) {
+            procOpCtx->processOpContext(*it);
+        }
+    }
+
     OperationContext* GlobalEnvironmentMongoD::newOpCtx() {
         return new OperationContextImpl();
     }
diff --git a/src/mongo/db/global_environment_d.h b/src/mongo/db/global_environment_d.h
index 540a01715f5..35a8d039902 100644
--- a/src/mongo/db/global_environment_d.h
+++ b/src/mongo/db/global_environment_d.h
@@ -28,7 +28,11 @@
 
 #pragma once
 
+#include <set>
+
 #include "mongo/db/global_environment_experiment.h"
+#include "mongo/util/concurrency/mutex.h"
+
 
 namespace mongo {
 
@@ -36,6 +40,8 @@ namespace mongo {
     public:
         GlobalEnvironmentMongoD();
 
+        ~GlobalEnvironmentMongoD();
+
         void setKillAllOperations();
 
         void unsetKillAllOperations();
@@ -44,10 +50,21 @@ namespace mongo {
 
         bool killOperation(AtomicUInt opId);
 
+        void registerOperationContext(OperationContext* txn);
+
+        void unregisterOperationContext(OperationContext* txn);
+
+        void forEachOperationContext(ProcessOperationContext* procOpCtx);
+
         OperationContext* newOpCtx();
 
     private:
         bool _globalKill;
+
+        typedef std::set<OperationContext*> OperationContextSet;
+
+        mongo::mutex _registeredOpContextsMutex;
+        OperationContextSet _registeredOpContexts;
     };
 
 }  // namespace mongo
diff --git a/src/mongo/db/global_environment_experiment.h b/src/mongo/db/global_environment_experiment.h
index ab923baf833..a7d1aaac81a 100644
--- a/src/mongo/db/global_environment_experiment.h
+++ b/src/mongo/db/global_environment_experiment.h
@@ -67,6 +67,48 @@ namespace mongo {
          **/
         virtual bool killOperation(AtomicUInt opId) = 0;
 
+        /**
+         * Registers the specified operation context on the global environment, so it is
+         * discoverable by diagnostics tools.
+         *
+         * This function must be thread-safe.
+         */
+        virtual void registerOperationContext(OperationContext* txn) = 0;
+
+        /**
+         * Unregisters a previously-registered operation context. It is an error to unregister the
+         * same context twice or to unregister a context, which has not previously been registered.
+         *
+         * This function must be thread-safe.
+         */
+        virtual void unregisterOperationContext(OperationContext* txn) = 0;
+
+        /**
+         * Notification object to be passed to forEachOperationContext so that certain processing
+         * can be done on all registered contexts.
+         */
+        class ProcessOperationContext {
+        public:
+
+            /**
+             * Invoked for each registered OperationContext. The pointer is guaranteed to be stable
+             * until the call returns.
+             * 
+             * Implementations of this method should not acquire locks or do any operations, which 
+             * might block and should generally do as little work as possible in order to not block
+             * the iteration or the release of the OperationContext.
+             */
+            virtual void processOpContext(OperationContext* txn) = 0;
+
+            virtual ~ProcessOperationContext() { }
+        };
+
+        /**
+         * Iterates over all registered operation contexts and invokes 
+         * ProcessOperationContext::processOpContext for each.
+         */
+        virtual void forEachOperationContext(ProcessOperationContext* procOpCtx) = 0;
+
         //
         // Factories for storage interfaces
         //
diff --git a/src/mongo/db/global_environment_noop.cpp b/src/mongo/db/global_environment_noop.cpp
index 1d9c7e5edf1..f7af618c5ca 100644
--- a/src/mongo/db/global_environment_noop.cpp
+++ b/src/mongo/db/global_environment_noop.cpp
@@ -44,6 +44,18 @@ namespace mongo {
         return false;
     }
 
+    void GlobalEnvironmentNoop::registerOperationContext(OperationContext* txn) {
+
+    }
+
+    void GlobalEnvironmentNoop::unregisterOperationContext(OperationContext* txn) {
+
+    }
+
+    void GlobalEnvironmentNoop::forEachOperationContext(ProcessOperationContext* procOpCtx) {
+
+    }
+
     OperationContext* GlobalEnvironmentNoop::newOpCtx() {
         return new OperationContextNoop();
     }
diff --git a/src/mongo/db/global_environment_noop.h b/src/mongo/db/global_environment_noop.h
index 2788c839afb..68644a303c1 100644
--- a/src/mongo/db/global_environment_noop.h
+++ b/src/mongo/db/global_environment_noop.h
@@ -40,6 +40,12 @@ namespace mongo {
 
         bool getKillAllOperations();
 
+        void registerOperationContext(OperationContext* txn);
+
+        void unregisterOperationContext(OperationContext* txn);
+
+        void forEachOperationContext(ProcessOperationContext* procOpCtx);
+
         OperationContext* newOpCtx();
     };
 
diff --git a/src/mongo/db/instance.cpp b/src/mongo/db/instance.cpp
index 17111a87b73..3894d07c10d 100644
--- a/src/mongo/db/instance.cpp
+++ b/src/mongo/db/instance.cpp
@@ -115,7 +115,7 @@ namespace mongo {
 
     MONGO_FP_DECLARE(rsStopGetMore);
 
-    void inProgCmd( Message &m, DbResponse &dbresponse ) {
+    static void inProgCmd( Message &m, DbResponse &dbresponse ) {
         DbMessage d(m);
         QueryMessage q(d);
         BSONObjBuilder b;
@@ -160,7 +160,10 @@ namespace mongo {
                     }
                     verify( co );
                     if( all || co->displayInCurop() ) {
-                        BSONObj info = co->info();
+                        BSONObjBuilder infoBuilder;
+                        co->reportState(&infoBuilder);
+
+                        const BSONObj info = infoBuilder.obj();
                         if ( all || m.matches( info )) {
                             vals.push_back( info );
                         }
@@ -1013,19 +1016,10 @@ namespace {
         return (unsigned long long )res;
     }
 
-    DBClientBase * createDirectClient() {
+    DBClientBase* createDirectClient() {
         return new DBDirectClient();
     }
 
-    MONGO_INITIALIZER_GENERAL(CreateJSDirectClient,
-                              ("StorageEngineInit"),
-                              MONGO_NO_DEPENDENTS)
-        (InitializerContext* context) {
-
-        directDBClient = createDirectClient();
-
-        return Status::OK();
-    }
 
     mongo::mutex exitMutex("exit");
     AtomicUInt numExitCalls = 0;
diff --git a/src/mongo/db/lockstate.cpp b/src/mongo/db/lockstate.cpp
index 30168ea8623..372a34c5641 100644
--- a/src/mongo/db/lockstate.cpp
+++ b/src/mongo/db/lockstate.cpp
@@ -151,7 +151,8 @@ namespace mongo {
 
     BSONObj LockState::reportState() {
         BSONObjBuilder b;
-        reportState( b );
+        reportState(&b);
+
         return b.obj();
     }
     
@@ -159,7 +160,7 @@ namespace mongo {
               thread. So be careful about thread safety here. For example reading 
               this->otherName would not be safe as-is!
     */
-    void LockState::reportState(BSONObjBuilder& res) {
+    void LockState::reportState(BSONObjBuilder* res) {
         BSONObjBuilder b;
         if( _threadState ) {
             char buf[2];
@@ -184,9 +185,10 @@ namespace mongo {
             }
         }
         BSONObj o = b.obj();
-        if( !o.isEmpty() ) 
-            res.append("locks", o);
-        res.append( "waitingForLock" , _lockPending );
+        if (!o.isEmpty()) {
+            res->append("locks", o);
+        }
+        res->append("waitingForLock", _lockPending);
     }
 
     void LockState::dump() const {
diff --git a/src/mongo/db/lockstate.h b/src/mongo/db/lockstate.h
index 8f17c793632..7f484c592a6 100644
--- a/src/mongo/db/lockstate.h
+++ b/src/mongo/db/lockstate.h
@@ -45,7 +45,7 @@ namespace mongo {
         void dump() const;
 
         BSONObj reportState();
-        void reportState(BSONObjBuilder& b);
+        void reportState(BSONObjBuilder* b);
         
         unsigned recursiveCount() const { return _recursive; }
 
diff --git a/src/mongo/db/operation_context.h b/src/mongo/db/operation_context.h
index 2fa4275ca5d..bab1b555e51 100644
--- a/src/mongo/db/operation_context.h
+++ b/src/mongo/db/operation_context.h
@@ -39,7 +39,7 @@
 
 
 namespace mongo {
-
+    class Client;
     class CurOp;
     class ProgressMeter;
 
@@ -95,9 +95,10 @@ namespace mongo {
          */
         virtual const char * getNS() const = 0;
 
-        //
-        // CurOp
-        //
+        /**
+         * Returns the client under which this context runs.
+         */
+        virtual Client* getClient() const = 0;
 
         /**
          * Returns CurOp. Caller does not own pointer
diff --git a/src/mongo/db/operation_context_impl.cpp b/src/mongo/db/operation_context_impl.cpp
index 44b613be389..4af1def603c 100644
--- a/src/mongo/db/operation_context_impl.cpp
+++ b/src/mongo/db/operation_context_impl.cpp
@@ -42,6 +42,12 @@ namespace mongo {
     OperationContextImpl::OperationContextImpl() {
         invariant( globalStorageEngine );
         _recovery.reset(globalStorageEngine->newRecoveryUnit(this));
+
+        getGlobalEnvironment()->registerOperationContext(this);
+    }
+
+    OperationContextImpl::~OperationContextImpl() {
+        getGlobalEnvironment()->unregisterOperationContext(this);
     }
 
     RecoveryUnit* OperationContextImpl::recoveryUnit() const {
@@ -64,6 +70,10 @@ namespace mongo {
         return getCurOp()->getNS();
     }
 
+    Client* OperationContextImpl::getClient() const {
+        return &cc();
+    }
+
     CurOp* OperationContextImpl::getCurOp() const {
         return cc().curop();
     }
diff --git a/src/mongo/db/operation_context_impl.h b/src/mongo/db/operation_context_impl.h
index d4dd56867c5..3acadbca4a5 100644
--- a/src/mongo/db/operation_context_impl.h
+++ b/src/mongo/db/operation_context_impl.h
@@ -39,7 +39,7 @@ namespace mongo {
     public:
         OperationContextImpl();
 
-        virtual ~OperationContextImpl() { }
+        virtual ~OperationContextImpl();
 
         virtual RecoveryUnit* recoveryUnit() const;
 
@@ -52,6 +52,8 @@ namespace mongo {
 
         virtual const char * getNS() const;
 
+        virtual Client* getClient() const;
+
         virtual CurOp* getCurOp() const;
 
         virtual void checkForInterrupt(bool heedMutex = true) const;
diff --git a/src/mongo/db/operation_context_noop.h b/src/mongo/db/operation_context_noop.h
index 26c497e6fce..527348b1537 100644
--- a/src/mongo/db/operation_context_noop.h
+++ b/src/mongo/db/operation_context_noop.h
@@ -47,7 +47,12 @@ namespace mongo {
 
         virtual ~OperationContextNoop() { }
 
-        CurOp* getCurOp() const {
+        virtual Client* getClient() const {
+            invariant(false);
+            return NULL;
+        }
+
+        virtual CurOp* getCurOp() const {
             invariant(false);
             return NULL;
         }
diff --git a/src/mongo/db/restapi.cpp b/src/mongo/db/restapi.cpp
index c01dfeb90e0..47f9e0d1421 100644
--- a/src/mongo/db/restapi.cpp
+++ b/src/mongo/db/restapi.cpp
@@ -108,11 +108,11 @@ namespace mongo {
 
             if ( method == "GET" ) {
                 responseCode = 200;
-                html = handleRESTQuery( db, fullns, action, params, responseCode, ss  );
+                html = handleRESTQuery(txn, fullns, action, params, responseCode, ss);
             }
             else if ( method == "POST" ) {
                 responseCode = 201;
-                handlePost( db, fullns, MiniWebServer::body( rq ), params, responseCode, ss  );
+                handlePost(txn, fullns, MiniWebServer::body(rq), params, responseCode, ss);
             }
             else {
                 responseCode = 400;
@@ -129,7 +129,7 @@ namespace mongo {
             responseMsg = ss.str();
         }
 
-        bool handleRESTQuery( DBDirectClient& db,
+        bool handleRESTQuery( OperationContext* txn,
                               const std::string& ns,
                               const std::string& action,
                               BSONObj & params,
@@ -170,6 +170,8 @@ namespace mongo {
             }
 
             BSONObj query = queryBuilder.obj();
+
+            DBDirectClient db(txn);
             auto_ptr<DBClientCursor> cursor = db.query( ns.c_str() , query, num , skip );
             uassert( 13085 , "query failed for dbwebserver" , cursor.get() );
 
@@ -232,7 +234,7 @@ namespace mongo {
         }
 
         // TODO Generate id and revision per couch POST spec
-        void handlePost( DBDirectClient& db,
+        void handlePost( OperationContext* txn,
                          const std::string& ns,
                          const char *body,
                          BSONObj& params,
@@ -240,6 +242,8 @@ namespace mongo {
                          stringstream & out ) {
             try {
                 BSONObj obj = fromjson( body );
+
+                DBDirectClient db(txn);
                 db.insert( ns.c_str(), obj );
             }
             catch ( ... ) {
@@ -259,7 +263,6 @@ namespace mongo {
                 return atoi( e.valuestr() );
             return def;
         }
-
     } restHandler;
 
     bool RestAdminAccess::haveAdminUsers(OperationContext* txn) const {
diff --git a/src/mongo/db/storage/heap1/heap1_test.cpp b/src/mongo/db/storage/heap1/heap1_test.cpp
index e343d4b956d..b41b3122898 100644
--- a/src/mongo/db/storage/heap1/heap1_test.cpp
+++ b/src/mongo/db/storage/heap1/heap1_test.cpp
@@ -50,6 +50,11 @@ namespace {
 
         virtual ~MyOperationContext() { }
 
+        Client* getClient() const {
+            invariant(false);
+            return NULL;
+        }
+
         CurOp* getCurOp() const {
             invariant(false);
             return NULL;
diff --git a/src/mongo/dbtests/dbhelper_tests.cpp b/src/mongo/dbtests/dbhelper_tests.cpp
index 06354880e42..e0aeb507e36 100644
--- a/src/mongo/dbtests/dbhelper_tests.cpp
+++ b/src/mongo/dbtests/dbhelper_tests.cpp
@@ -49,15 +49,17 @@ namespace mongo {
                 _min( 4 ), _max( 8 )
         {
         }
+
         void run() {
-            DBDirectClient client;
+            OperationContextImpl txn;
+            DBDirectClient client(&txn);
+
             for ( int i = 0; i < 10; ++i ) {
                 client.insert( ns, BSON( "_id" << i ) );
             }
 
             {
                 // Remove _id range [_min, _max).
-                OperationContextImpl txn;
                 Lock::DBWrite lk(txn.lockState(), ns);
                 Client::Context ctx( ns );
 
@@ -69,7 +71,7 @@ namespace mongo {
             }
 
             // Check that the expected documents remain.
-            ASSERT_EQUALS( expected(), docs() );
+            ASSERT_EQUALS( expected(), docs(&txn) );
         }
     private:
         BSONArray expected() const {
@@ -82,8 +84,9 @@ namespace mongo {
             }
             return bab.arr();
         }
-        BSONArray docs() const {
-            DBDirectClient client;
+
+        BSONArray docs(OperationContext* txn) const {
+            DBDirectClient client(txn);
             auto_ptr<DBClientCursor> cursor = client.query( ns,
                                                             Query().hint( BSON( "_id" << 1 ) ) );
             BSONArrayBuilder bab;
diff --git a/src/mongo/dbtests/gle_test.cpp b/src/mongo/dbtests/gle_test.cpp
index e804b167ed3..71b3642e3af 100644
--- a/src/mongo/dbtests/gle_test.cpp
+++ b/src/mongo/dbtests/gle_test.cpp
@@ -45,6 +45,7 @@ namespace {
         void run() {
             DBDirectClient client;
             client.insert(_ns, BSON( "test" << "test"));
+
             // Cannot mix fsync + j, will make command fail
             string gleString = client.getLastError(true, true, 10, 10);
             ASSERT_NOT_EQUALS(gleString, "");
@@ -59,6 +60,7 @@ namespace {
         void run() {
             DBDirectClient client;
             client.insert(_ns, BSON( "test" << "test"));
+
             // Make sure there was no error
             string gleString = client.getLastError();
             ASSERT_EQUALS(gleString, "");
@@ -73,6 +75,7 @@ namespace {
         void run() {
             DBDirectClient client;
             client.insert(_ns, BSON( "_id" << 1));
+
             // Make sure there was no error
             string gleString = client.getLastError();
             ASSERT_EQUALS(gleString, "");
diff --git a/src/mongo/dbtests/gridfstest.cpp b/src/mongo/dbtests/gridfstest.cpp
index edabefa1d32..768db4cc307 100644
--- a/src/mongo/dbtests/gridfstest.cpp
+++ b/src/mongo/dbtests/gridfstest.cpp
@@ -42,7 +42,8 @@ namespace {
     public:
         virtual void run() {
             DBDirectClient client;
-            GridFS grid( client, "gridtest" );
+
+            GridFS grid(client, "gridtest");
             grid.setChunkSize( 5 );
 
             ASSERT_EQUALS( 5U, grid.getChunkSize() );
diff --git a/src/mongo/dbtests/indexupdatetests.cpp b/src/mongo/dbtests/indexupdatetests.cpp
index f0cdf72e32e..3458181887a 100644
--- a/src/mongo/dbtests/indexupdatetests.cpp
+++ b/src/mongo/dbtests/indexupdatetests.cpp
@@ -43,9 +43,6 @@
 namespace IndexUpdateTests {
 
     static const char* const _ns = "unittests.indexupdate";
-#if 0
-    ExternalSortComparison* _aFirstSort = BtreeBasedBulkAccessMethod::getComparison(0, BSON("a" << 1));
-#endif
 
     /**
      * Test fixture for a write locked test using collection _ns.  Includes functionality to
@@ -55,9 +52,10 @@ namespace IndexUpdateTests {
     class IndexBuildBase {
     public:
         IndexBuildBase() :
-            _ctx(&_txn, _ns) {
+            _ctx(&_txn, _ns),
+            _client(&_txn) {
+
             _client.createCollection( _ns );
-            setGlobalEnvironment(new GlobalEnvironmentMongoD());
         }
         ~IndexBuildBase() {
             _client.dropCollection( _ns );
@@ -93,9 +91,9 @@ namespace IndexUpdateTests {
         }
 #endif
 
-        DBDirectClient _client;
         OperationContextImpl _txn;
         Client::WriteContext _ctx;
+        DBDirectClient _client;
     };
 
     /** addKeysToPhaseOne() adds keys from a collection's documents to an external sorter. */
diff --git a/src/mongo/dbtests/jstests.cpp b/src/mongo/dbtests/jstests.cpp
index 136d590b09f..400aceffd40 100644
--- a/src/mongo/dbtests/jstests.cpp
+++ b/src/mongo/dbtests/jstests.cpp
@@ -904,6 +904,7 @@ namespace JSTests {
         verify(0);
     }
 
+
     class Utf8Check {
     public:
         Utf8Check() { reset(); }
@@ -930,6 +931,7 @@ namespace JSTests {
             client.dropCollection( ns() );
         }
         static const char *ns() { return "unittest.jstests.utf8check"; }
+
         DBDirectClient client;
     };
 
@@ -947,6 +949,7 @@ namespace JSTests {
             client.dropCollection( ns() );
         }
         static const char *ns() { return "unittest.jstests.longutf8string"; }
+
         DBDirectClient client;
     };
 
@@ -1077,6 +1080,7 @@ namespace JSTests {
             virtual string jsonOut() const {
                 return json();
             }
+
             DBDirectClient client;
         };
 
@@ -1982,13 +1986,14 @@ namespace JSTests {
     class InvalidStoredJS {
     public:
         void run() {
-            DBDirectClient client;
             BSONObjBuilder query;
             query.append( "_id" , "invalidstoredjs1" );
             
             BSONObjBuilder update;
             update.append( "_id" , "invalidstoredjs1" );
             update.appendCode( "value" , "function () { db.test.find().forEach(function(obj) { continue; }); }" );
+
+            DBDirectClient client;
             client.update( "test.system.js" , query.obj() , update.obj() , true /* upsert */ );
 
             scoped_ptr<Scope> s( globalScriptEngine->newScope() );
diff --git a/src/mongo/dbtests/perftests.cpp b/src/mongo/dbtests/perftests.cpp
index 672e9b99a62..74eb31e8f68 100644
--- a/src/mongo/dbtests/perftests.cpp
+++ b/src/mongo/dbtests/perftests.cpp
@@ -68,18 +68,14 @@ namespace PerfTests {
 
     const bool profiling = false;
 
-    typedef DBDirectClient DBClientType;
-    //typedef DBClientConnection DBClientType;
-
     class ClientBase {
     public:
         // NOTE: Not bothering to backup the old error record.
         ClientBase() {
-            //_client.connect("localhost");
             mongo::lastError.reset( new LastError() );
         }
         virtual ~ClientBase() {
-            //mongo::lastError.release();
+
         }
     protected:
         void insert( const char *ns, BSONObj o ) {
@@ -91,9 +87,11 @@ namespace PerfTests {
         bool error() {
             return !_client.getPrevError().getField( "err" ).isNull();
         }
+
         DBClientBase* client() { return &_client; }
+
     private:
-        DBClientType _client;
+        DBDirectClient _client;
     };
 
     /* if you want recording of the timings, place the password for the perf database
@@ -358,7 +356,7 @@ namespace PerfTests {
             static int z;
             srand( ++z ^ (unsigned) time(0));
 #endif
-            DBClientType c;
+            DBDirectClient c;
             Client::initThreadIfNotAlready("perftestthr");
             const unsigned int Batch = batchSize();
             while( 1 ) {
diff --git a/src/mongo/dbtests/query_stage_fetch.cpp b/src/mongo/dbtests/query_stage_fetch.cpp
index 272e3ad822e..3414475baf9 100644
--- a/src/mongo/dbtests/query_stage_fetch.cpp
+++ b/src/mongo/dbtests/query_stage_fetch.cpp
@@ -78,6 +78,7 @@ namespace QueryStageFetch {
         DBDirectClient _client;
     };
 
+
     //
     // Test that a WSM with an obj is passed through verbatim.
     //
diff --git a/src/mongo/dbtests/query_stage_keep.cpp b/src/mongo/dbtests/query_stage_keep.cpp
index 5959ee17bee..3be756ae2a5 100644
--- a/src/mongo/dbtests/query_stage_keep.cpp
+++ b/src/mongo/dbtests/query_stage_keep.cpp
@@ -93,6 +93,7 @@ namespace QueryStageKeep {
         DBDirectClient _client;
     };
 
+
     // Test that we actually merge flagged results.
 
     //
diff --git a/src/mongo/dbtests/querytests.cpp b/src/mongo/dbtests/querytests.cpp
index 0ef81145036..ac70e48555f 100644
--- a/src/mongo/dbtests/querytests.cpp
+++ b/src/mongo/dbtests/querytests.cpp
@@ -190,10 +190,9 @@ namespace QueryTests {
     public:
         ClientBase() {
             mongo::lastError.reset( new LastError() );
-            setGlobalEnvironment(new GlobalEnvironmentMongoD());
         }
         ~ClientBase() {
-            //mongo::lastError.release();
+
         }
 
     protected:
diff --git a/src/mongo/dbtests/runner_registry.cpp b/src/mongo/dbtests/runner_registry.cpp
index 2964e14be00..b7c5981a27f 100644
--- a/src/mongo/dbtests/runner_registry.cpp
+++ b/src/mongo/dbtests/runner_registry.cpp
@@ -49,7 +49,9 @@ namespace RunnerRegistry {
 
     class RunnerRegistryBase {
     public:
-        RunnerRegistryBase() {
+        RunnerRegistryBase()
+            : _client(&_opCtx)
+        {
             _ctx.reset(new Client::WriteContext(&_opCtx, ns()));
             _client.dropCollection(ns());
 
@@ -94,11 +96,14 @@ namespace RunnerRegistry {
         }
 
         static const char* ns() { return "unittests.RunnerRegistryDiskLocInvalidation"; }
-        DBDirectClient _client;
-        auto_ptr<Client::WriteContext> _ctx;
+
+        // Order of these is important for initialization
         OperationContextImpl _opCtx;
+        auto_ptr<Client::WriteContext> _ctx;
+        DBDirectClient _client;
     };
 
+
     // Test that a registered runner receives invalidation notifications.
     class RunnerRegistryDiskLocInvalid : public RunnerRegistryBase {
     public:
diff --git a/src/mongo/dbtests/updatetests.cpp b/src/mongo/dbtests/updatetests.cpp
index f486dd0ce3a..e048ebc2d9f 100644
--- a/src/mongo/dbtests/updatetests.cpp
+++ b/src/mongo/dbtests/updatetests.cpp
@@ -61,7 +61,9 @@ namespace UpdateTests {
         bool error() {
             return !client_.getPrevError().getField( "err" ).isNull();
         }
-        DBDirectClient &client() { return client_; }
+
+        DBDirectClient& client() { return client_; }
+
     private:
         DBDirectClient client_;
     };
diff --git a/src/mongo/s/client_info.cpp b/src/mongo/s/client_info.cpp
index adffade0e8e..900dc70e84a 100644
--- a/src/mongo/s/client_info.cpp
+++ b/src/mongo/s/client_info.cpp
@@ -132,10 +132,6 @@ namespace mongo {
         return _tlInfo.get();
     }
 
-    bool ClientBasic::hasCurrent() {
-        return ClientInfo::exists();
-    }
-
     ClientBasic* ClientBasic::getCurrent() {
         return ClientInfo::get();
     }
diff --git a/src/mongo/scripting/engine.cpp b/src/mongo/scripting/engine.cpp
index 5a7789be8b3..c0c6d30f577 100644
--- a/src/mongo/scripting/engine.cpp
+++ b/src/mongo/scripting/engine.cpp
@@ -27,7 +27,7 @@
  *    then also delete it in the license file.
  */
 
-#include "mongo/pch.h"
+#include "mongo/platform/basic.h"
 
 #include "mongo/scripting/engine.h"
 
@@ -44,7 +44,6 @@
 namespace mongo {
     long long Scope::_lastVersion = 1;
     static const unsigned kMaxJsFileLength = std::numeric_limits<unsigned>::max() - 1;
-    DBClientBase* directDBClient;
 
     ScriptEngine::ScriptEngine() : _scopeInitCallback() {
     }
@@ -192,6 +191,7 @@ namespace mongo {
         _loadedVersion = _lastVersion;
         string coll = _localDBName + ".system.js";
 
+        DBClientBase* directDBClient = createDirectClient();
         auto_ptr<DBClientCursor> c = directDBClient->query(coll, Query(), 0, 0, NULL,
             QueryOption_SlaveOk, 0);
         massert(16669, "unable to get db client cursor from query", c.get());
diff --git a/src/mongo/scripting/engine.h b/src/mongo/scripting/engine.h
index 05061e82a19..1fb512a6a44 100644
--- a/src/mongo/scripting/engine.h
+++ b/src/mongo/scripting/engine.h
@@ -258,5 +258,4 @@ namespace mongo {
     const char* jsSkipWhiteSpace(const char* raw);
 
     extern ScriptEngine* globalScriptEngine;
-    extern DBClientBase* directDBClient;
 }