5 files changed, 124 insertions, 3 deletions
diff --git a/src/mongo/util/concurrency/msg.h b/src/mongo/util/concurrency/msg.h
index 0b9a7c5048c..6e8a3980246 100644
--- a/src/mongo/util/concurrency/msg.h
+++ b/src/mongo/util/concurrency/msg.h
@@ -19,6 +19,8 @@
 #pragma once
 
 #include <deque>
+
+#include <boost/thread/condition.hpp>
 #include "task.h"
 
 namespace mongo {
diff --git a/src/mongo/util/concurrency/mvar.h b/src/mongo/util/concurrency/mvar.h
index bc1855a85cc..d5ceb28ce30 100644
--- a/src/mongo/util/concurrency/mvar.h
+++ b/src/mongo/util/concurrency/mvar.h
@@ -17,6 +17,9 @@
 
 #pragma once
 
+#include <boost/thread/recursive_mutex.hpp>
+#include <boost/thread/condition.hpp>
+
 namespace mongo {
 
     /* This is based on haskell's MVar synchronization primitive:
diff --git a/src/mongo/util/concurrency/thread_pool.cpp b/src/mongo/util/concurrency/thread_pool.cpp
index b64a904cd4a..78eb05556a9 100644
--- a/src/mongo/util/concurrency/thread_pool.cpp
+++ b/src/mongo/util/concurrency/thread_pool.cpp
@@ -17,6 +17,9 @@
  */
 
 #include "pch.h"
+
+#include <boost/thread/thread.hpp>
+
 #include "thread_pool.h"
 #include "mvar.h"
 
diff --git a/src/mongo/util/concurrency/thread_pool.h b/src/mongo/util/concurrency/thread_pool.h
index ea2f801b63c..62a9cac57d1 100644
--- a/src/mongo/util/concurrency/thread_pool.h
+++ b/src/mongo/util/concurrency/thread_pool.h
@@ -17,8 +17,11 @@
 
 #pragma once
 
-#include <boost/function.hpp>
+#include <list>
+
 #include <boost/bind.hpp>
+#include <boost/function.hpp>
+#include <boost/thread/condition.hpp>
 
 namespace mongo {
 
@@ -63,8 +66,8 @@ namespace mongo {
             mongo::mutex _mutex;
             boost::condition _condition;
 
-            list<Worker*> _freeWorkers; //used as LIFO stack (always front)
-            list<Task> _tasks; //used as FIFO queue (push_back, pop_front)
+            std::list<Worker*> _freeWorkers; //used as LIFO stack (always front)
+            std::list<Task> _tasks; //used as FIFO queue (push_back, pop_front)
             int _tasksRemaining; // in queue + currently processing
             int _nThreads; // only used for sanity checking. could be removed in the future.
 
diff --git a/src/mongo/util/concurrency/ticketholder.h b/src/mongo/util/concurrency/ticketholder.h
new file mode 100644
index 00000000000..036d33fb9ef
--- /dev/null
+++ b/src/mongo/util/concurrency/ticketholder.h
@@ -0,0 +1,110 @@
+/*    Copyright 2009 10gen Inc.
+ *
+ *    Licensed under the Apache License, Version 2.0 (the "License");
+ *    you may not use this file except in compliance with the License.
+ *    You may obtain a copy of the License at
+ *
+ *    http://www.apache.org/licenses/LICENSE-2.0
+ *
+ *    Unless required by applicable law or agreed to in writing, software
+ *    distributed under the License is distributed on an "AS IS" BASIS,
+ *    WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ *    See the License for the specific language governing permissions and
+ *    limitations under the License.
+ */
+#pragma once
+
+#include <boost/thread/condition_variable.hpp>
+
+#include "mongo/util/concurrency/mutex.h"
+
+namespace mongo {
+
+    class TicketHolder {
+    public:
+        TicketHolder( int num ) : _mutex("TicketHolder") {
+            _outof = num;
+            _num = num;
+        }
+
+        bool tryAcquire() {
+            scoped_lock lk( _mutex );
+            return _tryAcquire();
+        }
+
+        void waitForTicket() {
+            scoped_lock lk( _mutex );
+
+            while( ! _tryAcquire() ) {
+                _newTicket.wait( lk.boost() );
+            }
+        }
+
+        void release() {
+            {
+                scoped_lock lk( _mutex );
+                _num++;
+            }
+            _newTicket.notify_one();
+        }
+
+        void resize( int newSize ) {
+            {
+                scoped_lock lk( _mutex );
+
+                int used = _outof - _num;
+                if ( used > newSize ) {
+                    cout << "ERROR: can't resize since we're using (" << used << ") more than newSize(" << newSize << ")" << endl;
+                    return;
+                }
+
+                _outof = newSize;
+                _num = _outof - used;
+            }
+
+            // Potentially wasteful, but easier to see is correct
+            _newTicket.notify_all();
+        }
+
+        int available() const {
+            return _num;
+        }
+
+        int used() const {
+            return _outof - _num;
+        }
+
+        int outof() const { return _outof; }
+
+    private:
+
+        bool _tryAcquire(){
+            if ( _num <= 0 ) {
+                if ( _num < 0 ) {
+                    cerr << "DISASTER! in TicketHolder" << endl;
+                }
+                return false;
+            }
+            _num--;
+            return true;
+        }
+
+        int _outof;
+        int _num;
+        mongo::mutex _mutex;
+        boost::condition_variable_any _newTicket;
+    };
+
+    class TicketHolderReleaser {
+    public:
+        TicketHolderReleaser( TicketHolder * holder ) {
+            _holder = holder;
+        }
+
+        ~TicketHolderReleaser() {
+            _holder->release();
+        }
+    private:
+        TicketHolder * _holder;
+    };
+}