bulk move of code to src/ SERVER-4551

1 files changed, 106 insertions, 0 deletions

diff --git a/src/mongo/util/queue.h b/src/mongo/util/queue.h
new file mode 100644
index 00000000000..4223bd6c256
--- /dev/null
+++ b/src/mongo/util/queue.h
@@ -0,0 +1,106 @@
+// @file queue.h
+
+/*    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 "../pch.h"
+
+#include <queue>
+
+#include "../util/timer.h"
+
+namespace mongo {
+
+    /**
+     * simple blocking queue
+     */
+    template<typename T> class BlockingQueue : boost::noncopyable {
+    public:
+        BlockingQueue() : _lock("BlockingQueue") { }
+
+        void push(T const& t) {
+            scoped_lock l( _lock );
+            _queue.push( t );
+            _condition.notify_one();
+        }
+
+        bool empty() const {
+            scoped_lock l( _lock );
+            return _queue.empty();
+        }
+
+        size_t size() const {
+            scoped_lock l( _lock );
+            return _queue.size();
+        }
+
+
+        bool tryPop( T & t ) {
+            scoped_lock l( _lock );
+            if ( _queue.empty() )
+                return false;
+
+            t = _queue.front();
+            _queue.pop();
+
+            return true;
+        }
+
+        T blockingPop() {
+
+            scoped_lock l( _lock );
+            while( _queue.empty() )
+                _condition.wait( l.boost() );
+
+            T t = _queue.front();
+            _queue.pop();
+            return t;
+        }
+
+
+        /**
+         * blocks waiting for an object until maxSecondsToWait passes
+         * if got one, return true and set in t
+         * otherwise return false and t won't be changed
+         */
+        bool blockingPop( T& t , int maxSecondsToWait ) {
+
+            Timer timer;
+
+            boost::xtime xt;
+            boost::xtime_get(&xt, boost::TIME_UTC);
+            xt.sec += maxSecondsToWait;
+
+            scoped_lock l( _lock );
+            while( _queue.empty() ) {
+                if ( ! _condition.timed_wait( l.boost() , xt ) )
+                    return false;
+            }
+
+            t = _queue.front();
+            _queue.pop();
+            return true;
+        }
+
+    private:
+        std::queue<T> _queue;
+
+        mutable mongo::mutex _lock;
+        boost::condition _condition;
+    };
+
+}