#3019: ObjectPool wait on borrow condition fix

Foundation/include/Poco/ObjectPool.h

@@ -217,20 +217,13 @@ public:
 	{
 		Poco::FastMutex::ScopedLock lock(_mutex);
 
-		if (!_pool.empty())
-		{
-			P pObject = _pool.back();
-			_pool.pop_back();
-			return activateObject(pObject);
-		}
-
-		if (_size >= _peakCapacity)
+		if (_size >= _peakCapacity && _pool.empty())
 		{
 			if (timeoutMilliseconds == 0)
 			{
 				return 0;
 			}
-			while (_size >= _peakCapacity)
+			while (_size >= _peakCapacity && _pool.empty())
 			{
 				if (!_availableCondition.tryWait(_mutex, timeoutMilliseconds))
 				{
@@ -240,10 +233,19 @@ public:
 			}
 		}
 
+		if (!_pool.empty())
+		{
+			P pObject = _pool.back();
+			_pool.pop_back();
+
+			return activateObject(pObject);
+		}
+
 		// _size < _peakCapacity
 		P pObject = _factory.createObject();
 		activateObject(pObject);
 		_size++;
+
 		return pObject;
 	}
 
@@ -260,6 +262,7 @@ public:
 				try
 				{
 					_pool.push_back(pObject);
+					_availableCondition.signal();
 					return;
 				}
 				catch (...)

Foundation/testsuite/src/ObjectPoolTest.cpp

@@ -13,6 +13,7 @@
 #include "CppUnit/TestSuite.h"
 #include "Poco/ObjectPool.h"
 #include "Poco/Exception.h"
+#include "Poco/Thread.h"
 
 
 using Poco::ObjectPool;
@@ -88,6 +89,27 @@ void ObjectPoolTest::testObjectPool()
 }
 
 
+void ObjectPoolTest::testObjectPoolWaitOnBorrowObject()
+{
+	ObjectPool<std::string, Poco::SharedPtr<std::string>> pool(1, 1);
+
+	Poco::SharedPtr<std::string> objectToReturnDuringBorrow = pool.borrowObject();
+
+	Poco::Thread threadToReturnObject;
+	threadToReturnObject.startFunc(
+		[&pool, &objectToReturnDuringBorrow]()
+		{
+			pool.returnObject(objectToReturnDuringBorrow);
+		}
+	);
+
+	Poco::SharedPtr<std::string> object = pool.borrowObject(1000);
+
+	threadToReturnObject.join();
+	assertFalse(object.isNull());
+}
+
+
 void ObjectPoolTest::setUp()
 {
 }
@@ -103,6 +125,7 @@ CppUnit::Test* ObjectPoolTest::suite()
 	CppUnit::TestSuite* pSuite = new CppUnit::TestSuite("ObjectPoolTest");
 
 	CppUnit_addTest(pSuite, ObjectPoolTest, testObjectPool);
+	CppUnit_addTest(pSuite, ObjectPoolTest, testObjectPoolWaitOnBorrowObject);
 
 	return pSuite;
 }

Foundation/testsuite/src/ObjectPoolTest.h

@@ -25,6 +25,7 @@ public:
 	~ObjectPoolTest();
 
 	void testObjectPool();
+	void testObjectPoolWaitOnBorrowObject();
 
 	void setUp();
 	void tearDown();