Memory management

C++

All libfacerec interface objects are stored in smart pointers (see pbio::LightSmartPtr and pbio::HeavySmartPtr). For convenience, each interface object T declares its own pointer type T::Ptr (for example, pbio::Template::Ptr), so do not use pbio::LightSmartPtr or pbio::HeavySmartPtr directly. Most of the objects use pbio::LightSmartPtr, which do not allow to store inherited types or use specific deleters to significantly reduce memory consumption.

If you use OpenCV / boost / C++ 11, you can set one of the following macros, so that the libfacerec uses a specific type of a smart pointer instead of pbio::HeavySmartPtr:

• PBIO_OPENCV_SMART_POINTER - for using cv::Ptr
• PBIO_BOOST_SMART_POINTER - for using boost::shared_ptr
• PBIO_CXX11_SMART_POINTER - for using std::shared_ptr

If none of these macros is defined, a pointer defined in include/pbio/shared_ptr/heavy_shared_ptr.h is used, which is actually a simplified version of an OpenCV smart pointer.

In any case, T::Ptr is a thread-safe shared smart pointer.

libfacerec library will be automatically unloaded when no interface object remains.

Java

To release memory from internal objects before it is automatically done by the garbage collector, use the dispose() method. After this method is called, only the isDisposed() method can be called from the object. If any other method is called, an exception will be thrown.

Example:

...
Capturer capturer = service.createCapturer(service.new Config("common_capturer.xml"));
...
capturer.dispose(); // release internal objects
if (capturer.isDisposed())
{
    System.out.println("object is disposed");
}
capturer.capture(image); // exception, object is disposed
// this line never be reached

C#

To release memory from internal objects before it is automatically done by the garbage collector, use the Dispose() method. After this method is called, access is allowed only to the isDisposed property. Otherwise, an exception will be thrown.

Example:

...
Capturer capturer = service.createCapturer("common_capturer.xml");
...
capturer.Dispose(); // release internal objects
if (capturer.IsDisposed)
{
    Console.WriteLine("object is disposed");
}
capturer.capture(image); // exception, object is disposed
// this line never be reached

Python

Destructors are called when an object gets destroyed. Python has a garbage collector that handles memory management automatically.

Example:

...
capturer = service.create_capturer("common_capturer.xml")
...
del capturer  # release internal objects

capturer.capture(image)  # exception, object is disposed
# this line never be reached