QFile::handle count limits

[evgenM]

#include <QApplication>
#include <QFile>
 
int main( int argc, char ** argv )
{
	QApplication app( argc, argv );
#ifdef Q_OS_WIN	
	QFile file("../src/main.cpp");
	int i = 1;
	while(1)
	{
		if (file.open(QIODevice::ReadOnly))
		{
			uchar* content = file.map(0, file.size());
			if (file.handle() == -1)
				break;
 
			file.unmap(content);
			++i;
		}
		else
		{
			printf("can't open file");
			break;
		}
		file.close();
	}
 
	printf("handle count = %i\n", i);
#endif
	return 0;
};

#include <QApplication>
#include <QFile>

int main( int argc, char ** argv )
{
	QApplication app( argc, argv );
#ifdef Q_OS_WIN	
	QFile file("../src/main.cpp");
	int i = 1;
	while(1)
	{
		if (file.open(QIODevice::ReadOnly))
		{
			uchar* content = file.map(0, file.size());
			if (file.handle() == -1)
				break;

			file.unmap(content);
			++i;
		}
		else
		{
			printf("can't open file");
			break;
		}
		file.close();
	}

	printf("handle count = %i\n", i);
#endif
	return 0;
};

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if call QFile::handle 2046 time, next time it always return "-1". It's problem only for windows.
Is my error or qt limit?