Limitations
| GDI overflow in Internet Explorer 7 prevents the graphical elements of the browser tabs from drawing correctly, and the address bar incorrectly appears by itself in the top-left corner of the desktop display area. In these example screenshots, approximately 49 windows were opened at the same time, using Windows XP with Service Pack 3 and Internet Explorer 7. |
Each time a window is opened, it consumes GDI objects. As the complexity of the window increases, with additional features such as buttons and images, its GDI object usage also increases. When too many objects are in use, Windows is unable to draw any more GDI objects, leading to misbehaving software and frozen and unresponsive program operation. The total available GDI objects varies from one version of Windows to the next: Windows 95, 98, and Millennium had a limit of 1,200 total objects; Windows 2000 has a limit of 16,384 objects; and Windows XP, Vista, and Windows 7 have a configurable limit (via the registry) that defaults to 10,000 objects per process (but a theoretical maximum of 65,536 for the entire session).
Earlier versions of Windows such as Windows 3.1 and Windows 98 included a Resource Meter program to allow the user to monitor how much of the total system GDI resources were in use. This resource meter ironically consumed GDI objects itself. Later versions such as Windows 2000 and Windows XP can report GDI object usage for each program in the Task Manager, but they cannot tell the user the total GDI capacity available.
Overflowing GDI capacity can affect Windows itself, preventing new windows from opening, menus from displaying, and alert boxes from appearing. The situation can be difficult to clear and can potentially require a forced hard-reset of the system, since it prevents core system programs from functioning.
For example, forcing a frozen process to end using the Task Manager normally makes an "Are you sure" alert window appear. With no free GDI, Windows beeps an error and the alert choice does not appear, so the GDI-overflowing processes cannot be terminated (unless the user uses taskkill command).
Sometimes a single application can consume the entire free desktop heap memory. There is a tool from Microsoft called Desktop Heap Monitor, which can show which application consumes what percent of the desktop heap.
Read more about this topic: Graphics Device Interface
Famous quotes containing the word limitations:
“No man could bring himself to reveal his true character, and, above all, his true limitations as a citizen and a Christian, his true meannesses, his true imbecilities, to his friends, or even to his wife. Honest autobiography is therefore a contradiction in terms: the moment a man considers himself, even in petto, he tries to gild and fresco himself.”
—H.L. (Henry Lewis)
“That all may be so, but when I begin to exercise that power I am not conscious of the power, but only of the limitations imposed on me.”
—William Howard Taft (1857–1930)
“Growing up means letting go of the dearest megalomaniacal dreams of our childhood. Growing up means knowing they can’t be fulfilled. Growing up means gaining the wisdom and skills to get what we want within the limitations imposed by reality—a reality which consists of diminished powers, restricted freedoms and, with the people we love, imperfect connections.”
—Judith Viorst (20th century)