JUST-IN-TIME DEBUGGING SYSTEM AND METHODS UNDER THE WINDOWS 3.0 AND WINDOWS 3.1 OPERATING SYSTEMS

The invention includes systems and methods for debugging an application program running under an operating system such as Windows.RTM. 3.0 or 3.1. Such an operating system allows registration of callback functions with an operating system exception handler. The operating system exception handler calls the registered callback functions in response to an exception generated by the application program until one of the callback functions indicates that the exception has been resolved. The invention includes a monitor program which is installed in program memory concurrently with the application program. The monitor program registers itself with the operating system exception handler to be called in response to an exception generated by the application program. When called, the monitor callback function finds the startup parameters of the application program which generated the exception and starts a debugging program, using the startup parameters. The debugging program, in accordance with normal characteristics of debugging programs, registers itself with the operating system exception handler and then yields to the operating system. The monitor program returns control to the operating system without indicating that the exception has been resolved. Thereafter, the exception handler calls the registered debugging program to initiate debugging of the application program which generated the exception.