Exception Dispatching - Win32 Programmer's Reference

Custom Search

Exception Dispatching

When a hardware or software exception occurs, the processor stops execution at the point at which the exception occurred and transfers control to the system. First, the system saves both the machine state of the current thread and information that describes the exception. The system then attempts to find an exception handler to handle the exception.

The machine state of the thread in which the exception occurred is saved in a CONTEXT structure. This information (called the context record) enables the system to continue execution at the point of the exception if the exception is successfully handled. The description of the exception (called the exception record) is saved in an EXCEPTION_RECORD structure. Because it stores the machine-dependent information of the context record separately from the machine-independent information of the exception record, the exception-handling mechanism is portable to different platforms. The information in both the context and exception records is available by means of the GetExceptionInformation function, and can be made available to any exception handlers that are executed as a result of the exception. The exception record includes the following information.

An exception code that identifies the type of exception.
Flags indicating whether the exception is continuable. Any attempt to continue execution after a noncontinuable exception generates another exception.
A pointer to another exception record. This facilitates creation of a linked list of exceptions if nested exceptions occur.
The address at which the exception occurred.
An array of 32-bit arguments that provide additional information about the exception.

When an exception occurs in user-mode code, the system goes through the following search for an exception handler:

The system first attempts to notify the process's debugger, if any.
If the process is not being debugged, or if the associated debugger does not handle the exception, the system attempts to locate a frame-based exception handler by searching the stack frames of the thread in which the exception occurred. The system searches the current stack frame first, then proceeds backward through preceding stack frames.
If no frame-based handler can be found, or no frame-based handler handles the exception, the system makes a second attempt to notify the process's debugger.
If the process is not being debugged, or if the associated debugger does not handle the exception, the system provides default handling based on the exception type. For most exceptions, the default action is to call the ExitProcess function.

When an exception occurs in kernel-mode code, the system searches the stack frames of the kernel stack in an attempt to locate an exception handler. If a handler cannot be located or no handler handles the exception, the system is shut down as if the ExitWindows function had been called.

Last news from Greatis Software

    Nostalgia .Net     .Net is powerful, but not all-powerful, so sometimes we need to use Win32 API for our .Net applications. It's simple enough with Platform Invoke if you have Win32 skill, but we do not always have time to dig the ancient documentation, declare the special types that are compatible with Win32, find the values of the Win32's constants and so on. Nostalgia .Net offers several simple-to-use classes, and components that will allow you to forget about the headache of Win32 and just use the power of Win32 in your application the same way as you use the native. Net classes. More »

Recommended software for developers

    Ultimate Pack     Component pack for Delphi and C++ Builder that contains runtime form designer, runtime object inspector, print suite and much more for the very special price. More »

    Form Designer .Net     Unique runtime form design solution that allows to edit any form in .Net WinForms application at runtime with full source codes for only 300 euro! More »

    Print Suite .Net     Print Suite .Net is a set of components for easy printing texts, images and grids from your WinForms applications. Full C# source codes are available More »

    Gradient Controls .Net     Gradient Controls .Net offers controls with gradient background feature. Labels, panels and so on... Full C# source codes are available More »

    Greatis iGrid     iGrid plots drawing grid right over your desktop, so you can use it everywhere, with any drawing application without any special plugins for different graphic editors. More »

All the contacts and projects

Dmitry Vasiliev (just.dmitry)

More Online Helps

Win32 Programmer's Reference
Win32 Multimedia Programmer's Reference
OLE Programmer's Reference
Microsoft Windows Pen API Programmer's Reference
Microsoft Windows Sockets 2 Reference
Microsoft Windows Telephony API (TAPI) Programmer's Reference
Unix Manual Pages

greatis just4fun network