Mail Archives: djgpp/1997/06/19/03:19:46
On Wed, 18 Jun 1997, Conrad Wei-Li Song wrote:
> I'm confused about why it is necessary to lock memory used by an
> exception handler. In the case where code resides in a currently
> paged-out location in memory, wouldn't a page fault occur and resume
> exception handling properly (assuming that the interrupt flag isn't
> cleared.
Page fault is an exception. Having an exception inside another
exception is a Bad Thing. Additionally, the first exception might
have happened during a DOS call (like when your program was reading a
file or printing to the screen) and the page fault handler also calls
DOS to read the swap file. Since DOS is non-reentrant, this is a
definite no-no.
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