This monitor communicates with the debugger using the DCC, and could arrange for example to single step only a single process while other processes ( and interrupt handlers ) continue running.
42.
If these timing constraints are not observed, the abort interrupt handler itself may be aborted, causing registers and / or memory to be changed in a possibly-undefined manner.
43.
How stacks work for kernel level " processes " and things like interrupt handlers is a rather difficult matter .-- Talk 00 : 25, 31 October 2010 ( UTC)
44.
If the hardware requires the interrupt be acknowledged, the CPU ( interrupt handler ) will do that, handle the valid DMA descriptors at the head, and return from the interrupt.
45.
Thus, the level-3 scheduler interrupt handler would temporarily raise IPL to 7 before accessing any actual scheduler data structures, then lower back to 3 before actually switching process contexts.
46.
The segment is expanded internally by the processor to 20 bits by shifting it 4 bits to the left, thus limiting real mode interrupt handlers to the first 1 megabyte of memory.
47.
Typically, the interrupt handler saves all other CPU registers it uses, unless they are used to return the result of an operation to the calling program ( in software called interrupts ).
48.
The system was remarkable at the time for having a built-in assembler, floating-point package, interrupt handler, and display editor ( similar to the Nova display editor ).
49.
So the clock interrupt handler requests a DPC object and adds it to the end of the DPC queue which will process the dispatching when the processor's IRQL drops to DPC / Dispatch level.
50.
Through the use of the real-time Linux kernel patch PREEMPT _ RT, support for full preemption of critical sections, interrupt handlers, and " interrupt disable " code sequences can be supported.
