replay debugging via vmware

[Michael Snyder]

Edward Peschko wrote:
> All,
> 
> I see from the recent messages that gdb is close to supporting
> reversible debugging - but is this reversible debugging in the sense
> of:
> 
> http://www.youtube.com/watch?v=RvMlihjqlhY

Yep, gdb's reverse debugging will support most or all of the
features that you see in the above demonstration, including
   * continue backwards to a breakpoint
   * continue backwards to a watchpoint

In fact, very soon, gdb will work with VMware workstation just like
you see in the demo (with a Linux guest OS).

> (ie: vmware's version). There was talk about it in the video
> (basically one recorded a indeterminant events in a run, and then
> replayed it so it could be reversed), but as it stood, all development
> was being done on visual studio.
> 
> If not, how does gdb's reversible debugging avoid being extremely slow?

The current gdb implementation (known as "process record / replay")
records and replays only the execution of a single linux process.
Less data equals greater performance.

VMware's implementation records everything that happens on
the entire virtual machine including the OS and bios.  It's
a somewhat more heavy-duty implementation, as well as somewhat
more complete.

When the time comes for VMware release, the user interface and
gdb commands will be exactly the same as those currently
supported for process record / replay.