dillon at apollo.backplane.com
Wed Oct 8 21:17:56 PDT 2003
:cvs diff: Diffing .
:RCS file: /home/dcvs/src/sys/sys/signalvar.h,v
:retrieving revision 1.5
:diff -r1.5 signalvar.h
:> sig_t ps_checkpoint; /* place to store checkpoint/restore upcall */
:> sig_t ps_restore;
sigacts has the ps_sigact array which I believe contains
128 signals by default. Since only 32 some odd signals are defined,
there are plenty of signals available for your checkpoint and restore
vectors (though I still think there is only a need for a checkpoint
signal, since the restore can simply resume the signal handler from
the point where it called freeze()). There are other little cleanups
you can do, but I'm sure you are already aware of them (e.g. converting
those macros like READ_CHECK into inlines and removing
I've played with it a bit, I think you are making excellent progress!
You even made it a kld. Wow.
We need to add a stty signal similar to how ^\ core's a program, to
checkpoint a program. That would be so cool.
Am I correct in that currently the program binary that was checkpointed
must do the restore? I tried writing a little program that restore'd
another program's checkpoint file but it seg faulted. So, presumably,
the next step is to save and restore filesystem-based file descriptors
so as to reacquire the original text image. That's a fairly tough nut
to crack, but the result will be incredibly powerful.
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