Re: [9fans] double lock in proc.c

This was many years ago (when my now-white beard was still merely grey). Not worth going back to reconstruct the arguments, but I'll send Giacomo and Nemo a copy of my proc.c to examine for themselves. I'd also be interested by your copy if proc.c. Thanks. -- David du Colombier

Re: [9fans] double lock in proc.c

I'm not convinced that I recall not being convinced ... :) Essentially I changed the order of lock acquire/release so that the canlock() loop in proc.c:/^postnote could be eliminated. Not significant for performance, but it seemed more elegant and I think it also avoided looking at any shared

Re: [9fans] double lock in proc.c

do you remember the proposal? thanks > El 24 jul 2017, a las 18:39, Erik Quanstrom escribió: > > I had a discussion with Richard about this a few years ago. Richard was no > longer convinced of the solution. at the time I agreed with his reasoning. > the comment

Re: [9fans] double lock in proc.c

I had a discussion with Richard about this a few years ago.  Richard was no longer convinced of the solution.  at the time I agreed with his reasoning.  the comment should be changed.- erikOn Jul 24, 2017 9:03 AM, Giacomo Tesio wrote:In /sys/src/9/port/proc.c a comment state:/**

[9fans] double lock in proc.c

In /sys/src/9/port/proc.c a comment state: /* * Expects that only one process can call wakeup for any given Rendez. * We hold both locks to ensure that r->p and p->r remain consistent. * Richard Miller has a better solution that doesn't require both to * be held simultaneously, but I'm a paranoid