Re: [patch] Fix for bz14333 -- race between atexit() and exit()

[Paul Pluzhnikov <ppluzhnikov at google dot com>]

On Mon, Jul 24, 2017 at 1:14 PM, Paul Pluzhnikov <ppluzhnikov@google.com> wrote:

>> Kind of, I guess.  When you write that __exit_funcs_lock protects
>> __exit_funcs, do you mean that it also protects the full list that this
>> global points to?  If so, please say that.
>
> Yes, Will do.

Done.

>> Does that fully remove the need for what looks like an (incorrect)
>> attempt to build a concurrent list?
>
> Probably. Let me review these. I suspect they are no longer necessary.

That is correct: the half-cooked atomic accesses are no longer
necessary, since all modifications (and reads) now happen under the
lock. I've removed them.


2017-07-31  Paul Pluzhnikov  <ppluzhnikov@google.com>
            Ricky Zhou <rickyz@google.com>
            Anoop V Chakkalakkal <anoop.vijayan@in.ibm.com>

        [BZ #14333]
        * stdlib/cxa_atexit.c (__internal_atexit): Use __exit_funcs_lock.
        Remove atomics.
        (__new_exitfn): Fail registration when we finished at_exit processing.
        * stdlib/cxa_finalize.c (__cxa_finalize): Likewise.
        * stdlib/on_exit.c (__on_exit): Likewise.
        * stdlib/exit.c (__exit_funcs_done): New variable.
        (__run_exit_handlers): Use __exit_funcs_lock.
        * stdlib/exit.h (__exit_funcs_lock, __exit_funcs_done): New
        declarations.
        * stdlib/Makefile (test-atexit-race, test-quick_at_exit-race)
        (test-cxa_atexit-race): New tests.
        * stdlib/test-atexit-race-common.c: New.
        * stdlib/test-atexit-race.c: New.
        * stdlib/test-at_quick_exit-race.c: New.
        * stdlib/test-cxa_atexit-race.c: New.




-- 
Paul Pluzhnikov

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