Re: [Libunwind-devel] interval based cache?

[Bert Wesarg]

I did re-enabled the per-thread cache back on here:

https://github.com/libunwind/libunwind/pull/8

Bert

On Wed, Apr 12, 2017 at 9:13 PM, Dave Watson <address@hidden> wrote:
> On 04/12/17 02:08 PM, Doug Moore wrote:
>> It's not clear to me that the cache is thread-safe; I don't see any locking
>> going on, so I wonder if there might be problems with multiple threads
>> reading/writing the global cache at once.  Has this problem been addressed?
>
> Gparser.c calls lock_acquire and lock_release if caching is UNW_CACHE_GLOBAL
>
> http://git.savannah.gnu.org/gitweb/?p=libunwind.git;a=blob;f=src/dwarf/Gparser.c;h=ede856e053e5d1716058d2e56165e9feb4a670e6;hb=HEAD#l571
>
> which are macros around sigprocmask + taking the lock with pthread_mutex_lock
>
> http://git.savannah.gnu.org/gitweb/?p=libunwind.git;a=blob;f=include/libunwind_i.h;h=ee2ea2fbec327b1f812baabbab98191ded830c56;hb=HEAD#l199
>
> For thread-local cache, it is indeed not really safe, looks like the
> TLS part of it was removed at some point in the past, and we should
> fix it eventually:
>
> http://git.savannah.gnu.org/gitweb/?p=libunwind.git;a=blob;f=include/dwarf.h;h=e29b8400ea90719d196cffebd184829ca12a0b98;hb=HEAD#l41
>
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