(L) Prelim RFR: 8132510: Replace ThreadLocalStorage with compiler/language-based thread-local variables

[David Holmes]

Sorry Thomas the all important:

src/os/posix/vm/threadLocalStorage_posix.cpp

was missing from the webrev. Now adding.

David
-----

On 12/11/2015 2:47 AM, Thomas Stüfe wrote:
>
> On Wed, Nov 11, 2015 at 5:36 PM, Thomas Stüfe <thomas.stuefe at gmail.com
> <mailto:thomas.stuefe at gmail.com>> wrote:
>
>     Hi David,
>
>     I get build errors on all my platforms.
>
>     I think the change misses #include "runtime/threadLocalStorage.hpp"
>     in a couple of places, at least thread.cpp and possible also the
>     os_xx_yy.cpp files.
>
>
> Sorry, I have to correct myself. It is a linker error, I do not find the
> implementations for the ThreadLocalStorage class methods anywhere. I
> applied your patch atop a freshly synced hs-rt repo:
>
> - .../hotspot $ hg log -l 3
> changeset:   9317:3b23f69bc887 8132510__thread_davids_change qbase qtip tip
> user:        stuefe
> date:        Wed Nov 11 16:12:14 2015 +0100
> summary:     imported patch 8132510__thread_davids_change
>
> changeset:   9316:f17e5edbe761 qparent
> user:        tschatzl
> date:        Tue Nov 10 11:07:15 2015 +0100
> summary:     8140689: Skip last young-only gc if nothing to do in the
> mixed gc phase
> Reviewed-by: mgerdin, drwhite
>
> on AIX I get:
>
> ld: 0711-317 ERROR: Undefined symbol: .ThreadLocalStorage::thread()
> ld: 0711-317 ERROR: Undefined symbol: .ThreadLocalStorage::is_initialized()
> ld: 0711-317 ERROR: Undefined symbol:
> .ThreadLocalStorage::set_thread(Thread*)
> ld: 0711-317 ERROR: Undefined symbol: .ThreadLocalStorage::init()
>
> Am I building wrong?
>
> Regards, Thomas
>
>
>     Will take another look tomorrow.
>
>     Thanks, Thomas
>
>     On Wed, Nov 11, 2015 at 9:19 AM, David Holmes
>     <david.holmes at oracle.com <mailto:david.holmes at oracle.com>> wrote:
>
>         Hi Thomas,
>
>         Okay here's the next revision:
>
>         http://cr.openjdk.java.net/~dholmes/8132510/webrev.v5/
>
>         I've reinstated a basic ThreadLocalStorage class which will only
>         need two implementations: a POSIX one, and a Windows one (still
>         TBD). This class is always initialized and
>         ThreadLocalStorage::thread() is used from the signal handlers
>         (as today).
>
>         For platforms that don't have __thread support they can define
>         USE_LIBRARY_BASED_TLS_ONLY at build time to only use the
>         ThreadLocalStorage implementation.
>
>         Obviously still need to get some performance numbers.
>
>         I'd appreciate it if you could retest AIX, though as all
>         platforms currently use pthread_get/setspecific I'm confident
>         there will be no platform issues.
>
>         Thanks,
>         David
>
>
>