(10) (M) RFR: 8174231: Factor out and share PlatformEvent and Parker code for POSIX systems

Thu May 18 14:40:38 UTC 2017

Hi David, Magnus,

compiles and works fine on AIX, but as mentioned before off-list to David I
see this stdout:

configure: No CLOCK_GETTIME_IN_LIBRT
configure: No CLOCK_GETTIME_IN_LIBRT

Also, the -DSUPPORTS_CLOCK_MONOTONIC appears twice on the command line.
Full compile command looks like this:

/bin/xlC_r -q64 -qpic -D_REENTRANT -D__STDC_FORMAT_MACROS
-DSUPPORTS_CLOCK_MONOTONIC -DSUPPORTS_CLOCK_MONOTONIC -DAIX -qtune=balanced
-qalias=noansi -qstrict -qtls=default -qlanglvl=c99vla -qlanglvl=noredefmac
-qnortti -qnoeh -qignerrno -qarch=ppc64 -DASSERT -DTARGET_ARCH_ppc
-DINCLUDE_SUFFIX_OS=_aix -DINCLUDE_SUFFIX_CPU=_ppc -DTARGET_COMPILER_xlc
-DPPC64 -DHOTSPOT_LIB_ARCH='"ppc64"' -DCOMPILER1 -DCOMPILER2
-DINCLUDE_JVMCI=0 -I/priv/d031900/openjdk/jdk10-hs/source/hotspot/src/share/vm
-I/priv/d031900/openjdk/jdk10-hs/source/hotspot/src/os/aix/vm
-I/priv/d031900/openjdk/jdk10-hs/source/hotspot/src/os/posix/vm
-I/priv/d031900/openjdk/jdk10-hs/source/hotspot/src/cpu/ppc/vm
-I/priv/d031900/openjdk/jdk10-hs/source/hotspot/src/os_cpu/aix_ppc/vm
-I/priv/d031900/openjdk/jdk10-hs/output/hotspot/variant-server/gensrc
-I/priv/d031900/openjdk/jdk10-hs/source/hotspot/src/share/vm/precompiled
-I/priv/d031900/openjdk/jdk10-hs/source/hotspot/src/share/vm/prims
-DDONT_USE_PRECOMPILED_HEADER -g -qsuppress=1540-0216 -qsuppress=1540-0198
-qsuppress=1540-1090 -qsuppress=1540-1639 -qsuppress=1540-1088
-qsuppress=1500-010 -O3 -qhot=level=1 -qinline -qinlglue
-DTHIS_FILE='"os_posix.cpp"' -c -qmakedep=gcc -MF
/priv/d031900/openjdk/jdk10-hs/output/hotspot/variant-server/libjvm/objs/os_posix.d
-o /priv/d031900/openjdk/jdk10-hs/output/hotspot/variant-server/libjvm/objs/os_posix.o
/priv/d031900/openjdk/jdk10-hs/source/hotspot/src/os/posix/vm/os_posix.cpp

 -DSUPPORTS_CLOCK_MONOTONIC is the only switch appearing twice. I'm
baffled. Do you have any idea?

Regards, Thomas

On Thu, May 18, 2017 at 12:06 PM, Magnus Ihse Bursie <
magnus.ihse.bursie at oracle.com> wrote:

>
>
> On 2017-05-18 09:35, David Holmes wrote:
>
>> On 18/05/2017 5:32 PM, Magnus Ihse Bursie wrote:
>>
>>> On 2017-05-18 08:25, David Holmes wrote:
>>>
>>>> Bug: https://bugs.openjdk.java.net/browse/JDK-8174231
>>>>
>>>> webrevs:
>>>>
>>>> Build-related: http://cr.openjdk.java.net/~dholmes/8174231/webrev.top/
>>>>
>>>
>>> Build changes look  good.
>>>
>>
>> Thanks Magnus! I just realized I left in the AC_MSG_NOTICE debugging
>> prints outs - do you want me to remove them? I suppose they may be useful
>> if something goes wrong on some platform.
>>
>
> I didn't even notice them. :-/
>
> It's a bit unfortunate we don't have a debug level on the logging from
> configure. :-( Otherwise they would have clearly belonged there.
>
> The AC_MSG_NOTICE messages stands out much from the rest of the configure
> log, so maybe it's better that you remove them. The logic itself is very
> simple, if the -D flags are missing then we can surely tell what happened.
> So yes, please remove them.
>
> Alternatively, rewrite them as CHECKING/RESULT, if you want to keep the
> logging. That way they match better the rest of the configure log (and also
> describes what you're doing). Just check if AC_SEARCH_LIBS prints some
> output (likely so, I think), then you can't do it in the middle of a
> CHECKING/RESULT pair, but have to do the CHECKING part after AC_SEARCH_LIBS.
>
> /Magnus
>
>
>
>> David
>>
>> /Magnus
>>>
>>>       hotspot:
>>>> http://cr.openjdk.java.net/~dholmes/8174231/webrev.hotspot/
>>>>
>>>> First a big thank you to Thomas Stuefe for testing various versions of
>>>> this on AIX.
>>>>
>>>> This is primarily a refactoring and cleanup exercise (ie lots of
>>>> deleted duplicated code!).
>>>>
>>>> I have taken the PlatformEvent, PlatformParker and Parker::* code, out
>>>> of os_linux and moved it into os_posix for use by Linux, OSX, BSD, AIX
>>>> and perhaps one day Solaris (more on that later).
>>>>
>>>> The Linux code was the most functionally complete, dealing with
>>>> correct use of CLOCK_MONOTONIC for relative timed waits, and the
>>>> default wall-clock for absolute timed waits. That functionality is
>>>> not, unfortunately, supported by all our POSIX platforms so there are
>>>> some configure time build checks to set some #defines, and then some
>>>> dynamic lookup at runtime**. We allow for the runtime environment to
>>>> be less capable than the build environment, but not the other way
>>>> around (without build time support we don't know the runtime types
>>>> needed to make library calls).
>>>>
>>>> ** There is some duplication of dynamic lookup code on Linux but this
>>>> can be cleaned up in future work if we refactor the time/clock code
>>>> into os_posix as well.
>>>>
>>>> The cleanup covers a number of things:
>>>> - removal of linux anachronisms that got "ported" into the other
>>>> platforms
>>>>   - eg EINTR can not be returned from the wait methods
>>>> - removal of solaris anachronisms that got ported into the linux code
>>>> and then on to other platforms
>>>>   - eg ETIMEDOUT is what we expect never ETIME
>>>> - removal of the ancient/obsolete os::*::allowdebug_blocked_signals()
>>>> from the Parker methods
>>>> - consolidation of unpackTime and compute_abstime into one utility
>>>> function
>>>> - use statics for things completely private to the implementation
>>>> rather than making them part of the os* API (eg access to condAttr
>>>> objects)
>>>> - cleanup up commentary and style within methods of the same class
>>>> - clean up coding style in places eg not using Names that start with
>>>> capitals.
>>>>
>>>> I have not tried to cleanup every single oddity, nor tried to
>>>> reconcile differences between the very similar in places PlatformEvent
>>>> and Park methods. For example PlatformEvent still examines the
>>>> FilterSpuriousWakeups** flag, and Parker still ignores it.
>>>>
>>>> ** Perhaps a candidate for deprecation and future removal.
>>>>
>>>> There is one mini "enhancement" slipped in this. I now explicitly
>>>> initialize mutexes with a mutexAttr object with its type set to
>>>> PTHREAD_MUTEX_NORMAL, instead of relying on the definition of
>>>> PTHREAD_MUTEX_DEFAULT. On FreesBSD the default is not "normal" but
>>>> "error checking" and so is slow. On all other current platforms there
>>>> is no effective change.
>>>>
>>>> Finally, Solaris is excluded from all this (other than the debug
>>>> signal blocking cleanup) because it potentially supports three
>>>> different low-level sync subsystems: UI thr*, Pthread, and direct LWP
>>>> sync. Solaris cleanup would be a separate RFE.
>>>>
>>>> No doubt I've overlooked mentioning something that someone will spot. :)
>>>>
>>>> Thanks,
>>>> David
>>>>
>>>
>>>
>