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<div class="moz-cite-prefix">Am 17.10.2017 um 23:10 schrieb Roman
Kennke:<br>
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<p>The SuspendibleThreadSet API for synchronizing any non-Java
thread with safepoints currently resides under gc/g1. It is
very useful for other GCs too (in particular, Shenandoah does
use it too), so I wanted to move it to a common location like
gc/common. Then Kim Barrett commented that it might actually
be useful for other threads outside GC land and to put it
under runtime/. So I did:</p>
<p><a moz-do-not-send="true"
href="http://cr.openjdk.java.net/%7Erkennke/8189276/webrev.00/">http://cr.openjdk.java.net/~rkennke/8189276/webrev.00/</a></p>
<p>I also added a generic hook to call the STS from safepoint
sync/desync, which is consequently used by G1 now. In other
words, the CollectedHeap API that Erik Ö introduced is no
longer used by G1. Only CMS still uses that API because it has
its own way to sync with safepoints. I filed <a
moz-do-not-send="true"
href="https://bugs.openjdk.java.net/browse/JDK-8189364">another
bug</a> for this. Although I have my doubt it will ever be
fixed. This seems to have been very carefully evolved (to put
it positive), and the risk of breaking it is relatively high,
and thus doesn't seem worth the struggle to make it fit the
STS.<br>
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<p>Issue:<br>
<a moz-do-not-send="true"
href="https://bugs.openjdk.java.net/browse/JDK-8189276">https://bugs.openjdk.java.net/browse/JDK-8189276</a></p>
<p>What do you think? Ok to go in?</p>
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Replying to myself here.<br>
I must admit that I am a bit reluctant to expose it to runtime/
unless there's a specific need for it. So maybe go back to the
original plan to move it into gc/common and leave all the rest
alone for now? What do others think?<br>
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Sorry, forgot to add something. One reason why we originally wanted
to move it to gc/common (a new directory) instead of the existing
gc/shared was that Erik H objected that gc/shared would be built
into the minimal VM, and we probably wouldn't want that unless
needed. However, moving it to runtime/ (without actual need), would
achieve just that. So unless we can name an actual thread that would
benefit from synchronizing using the STS, I suggest to leave the STS
code in gc/common for now?<br>
<br>
That would be:<br>
<a moz-do-not-send="true"
href="http://cr.openjdk.java.net/%7Erkennke/8189276/webrev.01/">http://cr.openjdk.java.net/~rkennke/8189276/webrev.01/</a><br>
<br>
Roman<br>
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