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<p>Not sure how helpful this is, but LWJGL recently implemented
io_uring and liburing bindings. Maybe the bindings and demo code
could serve as a reference for your experiments? The demo package
includes samples/benchmarks using both the low level io_uring and
high level liburing:
<a class="moz-txt-link-freetext" href="https://github.com/LWJGL/lwjgl3/tree/master/modules/samples/src/test/java/org/lwjgl/demo/system/linux/liburing">https://github.com/LWJGL/lwjgl3/tree/master/modules/samples/src/test/java/org/lwjgl/demo/system/linux/liburing</a></p>
<p>-DJ<br>
</p>
<div class="moz-cite-prefix">On 9/21/2022 6:39 PM, Gavin Ray wrote:<br>
</div>
<blockquote type="cite"
cite="mid:CAFtvWZP4yF8sMK_szTjK4cBKDTtu0wg6dfiYeceApjNKCpLoUg@mail.gmail.com">
<meta http-equiv="content-type" content="text/html; charset=UTF-8">
<div dir="ltr">
<div dir="ltr">Ahh okay, thank you.
<div><br>
</div>
<div>> In general inline functions (and function-like
macros) are not true library symbols, so there's not much
the Linker can do for them.</div>
<p>> If you need to access these, you would need a native
library wrapper which exposes them as regular symbols.</p>
<p><br>
</p>
<div>That makes sense -- I will look at patching liburing with
a dirty one-liner that strips "static inline" from the
definitions that have them then, ty =)</div>
<div><br>
</div>
<div>Do you anticipate any issues with using in/out-pointers
as things get passed back and forth from native to Java?</div>
<div>I tried to write a draft of how I think the translation
of a "hello world" io_uring program should be:</div>
<div><br>
</div>
<div><a
href=":https://gist.github.com/GavinRay97/8ea0997693c00f8df61968a98ba30135#file-io_uring-java"
moz-do-not-send="true" class="moz-txt-link-freetext">:https://gist.github.com/GavinRay97/8ea0997693c00f8df61968a98ba30135#file-io_uring-java</a><br>
</div>
<div><br>
</div>
<div>(The C version at the bottom is canonical/definitely
works)</div>
<div><br>
</div>
</div>
</div>
<br>
<div class="gmail_quote">
<div dir="ltr" class="gmail_attr">On Wed, Sep 21, 2022 at 5:13
PM Maurizio Cimadamore <<a
href="mailto:maurizio.cimadamore@oracle.com"
moz-do-not-send="true" class="moz-txt-link-freetext">maurizio.cimadamore@oracle.com</a>>
wrote:<br>
</div>
<blockquote class="gmail_quote" style="margin:0px 0px 0px
0.8ex;border-left:1px solid rgb(204,204,204);padding-left:1ex">
<div>
<p>Hi Gavin,<br>
thanks for the question - actually this might trip up
others as well, so it's always good to ask here.<br>
</p>
<p>I believe this has been fixed recently:</p>
<p><a href="https://github.com/openjdk/jextract/pull/70"
target="_blank" moz-do-not-send="true"
class="moz-txt-link-freetext">https://github.com/openjdk/jextract/pull/70</a></p>
<p>But the binary snapshots do not contain this fix.</p>
<p>In general inline functions (and function-like macros)
are not true library symbols, so there's not much the
Linker can do for them.</p>
<p>If you need to access these, you would need a native
library wrapper which exposes them as regular symbols.</p>
<p>(we'd like, at some point, to automate the wrapper
generation in jextract).</p>
<p>Maurizio<br>
</p>
<div>On 21/09/2022 20:35, Gavin Ray wrote:<br>
</div>
<blockquote type="cite">
<div dir="ltr">
<div dir="ltr">
<div dir="ltr">I'm not super familiar with how linking
and symbols work
<div><br>
</div>
<div>The liburing header is weird, it contains a mix
of definitions:</div>
<div><a
href="https://github.com/axboe/liburing/blob/master/src/include/liburing.h"
target="_blank" moz-do-not-send="true"
class="moz-txt-link-freetext">https://github.com/axboe/liburing/blob/master/src/include/liburing.h</a><br>
</div>
<div><br>
</div>
<div>Some of them are traditional header defs, like:</div>
<div><br>
</div>
</div>
<blockquote style="margin:0px 0px 0px
40px;border:none;padding:0px">
<div dir="ltr">
<div>
<div>int io_uring_queue_init(unsigned entries,
struct io_uring *ring, unsigned flags);</div>
</div>
<div><br>
</div>
</div>
</blockquote>
But there are a lot of them which are defined like
this:
<div>
<blockquote style="margin:0px 0px 0px
40px;border:none;padding:0px">
<div>
<div><br>
</div>
<div>static inline int io_uring_wait_cqe(struct
io_uring *ring, struct io_uring_cqe **cqe_ptr)</div>
</div>
<div><br>
</div>
</blockquote>
Using "objdump" on the ".so", I can see that none of
these "static inline" functions appear</div>
<div><br>
</div>
<div>I have an almost-working test of using io_uring
purely through Panama here, but it fails due to the
above:</div>
<div><a
href="https://github.com/GavinRay97/panama-liburing/blob/82f83a247bb78c26d787992fca28ea1b951dfd3c/lib/src/test/java/panama/liburing/LibraryTest.java#L25-L59"
target="_blank" moz-do-not-send="true"
class="moz-txt-link-freetext">https://github.com/GavinRay97/panama-liburing/blob/82f83a247bb78c26d787992fca28ea1b951dfd3c/lib/src/test/java/panama/liburing/LibraryTest.java#L25-L59</a><br>
</div>
<div><br>
</div>
<div>How are you meant to be able to use these from
the Foreign Memory API?</div>
<div>Do I need to write a second library and built it,
that re-exports these?</div>
<div><br>
</div>
<div>Thanks, and sorry for so many newbie questions</div>
<div><br>
</div>
<div><br>
</div>
</div>
</div>
</blockquote>
</div>
</blockquote>
</div>
</blockquote>
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