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<p>Hi Glavo,<br>
that's a very interesting comparison, thank you!</p>
<p>We will look into the C string -> Java string issue. There are
probably "tricks" [1] that native strlen does which we could
replicate in our Java code (or we could just do a trivial call to
strlen :-) ).</p>
<p>Aso for struct layouts, I think it is a reasonable request - e.g.
allow creation of struct layouts which are "padded" correctly. But
I think we'd still want to retain the "raw" variant, which might
be useful for tools such as jextract.</p>
<p>Cheers<br>
Maurizio<br>
</p>
<p><br>
</p>
<div class="moz-cite-prefix">On 24/03/2023 19:07, Glavo wrote:<br>
</div>
<blockquote type="cite" cite="mid:CAJL5A3=E+1pD7AKffx7pSMksq6jGWhL8B39XidPbO0+b8MW8zg@mail.gmail.com">
<div dir="ltr">I have run a series of benchmarks of Panama, JNI,
JNA, and JNR based on the latest JDK. Here is its GitHub
repository:<br>
<div><br>
</div>
<div> <a href="https://github.com/Glavo/java-ffi-benchmark" moz-do-not-send="true" class="moz-txt-link-freetext">https://github.com/Glavo/java-ffi-benchmark</a></div>
<div><br>
</div>
<div>Here I tested the performance of no-ops, accessing structs,
string conversions, and callbacks, respectively. I also tried
the new isTrivial linker option.</div>
<div>I summarized the results in README and charted them.<br>
</div>
<div><br>
</div>
<div>In this email, in addition to sharing the above results, I
would also like to talk about several issues I have
encountered<br>
</div>
<div><br>
</div>
<div>1. MemorySegment.getUtf8String is unexpectedly slow</div>
<div><br>
</div>
<blockquote style="margin:0 0 0 40px;border:none;padding:0px">
<div>Panama is much faster than JNA in most cases, but the
operation of converting C strings to Java strings is an
exception.</div>
<div>I checked the source code of JNA and Panama, and the
suspicious difference is that JNA uses strlen from the C
standard library, while Panama uses Java loops. </div>
<div>Perhaps this method can be optimized.</div>
</blockquote>
<div><br>
</div>
<div>2. StructLayout must manually specify all padding</div>
<div><br>
</div>
<blockquote style="margin:0 0 0 40px;border:none;padding:0px">
<div>Can we provide a convenient method for automatically
padding between fields based on alignment?</div>
<div>The current structLayout method is annoying for
situations where you need to manually simulate the layout of
a C struct.</div>
</blockquote>
<div><br>
</div>
<div>Glavo</div>
</div>
</blockquote>
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