<!DOCTYPE html><html><head>
<meta http-equiv="Content-Type" content="text/html; charset=utf-8">
</head>
<body>
<br>
<br>
<div class="moz-cite-prefix">On 26/02/2026 02:49, Mengyang Li wrote:<br>
</div>
<blockquote type="cite" cite="mid:CAJ_HiMuoPQ6wa8UvKoyvkD=mw9ES1ekBgg6_EFvxz96-3axfkA@mail.gmail.com"><!-- BaNnErBlUrFlE-HeAdEr-start -->
<style>#pfptBannerruzwtzt { all: revert !important; display: block !important;
visibility: visible !important; opacity: 1 !important;
background-color: #60beeb !important;
max-width: none !important; max-height: none !important }.pfptPrimaryButtonruzwtzt:hover, .pfptPrimaryButtonruzwtzt:focus {
background-color: #77a8c4 !important; }.pfptPrimaryButtonruzwtzt:active {
background-color: #8193a0 !important; }html:root, html:root>body { all: revert !important; display: block !important;
visibility: visible !important; opacity: 1 !important; }</style>
<!-- BaNnErBlUrFlE-HeAdEr-end -->
<!-- BaNnErBlUrFlE-BoDy-start -->
<!-- Preheader Text : BEGIN -->
<div style="display:none !important;display:none;visibility:hidden;mso-hide:all;font-size:1px;color:#ffffff;line-height:1px;max-height:0px;opacity:0;overflow:hidden;">
Hello everyone, With “Custom Scheduler Prototype v2”, the JDK
loads the class specified by
jdk. virtualThreadScheduler. implClass via the internal
AppClassLoader. This works for typical apps, but fails for
Spring Boot fat JARs where the application</div>
<!-- Preheader Text : END -->
<!-- Email Banner : BEGIN -->
<div style="display:none !important;display:none;visibility:hidden;mso-hide:all;font-size:1px;color:#ffffff;line-height:1px;max-height:0px;opacity:0;overflow:hidden;">ZjQcmQRYFpfptBannerStart</div>
<!--[if ((ie)|(mso))]>
<table border="0" cellspacing="0" cellpadding="0" width="100%" style="padding: 0px 0px 10px 0px; direction: ltr" lang="en"><tr><td>
<table border="0" cellspacing="0" cellpadding="0" style="padding: 0px 8px 6px 8px; width: 100%; border-radius:4px; border-top:4px solid #8193a0;background-color:#60beeb;"><tr><td valign="top">
<table align="left" border="0" cellspacing="0" cellpadding="0" style="padding: 0px 8px 4px 8px; font-size: 12px; line-height: 16px">
<tr><td style="color:#000000; font-family: 'Arial', sans-serif; font-weight:bold; font-size:14px; line-height: 20px; direction: ltr">
This Message Is From an Untrusted Sender
</td></tr>
<tr><td style="color:#000000; font-weight:normal; font-family: 'Arial', sans-serif; font-size:12px; direction: ltr">
You have not previously corresponded with this sender.
</td></tr>
</table>
<![if ie]><br clear="all"><![endif]>
<table align="right" border="0" cellspacing="0" cellpadding="0" style="padding: 0px 0px 4px 0px; font-size: 14px; line-height: 36px"><tr>
<td style="direction: ltr"> <a target="_blank" href="https://us-phishalarm-ewt.proofpoint.com/EWT/v1/ACWV5N9M2RV99hQ!Op20OCZDNWNhvTus2_N8MeJEQnesskq2r7GgxGykDyNNA4-uycq0qHDbuRK5bSU5gg4W_jImRrnOgyqomqy_2daMLpQS4OFFnoqBuitf0k9uHzHKvNGoQNctgSuh8FHXjJ0$" style="mso-padding-alt: 7px; padding: 7px; border-radius: 2px; border: 1px solid #666666; "><strong style="font-weight: normal; color: #000000; text-decoration: none; font-family: 'Arial', sans-serif; font-size: 14px;"> Report Suspicious </strong></a> </td>
</tr></table>
</td></tr></table>
</td></tr></table>
<![endif]-->
<!--[if !((ie)|(mso))]-->
<div dir="ltr" lang="en" id="pfptBannerruzwtzt" style="all: revert !important; display:block !important; text-align: left !important; margin: 0 0 10px 0 !important; padding:7px 16px 8px 16px !important; border-radius: 4px !important; min-width: 200px !important; background-color: #60beeb !important; background-color: #60beeb; border-top: 4px solid #8193a0 !important; border-top: 4px solid #8193a0;">
<div id="pfptBannerruzwtzt" style="all: unset !important; float:left !important; display:block !important; margin: 1px 0 1px 0 !important; max-width: 600px !important;">
<div id="pfptBannerruzwtzt" style="all: unset !important; display:block !important; visibility: visible !important; background-color: #60beeb !important; color:#000000 !important; color:#000000; font-family: 'Arial', sans-serif !important; font-family: 'Arial', sans-serif; font-weight:bold !important; font-weight:bold; font-size:14px !important; line-height:1.29 !important; line-height:1.29">
This Message Is From an Untrusted Sender </div>
<div id="pfptBannerruzwtzt" style="all: unset !important; display:block !important; visibility: visible !important; background-color: #60beeb !important; color:#000000 !important; color:#000000; font-weight:normal; font-family: 'Arial', sans-serif !important; font-family: 'Arial', sans-serif; font-size:12px !important; line-height:1.5 !important; line-height:1.5; margin-top:2px !important;">
You have not previously corresponded with this sender. </div>
</div>
<div id="pfptBannerruzwtzt" style="all: unset !important; float: right !important; display: block !important; display: block; margin-left: 16px !important; margin-top: 1px !important; text-align: right !important; width: fit-content !important; font-size: 12px !important">
<a id="pfptBannerruzwtzt" href="https://us-phishalarm-ewt.proofpoint.com/EWT/v1/ACWV5N9M2RV99hQ!Op20OCZDNWNhvTus2_N8MeJEQnesskq2r7GgxGykDyNNA4-uycq0qHDbuRK5bSU5gg4W_jImRrnOgyqomqy_2daMLpQS4OFFnoqBuitf0k9uHzHKvNGoQNctgSuh8FHXjJ0$" style="all: unset !important; display: inline-block !important; text-decoration: none" moz-do-not-send="true">
<div class="pfptPrimaryButtonruzwtzt" style="display: inline-block !important; display: inline-block; visibility: visible !important; opacity: 1 !important; color: #000000 !important; color: #000000; font-family: 'Arial', sans-serif !important; font-family: 'Arial', sans-serif; font-size: 14px !important; font-weight: normal !important; text-decoration: none !important; border-radius: 2px !important; margin-top: 3px !important; margin-bottom: 3px !important; margin-left: 16px !important; padding: 7.5px 16px !important; white-space: nowrap !important; width: fit-content !important;
border: 1px solid #666666"> Report Suspicious </div>
</a> </div>
<div style="clear: both !important; display: block !important; visibility: hidden !important; line-height: 0 !important; font-size: 0.01px !important; height: 0px"> </div>
</div>
<!--[endif]-->
<div style="display:none !important;display:none;visibility:hidden;mso-hide:all;font-size:1px;color:#ffffff;line-height:1px;max-height:0px;opacity:0;overflow:hidden;">ZjQcmQRYFpfptBannerEnd</div>
<!-- Email Banner : END -->
<!-- BaNnErBlUrFlE-BoDy-end -->
<div dir="ltr">
<p class="gmail-p1">:</p>
<p class="gmail-p1">
</p>
<p class="gmail-p1">Would it be feasible to switch to an
SPI (similar to JDBC) so custom schedulers are pluggable
under non-standard class loaders? Potentially the same
approach could apply to a pluggable Poller API.</p>
<br>
</div>
</blockquote>
In this prototype, the scheduler is configured system-wide and
cannot be changed mid-flight. It has to be visible to the
application class loader, otherwise there would be no way to
schedule virtual threads before the custom class loader is created.
It can be re-visited if efforts in this area go further than the
prototype. For now, the custom scheduler has to deployed on the
class path or module path.<br>
<br>
There is no Poller API. The class that I think you have found the
JDK internal class that supports blocking operations when using the
Socket and other networking APIs. It's not something that we want to
expose in any way. If the context for your comment is a library that
does syscalls directly (FFM or JNI) then the "primitive" that it can
use to park/unpark virtual threads is LockSupport.park/unpark, it
does not need Poller.<br>
<br>
-Alan<br>
</body>
</html>