<p></p>
<p>Ok, so the problem is with lwIP's <code>sock</code> implementation. That at least tells me, that <code>sock</code> is not completely broken ;-). As to <code>sys_arch_mbox_fetch</code>: It is very similar to what <code>gnrc_sock_recv()</code> does in <code>gnrc_sock.c</code> (the first is just more generalized). Could you check if there is any significant difference (e.g. <a class="issue-link js-issue-link" data-error-text="Failed to load title" data-id="992253402" data-permission-text="Title is private" data-url="https://github.com/RIOT-OS/RIOT/issues/16831" data-hovercard-type="pull_request" data-hovercard-url="/RIOT-OS/RIOT/pull/16831/hovercard" href="https://github.com/RIOT-OS/RIOT/pull/16831">#16831</a> was merged recently there) that could make a difference in your case? Maybe it is about time we add a <code>xtimer</code>/<code>ztimer</code> function for that kind of functionality (<code>xtimer_mbox_get_timeout()</code>...).</p>

<p style="font-size:small;-webkit-text-size-adjust:none;color:#666;">—<br />You are receiving this because you are subscribed to this thread.<br />Reply to this email directly, <a href="https://github.com/RIOT-OS/RIOT/pull/16853#issuecomment-920813527">view it on GitHub</a>, or <a href="https://github.com/notifications/unsubscribe-auth/ABE7WYBW7JX2B7ZAD6MQUVLUCHHJJANCNFSM5EABMHPA">unsubscribe</a>.<br />Triage notifications on the go with GitHub Mobile for <a href="https://apps.apple.com/app/apple-store/id1477376905?ct=notification-email&mt=8&pt=524675">iOS</a> or <a href="https://play.google.com/store/apps/details?id=com.github.android&referrer=utm_campaign%3Dnotification-email%26utm_medium%3Demail%26utm_source%3Dgithub">Android</a>.
<img src="https://github.com/notifications/beacon/ABE7WYC6ABFW5U5ZNNMMYO3UCHHJJA5CNFSM5EABMHPKYY3PNVWWK3TUL52HS4DFVREXG43VMVBW63LNMVXHJKTDN5WW2ZLOORPWSZGOG3RH7VY.gif" height="1" width="1" alt="" /></p>
<script type="application/ld+json">[
{
"@context": "http://schema.org",
"@type": "EmailMessage",
"potentialAction": {
"@type": "ViewAction",
"target": "https://github.com/RIOT-OS/RIOT/pull/16853#issuecomment-920813527",
"url": "https://github.com/RIOT-OS/RIOT/pull/16853#issuecomment-920813527",
"name": "View Pull Request"
},
"description": "View this Pull Request on GitHub",
"publisher": {
"@type": "Organization",
"name": "GitHub",
"url": "https://github.com"
}
}
]</script>