Newsgroups: php.internals
Path: news.php.net
Xref: news.php.net php.internals:129694
Precedence: list
MIME-Version: 1.0
References: <CAEKnhAFZXqWH20Cy2g6-0c2V1Vd4w-N0M4xefzt6tTEp90+LqQ@mail.gmail.com>
 <fb357558bd972ce0bdab7dfc8a2787f2@bastelstu.be> <CAEKnhAGCvfB7jSUqOn4yctFLLjY6nRLRObU+43M+OqnVFeTkxw@mail.gmail.com>
 <7351fc32-93fa-4a22-a311-20c5ec34e01c@bastelstu.be>
In-Reply-To: <7351fc32-93fa-4a22-a311-20c5ec34e01c@bastelstu.be>
Date: Fri, 26 Dec 2025 19:11:23 +0100
Message-ID: <CAEKnhAHD1FUaxvTqZKXxvMuRs7jLWWteEG_biLcdtws9VgkV5w@mail.gmail.com>
Subject: Re: [PHP-DEV] [RFC] Polling API
To: =?UTF-8?Q?Tim_D=C3=BCsterhus?= <tim@bastelstu.be>
Cc: PHP internals list <internals@lists.php.net>
Content-Type: multipart/alternative; boundary="000000000000eb18430646ded2d1"
From: bukka@php.net (Jakub Zelenka)

--000000000000eb18430646ded2d1
Content-Type: text/plain; charset="UTF-8"
Content-Transfer-Encoding: quoted-printable

Hi,

On Sun, Nov 23, 2025 at 4:05=E2=80=AFPM Tim D=C3=BCsterhus <tim@bastelstu.b=
e> wrote:

> Hi
>
> Apologies for the late reply. It was a few busy weeks leading up to the
> PHP 8.5 Release.
>
> When searching for the RFC text I just noticed that it does not appear
> to be listed in https://wiki.php.net/rfc#under_discussion yet.
>
>
This is fixed.


>
> >
> >> As an example PollContext::__construct() should probably throw a
> >> BackendUnavailableException or something like this. For
> >> PollContext::add() I'm wondering in which cases a handle =E2=80=9Ccann=
ot be
> >> added=E2=80=9D.
> >
> >
> > It fails if the same fd is added. This is also limitation of backends
> (e.g.
> > epoll does not allow the same fd to be added twice). I got error code f=
or
> > the specific errors so this should be probably exposed as well. It woul=
d
> > still make sense to differentiate that it's an exception for addition.
>
> I see. I was wondering if it would make sense to simply ignore the
> error, thus making the operation idempotent (more convenient for a
> high-level language like PHP). But I suppose that doesn't work, because
> the `$data` could be different?
>
>
Yeah data and events can be different.


> Exception-wise this should probably be a DuplicateHandleError (i.e.
> within the Error hierarchy, since it's a programming error to add
> duplicate handles).
>
>
I don't think users should be expected to keep track of added handles. So I
think that this is something that can be nicely handled and in some cases
it will be just fine to just catch it and ignore. So I wouldn't see this as
a programmer error and therefore the exception is more appropriate IMHO. I
created a specific exception for this called
\Io\Poll\HandleAlreadyWatchedException so it will be easy for users to
differentiate it.

Kind regards,

Jakub

--000000000000eb18430646ded2d1
Content-Type: text/html; charset="UTF-8"
Content-Transfer-Encoding: quoted-printable

<div dir=3D"ltr"><div>Hi,</div><br><div class=3D"gmail_quote gmail_quote_co=
ntainer"><div dir=3D"ltr" class=3D"gmail_attr">On Sun, Nov 23, 2025 at 4:05=
=E2=80=AFPM Tim D=C3=BCsterhus &lt;<a href=3D"mailto:tim@bastelstu.be">tim@=
bastelstu.be</a>&gt; wrote:<br></div><blockquote class=3D"gmail_quote" styl=
e=3D"margin:0px 0px 0px 0.8ex;border-left:1px solid rgb(204,204,204);paddin=
g-left:1ex">Hi<br>
<br>
Apologies for the late reply. It was a few busy weeks leading up to the <br=
>
PHP 8.5 Release.<br>
<br>
When searching for the RFC text I just noticed that it does not appear <br>
to be listed in <a href=3D"https://wiki.php.net/rfc#under_discussion" rel=
=3D"noreferrer" target=3D"_blank">https://wiki.php.net/rfc#under_discussion=
</a> yet.<br><br></blockquote><div><br></div><div>This is fixed.</div><div>=
=C2=A0</div><blockquote class=3D"gmail_quote" style=3D"margin:0px 0px 0px 0=
.8ex;border-left:1px solid rgb(204,204,204);padding-left:1ex">
<br>
&gt; <br>
&gt;&gt; As an example PollContext::__construct() should probably throw a<b=
r>
&gt;&gt; BackendUnavailableException or something like this. For<br>
&gt;&gt; PollContext::add() I&#39;m wondering in which cases a handle =E2=
=80=9Ccannot be<br>
&gt;&gt; added=E2=80=9D.<br>
&gt; <br>
&gt; <br>
&gt; It fails if the same fd is added. This is also limitation of backends =
(e.g.<br>
&gt; epoll does not allow the same fd to be added twice). I got error code =
for<br>
&gt; the specific errors so this should be probably exposed as well. It wou=
ld<br>
&gt; still make sense to differentiate that it&#39;s an exception for addit=
ion.<br>
<br>
I see. I was wondering if it would make sense to simply ignore the <br>
error, thus making the operation idempotent (more convenient for a <br>
high-level language like PHP). But I suppose that doesn&#39;t work, because=
 <br>
the `$data` could be different?<br>
<br></blockquote><div><br></div><div>Yeah data and events can be different.=
</div><div>=C2=A0</div><blockquote class=3D"gmail_quote" style=3D"margin:0p=
x 0px 0px 0.8ex;border-left:1px solid rgb(204,204,204);padding-left:1ex">
Exception-wise this should probably be a DuplicateHandleError (i.e. <br>
within the Error hierarchy, since it&#39;s a programming error to add <br>
duplicate handles).<br>
<br></blockquote><div><br></div><div>I don&#39;t think users should be expe=
cted to keep track of added handles. So I think that this is something that=
 can be nicely handled and in some cases it will be just fine to just catch=
 it and ignore. So I wouldn&#39;t see this as a programmer error and theref=
ore the exception is more appropriate IMHO. I created a specific exception =
for this called \Io\Poll\HandleAlreadyWatchedException so it will be easy f=
or users to differentiate it.</div><div><br></div><div>Kind regards,</div><=
div><br></div><div>Jakub</div></div></div>

--000000000000eb18430646ded2d1--