From: Philipp Stephani <p.stephani2@gmail.com>
To: "Elias Mårtenson" <lokedhs@gmail.com>, "Eli Zaretskii" <eliz@gnu.org>
Cc: emacs-devel <emacs-devel@gnu.org>
Subject: Re: call-process blocks the active thread
Date: Fri, 08 Sep 2017 11:27:29 +0000 [thread overview]
Message-ID: <CAArVCkQKyD-OEubNHvW7mC4X6JksoBeMRURFsDG=ZE1-D74AQA@mail.gmail.com> (raw)
In-Reply-To: <CADtN0WKoEv9oEd_q8JNC0_xk47p41m7Q_6kMF1i_cNXjekzBjQ@mail.gmail.com>
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Elias Mårtenson <lokedhs@gmail.com> schrieb am Fr., 8. Sep. 2017 um
13:00 Uhr:
> On 8 September 2017 at 15:01, Eli Zaretskii <eliz@gnu.org> wrote:
>
>> > From: Elias Mårtenson <lokedhs@gmail.com>
>> > Date: Fri, 8 Sep 2017 11:00:42 +0800
>> >
>> > As it turns out, ‘call-process’ hangs all of Emacs while the external
>> program is run.
>>
>> No, it hangs the calling thread, and the other threads wait for the
>> calling thread to yield. To avoid that, use start-process instead.
>>
>> This is not a bug.
>>
>
> I'm not entirely sure why you feel that distinction is important. At the
> end of the day, it's ‘start-process’ that doesn't yield while the external
> process runs. Is there a reason why it can't be changed so that it does?
>
Emacs threads can't run in parallel because they share global mutable state
(buffers etc.) without synchronization. `call-process' is guaranteed to not
affect the global state in "significant" ways, therefore it can't yield to
threads that could change the global state.
It's not possible to fix this.
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next prev parent reply other threads:[~2017-09-08 11:27 UTC|newest]
Thread overview: 10+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-09-08 3:00 call-process blocks the active thread Elias Mårtenson
2017-09-08 3:56 ` Eric Abrahamsen
2017-09-08 7:01 ` Eli Zaretskii
2017-09-08 7:45 ` Stefan Monnier
2017-09-08 8:06 ` Eli Zaretskii
2017-09-08 10:36 ` Elias Mårtenson
2017-09-08 11:27 ` Philipp Stephani [this message]
2017-09-08 12:16 ` Eli Zaretskii
2017-09-08 16:12 ` Tom Tromey
2017-09-08 18:43 ` Tom Tromey
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