From: Florian Weimer <fweimer@redhat.com>
To: Peng Yu <pengyu.ut@gmail.com>
Cc: Peng Yu via Libc-help <libc-help@sourceware.org>
Subject: Re: What is the point of IPC_PRIVATE of shmget?
Date: Mon, 12 Apr 2021 18:14:48 +0200 [thread overview]
Message-ID: <87sg3viio7.fsf@oldenburg.str.redhat.com> (raw)
In-Reply-To: <CABrM6wm3Lxj-b__WzYHYsAKbHpE9jvFg7QBSCV7TYxbYHNFVLg@mail.gmail.com> (Peng Yu's message of "Mon, 12 Apr 2021 11:12:50 -0500")
* Peng Yu:
> On Mon, Apr 12, 2021 at 11:07 AM Florian Weimer <fweimer@redhat.com> wrote:
>>
>> * Peng Yu via Libc-help:
>>
>> > I don't get the point of IPC_PRIVATE of shmget(). Since it is just
>> > used by the current process, why not just use malloc?
>> >
>> > Can anybody give a real example in which IPC_PRIVATE must be used, but
>> > malloc or other variant of *alloc functions are not appropriate to
>> > use? Thanks.
>>
>> shmget(2) says this:
>>
>> | BUGS
>> | The name choice IPC_PRIVATE was perhaps unfortunate, IPC_NEW
>> | would more clearly show its function.
>>
>> Does this answer your question?
>
> No. That is just a naming issue. It is still privately used by the
> current process instead of other processes.
Oh, it can be shared if the process forks. With malloc, you'd lose the
sharing.
Thanks,
Florian
next prev parent reply other threads:[~2021-04-12 16:14 UTC|newest]
Thread overview: 10+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-04-12 15:54 Peng Yu
2021-04-12 16:06 ` tomas
2021-04-12 16:07 ` Florian Weimer
2021-04-12 16:12 ` Peng Yu
2021-04-12 16:14 ` Florian Weimer [this message]
2021-04-12 16:18 ` Florian Weimer
2021-04-12 17:23 ` Peng Yu
2021-04-12 18:17 ` J Lumby
2021-04-12 17:55 ` Manfred
2021-04-12 19:05 ` Peng Yu
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