Re: [gentoo-user] Is my system (really) using nptl

[Michael Mol]

On Sun, Oct 14, 2012 at 3:19 PM, Florian Philipp <lists@×××××××××××.net> wrote:
> Am 14.10.2012 17:07, schrieb Michael Mol:
>> On Sun, Oct 14, 2012 at 5:31 AM, Florian Philipp <lists@×××××××××××.net> wrote:
>>> Am 14.10.2012 01:20, schrieb Michael Mol:
>>>> On Sat, Oct 13, 2012 at 4:18 PM, Canek Peláez Valdés <caneko@×××××.com> wrote:
>>>>> On Sat, Oct 13, 2012 at 2:50 PM, Michael Mol <mikemol@×××××.com> wrote:
>>>>> [snip]
>>>>>> (Well, I'm not certain that POSIX thinks of threads as parents to each other.
>>>>>
>>>>> Hence the reason I put "parent" in quotes, and I specified "actually,
>>>>> the thread that created it".
>>>>>
>>>>>> There are *numerous* IPC mechanisms available on Linux. For starters,
>>>>>> there are sockets (domain, IPv4, IPv6, et al), named pipes, signals,
>>>>>> mmap()'d files, messaging, etc.
>>>>>
>>>>> Yeah, none of them "easy and quickly" to use, or at least not if you
>>>>> compare it with shared memory.
>>>>
>>>> I assume you mean 'shared memory' in the 'many threads to an address
>>>> space', not the /dev/shm sense.
>>>>
>>>
>>> If we really want to be nit-picking, we have to assume 'shared memory'
>>> as in malloc'ed [1] or stack memory. Anonymous mmap'ed memory mappings
>>> are preserved across forks and changes in them can be shared since
>>> kernel 2.4.
>>
>> Absolutely.
>>
>>> [1] Yes, I know that malloc uses mmap but its mappings are MAP_PRIVATE.
>>
>> For the GNU libc, yeah. I noticed that in strace, and was amused.
>>
>
> Huh? Are there other libcs that do it differently? I can't imagine any
> alternative (except of the sbrk function from the bad old days).

These days, and outside of Windows? I'm not familiar with any.

-- 
:wq