Re: PROPOSAL: extend pipe() to support NULL argument.

[Albert ARIBAUD <albert.aribaud@free.fr>]

Changli Gao a écrit :
> On Mon, Jul 6, 2009 at 2:15 PM, Albert ARIBAUD<albert.aribaud@free.fr> wrote:
>>>
>>> pipe doesn't support llseek.
>> I wasn't thinking of actively seeking a file position, but simply that reads
>> and writes were independent (and both variable) in size, thus even without
>> (l)seeking, each endpoint has an independent read (resp. write) position to
>> track what's been read from (resp.written into) it at any time, and such a
>> position is, IIUC, single for a given fd, making a fd (a struct file)
>> insufficient for representing a pipe.
>>
>> Amicalement,
>> --
>> Albert.
>>
> pipe doesn't refer to pos when reading or writing. Please refer to
> pipe_read() and pipe_write() for more detail.

Hmm. Then how does pipe avoid overwriting what it's already written at the 
in endpoint, or reading twice the same data from the out endpoint?

Amicalement,
-- 
Albert.