Very Computer

by **Guillaume dubu** » Thu, 12 Nov 1998 04:00:00

Just two little question:
1:Why the size of PIPE_BUF is 4096 and not the size of
PAGE_SIZE?(perhaps POSIX's norms?).
2:Why the flag O_NODELAY is not implemented for pipe?(yes this flag is
not POSIX).

thank you in advance.
(Sorry my english is very poor...)

--
Dubun Guillaume

"...Unix, MS-DOS, and Windows NT (also known as the Good, the Bad, and
the Ugly)." (By Matt Welsh)

by **Andi Klee** » Thu, 12 Nov 1998 04:00:00

> Just two little question:
> 1:Why the size of PIPE_BUF is 4096 and not the size of
> PAGE_SIZE?(perhaps POSIX's norms?).

That is an oversight - it should be PAGE_SIZE. Thank you for reporting
the bug.

Quote:> 2:Why the flag O_NODELAY is not implemented for pipe?(yes this flag is
> not POSIX).

Hmm? The flag should work just fine one pipes, returning EAGAIN when the
pipe buffer is full. Do you have any evidence that it doesn't work?

-Andi

by **M Sweg** » Wed, 18 Nov 1998 04:00:00

: > Just two little question:
: > 1:Why the size of PIPE_BUF is 4096 and not the size of
: > PAGE_SIZE?(perhaps POSIX's norms?).
: That is an oversight - it should be PAGE_SIZE. Thank you for reporting
: the bug.

: > 2:Why the flag O_NODELAY is not implemented for pipe?(yes this flag is
: > not POSIX).

: Hmm? The flag should work just fine one pipes, returning EAGAIN when the
: pipe buffer is full. Do you have any evidence that it doesn't work?

: -Andi

I thought PIPE_BUF was 5120 bytes in size. However, I don't know why
it limited to such a weird number.

As for O_NODELAY, in Linux this is set to O_NONBLOCK. In Solaris
both values are different. Why is this the same?

--
Mike,

Very Computer

why size of PIPE_BUF is 4096

why size of PIPE_BUF is 4096

why size of PIPE_BUF is 4096

why size of PIPE_BUF is 4096