Re: [Alsa-devel] Why do I get broken pipe on write to a pcm in statePREPARED?

On Wed, 11 Sep 2002, Anders Torger wrote: > I use a RME9652 hammerfall with two periods (the hardware is that way). > > I watch a file descriptor associated to the output with select(), when > it gets ready for writing, I write data to the pcm with > snd_pcm_writen(). In the beginning, the sta

Re: [Alsa-devel] Why do I get broken pipe on write to a pcm in statePREPARED?

Anders Torger wrote: > >On Wednesday 11 September 2002 20.48, you wrote: >> On Wed, 11 Sep 2002, Anders Torger wrote: >> > I use a RME9652 hammerfall with two periods (the hardware is that >> > way). >> > >> > I watch a file descriptor associated to the output with select(), >> > when it gets rea

Re: [Alsa-devel] Why do I get broken pipe on write to a pcm in statePREPARED?

Anders Torger wrote: >On Wednesday 11 September 2002 23.52, you wrote: >> Anders Torger wrote: [...] >> >The problem here is that the output buffer is full, the pcm is not >> >RUNNING, but the file descriptor gets triggered anyway. When can >> > that happen? >> >> we had a hauntingly similar discu

Re: [Alsa-devel] Why do I get broken pipe on write to a pcm in statePREPARED?

Takashi Iwai wrote: >btw, the attached patch is a quick and untested hack to change the >behavior as you wish :) >please give a try. i've already worked around it, but i think we save future coders some work if we get this done right. anyways, your patch doesn't break jackd (ice) and my homegr

Re: [Alsa-devel] Why do I get broken pipe on write to a pcm in statePREPARED?

On Thu, 12 Sep 2002, Takashi Iwai wrote: > At Thu, 12 Sep 2002 13:48:56 +0200, > Anders Torger wrote: > > > (...snipped the analogy of pipes...) > > > > Well, I have the same opinion, I'd just like to give another example > > (actually the same all over again, but I want to make it obvious). F

Re: [Alsa-devel] Why do I get broken pipe on write to a pcm in statePREPARED?

Takashi Iwai wrote: >if it's on the blocking mode, the driver should block if it's possible >to do write in future _by any chance_. >if it's not on the blocking mode, the driver should return -EAGAIN. >and, the behavior of poll() depends on the behavior of write(). >if it blocks, then poll blocks

Re: [Alsa-devel] Why do I get broken pipe on write to a pcm in statePREPARED?

Tim Goetze wrote: > > Abramo Bagnara wrote: > > >> >I think that the best behaviour is the current and it's also the > >> >simplest to describe and to understand: poll/select never blocks when > >> >there is nothing to wait. > >> > > >> >... and in PREPARED state definitely there's nothing to wa

Re: [Alsa-devel] Why do I get broken pipe on write to a pcm in statePREPARED?

Anders Torger wrote: > > On Monday 16 September 2002 21.31, you wrote: > > I think that the best behaviour is the current and it's also the > > simplest to describe and to understand: poll/select never blocks when > > there is nothing to wait. > > > > ... and in PREPARED state definitely there's

Re: [Alsa-devel] Why do I get broken pipe on write to a pcm in statePREPARED?

On Tuesday 17 September 2002 10.12, you wrote: > Please use technical argumentations: pseudo statistical and > subjective ones does not worth a lot. Actually, that is exactly the type of argumentation you use yourself. It is not anything wrong with that either. It is always subjective why a cer

Re: [Alsa-devel] Why do I get broken pipe on write to a pcm in statePREPARED?

Abramo Bagnara wrote: >> let's imagine: >> >> * a single-threaded app. if the coder omits starting the stream before >> poll, he'll quickly find out that nothing is played/recorded, and that >> poll will hit the timeout, and consequently revise his code logic. > >It would be definitely not easy

Re: [Alsa-devel] Why do I get broken pipe on write to a pcm in statePREPARED?

On Tuesday 17 September 2002 11.05, you wrote: > Anders Torger wrote: > > On Monday 16 September 2002 21.31, you [Abramo Bagnara] wrote: > > > I think that the best behaviour is the current and it's also the > > > simplest to describe and to understand: poll/select never blocks > > > when there is

Re: [Alsa-devel] Why do I get broken pipe on write to a pcm in statePREPARED?

At Tue, 17 Sep 2002 11:05:44 +0200 (METDST), Clemens Ladisch wrote: > > Anders Torger wrote: > > On Monday 16 September 2002 21.31, you [Abramo Bagnara] wrote: > > > I think that the best behaviour is the current and it's also the > > > simplest to describe and to understand: poll/select never bl

Re: [Alsa-devel] Why do I get broken pipe on write to a pcm in statePREPARED?

At Tue, 17 Sep 2002 13:55:10 +0200 (CEST), tomasz motylewski wrote: > > On Tue, 17 Sep 2002, Takashi Iwai wrote: > > > > > but are you sure that this feature is really implemented? > > on my system, write() to an FIFO which is not opened for read doesn't > > fail, for example, > > % mkfifo

Re: [Alsa-devel] Why do I get broken pipe on write to a pcm in statePREPARED?

>IMHO the current behaviour is the proper behaviour as implemented by other >file descriptors, and as mandated by POSIX. > > >says regarding pipes, FIFOs and sockets: >| The write() function shall fail if: the discussion here is

Re: [Alsa-devel] Why do I get broken pipe on write to a pcm in statePREPARED?

On Tuesday 17 September 2002 14.52, you wrote: > At Tue, 17 Sep 2002 13:55:10 +0200 (CEST), > > tomasz motylewski wrote: > > On Tue, 17 Sep 2002, Takashi Iwai wrote: > > > but are you sure that this feature is really implemented? > > > on my system, write() to an FIFO which is not opened for read

Re: [Alsa-devel] Why do I get broken pipe on write to a pcm in statePREPARED?

>Please understand that it's very hard to satisfy everybody and I'm not >sure it's a worthy goal. Who do we know that would be unsatisfied by the proposed change in the behaviour of poll(2) on an ALSA device? --p --- Sponsored by: AMD - Your

Re: [Alsa-devel] Why do I get broken pipe on write to a pcm in statePREPARED?

On Tuesday 17 September 2002 15.03, you wrote: > >IMHO the current behaviour is the proper behaviour as implemented by > > other file descriptors, and as mandated by POSIX. > > > > > > > >says regarding pipes, FIFOs and sockets: >

Re: [Alsa-devel] Why do I get broken pipe on write to a pcm in statePREPARED?

On Tuesday 17 September 2002 16.40, Clemens Ladisch wrote: > > I feel that one can interpret both ways, so it is a quite open > > choice. Either way, one can state POSIX behaviour. Then the > > question becomes: what is the most usable behaviour? > > I think we have only two choices for POSIX-comp

Re: [Alsa-devel] Why do I get broken pipe on write to a pcm in statePREPARED?

On Wednesday 18 September 2002 21.57, Anders Torger wrote: > On Tuesday 17 September 2002 16.40, Clemens Ladisch wrote: > > > I feel that one can interpret both ways, so it is a quite open > > > choice. Either way, one can state POSIX behaviour. Then the > > > question becomes: what is the most us

Re: [Alsa-devel] Why do I get broken pipe on write to a pcm in statePREPARED?

At Fri, 4 Oct 2002 10:14:09 +0200, Anders Torger wrote: > > Uhhh... I guess ignoring me works just as well :-) not ignored but pending :) Abramo, do you still have objection to change the default behavior? i don't mind that even the new behavior is optional e.g. via snd_pcm_sw_params. but i b

Re: [Alsa-devel] Why do I get broken pipe on write to a pcm in statePREPARED?

Takashi Iwai wrote: > > At Fri, 4 Oct 2002 10:14:09 +0200, > Anders Torger wrote: > > > > Uhhh... I guess ignoring me works just as well :-) > > not ignored but pending :) > > Abramo, do you still have objection to change the default behavior? > > i don't mind that even the new behavior is opt

[Fwd: [Alsa-devel] Why do I get broken pipe on write to a pcm in statePREPARED?]

-- Abramo Bagnara mailto:[EMAIL PROTECTED] Opera Unica Phone: +39.546.656023 Via Emilia Interna, 140 48014 Castel Bolognese (RA) - Italy --- Begin Message --- [ abramo: please forward to [EMAIL PROTECTED] thanks. ] >I'm strongly convinced that

Re: [Alsa-devel] Why do I get broken pipe on write to a pcm in statePREPARED?

Paul Davis wrote: > > > [ abramo: please forward to [EMAIL PROTECTED] thanks. ] > > >I'm strongly convinced that to have poll waiting for something that > >cannot happens is a big mistake (also as an optional behaviour). > > there are several, perhaps even lots, of other device drivers in the

Re: [Alsa-devel] Why do I get broken pipe on write to a pcm in statePREPARED?

At Fri, 04 Oct 2002 20:04:00 +0200, Abramo Bagnara wrote: > > Takashi Iwai wrote: > > > > At Fri, 4 Oct 2002 10:14:09 +0200, > > Anders Torger wrote: > > > > > > Uhhh... I guess ignoring me works just as well :-) > > > > not ignored but pending :) > > > > Abramo, do you still have objection to

Re: [Alsa-devel] Why do I get broken pipe on write to a pcm in statePREPARED?

Takashi Iwai wrote: > > it CAN happen if you have multi-threads. > the problem is that we have no option to block the poll. If you have multi-thread you have other alternative to do that. OTOH application can't detect *why* poll is blocking with the change you advocate. > > That apart I'm sure

Re: [Alsa-devel] Why do I get broken pipe on write to a pcm in statePREPARED?

On Monday 07 October 2002 14.07, you wrote: > Takashi Iwai wrote: > > it CAN happen if you have multi-threads. > > the problem is that we have no option to block the poll. > > If you have multi-thread you have other alternative to do that. > OTOH application can't detect *why* poll is blocking wit

Re: [Alsa-devel] Why do I get broken pipe on write to a pcm in statePREPARED?

Abramo Bagnara wrote: >Takashi Iwai wrote: >> >> it CAN happen if you have multi-threads. >> the problem is that we have no option to block the poll. > >If you have multi-thread you have other alternative to do that. >OTOH application can't detect *why* poll is blocking with the change you >advo

Re: [Alsa-devel] Why do I get broken pipe on write to a pcm in statePREPARED?

Anders Torger wrote: > > On Monday 07 October 2002 14.07, you wrote: > > Takashi Iwai wrote: > > > it CAN happen if you have multi-threads. > > > the problem is that we have no option to block the poll. > > > > If you have multi-thread you have other alternative to do that. > > OTOH application c

Re: [Alsa-devel] Why do I get broken pipe on write to a pcm in statePREPARED?

Paul Davis wrote: > > >I'm not speaking about programming bugs. Suppose the PCM is stopped by > >another thread: you're screwed. > > why are you screwed? you're waiting (presumably) for data/space to be > ready in the PCM device. there isn't any (or more precisely, you're > waiting for changes i

Re: [Alsa-devel] Why do I get broken pipe on write to a pcm in statePREPARED?

At Mon, 07 Oct 2002 19:46:44 +0200, Abramo Bagnara wrote: > > > > but the current behavior is incorrect from the interpretation of > > > > POSIX. so this must be a bug. > > > > if we have to change it, then i would choose the new one, because > > > > it's more intuitive without exception. > > >

Re: [Alsa-devel] Why do I get broken pipe on write to a pcm in statePREPARED?

Abramo Bagnara <[EMAIL PROTECTED]> writes: > For what it worths my objections are still there. > > I'm strongly convinced that to have poll waiting for something that > cannot happens is a big mistake (also as an optional behaviour). The poll is waiting on some thread to start the PCM. It is i