On 11/04/2012 02:22 PM, Tanu Kaskinen wrote: > On Sat, 2012-11-03 at 19:51 +0100, David Henningsson wrote: >> 2012-11-03 17:19, Colin Guthrie skrev: >>> 'Twas brillig, and Tanu Kaskinen at 05/10/12 13:58 did gyre and gimble: >>>> On Wed, 2012-10-03 at 08:50 +0200, David Henningsson wrote: >>>>> On 10/02/2012 10:38 PM, Tanu Kaskinen wrote: >>>>>> On Mon, 2012-10-01 at 17:06 +0200, David Henningsson wrote: >>>>>>> If there is no silence memblock and no data, pa_memblockq_peek can >>>>>>> return NULL. In this case, do not crash on an assertion in >>>>>>> pa_memblock_acquire, but instead return a proper error to the client. >>>>>> If there is no data in the buffer, pa_stream_peek() is supposed to >>>>>> return NULL according to the documentation. And it does that: if there's >>>>>> no data, pa_memblock_peek() will return a negative value, causing >>>>>> pa_stream_peek() to return NULL. >>>>>> >>>>>> The problem is the case where the buffer does contain data, but not at >>>>>> the read index. That is, there is a hole in the buffer. The client >>>>>> documentation doesn't have any warnings about holes, so the only safe >>>>>> way to handle holes is to return silence. Fixing this should be a simple >>>>>> matter of giving a silence memchunk when creating record_memblockq. >>>>> I'm not so sure. Silence, as in all zeroes, might work for S16 audio >>>>> data, but what about other formats? Compressed audio? Peak audio (which >>>>> I think is the case here)? Etc. >>>> Good point. Regarding PCM, if pa_memchunk_silence() is used, the >>>> function will take care of filling the memory with appropriate content. >>>> But that doesn't work with compressed audio. >>>> >>>>> Also maybe it could also be valuable for the client to distinguish >>>>> between no data available, and valid zero data. >>>>> >>>>> How about returning NULL and adding to the documentation something like: >>>>> >>>>> -If no data is available this will return a NULL pointer. >>>>> +If no data is available (at the current read position), this will >>>>> return a NULL pointer. >>>> An addition: the client probably wants to know how large the hole is. It >>>> might be possible to figure that out somehow from the read index, but I >>>> think it would make sense to return the hole size in the length >>>> parameter. >>> This discussion seemed to stagnate. Is this worth fixing/documenting for >>> the 3.0 release? >>> >> Returning NULL seems to be the right thing to do here, even if >> gnome-control-center does not handle that very well IIRC. So we might >> need an additional patch in g-c-c. >> So assuming I commit a patch doing that. If somebody else wants to add >> logic to figure out how large the hole is, that could be discussed >> separately. >> Any objections? > > It's not clear what you meant by "add logic to figure out how large the > hole is". Add to where? pa_stream_peek() or gnome-control-center?
I was referring to your earlier comment "An addition: the client probably wants to know how large the hole is.", i e pa_stream_peek. > To me, reporting the hole length in the "nbytes" parameter of > pa_stream_peek() seems like the right thing to do, so I hope your patch > will do this. It does not: I was just suggesting to discuss that separately. -- David Henningsson, Canonical Ltd. https://launchpad.net/~diwic -- You received this bug notification because you are a member of Desktop Packages, which is subscribed to pulseaudio in Ubuntu. https://bugs.launchpad.net/bugs/1058200 Title: [sound]: gnome-control-center crashed with SIGABRT in pa_memblock_acquire() Status in “pulseaudio” package in Ubuntu: Fix Released Bug description: The Sound panel has been extremely crash-prone for the past oh, maybe 2 weeks. ProblemType: Crash DistroRelease: Ubuntu 12.10 Package: gnome-control-center 1:3.4.2-0ubuntu15 ProcVersionSignature: Ubuntu 3.5.0-15.23-generic 3.5.4 Uname: Linux 3.5.0-15-generic x86_64 ApportVersion: 2.5.2-0ubuntu4 Architecture: amd64 CrashCounter: 1 Date: Wed Sep 26 15:34:20 2012 ExecutablePath: /usr/bin/gnome-control-center ProcCmdline: gnome-control-center --overview Signal: 6 SourcePackage: gnome-control-center StacktraceTop: raise () from /lib/x86_64-linux-gnu/libc.so.6 abort () from /lib/x86_64-linux-gnu/libc.so.6 pa_memblock_acquire () from /usr/lib/x86_64-linux-gnu/pulseaudio/libpulsecommon-2.1.so pa_stream_peek () from /usr/lib/x86_64-linux-gnu/libpulse.so.0 ?? () from /usr/lib/control-center-1/panels/libsound.so Title: [sound]: gnome-control-center crashed with SIGABRT in raise() UpgradeStatus: No upgrade log present (probably fresh install) UserGroups: adm cdrom dip libvirtd lpadmin plugdev sambashare sbuild sudo usr_lib_gnome-control-center: activity-log-manager-control-center 0.9.4-0ubuntu3 deja-dup 23.92-0ubuntu1 gnome-control-center-signon 0.0.17-0ubuntu1 indicator-datetime 12.10.1-0ubuntu1 To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/pulseaudio/+bug/1058200/+subscriptions -- Mailing list: https://launchpad.net/~desktop-packages Post to : desktop-packages@lists.launchpad.net Unsubscribe : https://launchpad.net/~desktop-packages More help : https://help.launchpad.net/ListHelp
