Cool. I think the safe way to do it is much more complicated than just turning on the existing SHM vector.
>From what I understand it should work like so... Client connect to stream or dgram socket and (post auth) establishes that both parties believe they are on he same host and server offers to create SHM buffers for the client to use. The client may close the socket once SHM is setup, if it's done. Server should be able to query the socket, worst case using ident, to see what user is on the other end and set perms appropriately. The server might trust the client to supply perms and does so while applying a mask for sanity purposes. SHM buffers are per socket connection/pid and a single pid can ask for more than one, with some upper limit defined to prevent DOS. This adds more commands into the PA server and client, but I feel that both modes would benefit from a more robust SHM system. Having more than a single thread(client/server threads makes for a minimum of two) introduces locking concerns that just add latency. -- You received this bug notification because you are a member of Ubuntu Touch seeded packages, which is subscribed to pulseaudio in Ubuntu. https://bugs.launchpad.net/bugs/1007866 Title: System mode: SHM avaliblity. Status in pulseaudio package in Ubuntu: Confirmed Bug description: Hello, Let start with the most basic, I fully understand that System mode is taboo and unsupported by upstream. I understand there reasoning, well I don't get the part about "You shouldn't use system mode because we refuse to offer SHM support for it." That's just the pot calling the kettle black. In any case I'm using PA in system mode because I haven't been able to use dmix for various reasons, the closest I got was after 5 or 6 hacks I got silence and surround sound was forever out of my reach. I'm sure there are other vary rare cases where System mode may be the only logical option. What I needed out of dmix was to mix sound from several users, libvirt and others. Regardless of why, you should just take it on my authority that I have good reason for configuring a system this way. Attached you should find my /etc/default/pulseaudio file, it clearly is configured to forcibly enable SHM. However as the documentation suggests this feature is disabled in system mode. I know X does SHM and it nearly always runs as another user, so it should be technically possible... Politics and opinions aside. Would a patch for this be accepted into Ubuntu? ProblemType: Bug DistroRelease: Ubuntu 12.04 Package: pulseaudio 1:1.1-0ubuntu15 ProcVersionSignature: Ubuntu 3.2.0-23.31-lowlatency-pae 3.2.14 Uname: Linux 3.2.0-23-lowlatency-pae i686 AlsaVersion: Advanced Linux Sound Architecture Driver Version 1.0.24. ApportVersion: 2.0.1-0ubuntu5 Architecture: i386 ArecordDevices: **** List of CAPTURE Hardware Devices **** card 0: SB [HDA ATI SB], device 0: VT2020 Analog [VT2020 Analog] Subdevices: 2/2 Subdevice #0: subdevice #0 Subdevice #1: subdevice #1 AudioDevicesInUse: USER PID ACCESS COMMAND /dev/snd/controlC1: cheako 6904 F.... xfce4-volumed /dev/snd/controlC0: cheako 6904 F.... xfce4-volumed Card0.Amixer.info: Card hw:0 'SB'/'HDA ATI SB at 0xfe3f8000 irq 16' Mixer name : 'VIA VT2020' Components : 'HDA:11060441,104383e4,00100100' Controls : 46 Simple ctrls : 24 Card1.Amixer.info: Card hw:1 'HDMI'/'HDA ATI HDMI at 0xfe9ec000 irq 88' Mixer name : 'ATI R6xx HDMI' Components : 'HDA:1002aa01,00aa0100,00100000' Controls : 6 Simple ctrls : 1 Card1.Amixer.values: Simple mixer control 'IEC958',0 Capabilities: pswitch pswitch-joined penum Playback channels: Mono Mono: Playback [on] Date: Sat Jun 2 11:36:09 2012 PulseList: Error: command ['pacmd', 'list'] failed with exit code 1: No PulseAudio daemon running, or not running as session daemon. SourcePackage: pulseaudio UpgradeStatus: Upgraded to precise on 2012-01-03 (151 days ago) dmi.bios.date: 02/17/2011 dmi.bios.vendor: American Megatrends Inc. dmi.bios.version: 1902 dmi.board.asset.tag: To Be Filled By O.E.M. dmi.board.name: Crosshair IV Formula dmi.board.vendor: ASUSTeK Computer INC. dmi.board.version: Rev 1.xx dmi.chassis.asset.tag: Asset-1234567890 dmi.chassis.type: 3 dmi.chassis.vendor: Chassis Manufacture dmi.chassis.version: Chassis Version dmi.modalias: dmi:bvnAmericanMegatrendsInc.:bvr1902:bd02/17/2011:svnSystemmanufacturer:pnSystemProductName:pvrSystemVersion:rvnASUSTeKComputerINC.:rnCrosshairIVFormula:rvrRev1.xx:cvnChassisManufacture:ct3:cvrChassisVersion: dmi.product.name: System Product Name dmi.product.version: System Version dmi.sys.vendor: System manufacturer modified.conffile..etc.default.pulseaudio: [modified] modified.conffile..etc.pulse.daemon.conf: [modified] modified.conffile..etc.pulse.system.pa: [modified] mtime.conffile..etc.default.pulseaudio: 2012-06-01T23:52:21.454150 mtime.conffile..etc.pulse.daemon.conf: 2012-05-04T20:03:56.466470 mtime.conffile..etc.pulse.system.pa: 2012-05-31T19:30:49.734907 To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/pulseaudio/+bug/1007866/+subscriptions -- Mailing list: https://launchpad.net/~touch-packages Post to : [email protected] Unsubscribe : https://launchpad.net/~touch-packages More help : https://help.launchpad.net/ListHelp
