I have an application that uses ALSA for its sound output, using the default device which is set to go through dmix. I have multiple users who may log into the same machine to run the application. Initially, any user after the first user was unable to open sound because they couldn't get an IPC semaphore (I forget the exact error message). So I changed my alsa.conf line to set the permissions to allow other users to connect: defaults.pcm.ipc_perm 0666 Now, the first user grabs the semaphore and is marked as the owner. Any later user will also be able to grab the semaphore, but my application hangs on some semop() call. I notice the cnfig option 'ipc_key_add_uid' which will make a unique IPC key for each user, but I can't find any good documentation on whether that's actually what I want. If I have multiple users with multiple IPC keys, will their output all get mixed together via dmix? What is actually going on in that case? What is the semaphore actually protecting? I am especially confused because I found some examples on the web that set that configuration option to false, but commented the setting with "allow multiple users to share device". Um... which way is which? alsa-lib 1.0.14 kernel 2.6.18-8.el5 but using manually compiled alsa-driver 1.0.15 not the builtin ------------------------------------------------------------------------- SF.Net email is sponsored by: The Future of Linux Business White Paper from Novell. From the desktop to the data center, Linux is going mainstream. Let it simplify your IT future. http://altfarm.mediaplex.com/ad/ck/8857-50307-18918-4 _______________________________________________ Alsa-user mailing list Alsa-user@xxxxxxxxxxxxxxxxxxxxx https://lists.sourceforge.net/lists/listinfo/alsa-user
