On April 15, 2013 07:06:39 PM taktik wrote: > On Sat, Apr 13, 2013 at 9:34 AM, Dan MacDonald <allcoms@xxxxxxxxx> wrote: > > This has been great to see the devs of Ardour, qtractor and MusE all > > working on the same problem simultaneously! I can't say I've seen that > > before so it proves this plugin has peoples interest. > > Indeed! Thanks for all the feedback and comments. VSTs on Linux are > still pretty experimental. Would be great if we all (host and plugin > devs) could try to help each others here to get things working. No problem, glad to help. Still fairly fresh paint on the support in MusE, so we're learning too. > > As Kieran pointed out, I'm responsible for some parts of the plugin > backend in Glitch, so here are a few more comments and technical > details about previously discussed stuff: > > --- > > > Looks cool, but someone's understanding of the VST spec is wrong. Probably > > Ardour's. > > This puppy calls audioMasterNeedIdle while being instantiated. Not cool. > > Will fix A3 ASAP. > > From my understanding "audioMasterNeedIdle" should not directly result > into an idle call, but informs the host that the plugin wants > "effIdle" calls. The specs are not really clear here though. "effIdle" > also is NOT "effEditIdle" which drives the plugins GUIs, but a general > idle function which should be called even when the editor is not open. > We ended up removing the "audioMasterNeedIdle" call in Glitch 2.0.1 > now, which got released a few hours ago, cause this obviously caused > more troubles than fixing anything. > > We thought it's a good idea to call "audioMasterNeedIdle", to make > sure that we do get idle calls at all from the host. We do rely on > this on Linux, because we need to do some housekeeping in the UI > thread, but found no way to get constantly called in the UI thread > without relying on the host's idle calls. On Windows we do so via a > "SetTimer", on OSX via "InstallEventLoopTimer". On Linux there seems > to be no equivalent timer which gets called in the "XEvent" loop. > Juce based plugins workaround this by creating a new thread for just > this on Linux (a "message thread" in Juce terminology - if I remember > correctly) which does general UI thread housekeeping and also drives > the plugin GUI when the host does not call "effEditIdle". We wanted to > avoid creating a new thread for just this, cause such a thread will > then run concurrently with the host's UI thread which is a guarantee > for unnecessary overhead and of course in general a hassle to setup > and maintain. > > This is also the reason why the Glitch GUI does not work in qtractor > and muse. qtractor and muse do not call "effEditIdle", even when the > plugin GUI is open. Actually I did call it - but only once after opening the GUI, which turns out to be inadequate here. > So if qtractor and muse could be patched to call > "effEditIdle" for all open plugin editors this would avoid a lot of > hassle here. So as I mention in my reply here and to the company, this is what I did: We have a handy slow-rate QTimer slot in our synth classes, for GUI updates. So I simply call effEditIdle from it. By default the timer is about 20 times per second, and is user-adjustable. I'll try to get that patch in soon... > > it crashes during shutdown > > Tested this a lot during the last days on various systems, but could > not really replicate this here. Would be great if someone who could > easily replicate this before could test this again with the latest > Glitch 2.0.1 update. And If it still crashes, give us some more > details about the used system and host. A stack trace of such a crash > would help a lot too. Definitely some commonality here ! Without actually instantiating - just simple plugin discovery - I get this *identical* crash at host shutdown with these plugins: Glitch-2.0, DiscoveryDemo, HighLife-1.1, Tonespace =================================================== *** glibc detected *** ./muse2: double free or corruption (out): 0x08824c88 *** ======= Backtrace: ========= /lib/i386-linux-gnu/libc.so.6(+0x75ee2)[0x5646ee2] /usr/lib/i386-linux-gnu/libX11.so.6(+0x2431e)[0x485031e] /usr/lib/i386-linux-gnu/libX11.so.6(XrmDestroyDatabase+0x7d)[0x486bdfd] /usr/lib/i386-linux-gnu/libX11.so.6(_XFreeDisplayStructure+0x44b)[0x485256b] /usr/lib/i386-linux-gnu/libX11.so.6(XCloseDisplay+0xd9)[0x483f039] /usr/lib/i386-linux-gnu/libQtGui.so.4(+0x1c5c17)[0x109ac17] /usr/lib/i386-linux-gnu/libQtGui.so.4(_ZN12QApplicationD1Ev+0x44c)[0x101aa9c] ./muse2(_ZN15MuseApplicationD2Ev+0x2b)[0x8050e7f] ./muse2(main+0x2402)[0x80503db] /lib/i386-linux-gnu/libc.so.6(__libc_start_main+0xf3)[0x55ea4d3] ./muse2[0x804d5d1] =================================================== These plugins do not cause the crash, even when they are all loaded: AspectVST, BitMangler, Equinox, my_synth4, String_VST, String_FXVST, TAL-Dub-3, TAL-Reverb-3, TAL-Vocoder-2, VEX, ZR3. Rui, if you are reading this, you mention this mysterious crash in your QTractor code, to avoid the problem you let Qt implicitly unload the plugins rather than explicitly unloading them. But, I had no luck trying the same thing here for MusE. You mention that these crashes may be related to JUCE-based plugins. I would really like to solve this mysterious common problem. Using Lubuntu 12.04 here: Linux my-desktop 3.2.0-30-generic #48-Ubuntu SMP Fri Aug 24 16:54:40 UTC 2012 i686 athlon i386 GNU/Linux Thanks. Tim. > > > Greets, > Eduard / taktik / renoise.com _______________________________________________ Linux-audio-user mailing list Linux-audio-user@xxxxxxxxxxxxxxxxxxxx http://lists.linuxaudio.org/listinfo/linux-audio-user
