[PD-dev] libpd partly working with pd instances
Chris Clepper
cgclepper at gmail.com
Mon May 12 21:16:09 CEST 2014
Miller
Does that still prevent multiple instances of a libpd based VST from
loading in a host?
Chris
On Mon, May 12, 2014 at 10:12 AM, Miller Puckette <msp at ucsd.edu> wrote:
> I think the global shared symbol space will cause some confusion (patches
> will have to protect their sends and receives, etc., by fabricating local
> names using '$' characters.
>
> Also, it won't be possible to run several Pds concurrently on several
> threads - in a threaded environment, each Pd instance will have to lock
> all others out while it runs. (There might be a fix for that by replacing
> all static variables in Pd by thread-local ones, but this is untested and
> I'd hate to do it unless there's a real need for it, since it would involve
> systematically changing 100s of variable definitions in Pd.)
>
> I'm not sure about timing - that depends partly on the libpd release
> process
> that I'm not involved in.
>
> cheers
> Miller
> On Mon, May 12, 2014 at 09:45:25AM -0400, Rob Bairos wrote:
> > Hi Miller.
> > Thats very exciting news!
> > Can you give a brief synopsis of what you think the biggest remaining
> > limitations are and a rough timeline as to when a stable multi-instance
> > pdlib would be available for general use?
> >
> > Thanks again!
> > Rob Bairos.
> >
> >
> >
> > On Sun, May 11, 2014 at 3:00 AM, Miller Puckette <msp at ucsd.edu> wrote:
> >
> > > To Pd developers...
> > >
> > > I've adapted Pd to nternally use a "pdinstance" structure to allow
> > > multiple schedulers (including DSP chains) to run in one address space.
> > > With slight modification (see below) libpd can use this to run separate
> > > patches asynchronously.
> > >
> > > I tried to "instance-ize" all Pd symbols to keep them private but ran
> into
> > > seemingly insoluble problems, so am leaving all symbols global for now.
> > > (So patches used in pdlib, if they want to be usable in a
> multiple-instance
> > > scenaro, should protect all send/receive/table/delay/etc named objects
> with
> > > a $[0-9] somewhere.
> > >
> > > I didn't look hard, but I thnk pdlib now will need a way to send $
> > > arguments
> > > to patches via libpd_openfile() somehow. Also, libpd_init_audio() will
> > > want to
> > > make number of channels per-instance, etc. I've put some relevant
> comments
> > > in the test program I'll include below (and sorry for the length of
> this
> > > mail!)
> > >
> > > Here's how I modified libpd_wrapper/z_libpd.c:
> > >
> > > 55d54
> > > < sys_time = 0;
> > > 110c109
> > > < sched_tick(sys_time + sys_time_per_dsp_tick);
> > > ---
> > > > sched_tick();
> > > 130c129
> > > < sched_tick(sys_time + sys_time_per_dsp_tick); \
> > > ---
> > > > sched_tick(); \
> > >
> > > ----------------------
> > > and here (sorry again) is the test program, "pdtest2.c" adapted from
> > > libpd-master/samples/c_samples/c/pdtest.c :
> > > ---------------------
> > >
> > > #include <stdio.h>
> > > #include "z_libpd.h"
> > > #include "m_imp.h"
> > > #define TIMEUNITPERMSEC (32. * 441.)
> > >
> > > void pdprint(const char *s) {
> > > printf("%s", s);
> > > }
> > >
> > > void pdnoteon(int ch, int pitch, int vel) {
> > > printf("noteon: %d %d %d\n", ch, pitch, vel);
> > > }
> > >
> > > int main(int argc, char **argv) {
> > > t_pdinstance *pd1 = pdinstance_new(), *pd2 = pdinstance_new();
> > > if (argc < 3) {
> > > fprintf(stderr, "usage: %s file folder\n", argv[0]);
> > > return -1;
> > > }
> > >
> > > int srate = 44100;
> > > // maybe these two calls should be available per-instnace somehow:
> > > libpd_set_printhook(pdprint);
> > > libpd_set_noteonhook(pdnoteon);
> > > /* set a "current" instance before libpd_init() or else Pd will
> make
> > > an unnecessary third "default" instance. */
> > > pd_setinstance(pd1);
> > > libpd_init();
> > > /* ... here we'd sure like to be able to have number of channels be
> > > per-nstance. The sample rate is still global within Pd but we
> might
> > > also consider relaxing that restrction. */
> > > libpd_init_audio(1, 2, srate);
> > >
> > > float inbuf[64], outbuf[128]; // one input channel, two output
> channels
> > > // block size 64, one tick per buffer
> > >
> > > pd_setinstance(pd1); // talk to first pd instance
> > >
> > > // compute audio [; pd dsp 1(
> > > libpd_start_message(1); // one entry in list
> > > libpd_add_float(1.0f);
> > > libpd_finish_message("pd", "dsp");
> > >
> > > // open patch [; pd open file folder(
> > > libpd_openfile(argv[1], argv[2]);
> > >
> > > pd_setinstance(pd2);
> > >
> > > // compute audio [; pd dsp 1(
> > > libpd_start_message(1); // one entry in list
> > > libpd_add_float(1.0f);
> > > libpd_finish_message("pd", "dsp");
> > >
> > > // open patch [; pd open file folder(
> > > libpd_openfile(argv[1], argv[2]);
> > >
> > > /* the follownig two messages can be sent without setting the pd
> > > nstance
> > > and anyhow the symbols are global so they may affect multiple
> > > instances.
> > > However, if the messages change anyhing in the pd instacne
> structure
> > > (DSP state; current time; list of all canvases n our instance)
> those
> > > changes will apply to the current Pd nstance, so the earlier
> messages,
> > > for instance, were sensitive to which was the current one.
> > >
> > > Note also that I'm using the fact taht $0 is set to 1003, 1004, ...
> > > as patches are opened -it would be better to opent the patches with
> > > settable $1, etc parameters to libpd_openfile(). */
> > >
> > > // [; pd frequency 1 (
> > > libpd_start_message(1); // one entry in list
> > > libpd_add_float(1.0f);
> > > libpd_finish_message("1003-frequency", "float");
> > >
> > > // [; pd frequency 1 (
> > > libpd_start_message(1); // one entry in list
> > > libpd_add_float(2.0f);
> > > libpd_finish_message("1004-frequency", "float");
> > >
> > > // now run pd for ten seconds (logical time)
> > > int i, j;
> > > for (i = 0; i < 3; i++) {
> > > // fill inbuf here
> > > pd_setinstance(pd1);
> > > libpd_process_float(1, inbuf, outbuf);
> > > if (i < 2)
> > > {
> > > for (j = 0; j < 8; j++)
> > > printf("%f ", outbuf[j]);
> > > printf("\n");
> > > }
> > > pd_setinstance(pd2);
> > > libpd_process_float(1, inbuf, outbuf);
> > > if (i < 2)
> > > {
> > > for (j = 0; j < 8; j++)
> > > printf("%f ", outbuf[j]);
> > > printf("\n");
> > > }
> > > }
> > >
> > > return 0;
> > > }
> > >
> > > ----------------------
> > > I replaced "test.c" as follows:
> > > ---------------------
> > >
> > > #N canvas 406 290 450 300 10;
> > > #X obj 97 64 loadbang;
> > > #X obj 97 131 print;
> > > #X obj 186 106 dac~;
> > > #X obj 97 107 f 0;
> > > #X obj 128 107 + 1;
> > > #X obj 97 86 metro 2;
> > > #X obj 185 41 r \$0-frequency;
> > > #X obj 188 73 osc~;
> > > #X obj 248 127 print \$0-frequency;
> > > #X obj 248 97 loadbang;
> > > #X connect 0 0 5 0;
> > > #X connect 3 0 1 0;
> > > #X connect 3 0 4 0;
> > > #X connect 4 0 3 1;
> > > #X connect 5 0 3 0;
> > > #X connect 6 0 7 0;
> > > #X connect 6 0 8 0;
> > > #X connect 7 0 2 0;
> > > #X connect 7 0 2 1;
> > > #X connect 9 0 8 0;
> > >
> > > ----------------------------
> > > and got this output:
> > >
> > > print: 0
> > > 1003-frequency: bang
> > > print: 0
> > > 1004-frequency: bang
> > > 1003-frequency: 1
> > > 1004-frequency: 2
> > > 1.000000 1.000000 0.999999 0.999999 0.999998 0.999998 0.999997 0.999997
> > > 1.000000 1.000000 0.999998 0.999998 0.999996 0.999996 0.999995 0.999995
> > > print: 1
> > > 0.999944 0.999944 0.999943 0.999943 0.999942 0.999942 0.999941 0.999941
> > > print: 1
> > > 0.999815 0.999815 0.999810 0.999810 0.999804 0.999804 0.999799 0.999799
> > > print: 2
> > > print: 2
> > >
> > > ... Looks like there are 2 schedulers adn DSP chains running :)
> > >
> > > Miller
> > >
> > >
> > >
> > > _______________________________________________
> > > Pd-dev mailing list
> > > Pd-dev at iem.at
> > > http://lists.puredata.info/listinfo/pd-dev
> > >
>
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