jack_interposer.c

   1 // needed to use RTLD_NEXT from dlfcn.h
   2 #define _GNU_SOURCE
   3
   4 #include <stdio.h>
   5 #include <stdlib.h>
   6 #include <stdbool.h>
   7 #include <dlfcn.h>
   8 #include <poll.h>
   9 #include <jack/jack.h>
  10 #include <stdarg.h>
  11
  12 #define ABORT_ON_VIOLATION 1
  13
  14 // is set to 'true' when entering the process-callback and to 'false' when
  15 // leaving it. When set to 'true', calls to non-realtime functions will
  16 // cause warnings/errors.
  17 //
  18 // This assumes there is only 1 thread running at a time, thus introducing
  19 // the limitation that jack_interposer is only usable on single-CPU machines
  20 // (or machines configured to run the application under test on only 1 CPU).
  21 bool in_rt = false;
  22
  23 #include "checkers.c"
  24 #include "manual.c"
  25
  26 JackProcessCallback real_process_callback;
  27
  28 int interposed_process_callback(jack_nframes_t nframes, void* arg)
  29 {
  30   int result;
  31
  32   in_rt = true;
  33
  34   result = real_process_callback(nframes, arg);
  35
  36   in_rt = false;
  37
  38   return result;
  39 }
  40
  41 int jack_set_process_callback(jack_client_t* client,
  42         JackProcessCallback process_callback, void* arg)
  43 {
  44   static int (*func)() = NULL;
  45   int result;
  46
  47   if(!func)
  48     func = (int(*)()) dlsym(RTLD_NEXT, "jack_set_process_callback");
  49   if(!func)
  50   {
  51     fprintf(stderr, "Error dlsym'ing jack_set_process_callback\n");
  52     abort();
  53   }
  54
  55   real_process_callback = process_callback;
  56
  57   result = func(client, interposed_process_callback, arg);
  58
  59   return result;
  60 }