code.delx.au - pulseaudio/blob - src/pulsecore/ratelimit.c

   1 /***
   2   This file is part of PulseAudio.
   3
   4   Copyright 2009 Lennart Poettering
   5
   6   PulseAudio is free software; you can redistribute it and/or modify
   7   it under the terms of the GNU Lesser General Public License as
   8   published by the Free Software Foundation; either version 2 of the
   9   License, or (at your option) any later version.
  10
  11   PulseAudio is distributed in the hope that it will be useful, but
  12   WITHOUT ANY WARRANTY; without even the implied warranty of
  13   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
  14   General Public License for more details.
  15
  16   You should have received a copy of the GNU Lesser General Public
  17   License along with PulseAudio; if not, write to the Free Software
  18   Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307
  19   USA.
  20 ***/
  21
  22 #ifdef HAVE_CONFIG_H
  23 #include <config.h>
  24 #endif
  25
  26 #include <pulsecore/rtclock.h>
  27 #include <pulsecore/log.h>
  28 #include <pulsecore/mutex.h>
  29
  30 #include "ratelimit.h"
  31
  32 static pa_static_mutex mutex;
  33
  34 /* Modelled after Linux' lib/ratelimit.c by Dave Young
  35  * <hidave.darkstar@gmail.com>, which is licensed GPLv2. */
  36
  37 pa_bool_t pa_ratelimit_test(pa_ratelimit *r) {
  38     pa_usec_t now;
  39     pa_mutex *m;
  40
  41     now = pa_rtclock_usec();
  42
  43     m = pa_static_mutex_get(&mutex, FALSE, FALSE);
  44     pa_mutex_lock(m);
  45
  46     pa_assert(r);
  47     pa_assert(r->interval > 0);
  48     pa_assert(r->burst > 0);
  49
  50     if (r->begin <= 0 ||
  51         r->begin + r->interval < now) {
  52
  53         if (r->n_missed > 0)
  54             pa_log_warn("%u events suppressed", r->n_missed);
  55
  56         r->begin = now;
  57
  58         /* Reset counters */
  59         r->n_printed = 0;
  60         r->n_missed = 0;
  61         goto good;
  62     }
  63
  64     if (r->n_printed <= r->burst)
  65         goto good;
  66
  67     r->n_missed++;
  68     pa_mutex_unlock(m);
  69     return FALSE;
  70
  71 good:
  72     r->n_printed++;
  73     pa_mutex_unlock(m);
  74     return TRUE;
  75 }