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

   1 /* $Id$ */
   2
   3 /***
   4   This file is part of PulseAudio.
   5
   6   Copyright 2004-2006 Lennart Poettering
   7   Copyright 2006 Pierre Ossman <ossman@cendio.se> for Cendio AB
   8
   9   PulseAudio is free software; you can redistribute it and/or modify
  10   it under the terms of the GNU Lesser General Public License as
  11   published by the Free Software Foundation; either version 2.1 of the
  12   License, or (at your option) any later version.
  13
  14   PulseAudio is distributed in the hope that it will be useful, but
  15   WITHOUT ANY WARRANTY; without even the implied warranty of
  16   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
  17   Lesser General Public License for more details.
  18
  19   You should have received a copy of the GNU Lesser General Public
  20   License along with PulseAudio; if not, write to the Free Software
  21   Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307
  22   USA.
  23 ***/
  24
  25 #ifdef HAVE_CONFIG_H
  26 #include <config.h>
  27 #endif
  28
  29 #include <signal.h>
  30
  31 #include <pulsecore/macro.h>
  32 #include <pulsecore/flist.h>
  33 #include <pulsecore/once.h>
  34 #include <pulsecore/thread.h>
  35 #include <pulsecore/core-util.h>
  36
  37 #include "rtsig.h"
  38
  39 #ifdef SIGRTMIN
  40
  41 static void _free_rtsig(void *p) {
  42     pa_rtsig_put(PA_PTR_TO_INT(p));
  43 }
  44
  45 PA_STATIC_FLIST_DECLARE(rtsig_flist, pa_make_power_of_two(SIGRTMAX-SIGRTMIN+1), NULL);
  46 PA_STATIC_TLS_DECLARE(rtsig_tls, _free_rtsig);
  47
  48 static pa_atomic_t rtsig_current = PA_ATOMIC_INIT(-1);
  49
  50 static int rtsig_start = -1, rtsig_end = -1;
  51
  52 int pa_rtsig_get(void) {
  53     void *p;
  54     int sig;
  55
  56     if ((p = pa_flist_pop(PA_STATIC_FLIST_GET(rtsig_flist))))
  57         return PA_PTR_TO_INT(p);
  58
  59     sig = pa_atomic_dec(&rtsig_current);
  60
  61     pa_assert(sig <= SIGRTMAX);
  62     pa_assert(sig <= rtsig_end);
  63
  64     if (sig < rtsig_start) {
  65         pa_atomic_inc(&rtsig_current);
  66         return -1;
  67     }
  68
  69     return sig;
  70 }
  71
  72 int pa_rtsig_get_for_thread(void) {
  73     int sig;
  74     void *p;
  75
  76     if ((p = PA_STATIC_TLS_GET(rtsig_tls)))
  77         return PA_PTR_TO_INT(p);
  78
  79     if ((sig = pa_rtsig_get()) < 0)
  80         return -1;
  81
  82     PA_STATIC_TLS_SET(rtsig_tls, PA_INT_TO_PTR(sig));
  83     return sig;
  84 }
  85
  86 void pa_rtsig_put(int sig) {
  87     pa_assert(sig >= rtsig_start);
  88     pa_assert(sig <= rtsig_end);
  89
  90     pa_assert_se(pa_flist_push(PA_STATIC_FLIST_GET(rtsig_flist), PA_INT_TO_PTR(sig)) >= 0);
  91 }
  92
  93 void pa_rtsig_configure(int start, int end) {
  94     int s;
  95     sigset_t ss;
  96
  97     pa_assert(pa_atomic_load(&rtsig_current) == -1);
  98
  99     pa_assert(SIGRTMIN <= start);
 100     pa_assert(start <= end);
 101     pa_assert(end <= SIGRTMAX);
 102
 103     rtsig_start = start;
 104     rtsig_end = end;
 105
 106     sigemptyset(&ss);
 107
 108     for (s = rtsig_start; s <= rtsig_end; s++)
 109         pa_assert_se(sigaddset(&ss, s) == 0);
 110
 111     pa_assert(pthread_sigmask(SIG_BLOCK, &ss, NULL) == 0);
 112
 113     /* We allocate starting from the end */
 114     pa_atomic_store(&rtsig_current, rtsig_end);
 115 }
 116
 117 #else /* SIGRTMIN */
 118
 119 int pa_rtsig_get(void) {
 120     return -1;
 121 }
 122
 123 int pa_rtsig_get_for_thread(void) {
 124     return -1;
 125 }
 126
 127 void pa_rtsig_put(int sig) {
 128 }
 129
 130 void pa_rtsig_configure(int start, int end) {
 131 }
 132
 133 #endif /* SIGRTMIN */