src/pulsecore/hook-list.c

   1 /***
   2   This file is part of PulseAudio.
   3
   4   Copyright 2006 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 2.1 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/macro.h>
  27
  28 #include "hook-list.h"
  29
  30 void pa_hook_init(pa_hook *hook, void *data) {
  31     pa_assert(hook);
  32
  33     PA_LLIST_HEAD_INIT(pa_hook_slot, hook->slots);
  34     hook->n_dead = hook->n_firing = 0;
  35     hook->data = data;
  36 }
  37
  38 static void slot_free(pa_hook *hook, pa_hook_slot *slot) {
  39     pa_assert(hook);
  40     pa_assert(slot);
  41
  42     PA_LLIST_REMOVE(pa_hook_slot, hook->slots, slot);
  43
  44     pa_xfree(slot);
  45 }
  46
  47 void pa_hook_done(pa_hook *hook) {
  48     pa_assert(hook);
  49     pa_assert(hook->n_firing == 0);
  50
  51     while (hook->slots)
  52         slot_free(hook, hook->slots);
  53
  54     pa_hook_init(hook, NULL);
  55 }
  56
  57 pa_hook_slot* pa_hook_connect(pa_hook *hook, pa_hook_priority_t prio, pa_hook_cb_t cb, void *data) {
  58     pa_hook_slot *slot, *where, *prev;
  59
  60     pa_assert(cb);
  61
  62     slot = pa_xnew(pa_hook_slot, 1);
  63     slot->hook = hook;
  64     slot->dead = FALSE;
  65     slot->callback = cb;
  66     slot->data = data;
  67     slot->priority = prio;
  68
  69     prev = NULL;
  70     for (where = hook->slots; where; where = where->next) {
  71         if (prio < where->priority)
  72             break;
  73         prev = where;
  74     }
  75
  76     PA_LLIST_INSERT_AFTER(pa_hook_slot, hook->slots, prev, slot);
  77
  78     return slot;
  79 }
  80
  81 void pa_hook_slot_free(pa_hook_slot *slot) {
  82     pa_assert(slot);
  83     pa_assert(!slot->dead);
  84
  85     if (slot->hook->n_firing > 0) {
  86         slot->dead = TRUE;
  87         slot->hook->n_dead++;
  88     } else
  89         slot_free(slot->hook, slot);
  90 }
  91
  92 pa_hook_result_t pa_hook_fire(pa_hook *hook, void *data) {
  93     pa_hook_slot *slot, *next;
  94     pa_hook_result_t result = PA_HOOK_OK;
  95
  96     pa_assert(hook);
  97
  98     hook->n_firing ++;
  99
 100     PA_LLIST_FOREACH(slot, hook->slots) {
 101         if (slot->dead)
 102             continue;
 103
 104         if ((result = slot->callback(hook->data, data, slot->data)) != PA_HOOK_OK)
 105             break;
 106     }
 107
 108     hook->n_firing --;
 109     pa_assert(hook->n_firing >= 0);
 110
 111     for (slot = hook->slots; hook->n_dead > 0 && slot; slot = next) {
 112         next = slot->next;
 113
 114         if (slot->dead) {
 115             slot_free(hook, slot);
 116             hook->n_dead--;
 117         }
 118     }
 119
 120     pa_assert(hook->n_dead == 0);
 121
 122     return result;
 123 }
 124
 125 pa_bool_t pa_hook_is_firing(pa_hook *hook) {
 126     pa_assert(hook);
 127
 128     return hook->n_firing > 0;
 129 }