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 <pulse/xmalloc.h>
  27
  28 #include <pulsecore/macro.h>
  29
  30 #include "hook-list.h"
  31
  32 void pa_hook_init(pa_hook *hook, void *data) {
  33     pa_assert(hook);
  34
  35     PA_LLIST_HEAD_INIT(pa_hook_slot, hook->slots);
  36     hook->n_dead = hook->n_firing = 0;
  37     hook->data = data;
  38 }
  39
  40 static void slot_free(pa_hook *hook, pa_hook_slot *slot) {
  41     pa_assert(hook);
  42     pa_assert(slot);
  43
  44     PA_LLIST_REMOVE(pa_hook_slot, hook->slots, slot);
  45
  46     pa_xfree(slot);
  47 }
  48
  49 void pa_hook_done(pa_hook *hook) {
  50     pa_assert(hook);
  51     pa_assert(hook->n_firing == 0);
  52
  53     while (hook->slots)
  54         slot_free(hook, hook->slots);
  55
  56     pa_hook_init(hook, NULL);
  57 }
  58
  59 pa_hook_slot* pa_hook_connect(pa_hook *hook, pa_hook_priority_t prio, pa_hook_cb_t cb, void *data) {
  60     pa_hook_slot *slot, *where, *prev;
  61
  62     pa_assert(cb);
  63
  64     slot = pa_xnew(pa_hook_slot, 1);
  65     slot->hook = hook;
  66     slot->dead = FALSE;
  67     slot->callback = cb;
  68     slot->data = data;
  69     slot->priority = prio;
  70
  71     prev = NULL;
  72     for (where = hook->slots; where; where = where->next) {
  73         if (prio < where->priority)
  74             break;
  75         prev = where;
  76     }
  77
  78     PA_LLIST_INSERT_AFTER(pa_hook_slot, hook->slots, prev, slot);
  79
  80     return slot;
  81 }
  82
  83 void pa_hook_slot_free(pa_hook_slot *slot) {
  84     pa_assert(slot);
  85     pa_assert(!slot->dead);
  86
  87     if (slot->hook->n_firing > 0) {
  88         slot->dead = TRUE;
  89         slot->hook->n_dead++;
  90     } else
  91         slot_free(slot->hook, slot);
  92 }
  93
  94 pa_hook_result_t pa_hook_fire(pa_hook *hook, void *data) {
  95     pa_hook_slot *slot, *next;
  96     pa_hook_result_t result = PA_HOOK_OK;
  97
  98     pa_assert(hook);
  99
 100     hook->n_firing ++;
 101
 102     PA_LLIST_FOREACH(slot, hook->slots) {
 103         if (slot->dead)
 104             continue;
 105
 106         if ((result = slot->callback(hook->data, data, slot->data)) != PA_HOOK_OK)
 107             break;
 108     }
 109
 110     hook->n_firing --;
 111     pa_assert(hook->n_firing >= 0);
 112
 113     for (slot = hook->slots; hook->n_dead > 0 && slot; slot = next) {
 114         next = slot->next;
 115
 116         if (slot->dead) {
 117             slot_free(hook, slot);
 118             hook->n_dead--;
 119         }
 120     }
 121
 122     pa_assert(hook->n_dead == 0);
 123
 124     return result;
 125 }
 126
 127 pa_bool_t pa_hook_is_firing(pa_hook *hook) {
 128     pa_assert(hook);
 129
 130     return hook->n_firing > 0;
 131 }