src/pulsecore/module.c

   1 /***
   2   This file is part of PulseAudio.
   3
   4   Copyright 2004-2006 Lennart Poettering
   5   Copyright 2006 Pierre Ossman <ossman@cendio.se> for Cendio AB
   6
   7   PulseAudio is free software; you can redistribute it and/or modify
   8   it under the terms of the GNU Lesser General Public License as published
   9   by the Free Software Foundation; either version 2.1 of the License,
  10   or (at your option) any later version.
  11
  12   PulseAudio is distributed in the hope that it will be useful, but
  13   WITHOUT ANY WARRANTY; without even the implied warranty of
  14   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
  15   General Public License for more details.
  16
  17   You should have received a copy of the GNU Lesser General Public License
  18   along with PulseAudio; if not, write to the Free Software
  19   Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307
  20   USA.
  21 ***/
  22
  23 #ifdef HAVE_CONFIG_H
  24 #include <config.h>
  25 #endif
  26
  27 #include <limits.h>
  28 #include <stdio.h>
  29 #include <stdlib.h>
  30 #include <string.h>
  31 #include <errno.h>
  32 #include <ctype.h>
  33
  34 #include <pulse/timeval.h>
  35 #include <pulse/xmalloc.h>
  36 #include <pulse/proplist.h>
  37
  38 #include <pulsecore/core-subscribe.h>
  39 #include <pulsecore/log.h>
  40 #include <pulsecore/core-util.h>
  41 #include <pulsecore/macro.h>
  42 #include <pulsecore/ltdl-helper.h>
  43 #include <pulsecore/modinfo.h>
  44
  45 #include "module.h"
  46
  47 #define PA_SYMBOL_INIT "pa__init"
  48 #define PA_SYMBOL_DONE "pa__done"
  49 #define PA_SYMBOL_LOAD_ONCE "pa__load_once"
  50 #define PA_SYMBOL_GET_N_USED "pa__get_n_used"
  51
  52 pa_module* pa_module_load(pa_core *c, const char *name, const char *argument) {
  53     pa_module *m = NULL;
  54     pa_bool_t (*load_once)(void);
  55     pa_modinfo *mi;
  56
  57     pa_assert(c);
  58     pa_assert(name);
  59
  60     if (c->disallow_module_loading)
  61         goto fail;
  62
  63     m = pa_xnew(pa_module, 1);
  64     m->name = pa_xstrdup(name);
  65     m->argument = pa_xstrdup(argument);
  66     m->load_once = FALSE;
  67     m->proplist = pa_proplist_new();
  68
  69     if (!(m->dl = lt_dlopenext(name))) {
  70         pa_log("Failed to open module \"%s\": %s", name, lt_dlerror());
  71         goto fail;
  72     }
  73
  74     if ((load_once = (pa_bool_t (*)(void)) pa_load_sym(m->dl, name, PA_SYMBOL_LOAD_ONCE))) {
  75
  76         m->load_once = load_once();
  77
  78         if (m->load_once) {
  79             pa_module *i;
  80             uint32_t idx;
  81             /* OK, the module only wants to be loaded once, let's make sure it is */
  82
  83             for (i = pa_idxset_first(c->modules, &idx); i; i = pa_idxset_next(c->modules, &idx)) {
  84                 if (strcmp(name, i->name) == 0) {
  85                     pa_log("Module \"%s\" should be loaded once at most. Refusing to load.", name);
  86                     goto fail;
  87                 }
  88             }
  89         }
  90     }
  91
  92     if (!(m->init = (int (*)(pa_module*_m)) pa_load_sym(m->dl, name, PA_SYMBOL_INIT))) {
  93         pa_log("Failed to load module \"%s\": symbol \""PA_SYMBOL_INIT"\" not found.", name);
  94         goto fail;
  95     }
  96
  97     m->done = (void (*)(pa_module*_m)) pa_load_sym(m->dl, name, PA_SYMBOL_DONE);
  98     m->get_n_used = (int (*)(pa_module*_m)) pa_load_sym(m->dl, name, PA_SYMBOL_GET_N_USED);
  99     m->userdata = NULL;
 100     m->core = c;
 101     m->unload_requested = FALSE;
 102
 103     if (m->init(m) < 0) {
 104         pa_log_error("Failed to load  module \"%s\" (argument: \"%s\"): initialization failed.", name, argument ? argument : "");
 105         goto fail;
 106     }
 107
 108     pa_assert_se(pa_idxset_put(c->modules, m, &m->index) >= 0);
 109     pa_assert(m->index != PA_IDXSET_INVALID);
 110
 111     pa_log_info("Loaded \"%s\" (index: #%u; argument: \"%s\").", m->name, m->index, m->argument ? m->argument : "");
 112
 113     pa_subscription_post(c, PA_SUBSCRIPTION_EVENT_MODULE|PA_SUBSCRIPTION_EVENT_NEW, m->index);
 114
 115     if ((mi = pa_modinfo_get_by_handle(m->dl, name))) {
 116
 117         if (mi->author && !pa_proplist_contains(m->proplist, PA_PROP_MODULE_AUTHOR))
 118             pa_proplist_sets(m->proplist, PA_PROP_MODULE_AUTHOR, mi->author);
 119
 120         if (mi->description && !pa_proplist_contains(m->proplist, PA_PROP_MODULE_DESCRIPTION))
 121             pa_proplist_sets(m->proplist, PA_PROP_MODULE_DESCRIPTION, mi->description);
 122
 123         if (mi->version && !pa_proplist_contains(m->proplist, PA_PROP_MODULE_VERSION))
 124             pa_proplist_sets(m->proplist, PA_PROP_MODULE_VERSION, mi->version);
 125
 126         pa_modinfo_free(mi);
 127     }
 128
 129     return m;
 130
 131 fail:
 132
 133     if (m) {
 134         if (m->proplist)
 135             pa_proplist_free(m->proplist);
 136
 137         pa_xfree(m->argument);
 138         pa_xfree(m->name);
 139
 140         if (m->dl)
 141             lt_dlclose(m->dl);
 142
 143         pa_xfree(m);
 144     }
 145
 146     return NULL;
 147 }
 148
 149 static void pa_module_free(pa_module *m) {
 150     pa_assert(m);
 151     pa_assert(m->core);
 152
 153     pa_log_info("Unloading \"%s\" (index: #%u).", m->name, m->index);
 154
 155     if (m->done)
 156         m->done(m);
 157
 158     if (m->proplist)
 159         pa_proplist_free(m->proplist);
 160
 161     lt_dlclose(m->dl);
 162
 163     pa_log_info("Unloaded \"%s\" (index: #%u).", m->name, m->index);
 164
 165     pa_subscription_post(m->core, PA_SUBSCRIPTION_EVENT_MODULE|PA_SUBSCRIPTION_EVENT_REMOVE, m->index);
 166
 167     pa_xfree(m->name);
 168     pa_xfree(m->argument);
 169     pa_xfree(m);
 170 }
 171
 172 void pa_module_unload(pa_core *c, pa_module *m, pa_bool_t force) {
 173     pa_assert(c);
 174     pa_assert(m);
 175
 176     if (m->core->disallow_module_loading && !force)
 177         return;
 178
 179     if (!(m = pa_idxset_remove_by_data(c->modules, m, NULL)))
 180         return;
 181
 182     pa_module_free(m);
 183 }
 184
 185 void pa_module_unload_by_index(pa_core *c, uint32_t idx, pa_bool_t force) {
 186     pa_module *m;
 187     pa_assert(c);
 188     pa_assert(idx != PA_IDXSET_INVALID);
 189
 190     if (c->disallow_module_loading && !force)
 191         return;
 192
 193     if (!(m = pa_idxset_remove_by_index(c->modules, idx)))
 194         return;
 195
 196     pa_module_free(m);
 197 }
 198
 199 void pa_module_unload_all(pa_core *c) {
 200     pa_module *m;
 201     pa_assert(c);
 202
 203     while ((m = pa_idxset_steal_first(c->modules, NULL)))
 204         pa_module_free(m);
 205
 206     if (c->module_defer_unload_event) {
 207         c->mainloop->defer_free(c->module_defer_unload_event);
 208         c->module_defer_unload_event = NULL;
 209     }
 210 }
 211
 212 static void defer_cb(pa_mainloop_api*api, pa_defer_event *e, void *userdata) {
 213     void *state = NULL;
 214     pa_core *c = PA_CORE(userdata);
 215     pa_module *m;
 216
 217     pa_core_assert_ref(c);
 218     api->defer_enable(e, 0);
 219
 220     while ((m = pa_idxset_iterate(c->modules, &state, NULL)))
 221         if (m->unload_requested)
 222             pa_module_unload(c, m, TRUE);
 223 }
 224
 225 void pa_module_unload_request(pa_module *m, pa_bool_t force) {
 226     pa_assert(m);
 227
 228     if (m->core->disallow_module_loading && !force)
 229         return;
 230
 231     m->unload_requested = TRUE;
 232
 233     if (!m->core->module_defer_unload_event)
 234         m->core->module_defer_unload_event = m->core->mainloop->defer_new(m->core->mainloop, defer_cb, m->core);
 235
 236     m->core->mainloop->defer_enable(m->core->module_defer_unload_event, 1);
 237 }
 238
 239 void pa_module_unload_request_by_index(pa_core *c, uint32_t idx, pa_bool_t force) {
 240     pa_module *m;
 241     pa_assert(c);
 242
 243     if (!(m = pa_idxset_get_by_index(c->modules, idx)))
 244         return;
 245
 246     pa_module_unload_request(m, force);
 247 }
 248
 249 int pa_module_get_n_used(pa_module*m) {
 250     pa_assert(m);
 251
 252     if (!m->get_n_used)
 253         return -1;
 254
 255     return m->get_n_used(m);
 256 }