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

   1 /* $Id$ */
   2
   3 /***
   4   This file is part of PulseAudio.
   5
   6   Copyright 2006 Lennart Poettering
   7
   8   PulseAudio is free software; you can redistribute it and/or modify
   9   it under the terms of the GNU Lesser General Public License as
  10   published by the Free Software Foundation; either version 2.1 of the
  11   License, or (at your option) any later version.
  12
  13   PulseAudio is distributed in the hope that it will be useful, but
  14   WITHOUT ANY WARRANTY; without even the implied warranty of
  15   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
  16   Lesser General Public License for more details.
  17
  18   You should have received a copy of the GNU Lesser General Public
  19   License along with PulseAudio; if not, write to the Free Software
  20   Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307
  21   USA.
  22 ***/
  23
  24 #ifdef HAVE_CONFIG_H
  25 #include <config.h>
  26 #endif
  27
  28 #include <unistd.h>
  29 #include <errno.h>
  30
  31 #include <pulsecore/atomic.h>
  32 #include <pulsecore/log.h>
  33 #include <pulsecore/thread.h>
  34 #include <pulsecore/semaphore.h>
  35 #include <pulsecore/macro.h>
  36 #include <pulsecore/core-util.h>
  37 #include <pulsecore/flist.h>
  38 #include <pulse/xmalloc.h>
  39
  40 #include "asyncmsgq.h"
  41
  42 PA_STATIC_FLIST_DECLARE(asyncmsgq, 0, pa_xfree);
  43 PA_STATIC_FLIST_DECLARE(semaphores, 0, (void(*)(void*)) pa_semaphore_free);
  44
  45 struct asyncmsgq_item {
  46     int code;
  47     pa_msgobject *object;
  48     void *userdata;
  49     pa_free_cb_t free_cb;
  50     int64_t offset;
  51     pa_memchunk memchunk;
  52     pa_semaphore *semaphore;
  53     int ret;
  54 };
  55
  56 struct pa_asyncmsgq {
  57     PA_REFCNT_DECLARE;
  58     pa_asyncq *asyncq;
  59     pa_mutex *mutex; /* only for the writer side */
  60
  61     struct asyncmsgq_item *current;
  62 };
  63
  64 pa_asyncmsgq *pa_asyncmsgq_new(unsigned size) {
  65     pa_asyncmsgq *a;
  66
  67     a = pa_xnew(pa_asyncmsgq, 1);
  68
  69     PA_REFCNT_INIT(a);
  70     pa_assert_se(a->asyncq = pa_asyncq_new(size));
  71     pa_assert_se(a->mutex = pa_mutex_new(FALSE, TRUE));
  72     a->current = NULL;
  73
  74     return a;
  75 }
  76
  77 static void asyncmsgq_free(pa_asyncmsgq *a) {
  78     struct asyncmsgq_item *i;
  79     pa_assert(a);
  80
  81     while ((i = pa_asyncq_pop(a->asyncq, 0))) {
  82
  83         pa_assert(!i->semaphore);
  84
  85         if (i->object)
  86             pa_msgobject_unref(i->object);
  87
  88         if (i->memchunk.memblock)
  89             pa_memblock_unref(i->memchunk.memblock);
  90
  91         if (i->free_cb)
  92             i->free_cb(i->userdata);
  93
  94         if (pa_flist_push(PA_STATIC_FLIST_GET(asyncmsgq), i) < 0)
  95             pa_xfree(i);
  96     }
  97
  98     pa_asyncq_free(a->asyncq, NULL);
  99     pa_mutex_free(a->mutex);
 100     pa_xfree(a);
 101 }
 102
 103 pa_asyncmsgq* pa_asyncmsgq_ref(pa_asyncmsgq *q) {
 104     pa_assert(PA_REFCNT_VALUE(q) > 0);
 105
 106     PA_REFCNT_INC(q);
 107     return q;
 108 }
 109
 110 void pa_asyncmsgq_unref(pa_asyncmsgq* q) {
 111     pa_assert(PA_REFCNT_VALUE(q) > 0);
 112
 113     if (PA_REFCNT_DEC(q) <= 0)
 114         asyncmsgq_free(q);
 115 }
 116
 117 void pa_asyncmsgq_post(pa_asyncmsgq *a, pa_msgobject *object, int code, const void *userdata, int64_t offset, const pa_memchunk *chunk, pa_free_cb_t free_cb) {
 118     struct asyncmsgq_item *i;
 119     pa_assert(PA_REFCNT_VALUE(a) > 0);
 120
 121     if (!(i = pa_flist_pop(PA_STATIC_FLIST_GET(asyncmsgq))))
 122         i = pa_xnew(struct asyncmsgq_item, 1);
 123
 124     i->code = code;
 125     i->object = object ? pa_msgobject_ref(object) : NULL;
 126     i->userdata = (void*) userdata;
 127     i->free_cb = free_cb;
 128     i->offset = offset;
 129     if (chunk) {
 130         pa_assert(chunk->memblock);
 131         i->memchunk = *chunk;
 132         pa_memblock_ref(i->memchunk.memblock);
 133     } else
 134         pa_memchunk_reset(&i->memchunk);
 135     i->semaphore = NULL;
 136
 137     /* This mutex makes the queue multiple-writer safe. This lock is only used on the writing side */
 138     pa_mutex_lock(a->mutex);
 139     pa_assert_se(pa_asyncq_push(a->asyncq, i, 1) == 0);
 140     pa_mutex_unlock(a->mutex);
 141 }
 142
 143 int pa_asyncmsgq_send(pa_asyncmsgq *a, pa_msgobject *object, int code, const void *userdata, int64_t offset, const pa_memchunk *chunk) {
 144     struct asyncmsgq_item i;
 145     pa_assert(PA_REFCNT_VALUE(a) > 0);
 146
 147     i.code = code;
 148     i.object = object;
 149     i.userdata = (void*) userdata;
 150     i.free_cb = NULL;
 151     i.ret = -1;
 152     i.offset = offset;
 153     if (chunk) {
 154         pa_assert(chunk->memblock);
 155         i.memchunk = *chunk;
 156     } else
 157         pa_memchunk_reset(&i.memchunk);
 158
 159     if (!(i.semaphore = pa_flist_pop(PA_STATIC_FLIST_GET(semaphores))))
 160         i.semaphore = pa_semaphore_new(0);
 161
 162     pa_assert_se(i.semaphore);
 163
 164     /* Thus mutex makes the queue multiple-writer safe. This lock is only used on the writing side */
 165     pa_mutex_lock(a->mutex);
 166     pa_assert_se(pa_asyncq_push(a->asyncq, &i, 1) == 0);
 167     pa_mutex_unlock(a->mutex);
 168
 169     pa_semaphore_wait(i.semaphore);
 170
 171     if (pa_flist_push(PA_STATIC_FLIST_GET(semaphores), i.semaphore) < 0)
 172         pa_semaphore_free(i.semaphore);
 173
 174     return i.ret;
 175 }
 176
 177 int pa_asyncmsgq_get(pa_asyncmsgq *a, pa_msgobject **object, int *code, void **userdata, int64_t *offset, pa_memchunk *chunk, int wait) {
 178     pa_assert(PA_REFCNT_VALUE(a) > 0);
 179     pa_assert(!a->current);
 180
 181     if (!(a->current = pa_asyncq_pop(a->asyncq, wait))) {
 182 /*         pa_log("failure"); */
 183         return -1;
 184     }
 185
 186 /*     pa_log("success"); */
 187
 188     if (code)
 189         *code = a->current->code;
 190     if (userdata)
 191         *userdata = a->current->userdata;
 192     if (offset)
 193         *offset = a->current->offset;
 194     if (object) {
 195         if ((*object = a->current->object))
 196             pa_msgobject_assert_ref(*object);
 197     }
 198     if (chunk)
 199         *chunk = a->current->memchunk;
 200
 201 /*     pa_log_debug("Get q=%p object=%p (%s) code=%i data=%p chunk.length=%lu", (void*) a, (void*) a->current->object, a->current->object ? a->current->object->parent.type_name : NULL, a->current->code, (void*) a->current->userdata, (unsigned long) a->current->memchunk.length); */
 202
 203     return 0;
 204 }
 205
 206 void pa_asyncmsgq_done(pa_asyncmsgq *a, int ret) {
 207     pa_assert(PA_REFCNT_VALUE(a) > 0);
 208     pa_assert(a);
 209     pa_assert(a->current);
 210
 211     if (a->current->semaphore) {
 212         a->current->ret = ret;
 213         pa_semaphore_post(a->current->semaphore);
 214     } else {
 215
 216         if (a->current->free_cb)
 217             a->current->free_cb(a->current->userdata);
 218
 219         if (a->current->object)
 220             pa_msgobject_unref(a->current->object);
 221
 222         if (a->current->memchunk.memblock)
 223             pa_memblock_unref(a->current->memchunk.memblock);
 224
 225         if (pa_flist_push(PA_STATIC_FLIST_GET(asyncmsgq), a->current) < 0)
 226             pa_xfree(a->current);
 227     }
 228
 229     a->current = NULL;
 230 }
 231
 232 int pa_asyncmsgq_wait_for(pa_asyncmsgq *a, int code) {
 233     int c;
 234     pa_assert(PA_REFCNT_VALUE(a) > 0);
 235
 236     pa_asyncmsgq_ref(a);
 237
 238     do {
 239         pa_msgobject *o;
 240         void *data;
 241         int64_t offset;
 242         pa_memchunk chunk;
 243         int ret;
 244
 245         if (pa_asyncmsgq_get(a, &o, &c, &data, &offset, &chunk, 1) < 0)
 246             return -1;
 247
 248         ret = pa_asyncmsgq_dispatch(o, c, data, offset, &chunk);
 249         pa_asyncmsgq_done(a, ret);
 250
 251     } while (c != code);
 252
 253     pa_asyncmsgq_unref(a);
 254
 255     return 0;
 256 }
 257
 258 int pa_asyncmsgq_process_one(pa_asyncmsgq *a) {
 259     pa_msgobject *object;
 260     int code;
 261     void *data;
 262     pa_memchunk chunk;
 263     int64_t offset;
 264     int ret;
 265
 266     pa_assert(PA_REFCNT_VALUE(a) > 0);
 267
 268     if (pa_asyncmsgq_get(a, &object, &code, &data, &offset, &chunk, 0) < 0)
 269         return 0;
 270
 271     pa_asyncmsgq_ref(a);
 272     ret = pa_asyncmsgq_dispatch(object, code, data, offset, &chunk);
 273     pa_asyncmsgq_done(a, ret);
 274     pa_asyncmsgq_unref(a);
 275
 276     return 1;
 277 }
 278
 279 int pa_asyncmsgq_get_fd(pa_asyncmsgq *a) {
 280     pa_assert(PA_REFCNT_VALUE(a) > 0);
 281
 282     return pa_asyncq_get_fd(a->asyncq);
 283 }
 284
 285 int pa_asyncmsgq_before_poll(pa_asyncmsgq *a) {
 286     pa_assert(PA_REFCNT_VALUE(a) > 0);
 287
 288     return pa_asyncq_before_poll(a->asyncq);
 289 }
 290
 291 void pa_asyncmsgq_after_poll(pa_asyncmsgq *a) {
 292     pa_assert(PA_REFCNT_VALUE(a) > 0);
 293
 294     pa_asyncq_after_poll(a->asyncq);
 295 }
 296
 297 int pa_asyncmsgq_dispatch(pa_msgobject *object, int code, void *userdata, int64_t offset, pa_memchunk *memchunk) {
 298
 299     if (object)
 300         return object->process_msg(object, code, userdata, offset, memchunk);
 301
 302     return 0;
 303 }