src/pulsecore/asyncmsgq.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   Lesser 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 <unistd.h>
  27 #include <errno.h>
  28
  29 #include <pulse/xmalloc.h>
  30
  31 #include <pulsecore/macro.h>
  32 #include <pulsecore/log.h>
  33 #include <pulsecore/semaphore.h>
  34 #include <pulsecore/macro.h>
  35 #include <pulsecore/mutex.h>
  36 #include <pulsecore/flist.h>
  37
  38 #include "asyncmsgq.h"
  39
  40 PA_STATIC_FLIST_DECLARE(asyncmsgq, 0, pa_xfree);
  41 PA_STATIC_FLIST_DECLARE(semaphores, 0, (void(*)(void*)) pa_semaphore_free);
  42
  43 struct asyncmsgq_item {
  44     int code;
  45     pa_msgobject *object;
  46     void *userdata;
  47     pa_free_cb_t free_cb;
  48     int64_t offset;
  49     pa_memchunk memchunk;
  50     pa_semaphore *semaphore;
  51     int ret;
  52 };
  53
  54 struct pa_asyncmsgq {
  55     PA_REFCNT_DECLARE;
  56     pa_asyncq *asyncq;
  57     pa_mutex *mutex; /* only for the writer side */
  58
  59     struct asyncmsgq_item *current;
  60 };
  61
  62 pa_asyncmsgq *pa_asyncmsgq_new(unsigned size) {
  63     pa_asyncmsgq *a;
  64
  65     a = pa_xnew(pa_asyncmsgq, 1);
  66
  67     PA_REFCNT_INIT(a);
  68     pa_assert_se(a->asyncq = pa_asyncq_new(size));
  69     pa_assert_se(a->mutex = pa_mutex_new(FALSE, TRUE));
  70     a->current = NULL;
  71
  72     return a;
  73 }
  74
  75 static void asyncmsgq_free(pa_asyncmsgq *a) {
  76     struct asyncmsgq_item *i;
  77     pa_assert(a);
  78
  79     while ((i = pa_asyncq_pop(a->asyncq, FALSE))) {
  80
  81         pa_assert(!i->semaphore);
  82
  83         if (i->object)
  84             pa_msgobject_unref(i->object);
  85
  86         if (i->memchunk.memblock)
  87             pa_memblock_unref(i->memchunk.memblock);
  88
  89         if (i->free_cb)
  90             i->free_cb(i->userdata);
  91
  92         if (pa_flist_push(PA_STATIC_FLIST_GET(asyncmsgq), i) < 0)
  93             pa_xfree(i);
  94     }
  95
  96     pa_asyncq_free(a->asyncq, NULL);
  97     pa_mutex_free(a->mutex);
  98     pa_xfree(a);
  99 }
 100
 101 pa_asyncmsgq* pa_asyncmsgq_ref(pa_asyncmsgq *q) {
 102     pa_assert(PA_REFCNT_VALUE(q) > 0);
 103
 104     PA_REFCNT_INC(q);
 105     return q;
 106 }
 107
 108 void pa_asyncmsgq_unref(pa_asyncmsgq* q) {
 109     pa_assert(PA_REFCNT_VALUE(q) > 0);
 110
 111     if (PA_REFCNT_DEC(q) <= 0)
 112         asyncmsgq_free(q);
 113 }
 114
 115 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) {
 116     struct asyncmsgq_item *i;
 117     pa_assert(PA_REFCNT_VALUE(a) > 0);
 118
 119     if (!(i = pa_flist_pop(PA_STATIC_FLIST_GET(asyncmsgq))))
 120         i = pa_xnew(struct asyncmsgq_item, 1);
 121
 122     i->code = code;
 123     i->object = object ? pa_msgobject_ref(object) : NULL;
 124     i->userdata = (void*) userdata;
 125     i->free_cb = free_cb;
 126     i->offset = offset;
 127     if (chunk) {
 128         pa_assert(chunk->memblock);
 129         i->memchunk = *chunk;
 130         pa_memblock_ref(i->memchunk.memblock);
 131     } else
 132         pa_memchunk_reset(&i->memchunk);
 133     i->semaphore = NULL;
 134
 135     /* This mutex makes the queue multiple-writer safe. This lock is only used on the writing side */
 136     pa_mutex_lock(a->mutex);
 137     pa_asyncq_post(a->asyncq, i);
 138     pa_mutex_unlock(a->mutex);
 139 }
 140
 141 int pa_asyncmsgq_send(pa_asyncmsgq *a, pa_msgobject *object, int code, const void *userdata, int64_t offset, const pa_memchunk *chunk) {
 142     struct asyncmsgq_item i;
 143     pa_assert(PA_REFCNT_VALUE(a) > 0);
 144
 145     i.code = code;
 146     i.object = object;
 147     i.userdata = (void*) userdata;
 148     i.free_cb = NULL;
 149     i.ret = -1;
 150     i.offset = offset;
 151     if (chunk) {
 152         pa_assert(chunk->memblock);
 153         i.memchunk = *chunk;
 154     } else
 155         pa_memchunk_reset(&i.memchunk);
 156
 157     if (!(i.semaphore = pa_flist_pop(PA_STATIC_FLIST_GET(semaphores))))
 158         i.semaphore = pa_semaphore_new(0);
 159
 160     pa_assert_se(i.semaphore);
 161
 162     /* This mutex makes the queue multiple-writer safe. This lock is only used on the writing side */
 163     pa_mutex_lock(a->mutex);
 164     pa_assert_se(pa_asyncq_push(a->asyncq, &i, TRUE) == 0);
 165     pa_mutex_unlock(a->mutex);
 166
 167     pa_semaphore_wait(i.semaphore);
 168
 169     if (pa_flist_push(PA_STATIC_FLIST_GET(semaphores), i.semaphore) < 0)
 170         pa_semaphore_free(i.semaphore);
 171
 172     return i.ret;
 173 }
 174
 175 int pa_asyncmsgq_get(pa_asyncmsgq *a, pa_msgobject **object, int *code, void **userdata, int64_t *offset, pa_memchunk *chunk, pa_bool_t wait_op) {
 176     pa_assert(PA_REFCNT_VALUE(a) > 0);
 177     pa_assert(!a->current);
 178
 179     if (!(a->current = pa_asyncq_pop(a->asyncq, wait_op))) {
 180 /*         pa_log("failure"); */
 181         return -1;
 182     }
 183
 184 /*     pa_log("success"); */
 185
 186     if (code)
 187         *code = a->current->code;
 188     if (userdata)
 189         *userdata = a->current->userdata;
 190     if (offset)
 191         *offset = a->current->offset;
 192     if (object) {
 193         if ((*object = a->current->object))
 194             pa_msgobject_assert_ref(*object);
 195     }
 196     if (chunk)
 197         *chunk = a->current->memchunk;
 198
 199 /*     pa_log_debug("Get q=%p object=%p (%s) code=%i data=%p chunk.length=%lu", */
 200 /*                  (void*) a, */
 201 /*                  (void*) a->current->object, */
 202 /*                  a->current->object ? a->current->object->parent.type_name : NULL, */
 203 /*                  a->current->code, */
 204 /*                  (void*) a->current->userdata, */
 205 /*                  (unsigned long) a->current->memchunk.length); */
 206
 207     return 0;
 208 }
 209
 210 void pa_asyncmsgq_done(pa_asyncmsgq *a, int ret) {
 211     pa_assert(PA_REFCNT_VALUE(a) > 0);
 212     pa_assert(a);
 213     pa_assert(a->current);
 214
 215     if (a->current->semaphore) {
 216         a->current->ret = ret;
 217         pa_semaphore_post(a->current->semaphore);
 218     } else {
 219
 220         if (a->current->free_cb)
 221             a->current->free_cb(a->current->userdata);
 222
 223         if (a->current->object)
 224             pa_msgobject_unref(a->current->object);
 225
 226         if (a->current->memchunk.memblock)
 227             pa_memblock_unref(a->current->memchunk.memblock);
 228
 229         if (pa_flist_push(PA_STATIC_FLIST_GET(asyncmsgq), a->current) < 0)
 230             pa_xfree(a->current);
 231     }
 232
 233     a->current = NULL;
 234 }
 235
 236 int pa_asyncmsgq_wait_for(pa_asyncmsgq *a, int code) {
 237     int c;
 238     pa_assert(PA_REFCNT_VALUE(a) > 0);
 239
 240     pa_asyncmsgq_ref(a);
 241
 242     do {
 243         pa_msgobject *o;
 244         void *data;
 245         int64_t offset;
 246         pa_memchunk chunk;
 247         int ret;
 248
 249         if (pa_asyncmsgq_get(a, &o, &c, &data, &offset, &chunk, TRUE) < 0)
 250             return -1;
 251
 252         ret = pa_asyncmsgq_dispatch(o, c, data, offset, &chunk);
 253         pa_asyncmsgq_done(a, ret);
 254
 255     } while (c != code);
 256
 257     pa_asyncmsgq_unref(a);
 258
 259     return 0;
 260 }
 261
 262 int pa_asyncmsgq_process_one(pa_asyncmsgq *a) {
 263     pa_msgobject *object;
 264     int code;
 265     void *data;
 266     pa_memchunk chunk;
 267     int64_t offset;
 268     int ret;
 269
 270     pa_assert(PA_REFCNT_VALUE(a) > 0);
 271
 272     if (pa_asyncmsgq_get(a, &object, &code, &data, &offset, &chunk, FALSE) < 0)
 273         return 0;
 274
 275     pa_asyncmsgq_ref(a);
 276     ret = pa_asyncmsgq_dispatch(object, code, data, offset, &chunk);
 277     pa_asyncmsgq_done(a, ret);
 278     pa_asyncmsgq_unref(a);
 279
 280     return 1;
 281 }
 282
 283 int pa_asyncmsgq_read_fd(pa_asyncmsgq *a) {
 284     pa_assert(PA_REFCNT_VALUE(a) > 0);
 285
 286     return pa_asyncq_read_fd(a->asyncq);
 287 }
 288
 289 int pa_asyncmsgq_read_before_poll(pa_asyncmsgq *a) {
 290     pa_assert(PA_REFCNT_VALUE(a) > 0);
 291
 292     return pa_asyncq_read_before_poll(a->asyncq);
 293 }
 294
 295 void pa_asyncmsgq_read_after_poll(pa_asyncmsgq *a) {
 296     pa_assert(PA_REFCNT_VALUE(a) > 0);
 297
 298     pa_asyncq_read_after_poll(a->asyncq);
 299 }
 300
 301 int pa_asyncmsgq_write_fd(pa_asyncmsgq *a) {
 302     pa_assert(PA_REFCNT_VALUE(a) > 0);
 303
 304     return pa_asyncq_write_fd(a->asyncq);
 305 }
 306
 307 void pa_asyncmsgq_write_before_poll(pa_asyncmsgq *a) {
 308     pa_assert(PA_REFCNT_VALUE(a) > 0);
 309
 310     pa_asyncq_write_before_poll(a->asyncq);
 311 }
 312
 313 void pa_asyncmsgq_write_after_poll(pa_asyncmsgq *a) {
 314     pa_assert(PA_REFCNT_VALUE(a) > 0);
 315
 316     pa_asyncq_write_after_poll(a->asyncq);
 317 }
 318
 319 int pa_asyncmsgq_dispatch(pa_msgobject *object, int code, void *userdata, int64_t offset, pa_memchunk *memchunk) {
 320
 321     if (object)
 322         return object->process_msg(object, code, userdata, offset, pa_memchunk_isset(memchunk) ? memchunk : NULL);
 323
 324     return 0;
 325 }
 326
 327 void pa_asyncmsgq_flush(pa_asyncmsgq *a, pa_bool_t run) {
 328     pa_assert(PA_REFCNT_VALUE(a) > 0);
 329
 330     for (;;) {
 331         pa_msgobject *object;
 332         int code;
 333         void *data;
 334         int64_t offset;
 335         pa_memchunk chunk;
 336         int ret;
 337
 338         if (pa_asyncmsgq_get(a, &object, &code, &data, &offset, &chunk, FALSE) < 0)
 339             return;
 340
 341         if (!run) {
 342             pa_asyncmsgq_done(a, -1);
 343             continue;
 344         }
 345
 346         pa_asyncmsgq_ref(a);
 347         ret = pa_asyncmsgq_dispatch(object, code, data, offset, &chunk);
 348         pa_asyncmsgq_done(a, ret);
 349         pa_asyncmsgq_unref(a);
 350     }
 351 }
 352
 353 pa_bool_t pa_asyncmsgq_dispatching(pa_asyncmsgq *a) {
 354     pa_assert(PA_REFCNT_VALUE(a) > 0);
 355
 356     return !!a->current;
 357 }