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/atomic.h>
  32 #include <pulsecore/macro.h>
  33 #include <pulsecore/log.h>
  34 #include <pulsecore/thread.h>
  35 #include <pulsecore/semaphore.h>
  36 #include <pulsecore/macro.h>
  37 #include <pulsecore/core-util.h>
  38 #include <pulsecore/flist.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, FALSE))) {
  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_asyncq_post(a->asyncq, i);
 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     /* This 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, TRUE) == 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, pa_bool_t wait_op) {
 178     pa_assert(PA_REFCNT_VALUE(a) > 0);
 179     pa_assert(!a->current);
 180
 181     if (!(a->current = pa_asyncq_pop(a->asyncq, wait_op))) {
 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", */
 202 /*                  (void*) a, */
 203 /*                  (void*) a->current->object, */
 204 /*                  a->current->object ? a->current->object->parent.type_name : NULL, */
 205 /*                  a->current->code, */
 206 /*                  (void*) a->current->userdata, */
 207 /*                  (unsigned long) a->current->memchunk.length); */
 208
 209     return 0;
 210 }
 211
 212 void pa_asyncmsgq_done(pa_asyncmsgq *a, int ret) {
 213     pa_assert(PA_REFCNT_VALUE(a) > 0);
 214     pa_assert(a);
 215     pa_assert(a->current);
 216
 217     if (a->current->semaphore) {
 218         a->current->ret = ret;
 219         pa_semaphore_post(a->current->semaphore);
 220     } else {
 221
 222         if (a->current->free_cb)
 223             a->current->free_cb(a->current->userdata);
 224
 225         if (a->current->object)
 226             pa_msgobject_unref(a->current->object);
 227
 228         if (a->current->memchunk.memblock)
 229             pa_memblock_unref(a->current->memchunk.memblock);
 230
 231         if (pa_flist_push(PA_STATIC_FLIST_GET(asyncmsgq), a->current) < 0)
 232             pa_xfree(a->current);
 233     }
 234
 235     a->current = NULL;
 236 }
 237
 238 int pa_asyncmsgq_wait_for(pa_asyncmsgq *a, int code) {
 239     int c;
 240     pa_assert(PA_REFCNT_VALUE(a) > 0);
 241
 242     pa_asyncmsgq_ref(a);
 243
 244     do {
 245         pa_msgobject *o;
 246         void *data;
 247         int64_t offset;
 248         pa_memchunk chunk;
 249         int ret;
 250
 251         if (pa_asyncmsgq_get(a, &o, &c, &data, &offset, &chunk, TRUE) < 0)
 252             return -1;
 253
 254         ret = pa_asyncmsgq_dispatch(o, c, data, offset, &chunk);
 255         pa_asyncmsgq_done(a, ret);
 256
 257     } while (c != code);
 258
 259     pa_asyncmsgq_unref(a);
 260
 261     return 0;
 262 }
 263
 264 int pa_asyncmsgq_process_one(pa_asyncmsgq *a) {
 265     pa_msgobject *object;
 266     int code;
 267     void *data;
 268     pa_memchunk chunk;
 269     int64_t offset;
 270     int ret;
 271
 272     pa_assert(PA_REFCNT_VALUE(a) > 0);
 273
 274     if (pa_asyncmsgq_get(a, &object, &code, &data, &offset, &chunk, FALSE) < 0)
 275         return 0;
 276
 277     pa_asyncmsgq_ref(a);
 278     ret = pa_asyncmsgq_dispatch(object, code, data, offset, &chunk);
 279     pa_asyncmsgq_done(a, ret);
 280     pa_asyncmsgq_unref(a);
 281
 282     return 1;
 283 }
 284
 285 int pa_asyncmsgq_read_fd(pa_asyncmsgq *a) {
 286     pa_assert(PA_REFCNT_VALUE(a) > 0);
 287
 288     return pa_asyncq_read_fd(a->asyncq);
 289 }
 290
 291 int pa_asyncmsgq_read_before_poll(pa_asyncmsgq *a) {
 292     pa_assert(PA_REFCNT_VALUE(a) > 0);
 293
 294     return pa_asyncq_read_before_poll(a->asyncq);
 295 }
 296
 297 void pa_asyncmsgq_read_after_poll(pa_asyncmsgq *a) {
 298     pa_assert(PA_REFCNT_VALUE(a) > 0);
 299
 300     pa_asyncq_read_after_poll(a->asyncq);
 301 }
 302
 303 int pa_asyncmsgq_write_fd(pa_asyncmsgq *a) {
 304     pa_assert(PA_REFCNT_VALUE(a) > 0);
 305
 306     return pa_asyncq_write_fd(a->asyncq);
 307 }
 308
 309 void pa_asyncmsgq_write_before_poll(pa_asyncmsgq *a) {
 310     pa_assert(PA_REFCNT_VALUE(a) > 0);
 311
 312     pa_asyncq_write_before_poll(a->asyncq);
 313 }
 314
 315 void pa_asyncmsgq_write_after_poll(pa_asyncmsgq *a) {
 316     pa_assert(PA_REFCNT_VALUE(a) > 0);
 317
 318     pa_asyncq_write_after_poll(a->asyncq);
 319 }
 320
 321 int pa_asyncmsgq_dispatch(pa_msgobject *object, int code, void *userdata, int64_t offset, pa_memchunk *memchunk) {
 322
 323     if (object)
 324         return object->process_msg(object, code, userdata, offset, memchunk);
 325
 326     return 0;
 327 }
 328
 329 void pa_asyncmsgq_flush(pa_asyncmsgq *a, pa_bool_t run) {
 330     pa_assert(PA_REFCNT_VALUE(a) > 0);
 331
 332     for (;;) {
 333         pa_msgobject *object;
 334         int code;
 335         void *data;
 336         int64_t offset;
 337         pa_memchunk chunk;
 338         int ret;
 339
 340         if (pa_asyncmsgq_get(a, &object, &code, &data, &offset, &chunk, FALSE) < 0)
 341             return;
 342
 343         if (!run) {
 344             pa_asyncmsgq_done(a, -1);
 345             continue;
 346         }
 347
 348         pa_asyncmsgq_ref(a);
 349         ret = pa_asyncmsgq_dispatch(object, code, data, offset, &chunk);
 350         pa_asyncmsgq_done(a, ret);
 351         pa_asyncmsgq_unref(a);
 352     }
 353 }