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

   1 /* $Id$ */
   2
   3 /***
   4   This file is part of PulseAudio.
   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 <stdio.h>
  27 #include <stdlib.h>
  28 #include <assert.h>
  29 #include <string.h>
  30 #include <unistd.h>
  31
  32 #include <pulse/xmalloc.h>
  33
  34 #include <pulsecore/shm.h>
  35 #include <pulsecore/log.h>
  36 #include <pulsecore/hashmap.h>
  37
  38 #include "memblock.h"
  39
  40 #define PA_MEMPOOL_SLOTS_MAX 128
  41 #define PA_MEMPOOL_SLOT_SIZE (16*1024)
  42
  43 #define PA_MEMEXPORT_SLOTS_MAX 128
  44
  45 #define PA_MEMIMPORT_SLOTS_MAX 128
  46 #define PA_MEMIMPORT_SEGMENTS_MAX 16
  47
  48 struct pa_memimport_segment {
  49     pa_memimport *import;
  50     pa_shm memory;
  51     unsigned n_blocks;
  52 };
  53
  54 struct pa_memimport {
  55     pa_mempool *pool;
  56     pa_hashmap *segments;
  57     pa_hashmap *blocks;
  58
  59     /* Called whenever an imported memory block is no longer
  60      * needed. */
  61     pa_memimport_release_cb_t release_cb;
  62     void *userdata;
  63
  64     PA_LLIST_FIELDS(pa_memimport);
  65 };
  66
  67 struct memexport_slot {
  68     PA_LLIST_FIELDS(struct memexport_slot);
  69     pa_memblock *block;
  70 };
  71
  72 struct pa_memexport {
  73     pa_mempool *pool;
  74
  75     struct memexport_slot slots[PA_MEMEXPORT_SLOTS_MAX];
  76     PA_LLIST_HEAD(struct memexport_slot, free_slots);
  77     PA_LLIST_HEAD(struct memexport_slot, used_slots);
  78     unsigned n_init;
  79
  80     /* Called whenever a client from which we imported a memory block
  81        which we in turn exported to another client dies and we need to
  82        revoke the memory block accordingly */
  83     pa_memexport_revoke_cb_t revoke_cb;
  84     void *userdata;
  85
  86     PA_LLIST_FIELDS(pa_memexport);
  87 };
  88
  89 struct mempool_slot {
  90     PA_LLIST_FIELDS(struct mempool_slot);
  91     /* the actual data follows immediately hereafter */
  92 };
  93
  94 struct pa_mempool {
  95     pa_shm memory;
  96     size_t block_size;
  97     unsigned n_blocks, n_init;
  98
  99     PA_LLIST_HEAD(pa_memimport, imports);
 100     PA_LLIST_HEAD(pa_memexport, exports);
 101
 102     /* A list of free slots that may be reused */
 103     PA_LLIST_HEAD(struct mempool_slot, free_slots);
 104     PA_LLIST_HEAD(struct mempool_slot, used_slots);
 105
 106     pa_mempool_stat stat;
 107 };
 108
 109 static void segment_detach(pa_memimport_segment *seg);
 110
 111 static void stat_add(pa_memblock*b) {
 112     assert(b);
 113     assert(b->pool);
 114
 115     b->pool->stat.n_allocated ++;
 116     b->pool->stat.n_accumulated ++;
 117     b->pool->stat.allocated_size += b->length;
 118     b->pool->stat.accumulated_size += b->length;
 119
 120     if (b->type == PA_MEMBLOCK_IMPORTED) {
 121         b->pool->stat.n_imported++;
 122         b->pool->stat.imported_size += b->length;
 123     }
 124
 125     b->pool->stat.n_allocated_by_type[b->type]++;
 126     b->pool->stat.n_accumulated_by_type[b->type]++;
 127 }
 128
 129 static void stat_remove(pa_memblock *b) {
 130     assert(b);
 131     assert(b->pool);
 132
 133     assert(b->pool->stat.n_allocated > 0);
 134     assert(b->pool->stat.allocated_size >= b->length);
 135
 136     b->pool->stat.n_allocated --;
 137     b->pool->stat.allocated_size -= b->length;
 138
 139     if (b->type == PA_MEMBLOCK_IMPORTED) {
 140         assert(b->pool->stat.n_imported > 0);
 141         assert(b->pool->stat.imported_size >= b->length);
 142
 143         b->pool->stat.n_imported --;
 144         b->pool->stat.imported_size -= b->length;
 145     }
 146
 147     b->pool->stat.n_allocated_by_type[b->type]--;
 148 }
 149
 150 static pa_memblock *memblock_new_appended(pa_mempool *p, size_t length);
 151
 152 pa_memblock *pa_memblock_new(pa_mempool *p, size_t length) {
 153     pa_memblock *b;
 154
 155     assert(p);
 156     assert(length > 0);
 157
 158     if (!(b = pa_memblock_new_pool(p, length)))
 159         b = memblock_new_appended(p, length);
 160
 161     return b;
 162 }
 163
 164 static pa_memblock *memblock_new_appended(pa_mempool *p, size_t length) {
 165     pa_memblock *b;
 166
 167     assert(p);
 168     assert(length > 0);
 169
 170     b = pa_xmalloc(sizeof(pa_memblock) + length);
 171     b->type = PA_MEMBLOCK_APPENDED;
 172     b->read_only = 0;
 173     PA_REFCNT_INIT(b);
 174     b->length = length;
 175     b->data = (uint8_t*) b + sizeof(pa_memblock);
 176     b->pool = p;
 177
 178     stat_add(b);
 179     return b;
 180 }
 181
 182 static struct mempool_slot* mempool_allocate_slot(pa_mempool *p) {
 183     struct mempool_slot *slot;
 184     assert(p);
 185
 186     if (p->free_slots) {
 187         slot = p->free_slots;
 188         PA_LLIST_REMOVE(struct mempool_slot, p->free_slots, slot);
 189     } else if (p->n_init < p->n_blocks)
 190         slot = (struct mempool_slot*) ((uint8_t*) p->memory.ptr + (p->block_size * p->n_init++));
 191     else {
 192         pa_log_debug("Pool full");
 193         p->stat.n_pool_full++;
 194         return NULL;
 195     }
 196
 197     PA_LLIST_PREPEND(struct mempool_slot, p->used_slots, slot);
 198     return slot;
 199 }
 200
 201 static void* mempool_slot_data(struct mempool_slot *slot) {
 202     assert(slot);
 203
 204     return (uint8_t*) slot + sizeof(struct mempool_slot);
 205 }
 206
 207 static unsigned mempool_slot_idx(pa_mempool *p, void *ptr) {
 208     assert(p);
 209     assert((uint8_t*) ptr >= (uint8_t*) p->memory.ptr);
 210     assert((uint8_t*) ptr < (uint8_t*) p->memory.ptr + p->memory.size);
 211
 212     return ((uint8_t*) ptr - (uint8_t*) p->memory.ptr) / p->block_size;
 213 }
 214
 215 static struct mempool_slot* mempool_slot_by_ptr(pa_mempool *p, void *ptr) {
 216     unsigned idx;
 217
 218     if ((idx = mempool_slot_idx(p, ptr)) == (unsigned) -1)
 219         return NULL;
 220
 221     return (struct mempool_slot*) ((uint8_t*) p->memory.ptr + (idx * p->block_size));
 222 }
 223
 224 pa_memblock *pa_memblock_new_pool(pa_mempool *p, size_t length) {
 225     pa_memblock *b = NULL;
 226     struct mempool_slot *slot;
 227
 228     assert(p);
 229     assert(length > 0);
 230
 231     if (p->block_size - sizeof(struct mempool_slot) >= sizeof(pa_memblock) + length) {
 232
 233         if (!(slot = mempool_allocate_slot(p)))
 234             return NULL;
 235
 236         b = mempool_slot_data(slot);
 237         b->type = PA_MEMBLOCK_POOL;
 238         b->data = (uint8_t*) b + sizeof(pa_memblock);
 239
 240     } else if (p->block_size - sizeof(struct mempool_slot) >= length) {
 241
 242         if (!(slot = mempool_allocate_slot(p)))
 243             return NULL;
 244
 245         b = pa_xnew(pa_memblock, 1);
 246         b->type = PA_MEMBLOCK_POOL_EXTERNAL;
 247         b->data = mempool_slot_data(slot);
 248     } else {
 249         pa_log_debug("Memory block too large for pool: %u > %u", length, p->block_size - sizeof(struct mempool_slot));
 250         p->stat.n_too_large_for_pool++;
 251         return NULL;
 252     }
 253
 254     b->length = length;
 255     b->read_only = 0;
 256     PA_REFCNT_INIT(b);
 257     b->pool = p;
 258
 259     stat_add(b);
 260     return b;
 261 }
 262
 263 pa_memblock *pa_memblock_new_fixed(pa_mempool *p, void *d, size_t length, int read_only) {
 264     pa_memblock *b;
 265
 266     assert(p);
 267     assert(d);
 268     assert(length > 0);
 269
 270     b = pa_xnew(pa_memblock, 1);
 271     b->type = PA_MEMBLOCK_FIXED;
 272     b->read_only = read_only;
 273     PA_REFCNT_INIT(b);
 274     b->length = length;
 275     b->data = d;
 276     b->pool = p;
 277
 278     stat_add(b);
 279     return b;
 280 }
 281
 282 pa_memblock *pa_memblock_new_user(pa_mempool *p, void *d, size_t length, void (*free_cb)(void *p), int read_only) {
 283     pa_memblock *b;
 284
 285     assert(p);
 286     assert(d);
 287     assert(length > 0);
 288     assert(free_cb);
 289
 290     b = pa_xnew(pa_memblock, 1);
 291     b->type = PA_MEMBLOCK_USER;
 292     b->read_only = read_only;
 293     PA_REFCNT_INIT(b);
 294     b->length = length;
 295     b->data = d;
 296     b->per_type.user.free_cb = free_cb;
 297     b->pool = p;
 298
 299     stat_add(b);
 300     return b;
 301 }
 302
 303 pa_memblock* pa_memblock_ref(pa_memblock*b) {
 304     assert(b);
 305     assert(PA_REFCNT_VALUE(b) > 0);
 306
 307     PA_REFCNT_INC(b);
 308     return b;
 309 }
 310
 311 void pa_memblock_unref(pa_memblock*b) {
 312     assert(b);
 313     assert(PA_REFCNT_VALUE(b) > 0);
 314
 315     if (PA_REFCNT_DEC(b) > 0)
 316         return;
 317
 318     stat_remove(b);
 319
 320     switch (b->type) {
 321         case PA_MEMBLOCK_USER :
 322             assert(b->per_type.user.free_cb);
 323             b->per_type.user.free_cb(b->data);
 324
 325             /* Fall through */
 326
 327         case PA_MEMBLOCK_FIXED:
 328         case PA_MEMBLOCK_APPENDED :
 329             pa_xfree(b);
 330             break;
 331
 332         case PA_MEMBLOCK_IMPORTED : {
 333             pa_memimport_segment *segment;
 334
 335             segment = b->per_type.imported.segment;
 336             assert(segment);
 337             assert(segment->import);
 338
 339             pa_hashmap_remove(segment->import->blocks, PA_UINT32_TO_PTR(b->per_type.imported.id));
 340             segment->import->release_cb(segment->import, b->per_type.imported.id, segment->import->userdata);
 341
 342             if (-- segment->n_blocks <= 0)
 343                 segment_detach(segment);
 344
 345             pa_xfree(b);
 346             break;
 347         }
 348
 349         case PA_MEMBLOCK_POOL_EXTERNAL:
 350         case PA_MEMBLOCK_POOL: {
 351             struct mempool_slot *slot;
 352
 353             slot = mempool_slot_by_ptr(b->pool, b->data);
 354             assert(slot);
 355
 356             PA_LLIST_REMOVE(struct mempool_slot, b->pool->used_slots, slot);
 357             PA_LLIST_PREPEND(struct mempool_slot, b->pool->free_slots, slot);
 358
 359             if (b->type == PA_MEMBLOCK_POOL_EXTERNAL)
 360                 pa_xfree(b);
 361
 362             break;
 363         }
 364
 365         case PA_MEMBLOCK_TYPE_MAX:
 366         default:
 367             abort();
 368     }
 369 }
 370
 371 static void memblock_make_local(pa_memblock *b) {
 372     assert(b);
 373
 374     b->pool->stat.n_allocated_by_type[b->type]--;
 375
 376     if (b->length <= b->pool->block_size - sizeof(struct mempool_slot)) {
 377         struct mempool_slot *slot;
 378
 379         if ((slot = mempool_allocate_slot(b->pool))) {
 380             void *new_data;
 381             /* We can move it into a local pool, perfect! */
 382
 383             b->type = PA_MEMBLOCK_POOL_EXTERNAL;
 384             b->read_only = 0;
 385
 386             new_data = mempool_slot_data(slot);
 387             memcpy(new_data, b->data, b->length);
 388             b->data = new_data;
 389             goto finish;
 390         }
 391     }
 392
 393     /* Humm, not enough space in the pool, so lets allocate the memory with malloc() */
 394     b->type = PA_MEMBLOCK_USER;
 395     b->per_type.user.free_cb = pa_xfree;
 396     b->read_only = 0;
 397     b->data = pa_xmemdup(b->data, b->length);
 398
 399 finish:
 400     b->pool->stat.n_allocated_by_type[b->type]++;
 401     b->pool->stat.n_accumulated_by_type[b->type]++;
 402 }
 403
 404 void pa_memblock_unref_fixed(pa_memblock *b) {
 405     assert(b);
 406     assert(PA_REFCNT_VALUE(b) > 0);
 407     assert(b->type == PA_MEMBLOCK_FIXED);
 408
 409     if (PA_REFCNT_VALUE(b) > 1)
 410         memblock_make_local(b);
 411
 412     pa_memblock_unref(b);
 413 }
 414
 415 static void memblock_replace_import(pa_memblock *b) {
 416     pa_memimport_segment *seg;
 417
 418     assert(b);
 419     assert(b->type == PA_MEMBLOCK_IMPORTED);
 420
 421     assert(b->pool->stat.n_imported > 0);
 422     assert(b->pool->stat.imported_size >= b->length);
 423     b->pool->stat.n_imported --;
 424     b->pool->stat.imported_size -= b->length;
 425
 426     seg = b->per_type.imported.segment;
 427     assert(seg);
 428     assert(seg->import);
 429
 430     pa_hashmap_remove(
 431             seg->import->blocks,
 432             PA_UINT32_TO_PTR(b->per_type.imported.id));
 433
 434     memblock_make_local(b);
 435
 436     if (-- seg->n_blocks <= 0)
 437         segment_detach(seg);
 438 }
 439
 440 pa_mempool* pa_mempool_new(int shared) {
 441     size_t ps;
 442     pa_mempool *p;
 443
 444     p = pa_xnew(pa_mempool, 1);
 445
 446 #ifdef HAVE_SYSCONF
 447     ps = (size_t) sysconf(_SC_PAGESIZE);
 448 #elif defined(PAGE_SIZE)
 449         ps = (size_t) PAGE_SIZE;
 450 #else
 451         ps = 4096; /* Let's hope it's like x86. */
 452 #endif
 453
 454     p->block_size = (PA_MEMPOOL_SLOT_SIZE/ps)*ps;
 455
 456     if (p->block_size < ps)
 457         p->block_size = ps;
 458
 459     p->n_blocks = PA_MEMPOOL_SLOTS_MAX;
 460
 461     assert(p->block_size > sizeof(struct mempool_slot));
 462
 463     if (pa_shm_create_rw(&p->memory, p->n_blocks * p->block_size, shared, 0700) < 0) {
 464         pa_xfree(p);
 465         return NULL;
 466     }
 467
 468     p->n_init = 0;
 469
 470     PA_LLIST_HEAD_INIT(pa_memimport, p->imports);
 471     PA_LLIST_HEAD_INIT(pa_memexport, p->exports);
 472     PA_LLIST_HEAD_INIT(struct mempool_slot, p->free_slots);
 473     PA_LLIST_HEAD_INIT(struct mempool_slot, p->used_slots);
 474
 475     memset(&p->stat, 0, sizeof(p->stat));
 476
 477     return p;
 478 }
 479
 480 void pa_mempool_free(pa_mempool *p) {
 481     assert(p);
 482
 483     while (p->imports)
 484         pa_memimport_free(p->imports);
 485
 486     while (p->exports)
 487         pa_memexport_free(p->exports);
 488
 489     if (p->stat.n_allocated > 0)
 490         pa_log_warn("WARNING! Memory pool destroyed but not all memory blocks freed!");
 491
 492     pa_shm_free(&p->memory);
 493     pa_xfree(p);
 494 }
 495
 496 const pa_mempool_stat* pa_mempool_get_stat(pa_mempool *p) {
 497     assert(p);
 498
 499     return &p->stat;
 500 }
 501
 502 void pa_mempool_vacuum(pa_mempool *p) {
 503     struct mempool_slot *slot;
 504
 505     assert(p);
 506
 507     for (slot = p->free_slots; slot; slot = slot->next) {
 508         pa_shm_punch(&p->memory, (uint8_t*) slot + sizeof(struct mempool_slot) - (uint8_t*) p->memory.ptr, p->block_size - sizeof(struct mempool_slot));
 509     }
 510 }
 511
 512 int pa_mempool_get_shm_id(pa_mempool *p, uint32_t *id) {
 513     assert(p);
 514
 515     if (!p->memory.shared)
 516         return -1;
 517
 518     *id = p->memory.id;
 519
 520     return 0;
 521 }
 522
 523 int pa_mempool_is_shared(pa_mempool *p) {
 524     assert(p);
 525
 526     return !!p->memory.shared;
 527 }
 528
 529 /* For recieving blocks from other nodes */
 530 pa_memimport* pa_memimport_new(pa_mempool *p, pa_memimport_release_cb_t cb, void *userdata) {
 531     pa_memimport *i;
 532
 533     assert(p);
 534     assert(cb);
 535
 536     i = pa_xnew(pa_memimport, 1);
 537     i->pool = p;
 538     i->segments = pa_hashmap_new(NULL, NULL);
 539     i->blocks = pa_hashmap_new(NULL, NULL);
 540     i->release_cb = cb;
 541     i->userdata = userdata;
 542
 543     PA_LLIST_PREPEND(pa_memimport, p->imports, i);
 544     return i;
 545 }
 546
 547 static void memexport_revoke_blocks(pa_memexport *e, pa_memimport *i);
 548
 549 static pa_memimport_segment* segment_attach(pa_memimport *i, uint32_t shm_id) {
 550     pa_memimport_segment* seg;
 551
 552     if (pa_hashmap_size(i->segments) >= PA_MEMIMPORT_SEGMENTS_MAX)
 553         return NULL;
 554
 555     seg = pa_xnew(pa_memimport_segment, 1);
 556
 557     if (pa_shm_attach_ro(&seg->memory, shm_id) < 0) {
 558         pa_xfree(seg);
 559         return NULL;
 560     }
 561
 562     seg->import = i;
 563     seg->n_blocks = 0;
 564
 565     pa_hashmap_put(i->segments, PA_UINT32_TO_PTR(shm_id), seg);
 566     return seg;
 567 }
 568
 569 static void segment_detach(pa_memimport_segment *seg) {
 570     assert(seg);
 571
 572     pa_hashmap_remove(seg->import->segments, PA_UINT32_TO_PTR(seg->memory.id));
 573     pa_shm_free(&seg->memory);
 574     pa_xfree(seg);
 575 }
 576
 577 void pa_memimport_free(pa_memimport *i) {
 578     pa_memexport *e;
 579     pa_memblock *b;
 580
 581     assert(i);
 582
 583     /* If we've exported this block further we need to revoke that export */
 584     for (e = i->pool->exports; e; e = e->next)
 585         memexport_revoke_blocks(e, i);
 586
 587     while ((b = pa_hashmap_get_first(i->blocks)))
 588         memblock_replace_import(b);
 589
 590     assert(pa_hashmap_size(i->segments) == 0);
 591
 592     pa_hashmap_free(i->blocks, NULL, NULL);
 593     pa_hashmap_free(i->segments, NULL, NULL);
 594
 595     PA_LLIST_REMOVE(pa_memimport, i->pool->imports, i);
 596     pa_xfree(i);
 597 }
 598
 599 pa_memblock* pa_memimport_get(pa_memimport *i, uint32_t block_id, uint32_t shm_id, size_t offset, size_t size) {
 600     pa_memblock *b;
 601     pa_memimport_segment *seg;
 602
 603     assert(i);
 604
 605     if (pa_hashmap_size(i->blocks) >= PA_MEMIMPORT_SLOTS_MAX)
 606         return NULL;
 607
 608     if (!(seg = pa_hashmap_get(i->segments, PA_UINT32_TO_PTR(shm_id))))
 609         if (!(seg = segment_attach(i, shm_id)))
 610             return NULL;
 611
 612     if (offset+size > seg->memory.size)
 613         return NULL;
 614
 615     b = pa_xnew(pa_memblock, 1);
 616     b->type = PA_MEMBLOCK_IMPORTED;
 617     b->read_only = 1;
 618     PA_REFCNT_INIT(b);
 619     b->length = size;
 620     b->data = (uint8_t*) seg->memory.ptr + offset;
 621     b->pool = i->pool;
 622     b->per_type.imported.id = block_id;
 623     b->per_type.imported.segment = seg;
 624
 625     pa_hashmap_put(i->blocks, PA_UINT32_TO_PTR(block_id), b);
 626
 627     seg->n_blocks++;
 628
 629     stat_add(b);
 630
 631     return b;
 632 }
 633
 634 int pa_memimport_process_revoke(pa_memimport *i, uint32_t id) {
 635     pa_memblock *b;
 636     assert(i);
 637
 638     if (!(b = pa_hashmap_get(i->blocks, PA_UINT32_TO_PTR(id))))
 639         return -1;
 640
 641     memblock_replace_import(b);
 642     return 0;
 643 }
 644
 645 /* For sending blocks to other nodes */
 646 pa_memexport* pa_memexport_new(pa_mempool *p, pa_memexport_revoke_cb_t cb, void *userdata) {
 647     pa_memexport *e;
 648
 649     assert(p);
 650     assert(cb);
 651
 652     if (!p->memory.shared)
 653         return NULL;
 654
 655     e = pa_xnew(pa_memexport, 1);
 656     e->pool = p;
 657     PA_LLIST_HEAD_INIT(struct memexport_slot, e->free_slots);
 658     PA_LLIST_HEAD_INIT(struct memexport_slot, e->used_slots);
 659     e->n_init = 0;
 660     e->revoke_cb = cb;
 661     e->userdata = userdata;
 662
 663     PA_LLIST_PREPEND(pa_memexport, p->exports, e);
 664     return e;
 665 }
 666
 667 void pa_memexport_free(pa_memexport *e) {
 668     assert(e);
 669
 670     while (e->used_slots)
 671         pa_memexport_process_release(e, e->used_slots - e->slots);
 672
 673     PA_LLIST_REMOVE(pa_memexport, e->pool->exports, e);
 674     pa_xfree(e);
 675 }
 676
 677 int pa_memexport_process_release(pa_memexport *e, uint32_t id) {
 678     assert(e);
 679
 680     if (id >= e->n_init)
 681         return -1;
 682
 683     if (!e->slots[id].block)
 684         return -1;
 685
 686 /*     pa_log("Processing release for %u", id); */
 687
 688     assert(e->pool->stat.n_exported > 0);
 689     assert(e->pool->stat.exported_size >= e->slots[id].block->length);
 690
 691     e->pool->stat.n_exported --;
 692     e->pool->stat.exported_size -= e->slots[id].block->length;
 693
 694     pa_memblock_unref(e->slots[id].block);
 695     e->slots[id].block = NULL;
 696
 697     PA_LLIST_REMOVE(struct memexport_slot, e->used_slots, &e->slots[id]);
 698     PA_LLIST_PREPEND(struct memexport_slot, e->free_slots, &e->slots[id]);
 699
 700     return 0;
 701 }
 702
 703 static void memexport_revoke_blocks(pa_memexport *e, pa_memimport *i) {
 704     struct memexport_slot *slot, *next;
 705     assert(e);
 706     assert(i);
 707
 708     for (slot = e->used_slots; slot; slot = next) {
 709         uint32_t idx;
 710         next = slot->next;
 711
 712         if (slot->block->type != PA_MEMBLOCK_IMPORTED ||
 713             slot->block->per_type.imported.segment->import != i)
 714             continue;
 715
 716         idx = slot - e->slots;
 717         e->revoke_cb(e, idx, e->userdata);
 718         pa_memexport_process_release(e, idx);
 719     }
 720 }
 721
 722 static pa_memblock *memblock_shared_copy(pa_mempool *p, pa_memblock *b) {
 723     pa_memblock *n;
 724
 725     assert(p);
 726     assert(b);
 727
 728     if (b->type == PA_MEMBLOCK_IMPORTED ||
 729         b->type == PA_MEMBLOCK_POOL ||
 730         b->type == PA_MEMBLOCK_POOL_EXTERNAL) {
 731         assert(b->pool == p);
 732         return pa_memblock_ref(b);
 733     }
 734
 735     if (!(n = pa_memblock_new_pool(p, b->length)))
 736         return NULL;
 737
 738     memcpy(n->data, b->data, b->length);
 739     return n;
 740 }
 741
 742 int pa_memexport_put(pa_memexport *e, pa_memblock *b, uint32_t *block_id, uint32_t *shm_id, size_t *offset, size_t * size) {
 743     pa_shm *memory;
 744     struct memexport_slot *slot;
 745
 746     assert(e);
 747     assert(b);
 748     assert(block_id);
 749     assert(shm_id);
 750     assert(offset);
 751     assert(size);
 752     assert(b->pool == e->pool);
 753
 754     if (!(b = memblock_shared_copy(e->pool, b)))
 755         return -1;
 756
 757     if (e->free_slots) {
 758         slot = e->free_slots;
 759         PA_LLIST_REMOVE(struct memexport_slot, e->free_slots, slot);
 760     } else if (e->n_init < PA_MEMEXPORT_SLOTS_MAX) {
 761         slot = &e->slots[e->n_init++];
 762     } else {
 763         pa_memblock_unref(b);
 764         return -1;
 765     }
 766
 767     PA_LLIST_PREPEND(struct memexport_slot, e->used_slots, slot);
 768     slot->block = b;
 769     *block_id = slot - e->slots;
 770
 771 /*     pa_log("Got block id %u", *block_id); */
 772
 773     if (b->type == PA_MEMBLOCK_IMPORTED) {
 774         assert(b->per_type.imported.segment);
 775         memory = &b->per_type.imported.segment->memory;
 776     } else {
 777         assert(b->type == PA_MEMBLOCK_POOL || b->type == PA_MEMBLOCK_POOL_EXTERNAL);
 778         assert(b->pool);
 779         memory = &b->pool->memory;
 780     }
 781
 782     assert(b->data >= memory->ptr);
 783     assert((uint8_t*) b->data + b->length <= (uint8_t*) memory->ptr + memory->size);
 784
 785     *shm_id = memory->id;
 786     *offset = (uint8_t*) b->data - (uint8_t*) memory->ptr;
 787     *size = b->length;
 788
 789     e->pool->stat.n_exported ++;
 790     e->pool->stat.exported_size += b->length;
 791
 792     return 0;
 793 }