code.delx.au - pulseaudio/blob - src/pulsecore/memblock.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
   9   published by the Free Software Foundation; either version 2.1 of the
  10   License, 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   Lesser General Public License for more details
  16
  17   You should have received a copy of the GNU Lesser General Public
  18   License 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 <stdio.h>
  28 #include <stdlib.h>
  29 #include <string.h>
  30 #include <unistd.h>
  31 #include <signal.h>
  32 #include <errno.h>
  33
  34 #ifdef HAVE_VALGRIND_MEMCHECK_H
  35 #include <valgrind/memcheck.h>
  36 #endif
  37
  38 #include <pulse/xmalloc.h>
  39 #include <pulse/def.h>
  40
  41 #include <pulsecore/shm.h>
  42 #include <pulsecore/log.h>
  43 #include <pulsecore/hashmap.h>
  44 #include <pulsecore/semaphore.h>
  45 #include <pulsecore/mutex.h>
  46 #include <pulsecore/macro.h>
  47 #include <pulsecore/refcnt.h>
  48 #include <pulsecore/llist.h>
  49 #include <pulsecore/flist.h>
  50 #include <pulsecore/core-util.h>
  51 #include <pulsecore/memtrap.h>
  52
  53 #include "memblock.h"
  54
  55 /* We can allocate 64*1024*1024 bytes at maximum. That's 64MB. Please
  56  * note that the footprint is usually much smaller, since the data is
  57  * stored in SHM and our OS does not commit the memory before we use
  58  * it for the first time. */
  59 #define PA_MEMPOOL_SLOTS_MAX 1024
  60 #define PA_MEMPOOL_SLOT_SIZE (64*1024)
  61
  62 #define PA_MEMEXPORT_SLOTS_MAX 128
  63
  64 #define PA_MEMIMPORT_SLOTS_MAX 160
  65 #define PA_MEMIMPORT_SEGMENTS_MAX 16
  66
  67 struct pa_memblock {
  68     PA_REFCNT_DECLARE; /* the reference counter */
  69     pa_mempool *pool;
  70
  71     pa_memblock_type_t type;
  72
  73     pa_bool_t read_only:1;
  74     pa_bool_t is_silence:1;
  75
  76     pa_atomic_ptr_t data;
  77     size_t length;
  78
  79     pa_atomic_t n_acquired;
  80     pa_atomic_t please_signal;
  81
  82     union {
  83         struct {
  84             /* If type == PA_MEMBLOCK_USER this points to a function for freeing this memory block */
  85             pa_free_cb_t free_cb;
  86         } user;
  87
  88         struct {
  89             uint32_t id;
  90             pa_memimport_segment *segment;
  91         } imported;
  92     } per_type;
  93 };
  94
  95 struct pa_memimport_segment {
  96     pa_memimport *import;
  97     pa_shm memory;
  98     pa_memtrap *trap;
  99     unsigned n_blocks;
 100 };
 101
 102 /* A collection of multiple segments */
 103 struct pa_memimport {
 104     pa_mutex *mutex;
 105
 106     pa_mempool *pool;
 107     pa_hashmap *segments;
 108     pa_hashmap *blocks;
 109
 110     /* Called whenever an imported memory block is no longer
 111      * needed. */
 112     pa_memimport_release_cb_t release_cb;
 113     void *userdata;
 114
 115     PA_LLIST_FIELDS(pa_memimport);
 116 };
 117
 118 struct memexport_slot {
 119     PA_LLIST_FIELDS(struct memexport_slot);
 120     pa_memblock *block;
 121 };
 122
 123 struct pa_memexport {
 124     pa_mutex *mutex;
 125     pa_mempool *pool;
 126
 127     struct memexport_slot slots[PA_MEMEXPORT_SLOTS_MAX];
 128
 129     PA_LLIST_HEAD(struct memexport_slot, free_slots);
 130     PA_LLIST_HEAD(struct memexport_slot, used_slots);
 131     unsigned n_init;
 132
 133     /* Called whenever a client from which we imported a memory block
 134        which we in turn exported to another client dies and we need to
 135        revoke the memory block accordingly */
 136     pa_memexport_revoke_cb_t revoke_cb;
 137     void *userdata;
 138
 139     PA_LLIST_FIELDS(pa_memexport);
 140 };
 141
 142 struct pa_mempool {
 143     pa_semaphore *semaphore;
 144     pa_mutex *mutex;
 145
 146     pa_shm memory;
 147     size_t block_size;
 148     unsigned n_blocks;
 149
 150     pa_atomic_t n_init;
 151
 152     PA_LLIST_HEAD(pa_memimport, imports);
 153     PA_LLIST_HEAD(pa_memexport, exports);
 154
 155     /* A list of free slots that may be reused */
 156     pa_flist *free_slots;
 157
 158     pa_mempool_stat stat;
 159 };
 160
 161 static void segment_detach(pa_memimport_segment *seg);
 162
 163 PA_STATIC_FLIST_DECLARE(unused_memblocks, 0, pa_xfree);
 164
 165 /* No lock necessary */
 166 static void stat_add(pa_memblock*b) {
 167     pa_assert(b);
 168     pa_assert(b->pool);
 169
 170     pa_atomic_inc(&b->pool->stat.n_allocated);
 171     pa_atomic_add(&b->pool->stat.allocated_size, (int) b->length);
 172
 173     pa_atomic_inc(&b->pool->stat.n_accumulated);
 174     pa_atomic_add(&b->pool->stat.accumulated_size, (int) b->length);
 175
 176     if (b->type == PA_MEMBLOCK_IMPORTED) {
 177         pa_atomic_inc(&b->pool->stat.n_imported);
 178         pa_atomic_add(&b->pool->stat.imported_size, (int) b->length);
 179     }
 180
 181     pa_atomic_inc(&b->pool->stat.n_allocated_by_type[b->type]);
 182     pa_atomic_inc(&b->pool->stat.n_accumulated_by_type[b->type]);
 183 }
 184
 185 /* No lock necessary */
 186 static void stat_remove(pa_memblock *b) {
 187     pa_assert(b);
 188     pa_assert(b->pool);
 189
 190     pa_assert(pa_atomic_load(&b->pool->stat.n_allocated) > 0);
 191     pa_assert(pa_atomic_load(&b->pool->stat.allocated_size) >= (int) b->length);
 192
 193     pa_atomic_dec(&b->pool->stat.n_allocated);
 194     pa_atomic_sub(&b->pool->stat.allocated_size, (int) b->length);
 195
 196     if (b->type == PA_MEMBLOCK_IMPORTED) {
 197         pa_assert(pa_atomic_load(&b->pool->stat.n_imported) > 0);
 198         pa_assert(pa_atomic_load(&b->pool->stat.imported_size) >= (int) b->length);
 199
 200         pa_atomic_dec(&b->pool->stat.n_imported);
 201         pa_atomic_sub(&b->pool->stat.imported_size, (int) b->length);
 202     }
 203
 204     pa_atomic_dec(&b->pool->stat.n_allocated_by_type[b->type]);
 205 }
 206
 207 static pa_memblock *memblock_new_appended(pa_mempool *p, size_t length);
 208
 209 /* No lock necessary */
 210 pa_memblock *pa_memblock_new(pa_mempool *p, size_t length) {
 211     pa_memblock *b;
 212
 213     pa_assert(p);
 214     pa_assert(length);
 215
 216     if (!(b = pa_memblock_new_pool(p, length)))
 217         b = memblock_new_appended(p, length);
 218
 219     return b;
 220 }
 221
 222 /* No lock necessary */
 223 static pa_memblock *memblock_new_appended(pa_mempool *p, size_t length) {
 224     pa_memblock *b;
 225
 226     pa_assert(p);
 227     pa_assert(length);
 228
 229     /* If -1 is passed as length we choose the size for the caller. */
 230
 231     if (length == (size_t) -1)
 232         length = p->block_size - PA_ALIGN(sizeof(pa_memblock));
 233
 234     b = pa_xmalloc(PA_ALIGN(sizeof(pa_memblock)) + length);
 235     PA_REFCNT_INIT(b);
 236     b->pool = p;
 237     b->type = PA_MEMBLOCK_APPENDED;
 238     b->read_only = b->is_silence = FALSE;
 239     pa_atomic_ptr_store(&b->data, (uint8_t*) b + PA_ALIGN(sizeof(pa_memblock)));
 240     b->length = length;
 241     pa_atomic_store(&b->n_acquired, 0);
 242     pa_atomic_store(&b->please_signal, 0);
 243
 244     stat_add(b);
 245     return b;
 246 }
 247
 248 /* No lock necessary */
 249 static struct mempool_slot* mempool_allocate_slot(pa_mempool *p) {
 250     struct mempool_slot *slot;
 251     pa_assert(p);
 252
 253     if (!(slot = pa_flist_pop(p->free_slots))) {
 254         int idx;
 255
 256         /* The free list was empty, we have to allocate a new entry */
 257
 258         if ((unsigned) (idx = pa_atomic_inc(&p->n_init)) >= p->n_blocks)
 259             pa_atomic_dec(&p->n_init);
 260         else
 261             slot = (struct mempool_slot*) ((uint8_t*) p->memory.ptr + (p->block_size * (size_t) idx));
 262
 263         if (!slot) {
 264             if (pa_log_ratelimit(PA_LOG_DEBUG))
 265                 pa_log_debug("Pool full");
 266             pa_atomic_inc(&p->stat.n_pool_full);
 267             return NULL;
 268         }
 269     }
 270
 271 /* #ifdef HAVE_VALGRIND_MEMCHECK_H */
 272 /*     if (PA_UNLIKELY(pa_in_valgrind())) { */
 273 /*         VALGRIND_MALLOCLIKE_BLOCK(slot, p->block_size, 0, 0); */
 274 /*     } */
 275 /* #endif */
 276
 277     return slot;
 278 }
 279
 280 /* No lock necessary, totally redundant anyway */
 281 static inline void* mempool_slot_data(struct mempool_slot *slot) {
 282     return slot;
 283 }
 284
 285 /* No lock necessary */
 286 static unsigned mempool_slot_idx(pa_mempool *p, void *ptr) {
 287     pa_assert(p);
 288
 289     pa_assert((uint8_t*) ptr >= (uint8_t*) p->memory.ptr);
 290     pa_assert((uint8_t*) ptr < (uint8_t*) p->memory.ptr + p->memory.size);
 291
 292     return (unsigned) ((size_t) ((uint8_t*) ptr - (uint8_t*) p->memory.ptr) / p->block_size);
 293 }
 294
 295 /* No lock necessary */
 296 static struct mempool_slot* mempool_slot_by_ptr(pa_mempool *p, void *ptr) {
 297     unsigned idx;
 298
 299     if ((idx = mempool_slot_idx(p, ptr)) == (unsigned) -1)
 300         return NULL;
 301
 302     return (struct mempool_slot*) ((uint8_t*) p->memory.ptr + (idx * p->block_size));
 303 }
 304
 305 /* No lock necessary */
 306 pa_memblock *pa_memblock_new_pool(pa_mempool *p, size_t length) {
 307     pa_memblock *b = NULL;
 308     struct mempool_slot *slot;
 309     static int mempool_disable = 0;
 310
 311     pa_assert(p);
 312     pa_assert(length);
 313
 314     if (mempool_disable == 0)
 315         mempool_disable = getenv("PULSE_MEMPOOL_DISABLE") ? 1 : -1;
 316
 317     if (mempool_disable > 0)
 318         return NULL;
 319
 320     /* If -1 is passed as length we choose the size for the caller: we
 321      * take the largest size that fits in one of our slots. */
 322
 323     if (length == (size_t) -1)
 324         length = pa_mempool_block_size_max(p);
 325
 326     if (p->block_size >= PA_ALIGN(sizeof(pa_memblock)) + length) {
 327
 328         if (!(slot = mempool_allocate_slot(p)))
 329             return NULL;
 330
 331         b = mempool_slot_data(slot);
 332         b->type = PA_MEMBLOCK_POOL;
 333         pa_atomic_ptr_store(&b->data, (uint8_t*) b + PA_ALIGN(sizeof(pa_memblock)));
 334
 335     } else if (p->block_size >= length) {
 336
 337         if (!(slot = mempool_allocate_slot(p)))
 338             return NULL;
 339
 340         if (!(b = pa_flist_pop(PA_STATIC_FLIST_GET(unused_memblocks))))
 341             b = pa_xnew(pa_memblock, 1);
 342
 343         b->type = PA_MEMBLOCK_POOL_EXTERNAL;
 344         pa_atomic_ptr_store(&b->data, mempool_slot_data(slot));
 345
 346     } else {
 347         pa_log_debug("Memory block too large for pool: %lu > %lu", (unsigned long) length, (unsigned long) p->block_size);
 348         pa_atomic_inc(&p->stat.n_too_large_for_pool);
 349         return NULL;
 350     }
 351
 352     PA_REFCNT_INIT(b);
 353     b->pool = p;
 354     b->read_only = b->is_silence = FALSE;
 355     b->length = length;
 356     pa_atomic_store(&b->n_acquired, 0);
 357     pa_atomic_store(&b->please_signal, 0);
 358
 359     stat_add(b);
 360     return b;
 361 }
 362
 363 /* No lock necessary */
 364 pa_memblock *pa_memblock_new_fixed(pa_mempool *p, void *d, size_t length, pa_bool_t read_only) {
 365     pa_memblock *b;
 366
 367     pa_assert(p);
 368     pa_assert(d);
 369     pa_assert(length != (size_t) -1);
 370     pa_assert(length);
 371
 372     if (!(b = pa_flist_pop(PA_STATIC_FLIST_GET(unused_memblocks))))
 373         b = pa_xnew(pa_memblock, 1);
 374
 375     PA_REFCNT_INIT(b);
 376     b->pool = p;
 377     b->type = PA_MEMBLOCK_FIXED;
 378     b->read_only = read_only;
 379     b->is_silence = FALSE;
 380     pa_atomic_ptr_store(&b->data, d);
 381     b->length = length;
 382     pa_atomic_store(&b->n_acquired, 0);
 383     pa_atomic_store(&b->please_signal, 0);
 384
 385     stat_add(b);
 386     return b;
 387 }
 388
 389 /* No lock necessary */
 390 pa_memblock *pa_memblock_new_user(pa_mempool *p, void *d, size_t length, pa_free_cb_t free_cb, pa_bool_t read_only) {
 391     pa_memblock *b;
 392
 393     pa_assert(p);
 394     pa_assert(d);
 395     pa_assert(length);
 396     pa_assert(length != (size_t) -1);
 397     pa_assert(free_cb);
 398
 399     if (!(b = pa_flist_pop(PA_STATIC_FLIST_GET(unused_memblocks))))
 400         b = pa_xnew(pa_memblock, 1);
 401
 402     PA_REFCNT_INIT(b);
 403     b->pool = p;
 404     b->type = PA_MEMBLOCK_USER;
 405     b->read_only = read_only;
 406     b->is_silence = FALSE;
 407     pa_atomic_ptr_store(&b->data, d);
 408     b->length = length;
 409     pa_atomic_store(&b->n_acquired, 0);
 410     pa_atomic_store(&b->please_signal, 0);
 411
 412     b->per_type.user.free_cb = free_cb;
 413
 414     stat_add(b);
 415     return b;
 416 }
 417
 418 /* No lock necessary */
 419 pa_bool_t pa_memblock_is_read_only(pa_memblock *b) {
 420     pa_assert(b);
 421     pa_assert(PA_REFCNT_VALUE(b) > 0);
 422
 423     return b->read_only && PA_REFCNT_VALUE(b) == 1;
 424 }
 425
 426 /* No lock necessary */
 427 pa_bool_t pa_memblock_is_silence(pa_memblock *b) {
 428     pa_assert(b);
 429     pa_assert(PA_REFCNT_VALUE(b) > 0);
 430
 431     return b->is_silence;
 432 }
 433
 434 /* No lock necessary */
 435 void pa_memblock_set_is_silence(pa_memblock *b, pa_bool_t v) {
 436     pa_assert(b);
 437     pa_assert(PA_REFCNT_VALUE(b) > 0);
 438
 439     b->is_silence = v;
 440 }
 441
 442 /* No lock necessary */
 443 pa_bool_t pa_memblock_ref_is_one(pa_memblock *b) {
 444     int r;
 445     pa_assert(b);
 446
 447     pa_assert_se((r = PA_REFCNT_VALUE(b)) > 0);
 448
 449     return r == 1;
 450 }
 451
 452 /* No lock necessary */
 453 void* pa_memblock_acquire(pa_memblock *b) {
 454     pa_assert(b);
 455     pa_assert(PA_REFCNT_VALUE(b) > 0);
 456
 457     pa_atomic_inc(&b->n_acquired);
 458
 459     return pa_atomic_ptr_load(&b->data);
 460 }
 461
 462 /* No lock necessary, in corner cases locks by its own */
 463 void pa_memblock_release(pa_memblock *b) {
 464     int r;
 465     pa_assert(b);
 466     pa_assert(PA_REFCNT_VALUE(b) > 0);
 467
 468     r = pa_atomic_dec(&b->n_acquired);
 469     pa_assert(r >= 1);
 470
 471     /* Signal a waiting thread that this memblock is no longer used */
 472     if (r == 1 && pa_atomic_load(&b->please_signal))
 473         pa_semaphore_post(b->pool->semaphore);
 474 }
 475
 476 size_t pa_memblock_get_length(pa_memblock *b) {
 477     pa_assert(b);
 478     pa_assert(PA_REFCNT_VALUE(b) > 0);
 479
 480     return b->length;
 481 }
 482
 483 pa_mempool* pa_memblock_get_pool(pa_memblock *b) {
 484     pa_assert(b);
 485     pa_assert(PA_REFCNT_VALUE(b) > 0);
 486
 487     return b->pool;
 488 }
 489
 490 /* No lock necessary */
 491 pa_memblock* pa_memblock_ref(pa_memblock*b) {
 492     pa_assert(b);
 493     pa_assert(PA_REFCNT_VALUE(b) > 0);
 494
 495     PA_REFCNT_INC(b);
 496     return b;
 497 }
 498
 499 static void memblock_free(pa_memblock *b) {
 500     pa_assert(b);
 501
 502     pa_assert(pa_atomic_load(&b->n_acquired) == 0);
 503
 504     stat_remove(b);
 505
 506     switch (b->type) {
 507         case PA_MEMBLOCK_USER :
 508             pa_assert(b->per_type.user.free_cb);
 509             b->per_type.user.free_cb(pa_atomic_ptr_load(&b->data));
 510
 511             /* Fall through */
 512
 513         case PA_MEMBLOCK_FIXED:
 514             if (pa_flist_push(PA_STATIC_FLIST_GET(unused_memblocks), b) < 0)
 515                 pa_xfree(b);
 516
 517             break;
 518
 519         case PA_MEMBLOCK_APPENDED:
 520
 521             /* We could attached it unused_memblocks, but that would
 522              * probably waste some considerable memory */
 523             pa_xfree(b);
 524             break;
 525
 526         case PA_MEMBLOCK_IMPORTED: {
 527             pa_memimport_segment *segment;
 528             pa_memimport *import;
 529
 530             /* FIXME! This should be implemented lock-free */
 531
 532             pa_assert_se(segment = b->per_type.imported.segment);
 533             pa_assert_se(import = segment->import);
 534
 535             pa_mutex_lock(import->mutex);
 536
 537             pa_assert_se(pa_hashmap_remove(import->blocks, PA_UINT32_TO_PTR(b->per_type.imported.id)));
 538
 539             pa_assert(segment->n_blocks >= 1);
 540             if (-- segment->n_blocks <= 0)
 541                 segment_detach(segment);
 542
 543             pa_mutex_unlock(import->mutex);
 544
 545             import->release_cb(import, b->per_type.imported.id, import->userdata);
 546
 547             if (pa_flist_push(PA_STATIC_FLIST_GET(unused_memblocks), b) < 0)
 548                 pa_xfree(b);
 549
 550             break;
 551         }
 552
 553         case PA_MEMBLOCK_POOL_EXTERNAL:
 554         case PA_MEMBLOCK_POOL: {
 555             struct mempool_slot *slot;
 556             pa_bool_t call_free;
 557
 558             pa_assert_se(slot = mempool_slot_by_ptr(b->pool, pa_atomic_ptr_load(&b->data)));
 559
 560             call_free = b->type == PA_MEMBLOCK_POOL_EXTERNAL;
 561
 562 /* #ifdef HAVE_VALGRIND_MEMCHECK_H */
 563 /*             if (PA_UNLIKELY(pa_in_valgrind())) { */
 564 /*                 VALGRIND_FREELIKE_BLOCK(slot, b->pool->block_size); */
 565 /*             } */
 566 /* #endif */
 567
 568             /* The free list dimensions should easily allow all slots
 569              * to fit in, hence try harder if pushing this slot into
 570              * the free list fails */
 571             while (pa_flist_push(b->pool->free_slots, slot) < 0)
 572                 ;
 573
 574             if (call_free)
 575                 if (pa_flist_push(PA_STATIC_FLIST_GET(unused_memblocks), b) < 0)
 576                     pa_xfree(b);
 577
 578             break;
 579         }
 580
 581         case PA_MEMBLOCK_TYPE_MAX:
 582         default:
 583             pa_assert_not_reached();
 584     }
 585 }
 586
 587 /* No lock necessary */
 588 void pa_memblock_unref(pa_memblock*b) {
 589     pa_assert(b);
 590     pa_assert(PA_REFCNT_VALUE(b) > 0);
 591
 592     if (PA_REFCNT_DEC(b) > 0)
 593         return;
 594
 595     memblock_free(b);
 596 }
 597
 598 /* Self locked */
 599 static void memblock_wait(pa_memblock *b) {
 600     pa_assert(b);
 601
 602     if (pa_atomic_load(&b->n_acquired) > 0) {
 603         /* We need to wait until all threads gave up access to the
 604          * memory block before we can go on. Unfortunately this means
 605          * that we have to lock and wait here. Sniff! */
 606
 607         pa_atomic_inc(&b->please_signal);
 608
 609         while (pa_atomic_load(&b->n_acquired) > 0)
 610             pa_semaphore_wait(b->pool->semaphore);
 611
 612         pa_atomic_dec(&b->please_signal);
 613     }
 614 }
 615
 616 /* No lock necessary. This function is not multiple caller safe! */
 617 static void memblock_make_local(pa_memblock *b) {
 618     pa_assert(b);
 619
 620     pa_atomic_dec(&b->pool->stat.n_allocated_by_type[b->type]);
 621
 622     if (b->length <= b->pool->block_size) {
 623         struct mempool_slot *slot;
 624
 625         if ((slot = mempool_allocate_slot(b->pool))) {
 626             void *new_data;
 627             /* We can move it into a local pool, perfect! */
 628
 629             new_data = mempool_slot_data(slot);
 630             memcpy(new_data, pa_atomic_ptr_load(&b->data), b->length);
 631             pa_atomic_ptr_store(&b->data, new_data);
 632
 633             b->type = PA_MEMBLOCK_POOL_EXTERNAL;
 634             b->read_only = FALSE;
 635
 636             goto finish;
 637         }
 638     }
 639
 640     /* Humm, not enough space in the pool, so lets allocate the memory with malloc() */
 641     b->per_type.user.free_cb = pa_xfree;
 642     pa_atomic_ptr_store(&b->data, pa_xmemdup(pa_atomic_ptr_load(&b->data), b->length));
 643
 644     b->type = PA_MEMBLOCK_USER;
 645     b->read_only = FALSE;
 646
 647 finish:
 648     pa_atomic_inc(&b->pool->stat.n_allocated_by_type[b->type]);
 649     pa_atomic_inc(&b->pool->stat.n_accumulated_by_type[b->type]);
 650     memblock_wait(b);
 651 }
 652
 653 /* No lock necessary. This function is not multiple caller safe*/
 654 void pa_memblock_unref_fixed(pa_memblock *b) {
 655     pa_assert(b);
 656     pa_assert(PA_REFCNT_VALUE(b) > 0);
 657     pa_assert(b->type == PA_MEMBLOCK_FIXED);
 658
 659     if (PA_REFCNT_VALUE(b) > 1)
 660         memblock_make_local(b);
 661
 662     pa_memblock_unref(b);
 663 }
 664
 665 /* No lock necessary. */
 666 pa_memblock *pa_memblock_will_need(pa_memblock *b) {
 667     void *p;
 668
 669     pa_assert(b);
 670     pa_assert(PA_REFCNT_VALUE(b) > 0);
 671
 672     p = pa_memblock_acquire(b);
 673     pa_will_need(p, b->length);
 674     pa_memblock_release(b);
 675
 676     return b;
 677 }
 678
 679 /* Self-locked. This function is not multiple-caller safe */
 680 static void memblock_replace_import(pa_memblock *b) {
 681     pa_memimport_segment *segment;
 682     pa_memimport *import;
 683
 684     pa_assert(b);
 685     pa_assert(b->type == PA_MEMBLOCK_IMPORTED);
 686
 687     pa_assert(pa_atomic_load(&b->pool->stat.n_imported) > 0);
 688     pa_assert(pa_atomic_load(&b->pool->stat.imported_size) >= (int) b->length);
 689     pa_atomic_dec(&b->pool->stat.n_imported);
 690     pa_atomic_sub(&b->pool->stat.imported_size, (int) b->length);
 691
 692     pa_assert_se(segment = b->per_type.imported.segment);
 693     pa_assert_se(import = segment->import);
 694
 695     pa_mutex_lock(import->mutex);
 696
 697     pa_assert_se(pa_hashmap_remove(import->blocks, PA_UINT32_TO_PTR(b->per_type.imported.id)));
 698
 699     memblock_make_local(b);
 700
 701     pa_assert(segment->n_blocks >= 1);
 702     if (-- segment->n_blocks <= 0)
 703         segment_detach(segment);
 704
 705     pa_mutex_unlock(import->mutex);
 706 }
 707
 708 pa_mempool* pa_mempool_new(pa_bool_t shared, size_t size) {
 709     pa_mempool *p;
 710     char t1[PA_BYTES_SNPRINT_MAX], t2[PA_BYTES_SNPRINT_MAX];
 711
 712     p = pa_xnew(pa_mempool, 1);
 713
 714     p->mutex = pa_mutex_new(TRUE, TRUE);
 715     p->semaphore = pa_semaphore_new(0);
 716
 717     p->block_size = PA_PAGE_ALIGN(PA_MEMPOOL_SLOT_SIZE);
 718     if (p->block_size < PA_PAGE_SIZE)
 719         p->block_size = PA_PAGE_SIZE;
 720
 721     if (size <= 0)
 722         p->n_blocks = PA_MEMPOOL_SLOTS_MAX;
 723     else {
 724         p->n_blocks = (unsigned) (size / p->block_size);
 725
 726         if (p->n_blocks < 2)
 727             p->n_blocks = 2;
 728     }
 729
 730     if (pa_shm_create_rw(&p->memory, p->n_blocks * p->block_size, shared, 0700) < 0) {
 731         pa_xfree(p);
 732         return NULL;
 733     }
 734
 735     pa_log_debug("Using %s memory pool with %u slots of size %s each, total size is %s, maximum usable slot size is %lu",
 736                  p->memory.shared ? "shared" : "private",
 737                  p->n_blocks,
 738                  pa_bytes_snprint(t1, sizeof(t1), (unsigned) p->block_size),
 739                  pa_bytes_snprint(t2, sizeof(t2), (unsigned) (p->n_blocks * p->block_size)),
 740                  (unsigned long) pa_mempool_block_size_max(p));
 741
 742     memset(&p->stat, 0, sizeof(p->stat));
 743     pa_atomic_store(&p->n_init, 0);
 744
 745     PA_LLIST_HEAD_INIT(pa_memimport, p->imports);
 746     PA_LLIST_HEAD_INIT(pa_memexport, p->exports);
 747
 748     p->free_slots = pa_flist_new(p->n_blocks);
 749
 750     return p;
 751 }
 752
 753 void pa_mempool_free(pa_mempool *p) {
 754     pa_assert(p);
 755
 756     pa_mutex_lock(p->mutex);
 757
 758     while (p->imports)
 759         pa_memimport_free(p->imports);
 760
 761     while (p->exports)
 762         pa_memexport_free(p->exports);
 763
 764     pa_mutex_unlock(p->mutex);
 765
 766     pa_flist_free(p->free_slots, NULL);
 767
 768     if (pa_atomic_load(&p->stat.n_allocated) > 0) {
 769
 770         /* Ouch, somebody is retaining a memory block reference! */
 771
 772 #ifdef DEBUG_REF
 773         unsigned i;
 774         pa_flist *list;
 775
 776         /* Let's try to find at least one of those leaked memory blocks */
 777
 778         list = pa_flist_new(p->n_blocks);
 779
 780         for (i = 0; i < (unsigned) pa_atomic_load(&p->n_init); i++) {
 781             struct mempool_slot *slot;
 782             pa_memblock *b, *k;
 783
 784             slot = (struct mempool_slot*) ((uint8_t*) p->memory.ptr + (p->block_size * (size_t) i));
 785             b = mempool_slot_data(slot);
 786
 787             while ((k = pa_flist_pop(p->free_slots))) {
 788                 while (pa_flist_push(list, k) < 0)
 789                     ;
 790
 791                 if (b == k)
 792                     break;
 793             }
 794
 795             if (!k)
 796                 pa_log("REF: Leaked memory block %p", b);
 797
 798             while ((k = pa_flist_pop(list)))
 799                 while (pa_flist_push(p->free_slots, k) < 0)
 800                     ;
 801         }
 802
 803         pa_flist_free(list, NULL);
 804
 805 #endif
 806
 807         pa_log_error("Memory pool destroyed but not all memory blocks freed! %u remain.", pa_atomic_load(&p->stat.n_allocated));
 808
 809 /*         PA_DEBUG_TRAP; */
 810     }
 811
 812     pa_shm_free(&p->memory);
 813
 814     pa_mutex_free(p->mutex);
 815     pa_semaphore_free(p->semaphore);
 816
 817     pa_xfree(p);
 818 }
 819
 820 /* No lock necessary */
 821 const pa_mempool_stat* pa_mempool_get_stat(pa_mempool *p) {
 822     pa_assert(p);
 823
 824     return &p->stat;
 825 }
 826
 827 /* No lock necessary */
 828 size_t pa_mempool_block_size_max(pa_mempool *p) {
 829     pa_assert(p);
 830
 831     return p->block_size - PA_ALIGN(sizeof(pa_memblock));
 832 }
 833
 834 /* No lock necessary */
 835 void pa_mempool_vacuum(pa_mempool *p) {
 836     struct mempool_slot *slot;
 837     pa_flist *list;
 838
 839     pa_assert(p);
 840
 841     list = pa_flist_new(p->n_blocks);
 842
 843     while ((slot = pa_flist_pop(p->free_slots)))
 844         while (pa_flist_push(list, slot) < 0)
 845             ;
 846
 847     while ((slot = pa_flist_pop(list))) {
 848         pa_shm_punch(&p->memory, (size_t) ((uint8_t*) slot - (uint8_t*) p->memory.ptr), p->block_size);
 849
 850         while (pa_flist_push(p->free_slots, slot))
 851             ;
 852     }
 853
 854     pa_flist_free(list, NULL);
 855 }
 856
 857 /* No lock necessary */
 858 int pa_mempool_get_shm_id(pa_mempool *p, uint32_t *id) {
 859     pa_assert(p);
 860
 861     if (!p->memory.shared)
 862         return -1;
 863
 864     *id = p->memory.id;
 865
 866     return 0;
 867 }
 868
 869 /* No lock necessary */
 870 pa_bool_t pa_mempool_is_shared(pa_mempool *p) {
 871     pa_assert(p);
 872
 873     return !!p->memory.shared;
 874 }
 875
 876 /* For recieving blocks from other nodes */
 877 pa_memimport* pa_memimport_new(pa_mempool *p, pa_memimport_release_cb_t cb, void *userdata) {
 878     pa_memimport *i;
 879
 880     pa_assert(p);
 881     pa_assert(cb);
 882
 883     i = pa_xnew(pa_memimport, 1);
 884     i->mutex = pa_mutex_new(TRUE, TRUE);
 885     i->pool = p;
 886     i->segments = pa_hashmap_new(NULL, NULL);
 887     i->blocks = pa_hashmap_new(NULL, NULL);
 888     i->release_cb = cb;
 889     i->userdata = userdata;
 890
 891     pa_mutex_lock(p->mutex);
 892     PA_LLIST_PREPEND(pa_memimport, p->imports, i);
 893     pa_mutex_unlock(p->mutex);
 894
 895     return i;
 896 }
 897
 898 static void memexport_revoke_blocks(pa_memexport *e, pa_memimport *i);
 899
 900 /* Should be called locked */
 901 static pa_memimport_segment* segment_attach(pa_memimport *i, uint32_t shm_id) {
 902     pa_memimport_segment* seg;
 903
 904     if (pa_hashmap_size(i->segments) >= PA_MEMIMPORT_SEGMENTS_MAX)
 905         return NULL;
 906
 907     seg = pa_xnew0(pa_memimport_segment, 1);
 908
 909     if (pa_shm_attach_ro(&seg->memory, shm_id) < 0) {
 910         pa_xfree(seg);
 911         return NULL;
 912     }
 913
 914     seg->import = i;
 915     seg->trap = pa_memtrap_add(seg->memory.ptr, seg->memory.size);
 916
 917     pa_hashmap_put(i->segments, PA_UINT32_TO_PTR(seg->memory.id), seg);
 918     return seg;
 919 }
 920
 921 /* Should be called locked */
 922 static void segment_detach(pa_memimport_segment *seg) {
 923     pa_assert(seg);
 924
 925     pa_hashmap_remove(seg->import->segments, PA_UINT32_TO_PTR(seg->memory.id));
 926     pa_shm_free(&seg->memory);
 927
 928     if (seg->trap)
 929         pa_memtrap_remove(seg->trap);
 930
 931     pa_xfree(seg);
 932 }
 933
 934 /* Self-locked. Not multiple-caller safe */
 935 void pa_memimport_free(pa_memimport *i) {
 936     pa_memexport *e;
 937     pa_memblock *b;
 938
 939     pa_assert(i);
 940
 941     pa_mutex_lock(i->mutex);
 942
 943     while ((b = pa_hashmap_first(i->blocks)))
 944         memblock_replace_import(b);
 945
 946     pa_assert(pa_hashmap_size(i->segments) == 0);
 947
 948     pa_mutex_unlock(i->mutex);
 949
 950     pa_mutex_lock(i->pool->mutex);
 951
 952     /* If we've exported this block further we need to revoke that export */
 953     for (e = i->pool->exports; e; e = e->next)
 954         memexport_revoke_blocks(e, i);
 955
 956     PA_LLIST_REMOVE(pa_memimport, i->pool->imports, i);
 957
 958     pa_mutex_unlock(i->pool->mutex);
 959
 960     pa_hashmap_free(i->blocks, NULL, NULL);
 961     pa_hashmap_free(i->segments, NULL, NULL);
 962
 963     pa_mutex_free(i->mutex);
 964
 965     pa_xfree(i);
 966 }
 967
 968 /* Self-locked */
 969 pa_memblock* pa_memimport_get(pa_memimport *i, uint32_t block_id, uint32_t shm_id, size_t offset, size_t size) {
 970     pa_memblock *b = NULL;
 971     pa_memimport_segment *seg;
 972
 973     pa_assert(i);
 974
 975     pa_mutex_lock(i->mutex);
 976
 977     if ((b = pa_hashmap_get(i->blocks, PA_UINT32_TO_PTR(block_id)))) {
 978         pa_memblock_ref(b);
 979         goto finish;
 980     }
 981
 982     if (pa_hashmap_size(i->blocks) >= PA_MEMIMPORT_SLOTS_MAX)
 983         goto finish;
 984
 985     if (!(seg = pa_hashmap_get(i->segments, PA_UINT32_TO_PTR(shm_id))))
 986         if (!(seg = segment_attach(i, shm_id)))
 987             goto finish;
 988
 989     if (offset+size > seg->memory.size)
 990         goto finish;
 991
 992     if (!(b = pa_flist_pop(PA_STATIC_FLIST_GET(unused_memblocks))))
 993         b = pa_xnew(pa_memblock, 1);
 994
 995     PA_REFCNT_INIT(b);
 996     b->pool = i->pool;
 997     b->type = PA_MEMBLOCK_IMPORTED;
 998     b->read_only = TRUE;
 999     b->is_silence = FALSE;
1000     pa_atomic_ptr_store(&b->data, (uint8_t*) seg->memory.ptr + offset);
1001     b->length = size;
1002     pa_atomic_store(&b->n_acquired, 0);
1003     pa_atomic_store(&b->please_signal, 0);
1004     b->per_type.imported.id = block_id;
1005     b->per_type.imported.segment = seg;
1006
1007     pa_hashmap_put(i->blocks, PA_UINT32_TO_PTR(block_id), b);
1008
1009     seg->n_blocks++;
1010
1011     stat_add(b);
1012
1013 finish:
1014     pa_mutex_unlock(i->mutex);
1015
1016     return b;
1017 }
1018
1019 int pa_memimport_process_revoke(pa_memimport *i, uint32_t id) {
1020     pa_memblock *b;
1021     int ret = 0;
1022     pa_assert(i);
1023
1024     pa_mutex_lock(i->mutex);
1025
1026     if (!(b = pa_hashmap_get(i->blocks, PA_UINT32_TO_PTR(id)))) {
1027         ret = -1;
1028         goto finish;
1029     }
1030
1031     memblock_replace_import(b);
1032
1033 finish:
1034     pa_mutex_unlock(i->mutex);
1035
1036     return ret;
1037 }
1038
1039 /* For sending blocks to other nodes */
1040 pa_memexport* pa_memexport_new(pa_mempool *p, pa_memexport_revoke_cb_t cb, void *userdata) {
1041     pa_memexport *e;
1042
1043     pa_assert(p);
1044     pa_assert(cb);
1045
1046     if (!p->memory.shared)
1047         return NULL;
1048
1049     e = pa_xnew(pa_memexport, 1);
1050     e->mutex = pa_mutex_new(TRUE, TRUE);
1051     e->pool = p;
1052     PA_LLIST_HEAD_INIT(struct memexport_slot, e->free_slots);
1053     PA_LLIST_HEAD_INIT(struct memexport_slot, e->used_slots);
1054     e->n_init = 0;
1055     e->revoke_cb = cb;
1056     e->userdata = userdata;
1057
1058     pa_mutex_lock(p->mutex);
1059     PA_LLIST_PREPEND(pa_memexport, p->exports, e);
1060     pa_mutex_unlock(p->mutex);
1061     return e;
1062 }
1063
1064 void pa_memexport_free(pa_memexport *e) {
1065     pa_assert(e);
1066
1067     pa_mutex_lock(e->mutex);
1068     while (e->used_slots)
1069         pa_memexport_process_release(e, (uint32_t) (e->used_slots - e->slots));
1070     pa_mutex_unlock(e->mutex);
1071
1072     pa_mutex_lock(e->pool->mutex);
1073     PA_LLIST_REMOVE(pa_memexport, e->pool->exports, e);
1074     pa_mutex_unlock(e->pool->mutex);
1075
1076     pa_mutex_free(e->mutex);
1077     pa_xfree(e);
1078 }
1079
1080 /* Self-locked */
1081 int pa_memexport_process_release(pa_memexport *e, uint32_t id) {
1082     pa_memblock *b;
1083
1084     pa_assert(e);
1085
1086     pa_mutex_lock(e->mutex);
1087
1088     if (id >= e->n_init)
1089         goto fail;
1090
1091     if (!e->slots[id].block)
1092         goto fail;
1093
1094     b = e->slots[id].block;
1095     e->slots[id].block = NULL;
1096
1097     PA_LLIST_REMOVE(struct memexport_slot, e->used_slots, &e->slots[id]);
1098     PA_LLIST_PREPEND(struct memexport_slot, e->free_slots, &e->slots[id]);
1099
1100     pa_mutex_unlock(e->mutex);
1101
1102 /*     pa_log("Processing release for %u", id); */
1103
1104     pa_assert(pa_atomic_load(&e->pool->stat.n_exported) > 0);
1105     pa_assert(pa_atomic_load(&e->pool->stat.exported_size) >= (int) b->length);
1106
1107     pa_atomic_dec(&e->pool->stat.n_exported);
1108     pa_atomic_sub(&e->pool->stat.exported_size, (int) b->length);
1109
1110     pa_memblock_unref(b);
1111
1112     return 0;
1113
1114 fail:
1115     pa_mutex_unlock(e->mutex);
1116
1117     return -1;
1118 }
1119
1120 /* Self-locked */
1121 static void memexport_revoke_blocks(pa_memexport *e, pa_memimport *i) {
1122     struct memexport_slot *slot, *next;
1123     pa_assert(e);
1124     pa_assert(i);
1125
1126     pa_mutex_lock(e->mutex);
1127
1128     for (slot = e->used_slots; slot; slot = next) {
1129         uint32_t idx;
1130         next = slot->next;
1131
1132         if (slot->block->type != PA_MEMBLOCK_IMPORTED ||
1133             slot->block->per_type.imported.segment->import != i)
1134             continue;
1135
1136         idx = (uint32_t) (slot - e->slots);
1137         e->revoke_cb(e, idx, e->userdata);
1138         pa_memexport_process_release(e, idx);
1139     }
1140
1141     pa_mutex_unlock(e->mutex);
1142 }
1143
1144 /* No lock necessary */
1145 static pa_memblock *memblock_shared_copy(pa_mempool *p, pa_memblock *b) {
1146     pa_memblock *n;
1147
1148     pa_assert(p);
1149     pa_assert(b);
1150
1151     if (b->type == PA_MEMBLOCK_IMPORTED ||
1152         b->type == PA_MEMBLOCK_POOL ||
1153         b->type == PA_MEMBLOCK_POOL_EXTERNAL) {
1154         pa_assert(b->pool == p);
1155         return pa_memblock_ref(b);
1156     }
1157
1158     if (!(n = pa_memblock_new_pool(p, b->length)))
1159         return NULL;
1160
1161     memcpy(pa_atomic_ptr_load(&n->data), pa_atomic_ptr_load(&b->data), b->length);
1162     return n;
1163 }
1164
1165 /* Self-locked */
1166 int pa_memexport_put(pa_memexport *e, pa_memblock *b, uint32_t *block_id, uint32_t *shm_id, size_t *offset, size_t * size) {
1167     pa_shm *memory;
1168     struct memexport_slot *slot;
1169     void *data;
1170
1171     pa_assert(e);
1172     pa_assert(b);
1173     pa_assert(block_id);
1174     pa_assert(shm_id);
1175     pa_assert(offset);
1176     pa_assert(size);
1177     pa_assert(b->pool == e->pool);
1178
1179     if (!(b = memblock_shared_copy(e->pool, b)))
1180         return -1;
1181
1182     pa_mutex_lock(e->mutex);
1183
1184     if (e->free_slots) {
1185         slot = e->free_slots;
1186         PA_LLIST_REMOVE(struct memexport_slot, e->free_slots, slot);
1187     } else if (e->n_init < PA_MEMEXPORT_SLOTS_MAX)
1188         slot = &e->slots[e->n_init++];
1189     else {
1190         pa_mutex_unlock(e->mutex);
1191         pa_memblock_unref(b);
1192         return -1;
1193     }
1194
1195     PA_LLIST_PREPEND(struct memexport_slot, e->used_slots, slot);
1196     slot->block = b;
1197     *block_id = (uint32_t) (slot - e->slots);
1198
1199     pa_mutex_unlock(e->mutex);
1200 /*     pa_log("Got block id %u", *block_id); */
1201
1202     data = pa_memblock_acquire(b);
1203
1204     if (b->type == PA_MEMBLOCK_IMPORTED) {
1205         pa_assert(b->per_type.imported.segment);
1206         memory = &b->per_type.imported.segment->memory;
1207     } else {
1208         pa_assert(b->type == PA_MEMBLOCK_POOL || b->type == PA_MEMBLOCK_POOL_EXTERNAL);
1209         pa_assert(b->pool);
1210         memory = &b->pool->memory;
1211     }
1212
1213     pa_assert(data >= memory->ptr);
1214     pa_assert((uint8_t*) data + b->length <= (uint8_t*) memory->ptr + memory->size);
1215
1216     *shm_id = memory->id;
1217     *offset = (size_t) ((uint8_t*) data - (uint8_t*) memory->ptr);
1218     *size = b->length;
1219
1220     pa_memblock_release(b);
1221
1222     pa_atomic_inc(&e->pool->stat.n_exported);
1223     pa_atomic_add(&e->pool->stat.exported_size, (int) b->length);
1224
1225     return 0;
1226 }