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