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 /* A collection of multiple segments */
 100 struct pa_memimport {
 101     pa_mutex *mutex;
 102
 103     pa_mempool *pool;
 104     pa_hashmap *segments;
 105     pa_hashmap *blocks;
 106
 107     /* Called whenever an imported memory block is no longer
 108      * needed. */
 109     pa_memimport_release_cb_t release_cb;
 110     void *userdata;
 111
 112     PA_LLIST_FIELDS(pa_memimport);
 113 };
 114
 115 struct memexport_slot {
 116     PA_LLIST_FIELDS(struct memexport_slot);
 117     pa_memblock *block;
 118 };
 119
 120 struct pa_memexport {
 121     pa_mutex *mutex;
 122     pa_mempool *pool;
 123
 124     struct memexport_slot slots[PA_MEMEXPORT_SLOTS_MAX];
 125
 126     PA_LLIST_HEAD(struct memexport_slot, free_slots);
 127     PA_LLIST_HEAD(struct memexport_slot, used_slots);
 128     unsigned n_init;
 129
 130     /* Called whenever a client from which we imported a memory block
 131        which we in turn exported to another client dies and we need to
 132        revoke the memory block accordingly */
 133     pa_memexport_revoke_cb_t revoke_cb;
 134     void *userdata;
 135
 136     PA_LLIST_FIELDS(pa_memexport);
 137 };
 138
 139 struct pa_mempool {
 140     pa_semaphore *semaphore;
 141     pa_mutex *mutex;
 142
 143     pa_shm memory;
 144     size_t block_size;
 145     unsigned n_blocks;
 146
 147     pa_atomic_t n_init;
 148
 149     PA_LLIST_HEAD(pa_memimport, imports);
 150     PA_LLIST_HEAD(pa_memexport, exports);
 151
 152     /* A list of free slots that may be reused */
 153     pa_flist *free_slots;
 154
 155     pa_mempool_stat stat;
 156 };
 157
 158 static void segment_detach(pa_memimport_segment *seg);
 159
 160 PA_STATIC_FLIST_DECLARE(unused_memblocks, 0, pa_xfree);
 161
 162 /* No lock necessary */
 163 static void stat_add(pa_memblock*b) {
 164     pa_assert(b);
 165     pa_assert(b->pool);
 166
 167     pa_atomic_inc(&b->pool->stat.n_allocated);
 168     pa_atomic_add(&b->pool->stat.allocated_size, (int) b->length);
 169
 170     pa_atomic_inc(&b->pool->stat.n_accumulated);
 171     pa_atomic_add(&b->pool->stat.accumulated_size, (int) b->length);
 172
 173     if (b->type == PA_MEMBLOCK_IMPORTED) {
 174         pa_atomic_inc(&b->pool->stat.n_imported);
 175         pa_atomic_add(&b->pool->stat.imported_size, (int) b->length);
 176     }
 177
 178     pa_atomic_inc(&b->pool->stat.n_allocated_by_type[b->type]);
 179     pa_atomic_inc(&b->pool->stat.n_accumulated_by_type[b->type]);
 180 }
 181
 182 /* No lock necessary */
 183 static void stat_remove(pa_memblock *b) {
 184     pa_assert(b);
 185     pa_assert(b->pool);
 186
 187     pa_assert(pa_atomic_load(&b->pool->stat.n_allocated) > 0);
 188     pa_assert(pa_atomic_load(&b->pool->stat.allocated_size) >= (int) b->length);
 189
 190     pa_atomic_dec(&b->pool->stat.n_allocated);
 191     pa_atomic_sub(&b->pool->stat.allocated_size, (int) b->length);
 192
 193     if (b->type == PA_MEMBLOCK_IMPORTED) {
 194         pa_assert(pa_atomic_load(&b->pool->stat.n_imported) > 0);
 195         pa_assert(pa_atomic_load(&b->pool->stat.imported_size) >= (int) b->length);
 196
 197         pa_atomic_dec(&b->pool->stat.n_imported);
 198         pa_atomic_sub(&b->pool->stat.imported_size, (int) b->length);
 199     }
 200
 201     pa_atomic_dec(&b->pool->stat.n_allocated_by_type[b->type]);
 202 }
 203
 204 static pa_memblock *memblock_new_appended(pa_mempool *p, size_t length);
 205
 206 /* No lock necessary */
 207 pa_memblock *pa_memblock_new(pa_mempool *p, size_t length) {
 208     pa_memblock *b;
 209
 210     pa_assert(p);
 211     pa_assert(length);
 212
 213     if (!(b = pa_memblock_new_pool(p, length)))
 214         b = memblock_new_appended(p, length);
 215
 216     return b;
 217 }
 218
 219 /* No lock necessary */
 220 static pa_memblock *memblock_new_appended(pa_mempool *p, size_t length) {
 221     pa_memblock *b;
 222
 223     pa_assert(p);
 224     pa_assert(length);
 225
 226     /* If -1 is passed as length we choose the size for the caller. */
 227
 228     if (length == (size_t) -1)
 229         length = p->block_size - PA_ALIGN(sizeof(pa_memblock));
 230
 231     b = pa_xmalloc(PA_ALIGN(sizeof(pa_memblock)) + length);
 232     PA_REFCNT_INIT(b);
 233     b->pool = p;
 234     b->type = PA_MEMBLOCK_APPENDED;
 235     b->read_only = b->is_silence = FALSE;
 236     pa_atomic_ptr_store(&b->data, (uint8_t*) b + PA_ALIGN(sizeof(pa_memblock)));
 237     b->length = length;
 238     pa_atomic_store(&b->n_acquired, 0);
 239     pa_atomic_store(&b->please_signal, 0);
 240
 241     stat_add(b);
 242     return b;
 243 }
 244
 245 /* No lock necessary */
 246 static struct mempool_slot* mempool_allocate_slot(pa_mempool *p) {
 247     struct mempool_slot *slot;
 248     pa_assert(p);
 249
 250     if (!(slot = pa_flist_pop(p->free_slots))) {
 251         int idx;
 252
 253         /* The free list was empty, we have to allocate a new entry */
 254
 255         if ((unsigned) (idx = pa_atomic_inc(&p->n_init)) >= p->n_blocks)
 256             pa_atomic_dec(&p->n_init);
 257         else
 258             slot = (struct mempool_slot*) ((uint8_t*) p->memory.ptr + (p->block_size * (size_t) idx));
 259
 260         if (!slot) {
 261             if (pa_log_ratelimit())
 262                 pa_log_debug("Pool full");
 263             pa_atomic_inc(&p->stat.n_pool_full);
 264             return NULL;
 265         }
 266     }
 267
 268 /* #ifdef HAVE_VALGRIND_MEMCHECK_H */
 269 /*     if (PA_UNLIKELY(pa_in_valgrind())) { */
 270 /*         VALGRIND_MALLOCLIKE_BLOCK(slot, p->block_size, 0, 0); */
 271 /*     } */
 272 /* #endif */
 273
 274     return slot;
 275 }
 276
 277 /* No lock necessary, totally redundant anyway */
 278 static inline void* mempool_slot_data(struct mempool_slot *slot) {
 279     return slot;
 280 }
 281
 282 /* No lock necessary */
 283 static unsigned mempool_slot_idx(pa_mempool *p, void *ptr) {
 284     pa_assert(p);
 285
 286     pa_assert((uint8_t*) ptr >= (uint8_t*) p->memory.ptr);
 287     pa_assert((uint8_t*) ptr < (uint8_t*) p->memory.ptr + p->memory.size);
 288
 289     return (unsigned) ((size_t) ((uint8_t*) ptr - (uint8_t*) p->memory.ptr) / p->block_size);
 290 }
 291
 292 /* No lock necessary */
 293 static struct mempool_slot* mempool_slot_by_ptr(pa_mempool *p, void *ptr) {
 294     unsigned idx;
 295
 296     if ((idx = mempool_slot_idx(p, ptr)) == (unsigned) -1)
 297         return NULL;
 298
 299     return (struct mempool_slot*) ((uint8_t*) p->memory.ptr + (idx * p->block_size));
 300 }
 301
 302 /* No lock necessary */
 303 pa_memblock *pa_memblock_new_pool(pa_mempool *p, size_t length) {
 304     pa_memblock *b = NULL;
 305     struct mempool_slot *slot;
 306     static int mempool_disable = 0;
 307
 308     pa_assert(p);
 309     pa_assert(length);
 310
 311     if (mempool_disable == 0)
 312         mempool_disable = getenv("PULSE_MEMPOOL_DISABLE") ? 1 : -1;
 313
 314     if (mempool_disable > 0)
 315         return NULL;
 316
 317     /* If -1 is passed as length we choose the size for the caller: we
 318      * take the largest size that fits in one of our slots. */
 319
 320     if (length == (size_t) -1)
 321         length = pa_mempool_block_size_max(p);
 322
 323     if (p->block_size >= PA_ALIGN(sizeof(pa_memblock)) + length) {
 324
 325         if (!(slot = mempool_allocate_slot(p)))
 326             return NULL;
 327
 328         b = mempool_slot_data(slot);
 329         b->type = PA_MEMBLOCK_POOL;
 330         pa_atomic_ptr_store(&b->data, (uint8_t*) b + PA_ALIGN(sizeof(pa_memblock)));
 331
 332     } else if (p->block_size >= length) {
 333
 334         if (!(slot = mempool_allocate_slot(p)))
 335             return NULL;
 336
 337         if (!(b = pa_flist_pop(PA_STATIC_FLIST_GET(unused_memblocks))))
 338             b = pa_xnew(pa_memblock, 1);
 339
 340         b->type = PA_MEMBLOCK_POOL_EXTERNAL;
 341         pa_atomic_ptr_store(&b->data, mempool_slot_data(slot));
 342
 343     } else {
 344         pa_log_debug("Memory block too large for pool: %lu > %lu", (unsigned long) length, (unsigned long) p->block_size);
 345         pa_atomic_inc(&p->stat.n_too_large_for_pool);
 346         return NULL;
 347     }
 348
 349     PA_REFCNT_INIT(b);
 350     b->pool = p;
 351     b->read_only = b->is_silence = FALSE;
 352     b->length = length;
 353     pa_atomic_store(&b->n_acquired, 0);
 354     pa_atomic_store(&b->please_signal, 0);
 355
 356     stat_add(b);
 357     return b;
 358 }
 359
 360 /* No lock necessary */
 361 pa_memblock *pa_memblock_new_fixed(pa_mempool *p, void *d, size_t length, pa_bool_t read_only) {
 362     pa_memblock *b;
 363
 364     pa_assert(p);
 365     pa_assert(d);
 366     pa_assert(length != (size_t) -1);
 367     pa_assert(length);
 368
 369     if (!(b = pa_flist_pop(PA_STATIC_FLIST_GET(unused_memblocks))))
 370         b = pa_xnew(pa_memblock, 1);
 371
 372     PA_REFCNT_INIT(b);
 373     b->pool = p;
 374     b->type = PA_MEMBLOCK_FIXED;
 375     b->read_only = read_only;
 376     b->is_silence = FALSE;
 377     pa_atomic_ptr_store(&b->data, d);
 378     b->length = length;
 379     pa_atomic_store(&b->n_acquired, 0);
 380     pa_atomic_store(&b->please_signal, 0);
 381
 382     stat_add(b);
 383     return b;
 384 }
 385
 386 /* No lock necessary */
 387 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) {
 388     pa_memblock *b;
 389
 390     pa_assert(p);
 391     pa_assert(d);
 392     pa_assert(length);
 393     pa_assert(length != (size_t) -1);
 394     pa_assert(free_cb);
 395
 396     if (!(b = pa_flist_pop(PA_STATIC_FLIST_GET(unused_memblocks))))
 397         b = pa_xnew(pa_memblock, 1);
 398
 399     PA_REFCNT_INIT(b);
 400     b->pool = p;
 401     b->type = PA_MEMBLOCK_USER;
 402     b->read_only = read_only;
 403     b->is_silence = FALSE;
 404     pa_atomic_ptr_store(&b->data, d);
 405     b->length = length;
 406     pa_atomic_store(&b->n_acquired, 0);
 407     pa_atomic_store(&b->please_signal, 0);
 408
 409     b->per_type.user.free_cb = free_cb;
 410
 411     stat_add(b);
 412     return b;
 413 }
 414
 415 /* No lock necessary */
 416 pa_bool_t pa_memblock_is_read_only(pa_memblock *b) {
 417     pa_assert(b);
 418     pa_assert(PA_REFCNT_VALUE(b) > 0);
 419
 420     return b->read_only && PA_REFCNT_VALUE(b) == 1;
 421 }
 422
 423 /* No lock necessary */
 424 pa_bool_t pa_memblock_is_silence(pa_memblock *b) {
 425     pa_assert(b);
 426     pa_assert(PA_REFCNT_VALUE(b) > 0);
 427
 428     return b->is_silence;
 429 }
 430
 431 /* No lock necessary */
 432 void pa_memblock_set_is_silence(pa_memblock *b, pa_bool_t v) {
 433     pa_assert(b);
 434     pa_assert(PA_REFCNT_VALUE(b) > 0);
 435
 436     b->is_silence = v;
 437 }
 438
 439 /* No lock necessary */
 440 pa_bool_t pa_memblock_ref_is_one(pa_memblock *b) {
 441     int r;
 442     pa_assert(b);
 443
 444     pa_assert_se((r = PA_REFCNT_VALUE(b)) > 0);
 445
 446     return r == 1;
 447 }
 448
 449 /* No lock necessary */
 450 void* pa_memblock_acquire(pa_memblock *b) {
 451     pa_assert(b);
 452     pa_assert(PA_REFCNT_VALUE(b) > 0);
 453
 454     pa_atomic_inc(&b->n_acquired);
 455
 456     return pa_atomic_ptr_load(&b->data);
 457 }
 458
 459 /* No lock necessary, in corner cases locks by its own */
 460 void pa_memblock_release(pa_memblock *b) {
 461     int r;
 462     pa_assert(b);
 463     pa_assert(PA_REFCNT_VALUE(b) > 0);
 464
 465     r = pa_atomic_dec(&b->n_acquired);
 466     pa_assert(r >= 1);
 467
 468     /* Signal a waiting thread that this memblock is no longer used */
 469     if (r == 1 && pa_atomic_load(&b->please_signal))
 470         pa_semaphore_post(b->pool->semaphore);
 471 }
 472
 473 size_t pa_memblock_get_length(pa_memblock *b) {
 474     pa_assert(b);
 475     pa_assert(PA_REFCNT_VALUE(b) > 0);
 476
 477     return b->length;
 478 }
 479
 480 pa_mempool* pa_memblock_get_pool(pa_memblock *b) {
 481     pa_assert(b);
 482     pa_assert(PA_REFCNT_VALUE(b) > 0);
 483
 484     return b->pool;
 485 }
 486
 487 /* No lock necessary */
 488 pa_memblock* pa_memblock_ref(pa_memblock*b) {
 489     pa_assert(b);
 490     pa_assert(PA_REFCNT_VALUE(b) > 0);
 491
 492     PA_REFCNT_INC(b);
 493     return b;
 494 }
 495
 496 static void memblock_free(pa_memblock *b) {
 497     pa_assert(b);
 498
 499     pa_assert(pa_atomic_load(&b->n_acquired) == 0);
 500
 501     stat_remove(b);
 502
 503     switch (b->type) {
 504         case PA_MEMBLOCK_USER :
 505             pa_assert(b->per_type.user.free_cb);
 506             b->per_type.user.free_cb(pa_atomic_ptr_load(&b->data));
 507
 508             /* Fall through */
 509
 510         case PA_MEMBLOCK_FIXED:
 511             if (pa_flist_push(PA_STATIC_FLIST_GET(unused_memblocks), b) < 0)
 512                 pa_xfree(b);
 513
 514             break;
 515
 516         case PA_MEMBLOCK_APPENDED:
 517
 518             /* We could attached it unused_memblocks, but that would
 519              * probably waste some considerable memory */
 520             pa_xfree(b);
 521             break;
 522
 523         case PA_MEMBLOCK_IMPORTED: {
 524             pa_memimport_segment *segment;
 525             pa_memimport *import;
 526
 527             /* FIXME! This should be implemented lock-free */
 528
 529             pa_assert_se(segment = b->per_type.imported.segment);
 530             pa_assert_se(import = segment->import);
 531
 532             pa_mutex_lock(import->mutex);
 533
 534             pa_assert_se(pa_hashmap_remove(
 535                                  import->blocks,
 536                                  PA_UINT32_TO_PTR(b->per_type.imported.id)));
 537
 538             pa_assert(segment->n_blocks >= 1);
 539             if (-- segment->n_blocks <= 0)
 540                 segment_detach(segment);
 541
 542             pa_mutex_unlock(import->mutex);
 543
 544             import->release_cb(import, b->per_type.imported.id, import->userdata);
 545
 546             if (pa_flist_push(PA_STATIC_FLIST_GET(unused_memblocks), b) < 0)
 547                 pa_xfree(b);
 548
 549             break;
 550         }
 551
 552         case PA_MEMBLOCK_POOL_EXTERNAL:
 553         case PA_MEMBLOCK_POOL: {
 554             struct mempool_slot *slot;
 555             pa_bool_t call_free;
 556
 557             pa_assert_se(slot = mempool_slot_by_ptr(b->pool, pa_atomic_ptr_load(&b->data)));
 558
 559             call_free = b->type == PA_MEMBLOCK_POOL_EXTERNAL;
 560
 561 /* #ifdef HAVE_VALGRIND_MEMCHECK_H */
 562 /*             if (PA_UNLIKELY(pa_in_valgrind())) { */
 563 /*                 VALGRIND_FREELIKE_BLOCK(slot, b->pool->block_size); */
 564 /*             } */
 565 /* #endif */
 566
 567             /* The free list dimensions should easily allow all slots
 568              * to fit in, hence try harder if pushing this slot into
 569              * the free list fails */
 570             while (pa_flist_push(b->pool->free_slots, slot) < 0)
 571                 ;
 572
 573             if (call_free)
 574                 if (pa_flist_push(PA_STATIC_FLIST_GET(unused_memblocks), b) < 0)
 575                     pa_xfree(b);
 576
 577             break;
 578         }
 579
 580         case PA_MEMBLOCK_TYPE_MAX:
 581         default:
 582             pa_assert_not_reached();
 583     }
 584 }
 585
 586 /* No lock necessary */
 587 void pa_memblock_unref(pa_memblock*b) {
 588     pa_assert(b);
 589     pa_assert(PA_REFCNT_VALUE(b) > 0);
 590
 591     if (PA_REFCNT_DEC(b) > 0)
 592         return;
 593
 594     memblock_free(b);
 595 }
 596
 597 /* Self locked */
 598 static void memblock_wait(pa_memblock *b) {
 599     pa_assert(b);
 600
 601     if (pa_atomic_load(&b->n_acquired) > 0) {
 602         /* We need to wait until all threads gave up access to the
 603          * memory block before we can go on. Unfortunately this means
 604          * that we have to lock and wait here. Sniff! */
 605
 606         pa_atomic_inc(&b->please_signal);
 607
 608         while (pa_atomic_load(&b->n_acquired) > 0)
 609             pa_semaphore_wait(b->pool->semaphore);
 610
 611         pa_atomic_dec(&b->please_signal);
 612     }
 613 }
 614
 615 /* No lock necessary. This function is not multiple caller safe! */
 616 static void memblock_make_local(pa_memblock *b) {
 617     pa_assert(b);
 618
 619     pa_atomic_dec(&b->pool->stat.n_allocated_by_type[b->type]);
 620
 621     if (b->length <= b->pool->block_size) {
 622         struct mempool_slot *slot;
 623
 624         if ((slot = mempool_allocate_slot(b->pool))) {
 625             void *new_data;
 626             /* We can move it into a local pool, perfect! */
 627
 628             new_data = mempool_slot_data(slot);
 629             memcpy(new_data, pa_atomic_ptr_load(&b->data), b->length);
 630             pa_atomic_ptr_store(&b->data, new_data);
 631
 632             b->type = PA_MEMBLOCK_POOL_EXTERNAL;
 633             b->read_only = FALSE;
 634
 635             goto finish;
 636         }
 637     }
 638
 639     /* Humm, not enough space in the pool, so lets allocate the memory with malloc() */
 640     b->per_type.user.free_cb = pa_xfree;
 641     pa_atomic_ptr_store(&b->data, pa_xmemdup(pa_atomic_ptr_load(&b->data), b->length));
 642
 643     b->type = PA_MEMBLOCK_USER;
 644     b->read_only = FALSE;
 645
 646 finish:
 647     pa_atomic_inc(&b->pool->stat.n_allocated_by_type[b->type]);
 648     pa_atomic_inc(&b->pool->stat.n_accumulated_by_type[b->type]);
 649     memblock_wait(b);
 650 }
 651
 652 /* No lock necessary. This function is not multiple caller safe*/
 653 void pa_memblock_unref_fixed(pa_memblock *b) {
 654     pa_assert(b);
 655     pa_assert(PA_REFCNT_VALUE(b) > 0);
 656     pa_assert(b->type == PA_MEMBLOCK_FIXED);
 657
 658     if (PA_REFCNT_VALUE(b) > 1)
 659         memblock_make_local(b);
 660
 661     pa_memblock_unref(b);
 662 }
 663
 664 /* No lock necessary. */
 665 pa_memblock *pa_memblock_will_need(pa_memblock *b) {
 666     void *p;
 667
 668     pa_assert(b);
 669     pa_assert(PA_REFCNT_VALUE(b) > 0);
 670
 671     p = pa_memblock_acquire(b);
 672     pa_will_need(p, b->length);
 673     pa_memblock_release(b);
 674
 675     return b;
 676 }
 677
 678 /* Self-locked. This function is not multiple-caller safe */
 679 static void memblock_replace_import(pa_memblock *b) {
 680     pa_memimport_segment *segment;
 681     pa_memimport *import;
 682
 683     pa_assert(b);
 684     pa_assert(b->type == PA_MEMBLOCK_IMPORTED);
 685
 686     pa_assert(pa_atomic_load(&b->pool->stat.n_imported) > 0);
 687     pa_assert(pa_atomic_load(&b->pool->stat.imported_size) >= (int) b->length);
 688     pa_atomic_dec(&b->pool->stat.n_imported);
 689     pa_atomic_sub(&b->pool->stat.imported_size, (int) b->length);
 690
 691     pa_assert_se(segment = b->per_type.imported.segment);
 692     pa_assert_se(import = segment->import);
 693
 694     pa_mutex_lock(import->mutex);
 695
 696     pa_assert_se(pa_hashmap_remove(
 697                          import->blocks,
 698                          PA_UINT32_TO_PTR(b->per_type.imported.id)));
 699
 700     memblock_make_local(b);
 701
 702     pa_assert(segment->n_blocks >= 1);
 703     if (-- segment->n_blocks <= 0)
 704         segment_detach(segment);
 705
 706     pa_mutex_unlock(import->mutex);
 707 }
 708
 709 pa_mempool* pa_mempool_new(pa_bool_t shared, size_t size) {
 710     pa_mempool *p;
 711     char t1[PA_BYTES_SNPRINT_MAX], t2[PA_BYTES_SNPRINT_MAX];
 712
 713     p = pa_xnew(pa_mempool, 1);
 714
 715     p->mutex = pa_mutex_new(TRUE, TRUE);
 716     p->semaphore = pa_semaphore_new(0);
 717
 718     p->block_size = PA_PAGE_ALIGN(PA_MEMPOOL_SLOT_SIZE);
 719     if (p->block_size < PA_PAGE_SIZE)
 720         p->block_size = PA_PAGE_SIZE;
 721
 722     if (size <= 0)
 723         p->n_blocks = PA_MEMPOOL_SLOTS_MAX;
 724     else {
 725         p->n_blocks = (unsigned) (size / p->block_size);
 726
 727         if (p->n_blocks < 2)
 728             p->n_blocks = 2;
 729     }
 730
 731     if (pa_shm_create_rw(&p->memory, p->n_blocks * p->block_size, shared, 0700) < 0) {
 732         pa_xfree(p);
 733         return NULL;
 734     }
 735
 736     pa_log_debug("Using %s memory pool with %u slots of size %s each, total size is %s, maximum usable slot size is %lu",
 737                  p->memory.shared ? "shared" : "private",
 738                  p->n_blocks,
 739                  pa_bytes_snprint(t1, sizeof(t1), (unsigned) p->block_size),
 740                  pa_bytes_snprint(t2, sizeof(t2), (unsigned) (p->n_blocks * p->block_size)),
 741                  (unsigned long) pa_mempool_block_size_max(p));
 742
 743     memset(&p->stat, 0, sizeof(p->stat));
 744     pa_atomic_store(&p->n_init, 0);
 745
 746     PA_LLIST_HEAD_INIT(pa_memimport, p->imports);
 747     PA_LLIST_HEAD_INIT(pa_memexport, p->exports);
 748
 749     p->free_slots = pa_flist_new(p->n_blocks);
 750
 751     return p;
 752 }
 753
 754 void pa_mempool_free(pa_mempool *p) {
 755     pa_assert(p);
 756
 757     pa_mutex_lock(p->mutex);
 758
 759     while (p->imports)
 760         pa_memimport_free(p->imports);
 761
 762     while (p->exports)
 763         pa_memexport_free(p->exports);
 764
 765     pa_mutex_unlock(p->mutex);
 766
 767     pa_flist_free(p->free_slots, NULL);
 768
 769     if (pa_atomic_load(&p->stat.n_allocated) > 0) {
 770
 771         /* Ouch, somebody is retaining a memory block reference! */
 772
 773 #ifdef DEBUG_REF
 774         unsigned i;
 775         pa_flist *list;
 776
 777         /* Let's try to find at least one of those leaked memory blocks */
 778
 779         list = pa_flist_new(p->n_blocks);
 780
 781         for (i = 0; i < (unsigned) pa_atomic_load(&p->n_init); i++) {
 782             struct mempool_slot *slot;
 783             pa_memblock *b, *k;
 784
 785             slot = (struct mempool_slot*) ((uint8_t*) p->memory.ptr + (p->block_size * (size_t) i));
 786             b = mempool_slot_data(slot);
 787
 788             while ((k = pa_flist_pop(p->free_slots))) {
 789                 while (pa_flist_push(list, k) < 0)
 790                     ;
 791
 792                 if (b == k)
 793                     break;
 794             }
 795
 796             if (!k)
 797                 pa_log("REF: Leaked memory block %p", b);
 798
 799             while ((k = pa_flist_pop(list)))
 800                 while (pa_flist_push(p->free_slots, k) < 0)
 801                     ;
 802         }
 803
 804         pa_flist_free(list, NULL);
 805
 806 #endif
 807
 808         pa_log_error("Memory pool destroyed but not all memory blocks freed! %u remain.", pa_atomic_load(&p->stat.n_allocated));
 809
 810 /*         PA_DEBUG_TRAP; */
 811     }
 812
 813     pa_shm_free(&p->memory);
 814
 815     pa_mutex_free(p->mutex);
 816     pa_semaphore_free(p->semaphore);
 817
 818     pa_xfree(p);
 819 }
 820
 821 /* No lock necessary */
 822 const pa_mempool_stat* pa_mempool_get_stat(pa_mempool *p) {
 823     pa_assert(p);
 824
 825     return &p->stat;
 826 }
 827
 828 /* No lock necessary */
 829 size_t pa_mempool_block_size_max(pa_mempool *p) {
 830     pa_assert(p);
 831
 832     return p->block_size - PA_ALIGN(sizeof(pa_memblock));
 833 }
 834
 835 /* No lock necessary */
 836 void pa_mempool_vacuum(pa_mempool *p) {
 837     struct mempool_slot *slot;
 838     pa_flist *list;
 839
 840     pa_assert(p);
 841
 842     list = pa_flist_new(p->n_blocks);
 843
 844     while ((slot = pa_flist_pop(p->free_slots)))
 845         while (pa_flist_push(list, slot) < 0)
 846             ;
 847
 848     while ((slot = pa_flist_pop(list))) {
 849         pa_shm_punch(&p->memory, (size_t) ((uint8_t*) slot - (uint8_t*) p->memory.ptr), p->block_size);
 850
 851         while (pa_flist_push(p->free_slots, slot))
 852             ;
 853     }
 854
 855     pa_flist_free(list, NULL);
 856 }
 857
 858 /* No lock necessary */
 859 int pa_mempool_get_shm_id(pa_mempool *p, uint32_t *id) {
 860     pa_assert(p);
 861
 862     if (!p->memory.shared)
 863         return -1;
 864
 865     *id = p->memory.id;
 866
 867     return 0;
 868 }
 869
 870 /* No lock necessary */
 871 pa_bool_t pa_mempool_is_shared(pa_mempool *p) {
 872     pa_assert(p);
 873
 874     return !!p->memory.shared;
 875 }
 876
 877 /* For recieving blocks from other nodes */
 878 pa_memimport* pa_memimport_new(pa_mempool *p, pa_memimport_release_cb_t cb, void *userdata) {
 879     pa_memimport *i;
 880
 881     pa_assert(p);
 882     pa_assert(cb);
 883
 884     i = pa_xnew(pa_memimport, 1);
 885     i->mutex = pa_mutex_new(TRUE, TRUE);
 886     i->pool = p;
 887     i->segments = pa_hashmap_new(NULL, NULL);
 888     i->blocks = pa_hashmap_new(NULL, NULL);
 889     i->release_cb = cb;
 890     i->userdata = userdata;
 891
 892     pa_mutex_lock(p->mutex);
 893     PA_LLIST_PREPEND(pa_memimport, p->imports, i);
 894     pa_mutex_unlock(p->mutex);
 895
 896     return i;
 897 }
 898
 899 static void memexport_revoke_blocks(pa_memexport *e, pa_memimport *i);
 900
 901 /* Should be called locked */
 902 static pa_memimport_segment* segment_attach(pa_memimport *i, uint32_t shm_id) {
 903     pa_memimport_segment* seg;
 904
 905     if (pa_hashmap_size(i->segments) >= PA_MEMIMPORT_SEGMENTS_MAX)
 906         return NULL;
 907
 908     seg = pa_xnew0(pa_memimport_segment, 1);
 909
 910     if (pa_shm_attach_ro(&seg->memory, shm_id) < 0) {
 911         pa_xfree(seg);
 912         return NULL;
 913     }
 914
 915     seg->import = i;
 916     seg->trap = pa_memtrap_add(seg->memory.ptr, seg->memory.size);
 917
 918     pa_hashmap_put(i->segments, PA_UINT32_TO_PTR(seg->memory.id), seg);
 919     return seg;
 920 }
 921
 922 /* Should be called locked */
 923 static void segment_detach(pa_memimport_segment *seg) {
 924     pa_assert(seg);
 925
 926     pa_hashmap_remove(seg->import->segments, PA_UINT32_TO_PTR(seg->memory.id));
 927     pa_shm_free(&seg->memory);
 928
 929     if (seg->trap)
 930         pa_memtrap_remove(seg->trap);
 931
 932     pa_xfree(seg);
 933 }
 934
 935 /* Self-locked. Not multiple-caller safe */
 936 void pa_memimport_free(pa_memimport *i) {
 937     pa_memexport *e;
 938     pa_memblock *b;
 939
 940     pa_assert(i);
 941
 942     pa_mutex_lock(i->mutex);
 943
 944     while ((b = pa_hashmap_first(i->blocks)))
 945         memblock_replace_import(b);
 946
 947     pa_assert(pa_hashmap_size(i->segments) == 0);
 948
 949     pa_mutex_unlock(i->mutex);
 950
 951     pa_mutex_lock(i->pool->mutex);
 952
 953     /* If we've exported this block further we need to revoke that export */
 954     for (e = i->pool->exports; e; e = e->next)
 955         memexport_revoke_blocks(e, i);
 956
 957     PA_LLIST_REMOVE(pa_memimport, i->pool->imports, i);
 958
 959     pa_mutex_unlock(i->pool->mutex);
 960
 961     pa_hashmap_free(i->blocks, NULL, NULL);
 962     pa_hashmap_free(i->segments, NULL, NULL);
 963
 964     pa_mutex_free(i->mutex);
 965
 966     pa_xfree(i);
 967 }
 968
 969 /* Self-locked */
 970 pa_memblock* pa_memimport_get(pa_memimport *i, uint32_t block_id, uint32_t shm_id, size_t offset, size_t size) {
 971     pa_memblock *b = NULL;
 972     pa_memimport_segment *seg;
 973
 974     pa_assert(i);
 975
 976     pa_mutex_lock(i->mutex);
 977
 978     if ((b = pa_hashmap_get(i->blocks, PA_UINT32_TO_PTR(block_id)))) {
 979         pa_memblock_ref(b);
 980         goto finish;
 981     }
 982
 983     if (pa_hashmap_size(i->blocks) >= PA_MEMIMPORT_SLOTS_MAX)
 984         goto finish;
 985
 986     if (!(seg = pa_hashmap_get(i->segments, PA_UINT32_TO_PTR(shm_id))))
 987         if (!(seg = segment_attach(i, shm_id)))
 988             goto finish;
 989
 990     if (offset+size > seg->memory.size)
 991         goto finish;
 992
 993     if (!(b = pa_flist_pop(PA_STATIC_FLIST_GET(unused_memblocks))))
 994         b = pa_xnew(pa_memblock, 1);
 995
 996     PA_REFCNT_INIT(b);
 997     b->pool = i->pool;
 998     b->type = PA_MEMBLOCK_IMPORTED;
 999     b->read_only = TRUE;
1000     b->is_silence = FALSE;
1001     pa_atomic_ptr_store(&b->data, (uint8_t*) seg->memory.ptr + offset);
1002     b->length = size;
1003     pa_atomic_store(&b->n_acquired, 0);
1004     pa_atomic_store(&b->please_signal, 0);
1005     b->per_type.imported.id = block_id;
1006     b->per_type.imported.segment = seg;
1007
1008     pa_hashmap_put(i->blocks, PA_UINT32_TO_PTR(block_id), b);
1009
1010     seg->n_blocks++;
1011
1012     stat_add(b);
1013
1014 finish:
1015     pa_mutex_unlock(i->mutex);
1016
1017     return b;
1018 }
1019
1020 int pa_memimport_process_revoke(pa_memimport *i, uint32_t id) {
1021     pa_memblock *b;
1022     int ret = 0;
1023     pa_assert(i);
1024
1025     pa_mutex_lock(i->mutex);
1026
1027     if (!(b = pa_hashmap_get(i->blocks, PA_UINT32_TO_PTR(id)))) {
1028         ret = -1;
1029         goto finish;
1030     }
1031
1032     memblock_replace_import(b);
1033
1034 finish:
1035     pa_mutex_unlock(i->mutex);
1036
1037     return ret;
1038 }
1039
1040 /* For sending blocks to other nodes */
1041 pa_memexport* pa_memexport_new(pa_mempool *p, pa_memexport_revoke_cb_t cb, void *userdata) {
1042     pa_memexport *e;
1043
1044     pa_assert(p);
1045     pa_assert(cb);
1046
1047     if (!p->memory.shared)
1048         return NULL;
1049
1050     e = pa_xnew(pa_memexport, 1);
1051     e->mutex = pa_mutex_new(TRUE, TRUE);
1052     e->pool = p;
1053     PA_LLIST_HEAD_INIT(struct memexport_slot, e->free_slots);
1054     PA_LLIST_HEAD_INIT(struct memexport_slot, e->used_slots);
1055     e->n_init = 0;
1056     e->revoke_cb = cb;
1057     e->userdata = userdata;
1058
1059     pa_mutex_lock(p->mutex);
1060     PA_LLIST_PREPEND(pa_memexport, p->exports, e);
1061     pa_mutex_unlock(p->mutex);
1062     return e;
1063 }
1064
1065 void pa_memexport_free(pa_memexport *e) {
1066     pa_assert(e);
1067
1068     pa_mutex_lock(e->mutex);
1069     while (e->used_slots)
1070         pa_memexport_process_release(e, (uint32_t) (e->used_slots - e->slots));
1071     pa_mutex_unlock(e->mutex);
1072
1073     pa_mutex_lock(e->pool->mutex);
1074     PA_LLIST_REMOVE(pa_memexport, e->pool->exports, e);
1075     pa_mutex_unlock(e->pool->mutex);
1076
1077     pa_mutex_free(e->mutex);
1078     pa_xfree(e);
1079 }
1080
1081 /* Self-locked */
1082 int pa_memexport_process_release(pa_memexport *e, uint32_t id) {
1083     pa_memblock *b;
1084
1085     pa_assert(e);
1086
1087     pa_mutex_lock(e->mutex);
1088
1089     if (id >= e->n_init)
1090         goto fail;
1091
1092     if (!e->slots[id].block)
1093         goto fail;
1094
1095     b = e->slots[id].block;
1096     e->slots[id].block = NULL;
1097
1098     PA_LLIST_REMOVE(struct memexport_slot, e->used_slots, &e->slots[id]);
1099     PA_LLIST_PREPEND(struct memexport_slot, e->free_slots, &e->slots[id]);
1100
1101     pa_mutex_unlock(e->mutex);
1102
1103 /*     pa_log("Processing release for %u", id); */
1104
1105     pa_assert(pa_atomic_load(&e->pool->stat.n_exported) > 0);
1106     pa_assert(pa_atomic_load(&e->pool->stat.exported_size) >= (int) b->length);
1107
1108     pa_atomic_dec(&e->pool->stat.n_exported);
1109     pa_atomic_sub(&e->pool->stat.exported_size, (int) b->length);
1110
1111     pa_memblock_unref(b);
1112
1113     return 0;
1114
1115 fail:
1116     pa_mutex_unlock(e->mutex);
1117
1118     return -1;
1119 }
1120
1121 /* Self-locked */
1122 static void memexport_revoke_blocks(pa_memexport *e, pa_memimport *i) {
1123     struct memexport_slot *slot, *next;
1124     pa_assert(e);
1125     pa_assert(i);
1126
1127     pa_mutex_lock(e->mutex);
1128
1129     for (slot = e->used_slots; slot; slot = next) {
1130         uint32_t idx;
1131         next = slot->next;
1132
1133         if (slot->block->type != PA_MEMBLOCK_IMPORTED ||
1134             slot->block->per_type.imported.segment->import != i)
1135             continue;
1136
1137         idx = (uint32_t) (slot - e->slots);
1138         e->revoke_cb(e, idx, e->userdata);
1139         pa_memexport_process_release(e, idx);
1140     }
1141
1142     pa_mutex_unlock(e->mutex);
1143 }
1144
1145 /* No lock necessary */
1146 static pa_memblock *memblock_shared_copy(pa_mempool *p, pa_memblock *b) {
1147     pa_memblock *n;
1148
1149     pa_assert(p);
1150     pa_assert(b);
1151
1152     if (b->type == PA_MEMBLOCK_IMPORTED ||
1153         b->type == PA_MEMBLOCK_POOL ||
1154         b->type == PA_MEMBLOCK_POOL_EXTERNAL) {
1155         pa_assert(b->pool == p);
1156         return pa_memblock_ref(b);
1157     }
1158
1159     if (!(n = pa_memblock_new_pool(p, b->length)))
1160         return NULL;
1161
1162     memcpy(pa_atomic_ptr_load(&n->data), pa_atomic_ptr_load(&b->data), b->length);
1163     return n;
1164 }
1165
1166 /* Self-locked */
1167 int pa_memexport_put(pa_memexport *e, pa_memblock *b, uint32_t *block_id, uint32_t *shm_id, size_t *offset, size_t * size) {
1168     pa_shm *memory;
1169     struct memexport_slot *slot;
1170     void *data;
1171
1172     pa_assert(e);
1173     pa_assert(b);
1174     pa_assert(block_id);
1175     pa_assert(shm_id);
1176     pa_assert(offset);
1177     pa_assert(size);
1178     pa_assert(b->pool == e->pool);
1179
1180     if (!(b = memblock_shared_copy(e->pool, b)))
1181         return -1;
1182
1183     pa_mutex_lock(e->mutex);
1184
1185     if (e->free_slots) {
1186         slot = e->free_slots;
1187         PA_LLIST_REMOVE(struct memexport_slot, e->free_slots, slot);
1188     } else if (e->n_init < PA_MEMEXPORT_SLOTS_MAX)
1189         slot = &e->slots[e->n_init++];
1190     else {
1191         pa_mutex_unlock(e->mutex);
1192         pa_memblock_unref(b);
1193         return -1;
1194     }
1195
1196     PA_LLIST_PREPEND(struct memexport_slot, e->used_slots, slot);
1197     slot->block = b;
1198     *block_id = (uint32_t) (slot - e->slots);
1199
1200     pa_mutex_unlock(e->mutex);
1201 /*     pa_log("Got block id %u", *block_id); */
1202
1203     data = pa_memblock_acquire(b);
1204
1205     if (b->type == PA_MEMBLOCK_IMPORTED) {
1206         pa_assert(b->per_type.imported.segment);
1207         memory = &b->per_type.imported.segment->memory;
1208     } else {
1209         pa_assert(b->type == PA_MEMBLOCK_POOL || b->type == PA_MEMBLOCK_POOL_EXTERNAL);
1210         pa_assert(b->pool);
1211         memory = &b->pool->memory;
1212     }
1213
1214     pa_assert(data >= memory->ptr);
1215     pa_assert((uint8_t*) data + b->length <= (uint8_t*) memory->ptr + memory->size);
1216
1217     *shm_id = memory->id;
1218     *offset = (size_t) ((uint8_t*) data - (uint8_t*) memory->ptr);
1219     *size = b->length;
1220
1221     pa_memblock_release(b);
1222
1223     pa_atomic_inc(&e->pool->stat.n_exported);
1224     pa_atomic_add(&e->pool->stat.exported_size, (int) b->length);
1225
1226     return 0;
1227 }