summaryrefslogtreecommitdiff
path: root/gst/gstallocator.c
blob: c6763e1c2898f065d6d72e1eb0624a3e581c2a31 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
/* GStreamer
 * Copyright (C) 2011 Wim Taymans <wim.taymans@gmail.be>
 *
 * gstallocator.c: memory block allocator
 *
 * This library is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Library General Public
 * License as published by the Free Software Foundation; either
 * version 2 of the License, or (at your option) any later version.
 *
 * This library is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * Library General Public License for more details.
 *
 * You should have received a copy of the GNU Library General Public
 * License along with this library; if not, write to the
 * Free Software Foundation, Inc., 51 Franklin St, Fifth Floor,
 * Boston, MA 02110-1301, USA.
 */

/**
 * SECTION:gstallocator
 * @short_description: allocate memory blocks
 * @see_also: #GstMemory
 *
 * Memory is usually created by allocators with a gst_allocator_alloc()
 * method call. When %NULL is used as the allocator, the default allocator will
 * be used.
 *
 * New allocators can be registered with gst_allocator_register().
 * Allocators are identified by name and can be retrieved with
 * gst_allocator_find(). gst_allocator_set_default() can be used to change the
 * default allocator.
 *
 * New memory can be created with gst_memory_new_wrapped() that wraps the memory
 * allocated elsewhere.
 */

#ifdef HAVE_CONFIG_H
#include "config.h"
#endif

#include "gst_private.h"
#include "gstmemory.h"

GST_DEBUG_CATEGORY_STATIC (gst_allocator_debug);
#define GST_CAT_DEFAULT gst_allocator_debug

#define GST_ALLOCATOR_GET_PRIVATE(obj)  \
     (G_TYPE_INSTANCE_GET_PRIVATE ((obj), GST_TYPE_ALLOCATOR, GstAllocatorPrivate))

struct _GstAllocatorPrivate
{
  gpointer dummy;
};

#if defined(MEMORY_ALIGNMENT_MALLOC)
gsize gst_memory_alignment = 7;
#elif defined(MEMORY_ALIGNMENT_PAGESIZE)
/* we fill this in in the _init method */
gsize gst_memory_alignment = 0;
#elif defined(MEMORY_ALIGNMENT)
gsize gst_memory_alignment = MEMORY_ALIGNMENT - 1;
#else
#error "No memory alignment configured"
gsize gst_memory_alignment = 0;
#endif

/* the default allocator */
static GstAllocator *_default_allocator;

static GstAllocator *_sysmem_allocator;

/* registered allocators */
static GRWLock lock;
static GHashTable *allocators;

G_DEFINE_ABSTRACT_TYPE (GstAllocator, gst_allocator, GST_TYPE_OBJECT);

static void
gst_allocator_class_init (GstAllocatorClass * klass)
{
  g_type_class_add_private (klass, sizeof (GstAllocatorPrivate));

  GST_DEBUG_CATEGORY_INIT (gst_allocator_debug, "allocator", 0,
      "allocator debug");
}

static GstMemory *
_fallback_mem_copy (GstMemory * mem, gssize offset, gssize size)
{
  GstMemory *copy;
  GstMapInfo sinfo, dinfo;
  GstAllocationParams params = { 0, mem->align, 0, 0, };
  GstAllocator *allocator;

  if (!gst_memory_map (mem, &sinfo, GST_MAP_READ))
    return NULL;

  if (size == -1)
    size = sinfo.size > offset ? sinfo.size - offset : 0;

  /* use the same allocator as the memory we copy  */
  allocator = mem->allocator;
  if (GST_OBJECT_FLAG_IS_SET (allocator, GST_ALLOCATOR_FLAG_CUSTOM_ALLOC))
    allocator = NULL;
  copy = gst_allocator_alloc (allocator, size, &params);

  if (!gst_memory_map (copy, &dinfo, GST_MAP_WRITE)) {
    GST_CAT_WARNING (GST_CAT_MEMORY, "could not write map memory %p", copy);
    gst_allocator_free (mem->allocator, copy);
    gst_memory_unmap (mem, &sinfo);
    return NULL;
  }

  GST_CAT_DEBUG (GST_CAT_PERFORMANCE,
      "memcpy %" G_GSSIZE_FORMAT " memory %p -> %p", size, mem, copy);
  memcpy (dinfo.data, sinfo.data + offset, size);
  gst_memory_unmap (copy, &dinfo);
  gst_memory_unmap (mem, &sinfo);

  return copy;
}

static gboolean
_fallback_mem_is_span (GstMemory * mem1, GstMemory * mem2, gsize * offset)
{
  return FALSE;
}

static void
gst_allocator_init (GstAllocator * allocator)
{
  allocator->priv = GST_ALLOCATOR_GET_PRIVATE (allocator);

  allocator->mem_copy = _fallback_mem_copy;
  allocator->mem_is_span = _fallback_mem_is_span;
}

G_DEFINE_BOXED_TYPE (GstAllocationParams, gst_allocation_params,
    (GBoxedCopyFunc) gst_allocation_params_copy,
    (GBoxedFreeFunc) gst_allocation_params_free);

/**
 * gst_allocation_params_init:
 * @params: a #GstAllocationParams
 *
 * Initialize @params to its default values
 */
void
gst_allocation_params_init (GstAllocationParams * params)
{
  g_return_if_fail (params != NULL);

  memset (params, 0, sizeof (GstAllocationParams));
}

/**
 * gst_allocation_params_copy:
 * @params: (transfer none): a #GstAllocationParams
 *
 * Create a copy of @params.
 *
 * Free-function: gst_allocation_params_free
 *
 * Returns: (transfer full): a new ##GstAllocationParams, free with
 * gst_allocation_params_free().
 */
GstAllocationParams *
gst_allocation_params_copy (const GstAllocationParams * params)
{
  GstAllocationParams *result = NULL;

  if (params) {
    result =
        (GstAllocationParams *) g_slice_copy (sizeof (GstAllocationParams),
        params);
  }
  return result;
}

/**
 * gst_allocation_params_free:
 * @params: (in) (transfer full): a #GstAllocationParams
 *
 * Free @params
 */
void
gst_allocation_params_free (GstAllocationParams * params)
{
  g_slice_free (GstAllocationParams, params);
}

/**
 * gst_allocator_register:
 * @name: the name of the allocator
 * @allocator: (transfer full): #GstAllocator
 *
 * Registers the memory @allocator with @name. This function takes ownership of
 * @allocator.
 */
void
gst_allocator_register (const gchar * name, GstAllocator * allocator)
{
  g_return_if_fail (name != NULL);
  g_return_if_fail (allocator != NULL);

  GST_CAT_DEBUG (GST_CAT_MEMORY, "registering allocator %p with name \"%s\"",
      allocator, name);

  g_rw_lock_writer_lock (&lock);
  g_hash_table_insert (allocators, (gpointer) name, (gpointer) allocator);
  g_rw_lock_writer_unlock (&lock);
}

/**
 * gst_allocator_find:
 * @name: (allow-none): the name of the allocator
 *
 * Find a previously registered allocator with @name. When @name is %NULL, the
 * default allocator will be returned.
 *
 * Returns: (transfer full) (nullable): a #GstAllocator or %NULL when
 * the allocator with @name was not registered. Use gst_object_unref()
 * to release the allocator after usage.
 */
GstAllocator *
gst_allocator_find (const gchar * name)
{
  GstAllocator *allocator;

  g_rw_lock_reader_lock (&lock);
  if (name) {
    allocator = g_hash_table_lookup (allocators, (gconstpointer) name);
  } else {
    allocator = _default_allocator;
  }
  if (allocator)
    gst_object_ref (allocator);
  g_rw_lock_reader_unlock (&lock);

  return allocator;
}

/**
 * gst_allocator_set_default:
 * @allocator: (transfer full): a #GstAllocator
 *
 * Set the default allocator. This function takes ownership of @allocator.
 */
void
gst_allocator_set_default (GstAllocator * allocator)
{
  GstAllocator *old;

  g_return_if_fail (GST_IS_ALLOCATOR (allocator));

  g_rw_lock_writer_lock (&lock);
  old = _default_allocator;
  _default_allocator = allocator;
  g_rw_lock_writer_unlock (&lock);

  if (old)
    gst_object_unref (old);
}

/**
 * gst_allocator_alloc:
 * @allocator: (transfer none) (allow-none): a #GstAllocator to use
 * @size: size of the visible memory area
 * @params: (transfer none) (allow-none): optional parameters
 *
 * Use @allocator to allocate a new memory block with memory that is at least
 * @size big.
 *
 * The optional @params can specify the prefix and padding for the memory. If
 * %NULL is passed, no flags, no extra prefix/padding and a default alignment is
 * used.
 *
 * The prefix/padding will be filled with 0 if flags contains
 * #GST_MEMORY_FLAG_ZERO_PREFIXED and #GST_MEMORY_FLAG_ZERO_PADDED respectively.
 *
 * When @allocator is %NULL, the default allocator will be used.
 *
 * The alignment in @params is given as a bitmask so that @align + 1 equals
 * the amount of bytes to align to. For example, to align to 8 bytes,
 * use an alignment of 7.
 *
 * Returns: (transfer full): a new #GstMemory.
 */
GstMemory *
gst_allocator_alloc (GstAllocator * allocator, gsize size,
    GstAllocationParams * params)
{
  GstMemory *mem;
  static GstAllocationParams defparams = { 0, 0, 0, 0, };
  GstAllocatorClass *aclass;

  if (params) {
    g_return_val_if_fail (((params->align + 1) & params->align) == 0, NULL);
  } else {
    params = &defparams;
  }

  if (allocator == NULL)
    allocator = _default_allocator;

  aclass = GST_ALLOCATOR_GET_CLASS (allocator);
  if (aclass->alloc)
    mem = aclass->alloc (allocator, size, params);
  else
    mem = NULL;

  return mem;
}

/**
 * gst_allocator_free:
 * @allocator: (transfer none): a #GstAllocator to use
 * @memory: (transfer full): the memory to free
 *
 * Free @memory that was previously allocated with gst_allocator_alloc().
 */
void
gst_allocator_free (GstAllocator * allocator, GstMemory * memory)
{
  GstAllocatorClass *aclass;

  g_return_if_fail (GST_IS_ALLOCATOR (allocator));
  g_return_if_fail (memory != NULL);
  g_return_if_fail (memory->allocator == allocator);

  aclass = GST_ALLOCATOR_GET_CLASS (allocator);
  if (aclass->free)
    aclass->free (allocator, memory);
}

/* default memory implementation */
typedef struct
{
  GstMemory mem;

  gsize slice_size;
  guint8 *data;

  gpointer user_data;
  GDestroyNotify notify;
} GstMemorySystem;

typedef struct
{
  GstAllocator parent;
} GstAllocatorSysmem;

typedef struct
{
  GstAllocatorClass parent_class;
} GstAllocatorSysmemClass;

GType gst_allocator_sysmem_get_type (void);
G_DEFINE_TYPE (GstAllocatorSysmem, gst_allocator_sysmem, GST_TYPE_ALLOCATOR);

/* initialize the fields */
static inline void
_sysmem_init (GstMemorySystem * mem, GstMemoryFlags flags,
    GstMemory * parent, gsize slice_size,
    gpointer data, gsize maxsize, gsize align, gsize offset, gsize size,
    gpointer user_data, GDestroyNotify notify)
{
  gst_memory_init (GST_MEMORY_CAST (mem),
      flags, _sysmem_allocator, parent, maxsize, align, offset, size);

  mem->slice_size = slice_size;
  mem->data = data;
  mem->user_data = user_data;
  mem->notify = notify;
}

/* create a new memory block that manages the given memory */
static inline GstMemorySystem *
_sysmem_new (GstMemoryFlags flags,
    GstMemory * parent, gpointer data, gsize maxsize, gsize align, gsize offset,
    gsize size, gpointer user_data, GDestroyNotify notify)
{
  GstMemorySystem *mem;
  gsize slice_size;

  slice_size = sizeof (GstMemorySystem);

  mem = g_slice_alloc (slice_size);
  _sysmem_init (mem, flags, parent, slice_size,
      data, maxsize, align, offset, size, user_data, notify);

  return mem;
}

/* allocate the memory and structure in one block */
static GstMemorySystem *
_sysmem_new_block (GstMemoryFlags flags,
    gsize maxsize, gsize align, gsize offset, gsize size)
{
  GstMemorySystem *mem;
  gsize aoffset, slice_size, padding;
  guint8 *data;

  /* ensure configured alignment */
  align |= gst_memory_alignment;
  /* allocate more to compensate for alignment */
  maxsize += align;
  /* alloc header and data in one block */
  slice_size = sizeof (GstMemorySystem) + maxsize;

  mem = g_slice_alloc (slice_size);
  if (mem == NULL)
    return NULL;

  data = (guint8 *) mem + sizeof (GstMemorySystem);

  /* do alignment */
  if ((aoffset = ((guintptr) data & align))) {
    aoffset = (align + 1) - aoffset;
    data += aoffset;
    maxsize -= aoffset;
  }

  if (offset && (flags & GST_MEMORY_FLAG_ZERO_PREFIXED))
    memset (data, 0, offset);

  padding = maxsize - (offset + size);
  if (padding && (flags & GST_MEMORY_FLAG_ZERO_PADDED))
    memset (data + offset + size, 0, padding);

  _sysmem_init (mem, flags, NULL, slice_size, data, maxsize,
      align, offset, size, NULL, NULL);

  return mem;
}

static gpointer
_sysmem_map (GstMemorySystem * mem, gsize maxsize, GstMapFlags flags)
{
  return mem->data;
}

static gboolean
_sysmem_unmap (GstMemorySystem * mem)
{
  return TRUE;
}

static GstMemorySystem *
_sysmem_copy (GstMemorySystem * mem, gssize offset, gsize size)
{
  GstMemorySystem *copy;

  if (size == -1)
    size = mem->mem.size > offset ? mem->mem.size - offset : 0;

  copy = _sysmem_new_block (0, size, mem->mem.align, 0, size);
  GST_CAT_DEBUG (GST_CAT_PERFORMANCE,
      "memcpy %" G_GSIZE_FORMAT " memory %p -> %p", size, mem, copy);
  memcpy (copy->data, mem->data + mem->mem.offset + offset, size);

  return copy;
}

static GstMemorySystem *
_sysmem_share (GstMemorySystem * mem, gssize offset, gsize size)
{
  GstMemorySystem *sub;
  GstMemory *parent;

  /* find the real parent */
  if ((parent = mem->mem.parent) == NULL)
    parent = (GstMemory *) mem;

  if (size == -1)
    size = mem->mem.size - offset;

  /* the shared memory is always readonly */
  sub =
      _sysmem_new (GST_MINI_OBJECT_FLAGS (parent) |
      GST_MINI_OBJECT_FLAG_LOCK_READONLY, parent, mem->data, mem->mem.maxsize,
      mem->mem.align, mem->mem.offset + offset, size, NULL, NULL);

  return sub;
}

static gboolean
_sysmem_is_span (GstMemorySystem * mem1, GstMemorySystem * mem2, gsize * offset)
{

  if (offset) {
    GstMemorySystem *parent;

    parent = (GstMemorySystem *) mem1->mem.parent;

    *offset = mem1->mem.offset - parent->mem.offset;
  }

  /* and memory is contiguous */
  return mem1->data + mem1->mem.offset + mem1->mem.size ==
      mem2->data + mem2->mem.offset;
}

static GstMemory *
default_alloc (GstAllocator * allocator, gsize size,
    GstAllocationParams * params)
{
  gsize maxsize = size + params->prefix + params->padding;

  return (GstMemory *) _sysmem_new_block (params->flags,
      maxsize, params->align, params->prefix, size);
}

static void
default_free (GstAllocator * allocator, GstMemory * mem)
{
  GstMemorySystem *dmem = (GstMemorySystem *) mem;
  gsize slice_size;

  if (dmem->notify)
    dmem->notify (dmem->user_data);

  slice_size = dmem->slice_size;

#ifdef USE_POISONING
  /* just poison the structs, not all the data */
  memset (mem, 0xff, sizeof (GstMemorySystem));
#endif

  g_slice_free1 (slice_size, mem);
}

static void
gst_allocator_sysmem_finalize (GObject * obj)
{
  g_warning ("The default memory allocator was freed!");
}

static void
gst_allocator_sysmem_class_init (GstAllocatorSysmemClass * klass)
{
  GObjectClass *gobject_class;
  GstAllocatorClass *allocator_class;

  gobject_class = (GObjectClass *) klass;
  allocator_class = (GstAllocatorClass *) klass;

  gobject_class->finalize = gst_allocator_sysmem_finalize;

  allocator_class->alloc = default_alloc;
  allocator_class->free = default_free;
}

static void
gst_allocator_sysmem_init (GstAllocatorSysmem * allocator)
{
  GstAllocator *alloc = GST_ALLOCATOR_CAST (allocator);

  GST_CAT_DEBUG (GST_CAT_MEMORY, "init allocator %p", allocator);

  alloc->mem_type = GST_ALLOCATOR_SYSMEM;
  alloc->mem_map = (GstMemoryMapFunction) _sysmem_map;
  alloc->mem_unmap = (GstMemoryUnmapFunction) _sysmem_unmap;
  alloc->mem_copy = (GstMemoryCopyFunction) _sysmem_copy;
  alloc->mem_share = (GstMemoryShareFunction) _sysmem_share;
  alloc->mem_is_span = (GstMemoryIsSpanFunction) _sysmem_is_span;
}

void
_priv_gst_allocator_initialize (void)
{
  g_rw_lock_init (&lock);
  allocators = g_hash_table_new (g_str_hash, g_str_equal);

#ifdef HAVE_GETPAGESIZE
#ifdef MEMORY_ALIGNMENT_PAGESIZE
  gst_memory_alignment = getpagesize () - 1;
#endif
#endif

  GST_CAT_DEBUG (GST_CAT_MEMORY, "memory alignment: %" G_GSIZE_FORMAT,
      gst_memory_alignment);

  _sysmem_allocator = g_object_new (gst_allocator_sysmem_get_type (), NULL);

  gst_allocator_register (GST_ALLOCATOR_SYSMEM,
      gst_object_ref (_sysmem_allocator));

  _default_allocator = gst_object_ref (_sysmem_allocator);
}

/**
 * gst_memory_new_wrapped:
 * @flags: #GstMemoryFlags
 * @data: (array length=size) (element-type guint8) (transfer none): data to
 *   wrap
 * @maxsize: allocated size of @data
 * @offset: offset in @data
 * @size: size of valid data
 * @user_data: (allow-none): user_data
 * @notify: (allow-none) (scope async) (closure user_data): called with @user_data when the memory is freed
 *
 * Allocate a new memory block that wraps the given @data.
 *
 * The prefix/padding must be filled with 0 if @flags contains
 * #GST_MEMORY_FLAG_ZERO_PREFIXED and #GST_MEMORY_FLAG_ZERO_PADDED respectively.
 *
 * Returns: (transfer full): a new #GstMemory.
 */
GstMemory *
gst_memory_new_wrapped (GstMemoryFlags flags, gpointer data,
    gsize maxsize, gsize offset, gsize size, gpointer user_data,
    GDestroyNotify notify)
{
  GstMemorySystem *mem;

  g_return_val_if_fail (data != NULL, NULL);
  g_return_val_if_fail (offset + size <= maxsize, NULL);

  mem =
      _sysmem_new (flags, NULL, data, maxsize, 0, offset, size, user_data,
      notify);

  return (GstMemory *) mem;
}