1 /* GStreamer
2 * Copyright (C) 2011 Wim Taymans <wim.taymans@gmail.be>
3 *
4 * gstallocator.c: memory block allocator
5 *
6 * This library is free software; you can redistribute it and/or
7 * modify it under the terms of the GNU Library General Public
8 * License as published by the Free Software Foundation; either
9 * version 2 of the License, or (at your option) any later version.
10 *
11 * This library is distributed in the hope that it will be useful,
12 * but WITHOUT ANY WARRANTY; without even the implied warranty of
13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
14 * Library General Public License for more details.
15 *
16 * You should have received a copy of the GNU Library General Public
17 * License along with this library; if not, write to the
18 * Free Software Foundation, Inc., 51 Franklin St, Fifth Floor,
19 * Boston, MA 02110-1301, USA.
20 */
21
22 /**
23 * SECTION:gstallocator
24 * @short_description: allocate memory blocks
25 * @see_also: #GstMemory
26 *
27 * Memory is usually created by allocators with a gst_allocator_alloc()
28 * method call. When %NULL is used as the allocator, the default allocator will
29 * be used.
30 *
31 * New allocators can be registered with gst_allocator_register().
32 * Allocators are identified by name and can be retrieved with
33 * gst_allocator_find(). gst_allocator_set_default() can be used to change the
34 * default allocator.
35 *
36 * New memory can be created with gst_memory_new_wrapped() that wraps the memory
37 * allocated elsewhere.
38 */
39
40 #ifdef HAVE_CONFIG_H
41 #include "config.h"
42 #endif
43
44 #include "gst_private.h"
45 #include "gstmemory.h"
46
47 GST_DEBUG_CATEGORY_STATIC (gst_allocator_debug);
48 #define GST_CAT_DEFAULT gst_allocator_debug
49
50 #define GST_ALLOCATOR_GET_PRIVATE(obj) \
51 (G_TYPE_INSTANCE_GET_PRIVATE ((obj), GST_TYPE_ALLOCATOR, GstAllocatorPrivate))
52
53 struct _GstAllocatorPrivate
54 {
55 gpointer dummy;
56 };
57
58 #ifdef GSTREAMER_LITE
59 // In GStLite we require to have memory aligned to 16 bytes for RAW video.
60 // For now lets have all memory 16 bytes aligned.
61 gsize gst_memory_alignment = 15;
62 #else // GSTREAMER_LITE
63 #if defined(MEMORY_ALIGNMENT_MALLOC)
64 gsize gst_memory_alignment = 7;
65 #elif defined(MEMORY_ALIGNMENT_PAGESIZE)
66 /* we fill this in in the _init method */
67 gsize gst_memory_alignment = 0;
68 #elif defined(MEMORY_ALIGNMENT)
69 gsize gst_memory_alignment = MEMORY_ALIGNMENT - 1;
70 #else
71 #error "No memory alignment configured"
72 gsize gst_memory_alignment = 0;
73 #endif
74 #endif // GSTREAMER_LITE
75
76 /* the default allocator */
77 static GstAllocator *_default_allocator;
78
79 static GstAllocator *_sysmem_allocator;
80
81 /* registered allocators */
82 static GRWLock lock;
83 static GHashTable *allocators;
84
85 G_DEFINE_ABSTRACT_TYPE (GstAllocator, gst_allocator, GST_TYPE_OBJECT);
86
87 static void
88 gst_allocator_class_init (GstAllocatorClass * klass)
89 {
90 g_type_class_add_private (klass, sizeof (GstAllocatorPrivate));
91
92 GST_DEBUG_CATEGORY_INIT (gst_allocator_debug, "allocator", 0,
93 "allocator debug");
94 }
95
96 static GstMemory *
97 _fallback_mem_copy (GstMemory * mem, gssize offset, gssize size)
98 {
99 GstMemory *copy;
100 GstMapInfo sinfo, dinfo;
101 GstAllocationParams params = { 0, mem->align, 0, 0, };
102 GstAllocator *allocator;
103
104 if (!gst_memory_map (mem, &sinfo, GST_MAP_READ))
105 return NULL;
106
107 if (size == -1)
108 size = sinfo.size > offset ? sinfo.size - offset : 0;
109
110 /* use the same allocator as the memory we copy */
111 allocator = mem->allocator;
112 if (GST_OBJECT_FLAG_IS_SET (allocator, GST_ALLOCATOR_FLAG_CUSTOM_ALLOC))
113 allocator = NULL;
114 copy = gst_allocator_alloc (allocator, size, ¶ms);
115
116 if (!gst_memory_map (copy, &dinfo, GST_MAP_WRITE)) {
117 GST_CAT_WARNING (GST_CAT_MEMORY, "could not write map memory %p", copy);
118 gst_allocator_free (mem->allocator, copy);
119 gst_memory_unmap (mem, &sinfo);
120 return NULL;
121 }
122
123 GST_CAT_DEBUG (GST_CAT_PERFORMANCE,
124 "memcpy %" G_GSSIZE_FORMAT " memory %p -> %p", size, mem, copy);
125 memcpy (dinfo.data, sinfo.data + offset, size);
126 gst_memory_unmap (copy, &dinfo);
127 gst_memory_unmap (mem, &sinfo);
128
129 return copy;
130 }
131
132 static gboolean
133 _fallback_mem_is_span (GstMemory * mem1, GstMemory * mem2, gsize * offset)
134 {
135 return FALSE;
136 }
137
138 static void
139 gst_allocator_init (GstAllocator * allocator)
140 {
141 allocator->priv = GST_ALLOCATOR_GET_PRIVATE (allocator);
142
143 allocator->mem_copy = _fallback_mem_copy;
144 allocator->mem_is_span = _fallback_mem_is_span;
145 }
146
147 G_DEFINE_BOXED_TYPE (GstAllocationParams, gst_allocation_params,
148 (GBoxedCopyFunc) gst_allocation_params_copy,
149 (GBoxedFreeFunc) gst_allocation_params_free);
150
151 /**
152 * gst_allocation_params_init:
153 * @params: a #GstAllocationParams
154 *
155 * Initialize @params to its default values
156 */
157 void
158 gst_allocation_params_init (GstAllocationParams * params)
159 {
160 g_return_if_fail (params != NULL);
161
162 memset (params, 0, sizeof (GstAllocationParams));
163 }
164
165 /**
166 * gst_allocation_params_copy:
167 * @params: (transfer none): a #GstAllocationParams
168 *
169 * Create a copy of @params.
170 *
171 * Free-function: gst_allocation_params_free
172 *
173 * Returns: (transfer full): a new ##GstAllocationParams, free with
174 * gst_allocation_params_free().
175 */
176 GstAllocationParams *
177 gst_allocation_params_copy (const GstAllocationParams * params)
178 {
179 GstAllocationParams *result = NULL;
180
181 if (params) {
182 result =
183 (GstAllocationParams *) g_slice_copy (sizeof (GstAllocationParams),
184 params);
185 }
186 return result;
187 }
188
189 /**
190 * gst_allocation_params_free:
191 * @params: (in) (transfer full): a #GstAllocationParams
192 *
193 * Free @params
194 */
195 void
196 gst_allocation_params_free (GstAllocationParams * params)
197 {
198 g_slice_free (GstAllocationParams, params);
199 }
200
201 /**
202 * gst_allocator_register:
203 * @name: the name of the allocator
204 * @allocator: (transfer full): #GstAllocator
205 *
206 * Registers the memory @allocator with @name. This function takes ownership of
207 * @allocator.
208 */
209 void
210 gst_allocator_register (const gchar * name, GstAllocator * allocator)
211 {
212 g_return_if_fail (name != NULL);
213 g_return_if_fail (allocator != NULL);
214
215 GST_CAT_DEBUG (GST_CAT_MEMORY, "registering allocator %p with name \"%s\"",
216 allocator, name);
217
218 g_rw_lock_writer_lock (&lock);
219 g_hash_table_insert (allocators, (gpointer) name, (gpointer) allocator);
220 g_rw_lock_writer_unlock (&lock);
221 }
222
223 /**
224 * gst_allocator_find:
225 * @name: (allow-none): the name of the allocator
226 *
227 * Find a previously registered allocator with @name. When @name is %NULL, the
228 * default allocator will be returned.
229 *
230 * Returns: (transfer full) (nullable): a #GstAllocator or %NULL when
231 * the allocator with @name was not registered. Use gst_object_unref()
232 * to release the allocator after usage.
233 */
234 GstAllocator *
235 gst_allocator_find (const gchar * name)
236 {
237 GstAllocator *allocator;
238
239 g_rw_lock_reader_lock (&lock);
240 if (name) {
241 allocator = g_hash_table_lookup (allocators, (gconstpointer) name);
242 } else {
243 allocator = _default_allocator;
244 }
245 if (allocator)
246 gst_object_ref (allocator);
247 g_rw_lock_reader_unlock (&lock);
248
249 return allocator;
250 }
251
252 /**
253 * gst_allocator_set_default:
254 * @allocator: (transfer full): a #GstAllocator
255 *
256 * Set the default allocator. This function takes ownership of @allocator.
257 */
258 void
259 gst_allocator_set_default (GstAllocator * allocator)
260 {
261 GstAllocator *old;
262
263 g_return_if_fail (GST_IS_ALLOCATOR (allocator));
264
265 g_rw_lock_writer_lock (&lock);
266 old = _default_allocator;
267 _default_allocator = allocator;
268 g_rw_lock_writer_unlock (&lock);
269
270 if (old)
271 gst_object_unref (old);
272 }
273
274 /**
275 * gst_allocator_alloc:
276 * @allocator: (transfer none) (allow-none): a #GstAllocator to use
277 * @size: size of the visible memory area
278 * @params: (transfer none) (allow-none): optional parameters
279 *
280 * Use @allocator to allocate a new memory block with memory that is at least
281 * @size big.
282 *
283 * The optional @params can specify the prefix and padding for the memory. If
284 * %NULL is passed, no flags, no extra prefix/padding and a default alignment is
285 * used.
286 *
287 * The prefix/padding will be filled with 0 if flags contains
288 * #GST_MEMORY_FLAG_ZERO_PREFIXED and #GST_MEMORY_FLAG_ZERO_PADDED respectively.
289 *
290 * When @allocator is %NULL, the default allocator will be used.
291 *
292 * The alignment in @params is given as a bitmask so that @align + 1 equals
293 * the amount of bytes to align to. For example, to align to 8 bytes,
294 * use an alignment of 7.
295 *
296 * Returns: (transfer full): a new #GstMemory.
297 */
298 GstMemory *
299 gst_allocator_alloc (GstAllocator * allocator, gsize size,
300 GstAllocationParams * params)
301 {
302 GstMemory *mem;
303 static GstAllocationParams defparams = { 0, 0, 0, 0, };
304 GstAllocatorClass *aclass;
305
306 if (params) {
307 g_return_val_if_fail (((params->align + 1) & params->align) == 0, NULL);
308 } else {
309 params = &defparams;
310 }
311
312 if (allocator == NULL)
313 allocator = _default_allocator;
314
315 aclass = GST_ALLOCATOR_GET_CLASS (allocator);
316 if (aclass->alloc)
317 mem = aclass->alloc (allocator, size, params);
318 else
319 mem = NULL;
320
321 return mem;
322 }
323
324 /**
325 * gst_allocator_free:
326 * @allocator: (transfer none): a #GstAllocator to use
327 * @memory: (transfer full): the memory to free
328 *
329 * Free @memory that was previously allocated with gst_allocator_alloc().
330 */
331 void
332 gst_allocator_free (GstAllocator * allocator, GstMemory * memory)
333 {
334 GstAllocatorClass *aclass;
335
336 g_return_if_fail (GST_IS_ALLOCATOR (allocator));
337 g_return_if_fail (memory != NULL);
338 g_return_if_fail (memory->allocator == allocator);
339
340 aclass = GST_ALLOCATOR_GET_CLASS (allocator);
341 if (aclass->free)
342 aclass->free (allocator, memory);
343 }
344
345 /* default memory implementation */
346 typedef struct
347 {
348 GstMemory mem;
349
350 gsize slice_size;
351 guint8 *data;
352
353 gpointer user_data;
354 GDestroyNotify notify;
355 } GstMemorySystem;
356
357 typedef struct
358 {
359 GstAllocator parent;
360 } GstAllocatorSysmem;
361
362 typedef struct
363 {
364 GstAllocatorClass parent_class;
365 } GstAllocatorSysmemClass;
366
367 GType gst_allocator_sysmem_get_type (void);
368 G_DEFINE_TYPE (GstAllocatorSysmem, gst_allocator_sysmem, GST_TYPE_ALLOCATOR);
369
370 /* initialize the fields */
371 static inline void
372 _sysmem_init (GstMemorySystem * mem, GstMemoryFlags flags,
373 GstMemory * parent, gsize slice_size,
374 gpointer data, gsize maxsize, gsize align, gsize offset, gsize size,
375 gpointer user_data, GDestroyNotify notify)
376 {
377 gst_memory_init (GST_MEMORY_CAST (mem),
378 flags, _sysmem_allocator, parent, maxsize, align, offset, size);
379
380 mem->slice_size = slice_size;
381 mem->data = data;
382 mem->user_data = user_data;
383 mem->notify = notify;
384 }
385
386 /* create a new memory block that manages the given memory */
387 static inline GstMemorySystem *
388 _sysmem_new (GstMemoryFlags flags,
389 GstMemory * parent, gpointer data, gsize maxsize, gsize align, gsize offset,
390 gsize size, gpointer user_data, GDestroyNotify notify)
391 {
392 GstMemorySystem *mem;
393 gsize slice_size;
394
395 slice_size = sizeof (GstMemorySystem);
396
397 mem = g_slice_alloc (slice_size);
398 _sysmem_init (mem, flags, parent, slice_size,
399 data, maxsize, align, offset, size, user_data, notify);
400
401 return mem;
402 }
403
404 /* allocate the memory and structure in one block */
405 static GstMemorySystem *
406 _sysmem_new_block (GstMemoryFlags flags,
407 gsize maxsize, gsize align, gsize offset, gsize size)
408 {
409 GstMemorySystem *mem;
410 gsize aoffset, slice_size, padding;
411 guint8 *data;
412
413 /* ensure configured alignment */
414 align |= gst_memory_alignment;
415 /* allocate more to compensate for alignment */
416 maxsize += align;
417 /* alloc header and data in one block */
418 slice_size = sizeof (GstMemorySystem) + maxsize;
419
420 mem = g_slice_alloc (slice_size);
421 if (mem == NULL)
422 return NULL;
423
424 data = (guint8 *) mem + sizeof (GstMemorySystem);
425
426 /* do alignment */
427 if ((aoffset = ((guintptr) data & align))) {
428 aoffset = (align + 1) - aoffset;
429 data += aoffset;
430 maxsize -= aoffset;
431 }
432
433 if (offset && (flags & GST_MEMORY_FLAG_ZERO_PREFIXED))
434 memset (data, 0, offset);
435
436 padding = maxsize - (offset + size);
437 if (padding && (flags & GST_MEMORY_FLAG_ZERO_PADDED))
438 memset (data + offset + size, 0, padding);
439
440 _sysmem_init (mem, flags, NULL, slice_size, data, maxsize,
441 align, offset, size, NULL, NULL);
442
443 return mem;
444 }
445
446 static gpointer
447 _sysmem_map (GstMemorySystem * mem, gsize maxsize, GstMapFlags flags)
448 {
449 return mem->data;
450 }
451
452 static gboolean
453 _sysmem_unmap (GstMemorySystem * mem)
454 {
455 return TRUE;
456 }
457
458 static GstMemorySystem *
459 _sysmem_copy (GstMemorySystem * mem, gssize offset, gsize size)
460 {
461 GstMemorySystem *copy;
462
463 if (size == -1)
464 size = mem->mem.size > offset ? mem->mem.size - offset : 0;
465
466 copy = _sysmem_new_block (0, size, mem->mem.align, 0, size);
467 GST_CAT_DEBUG (GST_CAT_PERFORMANCE,
468 "memcpy %" G_GSIZE_FORMAT " memory %p -> %p", size, mem, copy);
469 memcpy (copy->data, mem->data + mem->mem.offset + offset, size);
470
471 return copy;
472 }
473
474 static GstMemorySystem *
475 _sysmem_share (GstMemorySystem * mem, gssize offset, gsize size)
476 {
477 GstMemorySystem *sub;
478 GstMemory *parent;
479
480 /* find the real parent */
481 if ((parent = mem->mem.parent) == NULL)
482 parent = (GstMemory *) mem;
483
484 if (size == -1)
485 size = mem->mem.size - offset;
486
487 /* the shared memory is always readonly */
488 sub =
489 _sysmem_new (GST_MINI_OBJECT_FLAGS (parent) |
490 GST_MINI_OBJECT_FLAG_LOCK_READONLY, parent, mem->data, mem->mem.maxsize,
491 mem->mem.align, mem->mem.offset + offset, size, NULL, NULL);
492
493 return sub;
494 }
495
496 static gboolean
497 _sysmem_is_span (GstMemorySystem * mem1, GstMemorySystem * mem2, gsize * offset)
498 {
499
500 if (offset) {
501 GstMemorySystem *parent;
502
503 parent = (GstMemorySystem *) mem1->mem.parent;
504
505 *offset = mem1->mem.offset - parent->mem.offset;
506 }
507
508 /* and memory is contiguous */
509 return mem1->data + mem1->mem.offset + mem1->mem.size ==
510 mem2->data + mem2->mem.offset;
511 }
512
513 static GstMemory *
514 default_alloc (GstAllocator * allocator, gsize size,
515 GstAllocationParams * params)
516 {
517 gsize maxsize = size + params->prefix + params->padding;
518
519 return (GstMemory *) _sysmem_new_block (params->flags,
520 maxsize, params->align, params->prefix, size);
521 }
522
523 static void
524 default_free (GstAllocator * allocator, GstMemory * mem)
525 {
526 GstMemorySystem *dmem = (GstMemorySystem *) mem;
527 gsize slice_size;
528
529 if (dmem->notify)
530 dmem->notify (dmem->user_data);
531
532 slice_size = dmem->slice_size;
533
534 #ifdef USE_POISONING
535 /* just poison the structs, not all the data */
536 memset (mem, 0xff, sizeof (GstMemorySystem));
537 #endif
538
539 g_slice_free1 (slice_size, mem);
540 }
541
542 static void
543 gst_allocator_sysmem_finalize (GObject * obj)
544 {
545 g_warning ("The default memory allocator was freed!");
546 }
547
548 static void
549 gst_allocator_sysmem_class_init (GstAllocatorSysmemClass * klass)
550 {
551 GObjectClass *gobject_class;
552 GstAllocatorClass *allocator_class;
553
554 gobject_class = (GObjectClass *) klass;
555 allocator_class = (GstAllocatorClass *) klass;
556
557 gobject_class->finalize = gst_allocator_sysmem_finalize;
558
559 allocator_class->alloc = default_alloc;
560 allocator_class->free = default_free;
561 }
562
563 static void
564 gst_allocator_sysmem_init (GstAllocatorSysmem * allocator)
565 {
566 GstAllocator *alloc = GST_ALLOCATOR_CAST (allocator);
567
568 GST_CAT_DEBUG (GST_CAT_MEMORY, "init allocator %p", allocator);
569
570 alloc->mem_type = GST_ALLOCATOR_SYSMEM;
571 alloc->mem_map = (GstMemoryMapFunction) _sysmem_map;
572 alloc->mem_unmap = (GstMemoryUnmapFunction) _sysmem_unmap;
573 alloc->mem_copy = (GstMemoryCopyFunction) _sysmem_copy;
574 alloc->mem_share = (GstMemoryShareFunction) _sysmem_share;
575 alloc->mem_is_span = (GstMemoryIsSpanFunction) _sysmem_is_span;
576 }
577
578 void
579 _priv_gst_allocator_initialize (void)
580 {
581 g_rw_lock_init (&lock);
582 allocators = g_hash_table_new (g_str_hash, g_str_equal);
583
584 #ifdef HAVE_GETPAGESIZE
585 #ifdef MEMORY_ALIGNMENT_PAGESIZE
586 gst_memory_alignment = getpagesize () - 1;
587 #endif
588 #endif
589
590 GST_CAT_DEBUG (GST_CAT_MEMORY, "memory alignment: %" G_GSIZE_FORMAT,
591 gst_memory_alignment);
592
593 _sysmem_allocator = g_object_new (gst_allocator_sysmem_get_type (), NULL);
594
595 gst_allocator_register (GST_ALLOCATOR_SYSMEM,
596 gst_object_ref (_sysmem_allocator));
597
598 _default_allocator = gst_object_ref (_sysmem_allocator);
599 }
600
601 /**
602 * gst_memory_new_wrapped:
603 * @flags: #GstMemoryFlags
604 * @data: (array length=size) (element-type guint8) (transfer none): data to
605 * wrap
606 * @maxsize: allocated size of @data
607 * @offset: offset in @data
608 * @size: size of valid data
609 * @user_data: (allow-none): user_data
610 * @notify: (allow-none) (scope async) (closure user_data): called with @user_data when the memory is freed
611 *
612 * Allocate a new memory block that wraps the given @data.
613 *
614 * The prefix/padding must be filled with 0 if @flags contains
615 * #GST_MEMORY_FLAG_ZERO_PREFIXED and #GST_MEMORY_FLAG_ZERO_PADDED respectively.
616 *
617 * Returns: (transfer full): a new #GstMemory.
618 */
619 GstMemory *
620 gst_memory_new_wrapped (GstMemoryFlags flags, gpointer data,
621 gsize maxsize, gsize offset, gsize size, gpointer user_data,
622 GDestroyNotify notify)
623 {
624 GstMemorySystem *mem;
625
626 g_return_val_if_fail (data != NULL, NULL);
627 g_return_val_if_fail (offset + size <= maxsize, NULL);
628
629 mem =
630 _sysmem_new (flags, NULL, data, maxsize, 0, offset, size, user_data,
631 notify);
632
633 return (GstMemory *) mem;
634 }