2 * Copyright (C) 2011 Wim Taymans <wim.taymans@gmail.be>
4 * gstallocator.c: memory block allocator
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.
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.
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.
23 * SECTION:gstallocator
24 * @title: GstAllocator
25 * @short_description: allocate memory blocks
26 * @see_also: #GstMemory
31 * Memory is usually created by allocators with a gst_allocator_alloc()
32 * method call. When %NULL is used as the allocator, the default allocator will
35 * New allocators can be registered with gst_allocator_register().
36 * Allocators are identified by name and can be retrieved with
37 * gst_allocator_find(). gst_allocator_set_default() can be used to change the
40 * New memory can be created with gst_memory_new_wrapped() that wraps the memory
41 * allocated elsewhere.
48 #include "gst_private.h"
49 #include "gstmemory.h"
51 GST_DEBUG_CATEGORY_STATIC (gst_allocator_debug);
52 #define GST_CAT_DEFAULT gst_allocator_debug
54 struct _GstAllocatorPrivate
59 #if defined(MEMORY_ALIGNMENT_MALLOC)
60 gsize gst_memory_alignment = 7;
61 #elif defined(MEMORY_ALIGNMENT_PAGESIZE)
62 /* we fill this in in the _init method */
63 gsize gst_memory_alignment = 0;
64 #elif defined(MEMORY_ALIGNMENT)
65 gsize gst_memory_alignment = MEMORY_ALIGNMENT - 1;
67 #error "No memory alignment configured"
68 gsize gst_memory_alignment = 0;
71 /* the default allocator */
72 static GstAllocator *_default_allocator;
74 static GstAllocator *_sysmem_allocator;
76 /* registered allocators */
78 static GHashTable *allocators;
80 G_DEFINE_ABSTRACT_TYPE_WITH_PRIVATE (GstAllocator, gst_allocator,
84 gst_allocator_class_init (GstAllocatorClass * klass)
86 GST_DEBUG_CATEGORY_INIT (gst_allocator_debug, "allocator", 0,
91 _fallback_mem_copy (GstMemory * mem, gssize offset, gssize size)
94 GstMapInfo sinfo, dinfo;
95 GstAllocationParams params = { 0, mem->align, 0, 0, };
96 GstAllocator *allocator;
98 if (!gst_memory_map (mem, &sinfo, GST_MAP_READ))
102 size = sinfo.size > offset ? sinfo.size - offset : 0;
104 /* use the same allocator as the memory we copy */
105 allocator = mem->allocator;
106 if (GST_OBJECT_FLAG_IS_SET (allocator, GST_ALLOCATOR_FLAG_CUSTOM_ALLOC))
108 copy = gst_allocator_alloc (allocator, size, ¶ms);
110 if (!gst_memory_map (copy, &dinfo, GST_MAP_WRITE)) {
111 GST_CAT_WARNING (GST_CAT_MEMORY, "could not write map memory %p", copy);
112 gst_allocator_free (mem->allocator, copy);
113 gst_memory_unmap (mem, &sinfo);
117 GST_CAT_DEBUG (GST_CAT_PERFORMANCE,
118 "memcpy %" G_GSSIZE_FORMAT " memory %p -> %p", size, mem, copy);
119 memcpy (dinfo.data, sinfo.data + offset, size);
120 gst_memory_unmap (copy, &dinfo);
121 gst_memory_unmap (mem, &sinfo);
127 _fallback_mem_is_span (GstMemory * mem1, GstMemory * mem2, gsize * offset)
133 gst_allocator_init (GstAllocator * allocator)
135 allocator->priv = gst_allocator_get_instance_private (allocator);
137 allocator->mem_copy = _fallback_mem_copy;
138 allocator->mem_is_span = _fallback_mem_is_span;
141 G_DEFINE_BOXED_TYPE (GstAllocationParams, gst_allocation_params,
142 (GBoxedCopyFunc) gst_allocation_params_copy,
143 (GBoxedFreeFunc) gst_allocation_params_free);
146 * gst_allocation_params_new:
148 * Create a new #GstAllocationParams on the heap. This function is for
149 * use in GStreamer language bindings. In your own code, you can just
150 * declare a #GstAllocationParams on the stack or in a struct, and
151 * call gst_allocation_params_init() to initialize it.
153 * You do not need to call gst_allocation_params_init() on the instance
154 * returned by this function.
156 * Returns: (transfer full) (not nullable): a new #GstAllocationParams
160 GstAllocationParams *
161 gst_allocation_params_new (void)
163 /* Call new() and then init(), rather than calling new0(), in case
164 * init() ever changes to something other than a memset(). */
165 GstAllocationParams *result = g_slice_new (GstAllocationParams);
166 gst_allocation_params_init (result);
171 * gst_allocation_params_init:
172 * @params: a #GstAllocationParams
174 * Initialize @params to its default values
177 gst_allocation_params_init (GstAllocationParams * params)
179 g_return_if_fail (params != NULL);
181 memset (params, 0, sizeof (GstAllocationParams));
185 * gst_allocation_params_copy:
186 * @params: (transfer none) (nullable): a #GstAllocationParams
188 * Create a copy of @params.
190 * Returns: (transfer full) (nullable): a new #GstAllocationParams.
192 GstAllocationParams *
193 gst_allocation_params_copy (const GstAllocationParams * params)
195 GstAllocationParams *result = NULL;
199 (GstAllocationParams *) g_slice_copy (sizeof (GstAllocationParams),
206 * gst_allocation_params_free:
207 * @params: (in) (transfer full): a #GstAllocationParams
212 gst_allocation_params_free (GstAllocationParams * params)
214 g_slice_free (GstAllocationParams, params);
218 * gst_allocator_register:
219 * @name: the name of the allocator
220 * @allocator: (transfer full): #GstAllocator
222 * Registers the memory @allocator with @name.
225 gst_allocator_register (const gchar * name, GstAllocator * allocator)
227 g_return_if_fail (name != NULL);
228 g_return_if_fail (allocator != NULL);
230 GST_CAT_DEBUG (GST_CAT_MEMORY, "registering allocator %p with name \"%s\"",
233 g_rw_lock_writer_lock (&lock);
234 /* The ref will never be released */
235 GST_OBJECT_FLAG_SET (allocator, GST_OBJECT_FLAG_MAY_BE_LEAKED);
236 g_hash_table_insert (allocators, (gpointer) name, (gpointer) allocator);
237 g_rw_lock_writer_unlock (&lock);
241 * gst_allocator_find:
242 * @name: (allow-none): the name of the allocator
244 * Find a previously registered allocator with @name. When @name is %NULL, the
245 * default allocator will be returned.
247 * Returns: (transfer full) (nullable): a #GstAllocator or %NULL when
248 * the allocator with @name was not registered.
251 gst_allocator_find (const gchar * name)
253 GstAllocator *allocator;
255 g_rw_lock_reader_lock (&lock);
257 allocator = g_hash_table_lookup (allocators, (gconstpointer) name);
259 allocator = _default_allocator;
262 gst_object_ref (allocator);
263 g_rw_lock_reader_unlock (&lock);
269 * gst_allocator_set_default:
270 * @allocator: (transfer full): a #GstAllocator
272 * Set the default allocator.
275 gst_allocator_set_default (GstAllocator * allocator)
279 g_return_if_fail (GST_IS_ALLOCATOR (allocator));
281 g_rw_lock_writer_lock (&lock);
282 old = _default_allocator;
283 _default_allocator = allocator;
284 g_rw_lock_writer_unlock (&lock);
287 gst_object_unref (old);
291 * gst_allocator_alloc:
292 * @allocator: (transfer none) (allow-none): a #GstAllocator to use
293 * @size: size of the visible memory area
294 * @params: (transfer none) (allow-none): optional parameters
296 * Use @allocator to allocate a new memory block with memory that is at least
299 * The optional @params can specify the prefix and padding for the memory. If
300 * %NULL is passed, no flags, no extra prefix/padding and a default alignment is
303 * The prefix/padding will be filled with 0 if flags contains
304 * #GST_MEMORY_FLAG_ZERO_PREFIXED and #GST_MEMORY_FLAG_ZERO_PADDED respectively.
306 * When @allocator is %NULL, the default allocator will be used.
308 * The alignment in @params is given as a bitmask so that @align + 1 equals
309 * the amount of bytes to align to. For example, to align to 8 bytes,
310 * use an alignment of 7.
312 * Returns: (transfer full) (nullable): a new #GstMemory.
315 gst_allocator_alloc (GstAllocator * allocator, gsize size,
316 GstAllocationParams * params)
319 static GstAllocationParams defparams = { 0, 0, 0, 0, };
320 GstAllocatorClass *aclass;
323 g_return_val_if_fail (((params->align + 1) & params->align) == 0, NULL);
328 if (allocator == NULL)
329 allocator = _default_allocator;
331 aclass = GST_ALLOCATOR_GET_CLASS (allocator);
333 mem = aclass->alloc (allocator, size, params);
341 * gst_allocator_free:
342 * @allocator: (transfer none): a #GstAllocator to use
343 * @memory: (transfer full): the memory to free
345 * Free @memory that was previously allocated with gst_allocator_alloc().
348 gst_allocator_free (GstAllocator * allocator, GstMemory * memory)
350 GstAllocatorClass *aclass;
352 g_return_if_fail (GST_IS_ALLOCATOR (allocator));
353 g_return_if_fail (memory != NULL);
354 g_return_if_fail (memory->allocator == allocator);
356 aclass = GST_ALLOCATOR_GET_CLASS (allocator);
358 aclass->free (allocator, memory);
361 /* default memory implementation */
370 GDestroyNotify notify;
376 } GstAllocatorSysmem;
380 GstAllocatorClass parent_class;
381 } GstAllocatorSysmemClass;
383 static GType gst_allocator_sysmem_get_type (void);
384 G_DEFINE_TYPE (GstAllocatorSysmem, gst_allocator_sysmem, GST_TYPE_ALLOCATOR);
386 /* initialize the fields */
388 _sysmem_init (GstMemorySystem * mem, GstMemoryFlags flags,
389 GstMemory * parent, gsize slice_size,
390 gpointer data, gsize maxsize, gsize align, gsize offset, gsize size,
391 gpointer user_data, GDestroyNotify notify)
393 gst_memory_init (GST_MEMORY_CAST (mem),
394 flags, _sysmem_allocator, parent, maxsize, align, offset, size);
396 mem->slice_size = slice_size;
398 mem->user_data = user_data;
399 mem->notify = notify;
402 /* create a new memory block that manages the given memory */
403 static inline GstMemorySystem *
404 _sysmem_new (GstMemoryFlags flags,
405 GstMemory * parent, gpointer data, gsize maxsize, gsize align, gsize offset,
406 gsize size, gpointer user_data, GDestroyNotify notify)
408 GstMemorySystem *mem;
411 slice_size = sizeof (GstMemorySystem);
413 mem = g_slice_alloc (slice_size);
414 _sysmem_init (mem, flags, parent, slice_size,
415 data, maxsize, align, offset, size, user_data, notify);
420 /* allocate the memory and structure in one block */
421 static GstMemorySystem *
422 _sysmem_new_block (GstMemoryFlags flags,
423 gsize maxsize, gsize align, gsize offset, gsize size)
425 GstMemorySystem *mem;
426 gsize aoffset, slice_size, padding;
429 /* ensure configured alignment */
430 align |= gst_memory_alignment;
431 /* allocate more to compensate for alignment */
433 /* alloc header and data in one block */
434 slice_size = sizeof (GstMemorySystem) + maxsize;
436 mem = g_slice_alloc (slice_size);
440 data = (guint8 *) mem + sizeof (GstMemorySystem);
443 if ((aoffset = ((guintptr) data & align))) {
444 aoffset = (align + 1) - aoffset;
449 if (offset && (flags & GST_MEMORY_FLAG_ZERO_PREFIXED))
450 memset (data, 0, offset);
452 padding = maxsize - (offset + size);
453 if (padding && (flags & GST_MEMORY_FLAG_ZERO_PADDED))
454 memset (data + offset + size, 0, padding);
456 _sysmem_init (mem, flags, NULL, slice_size, data, maxsize,
457 align, offset, size, NULL, NULL);
463 _sysmem_map (GstMemorySystem * mem, gsize maxsize, GstMapFlags flags)
469 _sysmem_unmap (GstMemorySystem * mem)
474 static GstMemorySystem *
475 _sysmem_copy (GstMemorySystem * mem, gssize offset, gsize size)
477 GstMemorySystem *copy;
480 size = mem->mem.size > offset ? mem->mem.size - offset : 0;
482 copy = _sysmem_new_block (0, size, mem->mem.align, 0, size);
483 GST_CAT_DEBUG (GST_CAT_PERFORMANCE,
484 "memcpy %" G_GSIZE_FORMAT " memory %p -> %p", size, mem, copy);
485 memcpy (copy->data, mem->data + mem->mem.offset + offset, size);
490 static GstMemorySystem *
491 _sysmem_share (GstMemorySystem * mem, gssize offset, gsize size)
493 GstMemorySystem *sub;
496 /* find the real parent */
497 if ((parent = mem->mem.parent) == NULL)
498 parent = (GstMemory *) mem;
501 size = mem->mem.size - offset;
503 /* the shared memory is always readonly */
505 _sysmem_new (GST_MINI_OBJECT_FLAGS (parent) |
506 GST_MINI_OBJECT_FLAG_LOCK_READONLY, parent, mem->data, mem->mem.maxsize,
507 mem->mem.align, mem->mem.offset + offset, size, NULL, NULL);
513 _sysmem_is_span (GstMemorySystem * mem1, GstMemorySystem * mem2, gsize * offset)
517 GstMemorySystem *parent;
519 parent = (GstMemorySystem *) mem1->mem.parent;
521 *offset = mem1->mem.offset - parent->mem.offset;
524 /* and memory is contiguous */
525 return mem1->data + mem1->mem.offset + mem1->mem.size ==
526 mem2->data + mem2->mem.offset;
530 default_alloc (GstAllocator * allocator, gsize size,
531 GstAllocationParams * params)
533 gsize maxsize = size + params->prefix + params->padding;
535 return (GstMemory *) _sysmem_new_block (params->flags,
536 maxsize, params->align, params->prefix, size);
540 default_free (GstAllocator * allocator, GstMemory * mem)
542 GstMemorySystem *dmem = (GstMemorySystem *) mem;
546 dmem->notify (dmem->user_data);
548 slice_size = dmem->slice_size;
551 /* just poison the structs, not all the data */
552 memset (mem, 0xff, sizeof (GstMemorySystem));
555 g_slice_free1 (slice_size, mem);
559 gst_allocator_sysmem_finalize (GObject * obj)
561 /* Don't raise warnings if we are shutting down */
562 if (_default_allocator)
563 g_warning ("The default memory allocator was freed!");
565 ((GObjectClass *) gst_allocator_sysmem_parent_class)->finalize (obj);
569 gst_allocator_sysmem_class_init (GstAllocatorSysmemClass * klass)
571 GObjectClass *gobject_class;
572 GstAllocatorClass *allocator_class;
574 gobject_class = (GObjectClass *) klass;
575 allocator_class = (GstAllocatorClass *) klass;
577 gobject_class->finalize = gst_allocator_sysmem_finalize;
579 allocator_class->alloc = default_alloc;
580 allocator_class->free = default_free;
584 gst_allocator_sysmem_init (GstAllocatorSysmem * allocator)
586 GstAllocator *alloc = GST_ALLOCATOR_CAST (allocator);
588 GST_CAT_DEBUG (GST_CAT_MEMORY, "init allocator %p", allocator);
590 alloc->mem_type = GST_ALLOCATOR_SYSMEM;
591 alloc->mem_map = (GstMemoryMapFunction) _sysmem_map;
592 alloc->mem_unmap = (GstMemoryUnmapFunction) _sysmem_unmap;
593 alloc->mem_copy = (GstMemoryCopyFunction) _sysmem_copy;
594 alloc->mem_share = (GstMemoryShareFunction) _sysmem_share;
595 alloc->mem_is_span = (GstMemoryIsSpanFunction) _sysmem_is_span;
599 _priv_gst_allocator_initialize (void)
601 g_rw_lock_init (&lock);
602 allocators = g_hash_table_new_full (g_str_hash, g_str_equal, NULL,
605 #ifdef HAVE_GETPAGESIZE
606 #ifdef MEMORY_ALIGNMENT_PAGESIZE
607 gst_memory_alignment = getpagesize () - 1;
611 GST_CAT_DEBUG (GST_CAT_MEMORY, "memory alignment: %" G_GSIZE_FORMAT,
612 gst_memory_alignment);
614 _sysmem_allocator = g_object_new (gst_allocator_sysmem_get_type (), NULL);
616 /* Clear floating flag */
617 gst_object_ref_sink (_sysmem_allocator);
619 gst_allocator_register (GST_ALLOCATOR_SYSMEM,
620 gst_object_ref (_sysmem_allocator));
622 _default_allocator = gst_object_ref (_sysmem_allocator);
626 _priv_gst_allocator_cleanup (void)
628 gst_object_unref (_sysmem_allocator);
629 _sysmem_allocator = NULL;
631 gst_object_unref (_default_allocator);
632 _default_allocator = NULL;
634 g_clear_pointer (&allocators, g_hash_table_unref);
638 * gst_memory_new_wrapped:
639 * @flags: #GstMemoryFlags
640 * @data: (array length=size) (element-type guint8) (transfer none): data to
642 * @maxsize: allocated size of @data
643 * @offset: offset in @data
644 * @size: size of valid data
645 * @user_data: (allow-none): user_data
646 * @notify: (allow-none) (scope async) (closure user_data): called with @user_data when the memory is freed
648 * Allocate a new memory block that wraps the given @data.
650 * The prefix/padding must be filled with 0 if @flags contains
651 * #GST_MEMORY_FLAG_ZERO_PREFIXED and #GST_MEMORY_FLAG_ZERO_PADDED respectively.
653 * Returns: (transfer full) (nullable): a new #GstMemory.
656 gst_memory_new_wrapped (GstMemoryFlags flags, gpointer data,
657 gsize maxsize, gsize offset, gsize size, gpointer user_data,
658 GDestroyNotify notify)
660 GstMemorySystem *mem;
662 g_return_val_if_fail (data != NULL, NULL);
663 g_return_val_if_fail (offset + size <= maxsize, NULL);
666 _sysmem_new (flags, NULL, data, maxsize, 0, offset, size, user_data,
669 return (GstMemory *) mem;