gstreamer/gst/gstallocator.c

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/* 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., 59 Temple Place - Suite 330,
* Boston, MA 02111-1307, 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.
*
* Last reviewed on 2012-07-09 (0.11.3)
*/
#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)
size_t gst_memory_alignment = 7;
#elif defined(MEMORY_ALIGNMENT_PAGESIZE)
/* we fill this in in the _init method */
size_t gst_memory_alignment = 0;
#elif defined(MEMORY_ALIGNMENT)
size_t gst_memory_alignment = MEMORY_ALIGNMENT - 1;
#else
#error "No memory alignment configured"
size_t 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, };
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 */
copy = gst_allocator_alloc (mem->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_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: 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): 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;
} GstMemoryDefault;
typedef struct
{
GstAllocator parent;
} GstDefaultAllocator;
typedef struct
{
GstAllocatorClass parent_class;
} GstDefaultAllocatorClass;
GType gst_default_allocator_get_type (void);
G_DEFINE_TYPE (GstDefaultAllocator, gst_default_allocator, GST_TYPE_ALLOCATOR);
/* initialize the fields */
static inline void
_default_mem_init (GstMemoryDefault * 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 GstMemoryDefault *
_default_mem_new (GstMemoryFlags flags,
GstMemory * parent, gpointer data, gsize maxsize, gsize align, gsize offset,
gsize size, gpointer user_data, GDestroyNotify notify)
{
GstMemoryDefault *mem;
gsize slice_size;
slice_size = sizeof (GstMemoryDefault);
mem = g_slice_alloc (slice_size);
_default_mem_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 GstMemoryDefault *
_default_mem_new_block (GstMemoryFlags flags,
gsize maxsize, gsize align, gsize offset, gsize size)
{
GstMemoryDefault *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 (GstMemoryDefault) + maxsize;
mem = g_slice_alloc (slice_size);
if (mem == NULL)
return NULL;
data = (guint8 *) mem + sizeof (GstMemoryDefault);
/* 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);
_default_mem_init (mem, flags, NULL, slice_size, data, maxsize,
align, offset, size, NULL, NULL);
return mem;
}
static gpointer
_default_mem_map (GstMemoryDefault * mem, gsize maxsize, GstMapFlags flags)
{
return mem->data;
}
static gboolean
_default_mem_unmap (GstMemoryDefault * mem)
{
return TRUE;
}
static GstMemoryDefault *
_default_mem_copy (GstMemoryDefault * mem, gssize offset, gsize size)
{
GstMemoryDefault *copy;
if (size == -1)
size = mem->mem.size > offset ? mem->mem.size - offset : 0;
copy =
_default_mem_new_block (0, mem->mem.maxsize, mem->mem.align,
mem->mem.offset + offset, size);
GST_CAT_DEBUG (GST_CAT_PERFORMANCE,
"memcpy %" G_GSIZE_FORMAT " memory %p -> %p", mem->mem.maxsize, mem,
copy);
memcpy (copy->data, mem->data, mem->mem.maxsize);
return copy;
}
static GstMemoryDefault *
_default_mem_share (GstMemoryDefault * mem, gssize offset, gsize size)
{
GstMemoryDefault *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 =
_default_mem_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
_default_mem_is_span (GstMemoryDefault * mem1, GstMemoryDefault * mem2,
gsize * offset)
{
if (offset) {
GstMemoryDefault *parent;
parent = (GstMemoryDefault *) 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 *) _default_mem_new_block (params->flags,
maxsize, params->align, params->prefix, size);
}
static void
default_free (GstAllocator * allocator, GstMemory * mem)
{
GstMemoryDefault *dmem = (GstMemoryDefault *) 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 (GstMemoryDefault));
#endif
g_slice_free1 (slice_size, mem);
}
static void
gst_default_allocator_finalize (GObject * obj)
{
g_warning ("The default memory allocator was freed!");
}
static void
gst_default_allocator_class_init (GstDefaultAllocatorClass * klass)
{
GObjectClass *gobject_class;
GstAllocatorClass *allocator_class;
gobject_class = (GObjectClass *) klass;
allocator_class = (GstAllocatorClass *) klass;
gobject_class->finalize = gst_default_allocator_finalize;
allocator_class->alloc = default_alloc;
allocator_class->free = default_free;
}
static void
gst_default_allocator_init (GstDefaultAllocator * 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) _default_mem_map;
alloc->mem_unmap = (GstMemoryUnmapFunction) _default_mem_unmap;
alloc->mem_copy = (GstMemoryCopyFunction) _default_mem_copy;
alloc->mem_share = (GstMemoryShareFunction) _default_mem_share;
alloc->mem_is_span = (GstMemoryIsSpanFunction) _default_mem_is_span;
}
void
_priv_gst_memory_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_default_allocator_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: data to wrap
* @maxsize: allocated size of @data
* @offset: offset in @data
* @size: size of valid data
* @user_data: user_data
* @notify: 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: a new #GstMemory.
*/
GstMemory *
gst_memory_new_wrapped (GstMemoryFlags flags, gpointer data,
gsize maxsize, gsize offset, gsize size, gpointer user_data,
GDestroyNotify notify)
{
GstMemoryDefault *mem;
g_return_val_if_fail (data != NULL, NULL);
g_return_val_if_fail (offset + size <= maxsize, NULL);
mem =
_default_mem_new (flags, NULL, data, maxsize, 0, offset, size, user_data,
notify);
return (GstMemory *) mem;
}