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141 lines
3.4 KiB
C
141 lines
3.4 KiB
C
/* GStreamer
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* Copyright (C) 2012 Wim Taymans <wim.taymans@gmail.be>
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*
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* This library is free software; you can redistribute it and/or
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* modify it under the terms of the GNU Library General Public
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* License as published by the Free Software Foundation; either
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* version 2 of the License, or (at your option) any later version.
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*
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* This library is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
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* Library General Public License for more details.
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*
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* You should have received a copy of the GNU Library General Public
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* License along with this library; if not, write to the
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* Free Software Foundation, Inc., 59 Temple Place - Suite 330,
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* Boston, MA 02111-1307, USA.
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*/
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#include "my-memory.h"
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static GstAllocator *_my_allocator;
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typedef struct
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{
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GstMemory mem;
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gpointer data;
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} MyMemory;
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static GstMemory *
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_my_alloc_alloc (GstAllocator * allocator, gsize size,
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GstAllocationParams * params, gpointer user_data)
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{
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MyMemory *mem;
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gsize maxsize = size + params->prefix + params->padding;
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GST_DEBUG ("alloc from allocator %p", allocator);
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mem = g_slice_new (MyMemory);
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gst_memory_init (GST_MEMORY_CAST (mem), params->flags, allocator, NULL,
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maxsize, params->align, params->prefix, size);
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mem->data = NULL;
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return (GstMemory *) mem;
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}
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static gpointer
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_my_mem_map (MyMemory * mem, gsize maxsize, GstMapFlags flags)
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{
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gpointer res;
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while (TRUE) {
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if ((res = g_atomic_pointer_get (&mem->data)) != NULL)
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break;
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res = g_malloc (maxsize);
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if (g_atomic_pointer_compare_and_exchange (&mem->data, NULL, res))
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break;
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g_free (res);
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}
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GST_DEBUG ("%p: mapped %p", mem, res);
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return res;
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}
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static gboolean
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_my_mem_unmap (MyMemory * mem)
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{
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GST_DEBUG ("%p: unmapped", mem);
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return TRUE;
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}
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static void
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_my_mem_free (MyMemory * mem)
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{
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g_free (mem->data);
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g_slice_free (MyMemory, mem);
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GST_DEBUG ("%p: freed", mem);
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}
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static MyMemory *
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_my_mem_share (MyMemory * mem, gssize offset, gsize size)
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{
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MyMemory *sub;
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GstMemory *parent;
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GST_DEBUG ("%p: share %" G_GSSIZE_FORMAT " %" G_GSIZE_FORMAT, mem, offset,
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size);
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/* find the real parent */
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if ((parent = mem->mem.parent) == NULL)
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parent = (GstMemory *) mem;
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if (size == -1)
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size = mem->mem.size - offset;
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sub = g_slice_new (MyMemory);
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/* the shared memory is always readonly */
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gst_memory_init (GST_MEMORY_CAST (sub), GST_MINI_OBJECT_FLAGS (parent) |
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GST_MINI_OBJECT_FLAG_LOCK_READONLY, mem->mem.allocator, parent,
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mem->mem.maxsize, mem->mem.align, mem->mem.offset + offset, size);
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/* install pointer */
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sub->data = _my_mem_map (mem, mem->mem.maxsize, GST_MAP_READ);
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return sub;
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}
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static void
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free_allocator (GstMiniObject * obj)
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{
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g_slice_free (GstAllocator, (GstAllocator *) obj);
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}
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void
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my_memory_init (void)
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{
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static const GstMemoryInfo info = {
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"MyMemory",
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(GstAllocatorAllocFunction) _my_alloc_alloc,
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(GstMemoryMapFunction) _my_mem_map,
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(GstMemoryUnmapFunction) _my_mem_unmap,
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(GstMemoryFreeFunction) _my_mem_free,
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(GstMemoryCopyFunction) NULL,
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(GstMemoryShareFunction) _my_mem_share,
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(GstMemoryIsSpanFunction) NULL,
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};
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_my_allocator = g_slice_new (GstAllocator);
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gst_allocator_init (_my_allocator, 0, &info, free_allocator);
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gst_allocator_register ("MyMemory", gst_allocator_ref (_my_allocator));
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}
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