gstreamer/tests/memchunk/gstmemchunk.c

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#include "gstmemchunk.h"
#ifdef __SMP__
#define CHUNK_LOCK "lock ; "
#else
#define CHUNK_LOCK ""
#endif
#define GST_MEM_CHUNK_AREA(chunk) (((GstMemChunkElement*)(chunk))->area)
#define GST_MEM_CHUNK_DATA(chunk) ((gpointer)(((GstMemChunkElement*)(chunk)) + 1))
#define GST_MEM_CHUNK_LINK(mem) ((GstMemChunkElement*)((guint8*)(mem) - sizeof (GstMemChunkElement)))
/*******************************************************
* area size
* +-----------------------------------------+
* chunk size
* +------------+
*
* !next!data... !next!data.... !next!data...
* ! ^ ! ^ !
* +-------------+ +------------+ +---> NULL
*
*/
static gboolean
populate (GstMemChunk *mem_chunk)
{
guint8 *area;
gint i;
if (mem_chunk->cleanup)
return FALSE;
area = (guint8 *) g_malloc (mem_chunk->area_size);
g_print ("alloc %p\n", area);
for (i=0; i < mem_chunk->area_size; i += mem_chunk->chunk_size) {
GST_MEM_CHUNK_AREA (area + i) = (GstMemChunkElement *)area;
gst_mem_chunk_free (mem_chunk, GST_MEM_CHUNK_DATA (area + i));
}
return TRUE;
}
GstMemChunk*
gst_mem_chunk_new (gchar* name, gint atom_size, gulong area_size, gint type)
{
GstMemChunk *mem_chunk;
g_return_val_if_fail (atom_size > 0, NULL);
g_return_val_if_fail (area_size >= atom_size, NULL);
mem_chunk = g_malloc (sizeof (GstMemChunk));
mem_chunk->chunk_size = atom_size + sizeof (GstMemChunkElement);
area_size = (area_size/atom_size) * mem_chunk->chunk_size;
mem_chunk->name = g_strdup (name);
mem_chunk->free = NULL;
mem_chunk->cnt = 0;
mem_chunk->atom_size = atom_size;
mem_chunk->area_size = area_size;
mem_chunk->cleanup = FALSE;
populate (mem_chunk);
return mem_chunk;
}
static gboolean
free_area (gpointer key, gpointer value, gpointer user_data)
{
g_print ("free %p\n", key);
g_free (key);
return TRUE;
}
void
gst_mem_chunk_destroy (GstMemChunk *mem_chunk)
{
GHashTable *elements = g_hash_table_new (NULL, NULL);
gpointer data;
mem_chunk->cleanup = TRUE;
data = gst_mem_chunk_alloc (mem_chunk);
while (data) {
GstMemChunkElement *elem = GST_MEM_CHUNK_LINK (data);
g_hash_table_insert (elements, GST_MEM_CHUNK_AREA (elem), NULL);
data = gst_mem_chunk_alloc (mem_chunk);
}
g_hash_table_foreach_remove (elements, free_area, NULL);
g_hash_table_destroy (elements);
g_free (mem_chunk->name);
g_free (mem_chunk);
}
gpointer
gst_mem_chunk_alloc (GstMemChunk *mem_chunk)
{
GstMemChunkElement *chunk = NULL;
g_return_val_if_fail (mem_chunk != NULL, NULL);
again:
__asm__ __volatile__ (" testl %%eax, %%eax \n\t"
" jz 20f \n"
"10: \t"
" movl (%%eax), %%ebx \n\t"
" movl %%edx, %%ecx \n\t"
" incl %%ecx \n\t"
CHUNK_LOCK "cmpxchg8b %1 \n\t"
" jz 20f \n\t"
" testl %%eax, %%eax \n\t"
" jnz 10b \n"
"20:\t"
:"=a" (chunk)
:"m" (*mem_chunk), "a" (mem_chunk->free), "d" (mem_chunk->cnt)
:"ecx", "ebx");
if (!chunk) {
//g_print ("extending\n");
if (populate (mem_chunk))
goto again;
else
return NULL;
}
return GST_MEM_CHUNK_DATA (chunk);
}
gpointer
gst_mem_chunk_alloc0 (GstMemChunk *mem_chunk)
{
gpointer mem = gst_mem_chunk_alloc (mem_chunk);
if (mem)
memset (mem, 0, mem_chunk->atom_size);
return mem;
}
void
gst_mem_chunk_free (GstMemChunk *mem_chunk, gpointer mem)
{
GstMemChunkElement *chunk;
g_return_if_fail (mem_chunk != NULL);
g_return_if_fail (mem != NULL);
chunk = GST_MEM_CHUNK_LINK (mem);
__asm__ __volatile__ ( "1: \t"
" movl %2, (%1) \n"
CHUNK_LOCK "cmpxchg %1, %0 \n\t"
" jnz 1b \n\t"
:
:"m" (*mem_chunk), "r" (chunk), "a" (mem_chunk->free));
}