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- First pass at cleaning up the atomic mess

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Original commit message from CVS:
- First pass at cleaning up the atomic mess
- moved weird asm to datastructure that makes sense
- this should also make the trasition to libatomic less painful
This commit is contained in:
Wim Taymans 2002-12-29 19:19:45 +00:00
parent a09fefa6a6
commit 8854eac118
5 changed files with 218 additions and 168 deletions
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1
gst/Makefile.am
View file

@ -135,6 +135,7 @@ gst_headers = \
gstsystemclock.h \
gstthread.h \
gsttrace.h \
gsttrashstack.h \
gsttype.h \
gsttypefind.h \
gstutils.h \

132
gst/gstatomic.h
View file

@ -113,138 +113,6 @@ G_STMT_START { \
#endif /* HAVE_ATOMIC_H */
typedef struct _GstAtomicSwap GstAtomicSwap;
#define GST_ATOMIC_SWAP_VALUE(swap) ((swap)->value)
struct _GstAtomicSwap {
volatile gpointer value;
volatile gulong cnt; /* for the ABA problem */
GMutex *lock; /* lock for C fallback */
};
#if defined (__i386__) && defined (__GNUC__) && __GNUC__ >= 2
#define GST_ATOMIC_LOCK "lock ; "
#define _GST_ATOMIC_SWAP_INIT(swap,val) \
G_STMT_START { \
(swap)->value = (gpointer)(val); \
(swap)->cnt = 0; \
} G_STMT_END
#define _GST_ATOMIC_SWAP(swap, val) \
G_STMT_START { \
__asm__ __volatile__ ("1:" \
" movl %2, (%1);" \
GST_ATOMIC_LOCK "cmpxchg %1, %0;" \
" jnz 1b;" \
: \
: "m" (*swap), \
"r" (val), \
"a" ((swap)->value)); \
} G_STMT_END
#define _GST_ATOMIC_SWAP_GET(swap, val, res) \
G_STMT_START { \
__asm__ __volatile__ (" testl %%eax, %%eax;" \
" jz 20f;" \
"10:" \
" movl (%%eax), %%ebx;" \
" movl %%edx, %%ecx;" \
" incl %%ecx;" \
GST_ATOMIC_LOCK "cmpxchg8b %1;" \
" jnz 10b;" \
"20:\t" \
: "=a" (*res) \
: "m" (*(swap)), \
"a" (val), \
"d" ((swap)->cnt) \
: "ecx", "ebx"); \
} G_STMT_END
#elif defined (__powerpcfoobarred__) && defined (__GNUC__) && __GNUC__ >= 2
#define _GST_ATOMIC_SWAP_INIT(swap,val) \
G_STMT_START { \
(swap)->value = (gpointer)(val); \
(swap)->cnt = 0; \
} G_STMT_END
#define _GST_ATOMIC_SWAP(swap, val) \
G_STMT_START { \
int tmp; \
__asm__ __volatile__ ("1:" \
" lwarx %0, 0, %2 \n" \
" stwcx. %3, 0, %2 \n" \
" bne- 1b \n" \
: "=&r" (tmp), \
"=m" (*swap) \
: "r" (swap), \
"r" (val), \
"m" (* swap) \
: "9", "cc"); \
} G_STMT_END
#define _GST_ATOMIC_SWAP_GET(swap, val, res) \
G_STMT_START { \
__asm__ __volatile__ ("1:" \
" lwarx %0, 0, %2 \n" \
" stwcx. %3, 0, %2 \n" \
" bne- 1b \n" \
: "=&r" (*(res)), \
"=m" (*swap) \
: "r" (swap), \
"r" (val), \
"m" (*swap) \
: "cc"); \
} G_STMT_END
#else
#define _GST_ATOMIC_SWAP_INIT(swap,val) \
G_STMT_START { \
(swap)->lock = g_mutex_new(); \
(swap)->value = (gpointer)val; \
} G_STMT_END
#define _GST_ATOMIC_SWAP(swap, val) \
G_STMT_START { \
gpointer tmp; \
g_mutex_lock ((swap)->lock); \
tmp = (swap)->value; \
(swap)->value = val; \
((gpointer)*val) = tmp; \
g_mutex_unlock ((swap)->lock); \
} G_STMT_END
#define _GST_ATOMIC_SWAP_GET(swap, val, res) \
G_STMT_START { \
if (val) { \
gpointer tmp; \
gint *tmp2; /* this is pretty EVIL */ \
g_mutex_lock ((swap)->lock); \
tmp = (swap)->value; \
tmp2 = val; \
(swap)->value = (gpointer)*tmp2; \
(*res) = (gpointer) (*tmp2 = (gint*)tmp); \
g_mutex_unlock ((swap)->lock); \
} \
} G_STMT_END
#endif
/* initialize the swap structure with an initial value */
#define GST_ATOMIC_SWAP_INIT(swap,val) _GST_ATOMIC_SWAP_INIT(swap, val)
/* atomically swap the contents the swap value with the value pointed to
* by val. */
#define GST_ATOMIC_SWAP(swap, val) _GST_ATOMIC_SWAP(swap, val)
/* atomically swap the contents the swap value with the value pointed to
* by val. The new value of the swap value is returned in the memory pointed
* to by res */
#define GST_ATOMIC_SWAP_GET(swap,val,res) _GST_ATOMIC_SWAP_GET(swap, val, res)
G_END_DECLS
#endif /* __GST_ATOMIC_H__ */

52
gst/gstmemchunk.c
View file

@ -20,22 +20,43 @@
#include <string.h> /* memset */
#include "gstlog.h"
#include "gstmemchunk.h"
#include "gstutils.h"
#include "gstmemchunk.h"
#define __GST_TRASH_STACK_C__
#include "gsttrashstack.h"
#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)))
typedef struct _GstMemChunkElement GstMemChunkElement;
struct _GstMemChunkElement
{
GstTrashStackElement elem; /* make sure we can safely push it on the trashstack */
gpointer area; /* pointer to data areas */
};
struct _GstMemChunk
{
GstTrashStack stack;
gchar *name;
gulong area_size;
gulong chunk_size;
gulong atom_size;
gboolean cleanup;
};
/*******************************************************
* area size
* +-----------------------------------------+
* +-------------------------------------------------------+
* chunk size
* +------------+
* +-----------------+
*
* !next!data... !next!data.... !next!data...
* ! ^ ! ^ !
* +-------------+ +------------+ +---> NULL
* !next!area|data... !next!area!data.... !next!area!data...
* ! ^ ! ^ !
* +------------------+ +-----------------+ +--------> NULL
*
*/
static gboolean
@ -46,12 +67,12 @@ populate (GstMemChunk *mem_chunk)
if (mem_chunk->cleanup)
return FALSE;
area = (guint8 *) g_malloc0 (mem_chunk->area_size);
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));
GST_MEM_CHUNK_AREA (area + i) = area;
gst_trash_stack_push (&mem_chunk->stack, area + i);
}
return TRUE;
@ -87,7 +108,7 @@ gst_mem_chunk_new (gchar* name, gint atom_size, gulong area_size, gint type)
mem_chunk->atom_size = atom_size;
mem_chunk->area_size = area_size;
mem_chunk->cleanup = FALSE;
GST_ATOMIC_SWAP_INIT (&mem_chunk->swap, NULL);
gst_trash_stack_init (&mem_chunk->stack);
populate (mem_chunk);
@ -144,21 +165,20 @@ gst_mem_chunk_destroy (GstMemChunk *mem_chunk)
gpointer
gst_mem_chunk_alloc (GstMemChunk *mem_chunk)
{
GstMemChunkElement *chunk = NULL;
GstMemChunkElement *chunk;
g_return_val_if_fail (mem_chunk != NULL, NULL);
again:
GST_ATOMIC_SWAP_GET (&mem_chunk->swap,
GST_ATOMIC_SWAP_VALUE (&mem_chunk->swap),
&chunk);
chunk = gst_trash_stack_pop (&mem_chunk->stack);
/* chunk is empty, try to refill */
if (!chunk) {
if (populate (mem_chunk))
goto again;
else
return NULL;
}
return GST_MEM_CHUNK_DATA (chunk);
}
@ -200,5 +220,5 @@ gst_mem_chunk_free (GstMemChunk *mem_chunk, gpointer mem)
chunk = GST_MEM_CHUNK_LINK (mem);
GST_ATOMIC_SWAP (&mem_chunk->swap, &chunk->link);
gst_trash_stack_push (&mem_chunk->stack, chunk);
}

20
gst/gstmemchunk.h
View file

@ -21,30 +21,10 @@
#define __GST_MEM_CHUNK_H__
#include <glib.h>
#include <gst/gstatomic.h>
G_BEGIN_DECLS
typedef struct _GstMemChunk GstMemChunk;
typedef struct _GstMemChunkElement GstMemChunkElement;
struct _GstMemChunkElement
{
GstMemChunkElement *link; /* next cell in the lifo */
GstMemChunkElement *area;
};
struct _GstMemChunk
{
GstAtomicSwap swap;
gchar *name;
gulong area_size;
gulong chunk_size;
gulong atom_size;
gboolean cleanup;
GMutex *lock;
};
GstMemChunk* gst_mem_chunk_new (gchar *name,
gint atom_size,

181
gst/gsttrashstack.h Normal file
View file

@ -0,0 +1,181 @@
/* GStreamer
* Copyright (C) <1999> Erik Walthinsen <omega@cse.ogi.edu>
*
* 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.
*/
#ifndef __GST_TRASH_STACK_H__
#define __GST_TRASH_STACK_H__
#ifdef HAVE_CONFIG_H
# include "config.h"
#endif
#include <glib.h>
G_BEGIN_DECLS
typedef struct _GstTrashStack GstTrashStack;
typedef struct _GstTrashStackElement GstTrashStackElement;
struct _GstTrashStackElement {
GstTrashStackElement *next;
};
struct _GstTrashStack {
volatile gpointer head;
volatile gulong count; /* for the ABA problem */
GMutex *lock; /* lock for C fallback */
};
G_INLINE_FUNC GstTrashStack* gst_trash_stack_new (void);
G_INLINE_FUNC void gst_trash_stack_init (GstTrashStack *stack);
G_INLINE_FUNC void gst_trash_stack_destroy (GstTrashStack *stack);
G_INLINE_FUNC void gst_trash_stack_free (GstTrashStack *stack);
G_INLINE_FUNC void gst_trash_stack_push (GstTrashStack *stack, gpointer mem);
G_INLINE_FUNC gpointer gst_trash_stack_pop (GstTrashStack *stack);
#if defined (G_CAN_INLINE) || defined (__GST_TRASH_STACK_C__)
#if defined (__i386__) && defined (__GNUC__) && __GNUC__ >= 2
/*
* intel ia32 optimized lockfree implementations
*/
G_INLINE_FUNC void
gst_trash_stack_init (GstTrashStack *stack)
{
stack->head = NULL;
stack->count = 0;
}
G_INLINE_FUNC void
gst_trash_stack_destroy (GstTrashStack *stack)
{
}
G_INLINE_FUNC void
gst_trash_stack_push (GstTrashStack *stack, gpointer mem)
{
__asm__ __volatile__ (
"1: \n\t"
" movl %2, (%1); \n\t"
" lock; cmpxchg %1, %0; \n\t"
" jnz 1b; \n"
:
: "m" (*stack),
"r" (mem),
"a" (stack->head)
);
}
G_INLINE_FUNC gpointer
gst_trash_stack_pop (GstTrashStack *stack)
{
GstTrashStackElement *head;
__asm__ __volatile__ (
" testl %%eax, %%eax; \n\t"
" jz 20f; \n\t"
"10: \n\t"
" movl (%%eax), %%ebx; \n\t"
" movl %%edx, %%ecx; \n\t"
" incl %%ecx; \n\t"
" lock; cmpxchg8b %1; \n\t"
" jnz 10b; \n\t"
"20: \n"
: "=a" (head)
: "m" (*stack),
"a" (stack->head),
"d" (stack->count)
: "ecx", "ebx"
);
return head;
}
#else
/*
* generic implementation
*/
G_INLINE_FUNC void
gst_trash_stack_init (GstTrashStack *stack)
{
stack->head = NULL;
stack->lock = g_mutex_new();
}
G_INLINE_FUNC void
gst_trash_stack_destroy (GstTrashStack *stack)
{
g_mutex_free (stack->lock);
}
G_INLINE_FUNC void
gst_trash_stack_push (GstTrashStack *stack, gpointer mem)
{
GstTrashStackElement *elem = (GstTrashStackElement *) mem;
g_mutex_lock (stack->lock);
elem->next = stack->head;
stack->head = elem;
g_mutex_unlock (stack->lock);
}
G_INLINE_FUNC gpointer
gst_trash_stack_pop (GstTrashStack *stack)
{
GstTrashStackElement *head;
g_mutex_lock (stack->lock);
head = (GstTrashStackElement *) stack->head;
if (head)
stack->head = head->next;
g_mutex_unlock (stack->lock);
return head;
}
#endif
/*
* common functions
*/
G_INLINE_FUNC GstTrashStack*
gst_trash_stack_new (void)
{
GstTrashStack *stack;
stack = g_new (GstTrashStack, 1);
gst_trash_stack_init (stack);
return stack;
}
G_INLINE_FUNC void
gst_trash_stack_free (GstTrashStack *stack)
{
gst_trash_stack_destroy (stack);
g_free (stack);
}
#endif /* defined (G_CAN_INLINE) || defined (__GST_TRASH_STACK_C__)*/
G_END_DECLS
#endif /* __GST_TRASH_STACK_H__ */