Commit 34f3dfb1 authored by Rémi Denis-Courmont's avatar Rémi Denis-Courmont

Atomic operations (currently same ones as in garbage collector)

parent d0248515
/*****************************************************************************
* vlc_atomic.h:
*****************************************************************************
* Copyright (C) 2010 Rémi Denis-Courmont
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* This program 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 General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston MA 02110-1301, USA.
*****************************************************************************/
#ifndef VLC_ATOMIC_H
# define VLC_ATOMIC_H
/**
* \file
* Atomic operations do not require locking, but they are not very powerful.
*/
/**
* Memory storage space for an atom. Never access it directly.
*/
typedef union
{
uintptr_t u;
intptr_t s;
} vlc_atomic_t;
/* All functions return the atom value _after_ the operation. */
VLC_EXPORT(uintptr_t, vlc_atomic_get, (const vlc_atomic_t *));
VLC_EXPORT(uintptr_t, vlc_atomic_set, (vlc_atomic_t *, uintptr_t));
VLC_EXPORT(uintptr_t, vlc_atomic_add, (vlc_atomic_t *, uintptr_t));
static inline uintptr_t vlc_atomic_sub (vlc_atomic_t *atom, uintptr_t v)
{
return vlc_atomic_add (atom, -v);
}
static inline uintptr_t vlc_atomic_inc (vlc_atomic_t *atom)
{
return vlc_atomic_add (atom, 1);
}
static inline uintptr_t vlc_atomic_dec (vlc_atomic_t *atom)
{
return vlc_atomic_sub (atom, 1);
}
#endif
......@@ -46,6 +46,7 @@ pluginsinclude_HEADERS = \
../include/vlc_aout_mixer.h \
../include/vlc_arrays.h \
../include/vlc_art_finder.h \
../include/vlc_atomic.h \
../include/vlc_avcodec.h \
../include/vlc_bits.h \
../include/vlc_block.h \
......@@ -271,17 +272,20 @@ endif
endif
SOURCES_libvlc_beos = \
misc/atomic.c \
misc/pthread.c \
$(NULL)
SOURCES_libvlc_darwin = \
config/dirs_macos.c \
misc/atomic.c \
misc/pthread.c \
misc/darwin_specific.c \
$(NULL)
SOURCES_libvlc_linux = \
config/dirs_xdg.c \
misc/atomic.c \
misc/pthread.c \
misc/linux_specific.c \
$(NULL)
......@@ -289,12 +293,14 @@ SOURCES_libvlc_linux = \
SOURCES_libvlc_win32 = \
win32/dirs.c \
win32/specific.c \
win32/atomic.c \
win32/thread.c \
win32/winsock.c \
$(NULL)
SOURCES_libvlc_other = \
config/dirs_xdg.c \
misc/atomic.c \
misc/pthread.c \
misc/not_specific.c
......
......@@ -497,6 +497,9 @@ vlc_clone
VLC_CompileBy
VLC_CompileHost
VLC_Compiler
vlc_atomic_get
vlc_atomic_set
vlc_atomic_add
vlc_cond_broadcast
vlc_cond_destroy
vlc_cond_init
......
/*****************************************************************************
* atomic.c:
*****************************************************************************
* Copyright (C) 2010 Rémi Denis-Courmont
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* This program 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 General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston MA 02110-1301, USA.
*****************************************************************************/
#ifdef HAVE_CONFIG_H
# include <config.h>
#endif
#include <vlc_common.h>
#include <vlc_atomic.h>
#if defined (__GCC_HAVE_SYNC_COMPARE_AND_SWAP_4)
/* GCC intrinsics */
uintptr_t vlc_atomic_get (const vlc_atomic_t *atom)
{
__sync_synchronize ();
return atom->u;
}
uintptr_t vlc_atomic_set (vlc_atomic_t *atom, uintptr_t v)
{
atom->u = v;
__sync_synchronize ();
return v;
}
uintptr_t vlc_atomic_add (vlc_atomic_t *atom, uintptr_t v)
{
return __sync_add_and_fetch (&atom->u, v);
}
#else
/* Worst-case fallback implementation with a mutex */
static vlc_mutex_t lock = VLC_STATIC_MUTEX;
uintptr_t vlc_atomic_get (const vlc_atomic_t *atom)
{
uintptr_t v;
vlc_mutex_lock (&lock);
v = atom->u;
vlc_mutex_unlock (&lock);
return v;
}
uintptr_t vlc_atomic_set (vlc_atomic_t *atom, uintptr_t v)
{
vlc_mutex_lock (&lock);
atom->u = v;
vlc_mutex_unlock (&lock);
return v;
}
uintptr_t vlc_atomic_add (vlc_atomic_t *atom, uintptr_t v)
{
vlc_mutex_lock (&lock);
atom->u += v;
v = atom->u;
vlc_mutex_unlock (&lock);
return v;
}
#endif
/*****************************************************************************
* atomic.c:
*****************************************************************************
* Copyright (C) 2010 Rémi Denis-Courmont
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* This program 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 General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston MA 02110-1301, USA.
*****************************************************************************/
#ifdef HAVE_CONFIG_H
# include <config.h>
#endif
#include <vlc_common.h>
#include <vlc_atomic.h>
uintptr_t vlc_atomic_get (const vlc_atomic_t *atom)
{
return atom->u;
}
uintptr_t vlc_atomic_set (vlc_atomic_t *atom, uintptr_t v)
{
atom->u = v;
return v;
}
uintptr_t vlc_atomic_add (vlc_atomic_t *atom, uintptr_t v)
{
#if defined (WIN64)
return InterlockedAdd64 (&atom->s, v);
#else
return InterlockedAdd (&atom->s, v);
#endif
}
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