Commit 65f1d45d authored by Ronald S. Bultje's avatar Ronald S. Bultje Committed by Anton Khirnov
Browse files

lavu: add support for atomic operations.



These could be used for reference counting, or for keeping track of
decoding progress in references in multithreaded decoders.

Support is provided by gcc/msvc/suncc intrinsics, with a fallback using
pthread mutexes.
Signed-off-by: default avatarAnton Khirnov <anton@khirnov.net>
parent eae0879d
......@@ -1285,9 +1285,11 @@ HAVE_LIST="
loongson
machine_ioctl_bt848_h
machine_ioctl_meteor_h
machine_rw_barrier
malloc_h
MapViewOfFile
memalign
MemoryBarrier
mkstemp
mm_empty
mmap
......@@ -1322,6 +1324,7 @@ HAVE_LIST="
struct_v4l2_frmivalenum_discrete
symver_asm_label
symver_gnu_asm
sync_synchronize
sysconf
sysctl
sys_mman_h
......@@ -3453,6 +3456,9 @@ check_func strerror_r
check_func strptime
check_func strtok_r
check_func sched_getaffinity
check_builtin sync_synchronize "" "__sync_synchronize()"
check_builtin machine_rw_barrier mbarrier.h "__machine_rw_barrier()"
check_builtin MemoryBarrier windows.h "MemoryBarrier()"
check_func sysconf
check_func sysctl
check_func usleep
......
......@@ -54,6 +54,7 @@ BUILT_HEADERS = avconfig.h
OBJS = adler32.o \
aes.o \
atomic.o \
audio_fifo.o \
avstring.o \
base64.o \
......@@ -100,6 +101,7 @@ SKIPHEADERS = old_pix_fmts.h
TESTPROGS = adler32 \
aes \
atomic \
avstring \
base64 \
blowfish \
......
/*
* Copyright (c) 2012 Ronald S. Bultje <rsbultje@gmail.com>
*
* This file is part of Libav.
*
* Libav is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation; either
* version 2.1 of the License, or (at your option) any later version.
*
* Libav 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
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with Libav; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
*/
#include "atomic.h"
#if !HAVE_MEMORYBARRIER && !HAVE_SYNC_SYNCHRONIZE && !HAVE_MACHINE_RW_BARRIER
#if HAVE_PTHREADS
#include <pthread.h>
static pthread_mutex_t atomic_lock = PTHREAD_MUTEX_INITIALIZER;
int avpriv_atomic_int_get(volatile int *ptr)
{
int res;
pthread_mutex_lock(&atomic_lock);
res = *ptr;
pthread_mutex_unlock(&atomic_lock);
return res;
}
void avpriv_atomic_int_set(volatile int *ptr, int val)
{
pthread_mutex_lock(&atomic_lock);
*ptr = val;
pthread_mutex_unlock(&atomic_lock);
}
int avpriv_atomic_int_add_and_fetch(volatile int *ptr, int inc)
{
int res;
pthread_mutex_lock(&atomic_lock);
*ptr += inc;
res = *ptr;
pthread_mutex_unlock(&atomic_lock);
return res;
}
void *avpriv_atomic_ptr_cas(void * volatile *ptr, void *oldval, void *newval)
{
void *ret;
pthread_mutex_lock(&atomic_lock);
ret = *ptr;
if (*ptr == oldval)
*ptr = newval;
pthread_mutex_unlock(&atomic_lock);
return ret;
}
#elif !HAVE_THREADS
int avpriv_atomic_int_get(volatile int *ptr)
{
return *ptr;
}
void avpriv_atomic_int_set(volatile int *ptr, int val)
{
*ptr = val;
}
int avpriv_atomic_int_add_and_fetch(volatile int *ptr, int inc)
{
*ptr += inc;
return *ptr;
}
void *avpriv_atomic_ptr_cas(void * volatile *ptr, void *oldval, void *newval)
{
if (*ptr == oldval) {
*ptr = newval;
return oldval;
}
return *ptr;
}
#else
#error "Threading is enabled, but there is no implementation of atomic operations available"
#endif /* HAVE_PTHREADS */
#endif /* !HAVE_MEMORYBARRIER && !HAVE_SYNC_SYNCHRONIZE && !HAVE_MACHINE_RW_BARRIER */
#ifdef TEST
#include <assert.h>
int main(void)
{
volatile int val = 1;
int res;
res = avpriv_atomic_int_add_and_fetch(&val, 1);
assert(res == 2);
avpriv_atomic_int_set(&val, 3);
res = avpriv_atomic_int_get(&val);
assert(res == 3);
return 0;
}
#endif
/*
* Copyright (c) 2012 Ronald S. Bultje <rsbultje@gmail.com>
*
* This file is part of Libav.
*
* Libav is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation; either
* version 2.1 of the License, or (at your option) any later version.
*
* Libav 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
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with Libav; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
*/
#ifndef AVUTIL_ATOMIC_H
#define AVUTIL_ATOMIC_H
#include "config.h"
#if HAVE_MEMORYBARRIER
#include "atomic_win32.h"
#elif HAVE_SYNC_SYNCHRONIZE
#include "atomic_gcc.h"
#elif HAVE_MACHINE_RW_BARRIER
#include "atomic_suncc.h"
#else
/**
* Load the current value stored in an atomic integer.
*
* @param ptr atomic integer
* @return the current value of the atomic integer
* @note This acts as a memory barrier.
*/
int avpriv_atomic_int_get(volatile int *ptr);
/**
* Store a new value in an atomic integer.
*
* @param ptr atomic integer
* @param val the value to store in the atomic integer
* @note This acts as a memory barrier.
*/
void avpriv_atomic_int_set(volatile int *ptr, int val);
/**
* Add a value to an atomic integer.
*
* @param ptr atomic integer
* @param inc the value to add to the atomic integer (may be negative)
* @return the new value of the atomic integer.
* @note This does NOT act as a memory barrier. This is primarily
* intended for reference counting.
*/
int avpriv_atomic_int_add_and_fetch(volatile int *ptr, int inc);
/**
* Atomic pointer compare and swap.
*
* @param ptr pointer to the pointer to operate on
* @param oldval do the swap if the current value of *ptr equals to oldval
* @param newval value to replace *ptr with
* @return the value of *ptr before comparison
*/
void *avpriv_atomic_ptr_cas(void * volatile *ptr, void *oldval, void *newval);
#endif /* HAVE_MEMORYBARRIER */
#endif /* AVUTIL_ATOMIC_H */
/*
* Copyright (c) 2012 Ronald S. Bultje <rsbultje@gmail.com>
*
* This file is part of Libav.
*
* Libav is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation; either
* version 2.1 of the License, or (at your option) any later version.
*
* Libav 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
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with Libav; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
*/
#include "atomic.h"
#define avpriv_atomic_int_get atomic_int_get_gcc
static inline int atomic_int_get_gcc(volatile int *ptr)
{
__sync_synchronize();
return *ptr;
}
#define avpriv_atomic_int_set atomic_int_set_gcc
static inline void atomic_int_set_gcc(volatile int *ptr, int val)
{
*ptr = val;
__sync_synchronize();
}
#define avpriv_atomic_int_add_and_fetch atomic_int_add_and_fetch_gcc
static inline int atomic_int_add_and_fetch_gcc(volatile int *ptr, int inc)
{
return __sync_add_and_fetch(ptr, inc);
}
#define avpriv_atomic_ptr_cas atomic_ptr_cas_gcc
static inline void *atomic_ptr_cas_gcc(void * volatile *ptr,
void *oldval, void *newval)
{
return __sync_val_compare_and_swap(ptr, oldval, newval);
}
/*
*
* This file is part of Libav.
*
* Libav is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation; either
* version 2.1 of the License, or (at your option) any later version.
*
* Libav 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
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with Libav; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
*/
#include <atomic.h>
#include <mbarrier.h>
#include "atomic.h"
#define avpriv_atomic_int_get atomic_int_get_suncc
static inline int atomic_int_get_suncc(volatile int *ptr)
{
__machine_rw_barrier();
return *ptr;
}
#define avpriv_atomic_int_set atomic_int_set_suncc
static inline void atomic_int_set_suncc(volatile int *ptr, int val)
{
*ptr = val;
__machine_rw_barrier();
}
#define avpriv_atomic_int_add_and_fetch atomic_int_add_and_fetch_suncc
static inline int atomic_int_add_and_fetch_suncc(volatile int *ptr, int inc)
{
return atomic_add_int_nv(ptr, inc);
}
#define avpriv_atomic_ptr_cas atomic_ptr_cas_suncc
static inline void *atomic_ptr_cas_suncc(void * volatile *ptr,
void *oldval, void *newval)
{
return atomic_cas_ptr(ptr, oldval, newval);
}
/*
* Copyright (c) 2012 Ronald S. Bultje <rsbultje@gmail.com>
*
* This file is part of Libav.
*
* Libav is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation; either
* version 2.1 of the License, or (at your option) any later version.
*
* Libav 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
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with Libav; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
*/
#include <windows.h>
#include "atomic.h"
#define avpriv_atomic_int_get atomic_int_get_win32
static inline int atomic_int_get_win32(volatile int *ptr)
{
MemoryBarrier();
return *ptr;
}
#define avpriv_atomic_int_set atomic_int_set_win32
static inline void atomic_int_set_win32(volatile int *ptr, int val)
{
*ptr = val;
MemoryBarrier();
}
#define avpriv_atomic_int_add_and_fetch atomic_int_add_and_fetch_win32
static inline int atomic_int_add_and_fetch_win32(volatile int *ptr, int inc)
{
return inc + InterlockedExchangeAdd(ptr, inc);
}
#define avpriv_atomic_ptr_cas atomic_ptr_cas_win32
static inline void *atomic_ptr_cas_win32(void * volatile *ptr,
void *oldval, void *newval)
{
return InterlockedCompareExchangePointer(ptr, newval, oldval);
}
......@@ -8,6 +8,11 @@ fate-aes: libavutil/aes-test$(EXESUF)
fate-aes: CMD = run libavutil/aes-test
fate-aes: REF = /dev/null
FATE_LIBAVUTIL += fate-atomic
fate-atomic: libavutil/atomic-test$(EXESUF)
fate-atomic: CMD = run libavutil/atomic-test
fate-atomic: REF = /dev/null
FATE_LIBAVUTIL += fate-avstring
fate-avstring: libavutil/avstring-test$(EXESUF)
fate-avstring: CMD = run libavutil/avstring-test
......
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