From 65f1d45dcc71186ede72fff950996099d23359bd Mon Sep 17 00:00:00 2001 From: "Ronald S. Bultje" Date: Sun, 2 Dec 2012 14:34:50 -0800 Subject: 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: Anton Khirnov --- libavutil/Makefile | 2 + libavutil/atomic.c | 123 +++++++++++++++++++++++++++++++++++++++++++++++ libavutil/atomic.h | 74 ++++++++++++++++++++++++++++ libavutil/atomic_gcc.h | 48 ++++++++++++++++++ libavutil/atomic_suncc.h | 51 ++++++++++++++++++++ libavutil/atomic_win32.h | 50 +++++++++++++++++++ 6 files changed, 348 insertions(+) create mode 100644 libavutil/atomic.c create mode 100644 libavutil/atomic.h create mode 100644 libavutil/atomic_gcc.h create mode 100644 libavutil/atomic_suncc.h create mode 100644 libavutil/atomic_win32.h (limited to 'libavutil') diff --git a/libavutil/Makefile b/libavutil/Makefile index 465b2fc207..4406b1386d 100644 --- a/libavutil/Makefile +++ b/libavutil/Makefile @@ -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 \ diff --git a/libavutil/atomic.c b/libavutil/atomic.c new file mode 100644 index 0000000000..8fa2532fd6 --- /dev/null +++ b/libavutil/atomic.c @@ -0,0 +1,123 @@ +/* + * Copyright (c) 2012 Ronald S. Bultje + * + * 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 + +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 + +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 diff --git a/libavutil/atomic.h b/libavutil/atomic.h new file mode 100644 index 0000000000..dad93bd1aa --- /dev/null +++ b/libavutil/atomic.h @@ -0,0 +1,74 @@ +/* + * Copyright (c) 2012 Ronald S. Bultje + * + * 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 */ diff --git a/libavutil/atomic_gcc.h b/libavutil/atomic_gcc.h new file mode 100644 index 0000000000..e2f3fe1330 --- /dev/null +++ b/libavutil/atomic_gcc.h @@ -0,0 +1,48 @@ +/* + * Copyright (c) 2012 Ronald S. Bultje + * + * 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); +} diff --git a/libavutil/atomic_suncc.h b/libavutil/atomic_suncc.h new file mode 100644 index 0000000000..85373f5564 --- /dev/null +++ b/libavutil/atomic_suncc.h @@ -0,0 +1,51 @@ +/* + * + * 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 +#include + +#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); +} + diff --git a/libavutil/atomic_win32.h b/libavutil/atomic_win32.h new file mode 100644 index 0000000000..6ae61f6c4d --- /dev/null +++ b/libavutil/atomic_win32.h @@ -0,0 +1,50 @@ +/* + * Copyright (c) 2012 Ronald S. Bultje + * + * 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 + +#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); +} -- cgit v1.2.3