Commit 1af615683e4a1a858407afbaa2fd686842da7e49 put initializing the ff_fft_offsets_lut (which is typically used if FFT_FIXED_32) behind an ff_thread_once() to make ff_fft_init() thread-safe; yet there is a second place where said table may be initialized which is not guarded by this AVOnce: ff_fft_init_mips(). MIPS uses this LUT even for ordinary floating point FFTs, so that ff_fft_init() is not thread-safe (on MIPS) for both 32bit fixed-point as well as floating-point FFTs; e.g. ff_mdct_init() inherits this flaw and therefore initializing e.g. the AAC decoders is not thread-safe (on MIPS) despite them having FF_CODEC_CAP_INIT_CLEANUP set. This commit fixes this by moving the AVOnce to fft_init_table.c and using it to guard all initializations of ff_fft_offsets_lut. (It is not that bad in practice, because every entry of ff_fft_offsets_lut is never read during initialization and is only once ever written to (namely to its final value); but even these are conflicting actions which are (by definition) data races and lead to undefined behaviour.) Signed-off-by: Andreas Rheinhardt <andreas.rheinhardt@gmail.com> (cherry picked from commit b9c1ab89078d862e0146c9d7ed277addd770e3a3)
		
			
				
	
	
		
			67 lines
		
	
	
		
			2.8 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
			
		
		
	
	
			67 lines
		
	
	
		
			2.8 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
/*
 | 
						|
 * Copyright (c) 2012
 | 
						|
 *      MIPS Technologies, Inc., California.
 | 
						|
 *
 | 
						|
 * Redistribution and use in source and binary forms, with or without
 | 
						|
 * modification, are permitted provided that the following conditions
 | 
						|
 * are met:
 | 
						|
 * 1. Redistributions of source code must retain the above copyright
 | 
						|
 *    notice, this list of conditions and the following disclaimer.
 | 
						|
 * 2. Redistributions in binary form must reproduce the above copyright
 | 
						|
 *    notice, this list of conditions and the following disclaimer in the
 | 
						|
 *    documentation and/or other materials provided with the distribution.
 | 
						|
 * 3. Neither the name of the MIPS Technologies, Inc., nor the names of its
 | 
						|
 *    contributors may be used to endorse or promote products derived from
 | 
						|
 *    this software without specific prior written permission.
 | 
						|
 *
 | 
						|
 * THIS SOFTWARE IS PROVIDED BY THE MIPS TECHNOLOGIES, INC. ``AS IS'' AND
 | 
						|
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 | 
						|
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 | 
						|
 * ARE DISCLAIMED.  IN NO EVENT SHALL THE MIPS TECHNOLOGIES, INC. BE LIABLE
 | 
						|
 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 | 
						|
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 | 
						|
 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 | 
						|
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 | 
						|
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 | 
						|
 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 | 
						|
 * SUCH DAMAGE.
 | 
						|
 *
 | 
						|
 * Authors:  Stanislav Ocovaj (socovaj@mips.com)
 | 
						|
 *           Goran Cordasic   (goran@mips.com)
 | 
						|
 *           Djordje Pesut    (djordje@mips.com)
 | 
						|
 *
 | 
						|
 * This file is part of FFmpeg.
 | 
						|
 *
 | 
						|
 * FFmpeg 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.
 | 
						|
 *
 | 
						|
 * FFmpeg 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 FFmpeg; if not, write to the Free Software
 | 
						|
 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
 | 
						|
 */
 | 
						|
 | 
						|
/**
 | 
						|
 * @file
 | 
						|
 * definitions and tables for FFT
 | 
						|
 */
 | 
						|
#ifndef AVCODEC_FFT_TABLE_H
 | 
						|
#define AVCODEC_FFT_TABLE_H
 | 
						|
 | 
						|
#include "libavcodec/fft.h"
 | 
						|
 | 
						|
#define MAX_LOG2_NFFT 17 //!< Specifies maximum allowed fft size
 | 
						|
#define MAX_FFT_SIZE (1 << MAX_LOG2_NFFT)
 | 
						|
 | 
						|
extern const int32_t ff_w_tab_sr[];
 | 
						|
extern uint16_t ff_fft_offsets_lut[];
 | 
						|
void ff_fft_lut_init(void);
 | 
						|
 | 
						|
#endif /* AVCODEC_FFT_TABLE_H */
 |