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LiteOS-Reading/src/kernel/base/los_bitmap.c

81 lines
2.7 KiB

/* ----------------------------------------------------------------------------
* Copyright (c) Huawei Technologies Co., Ltd. 2013-2019. All rights reserved.
* Description: BitMap
* Author: Huawei LiteOS Team
* Create: 2013-01-01
* 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 copyright holder 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 COPYRIGHT HOLDERS AND CONTRIBUTORS
* "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 COPYRIGHT HOLDER OR
* CONTRIBUTORS 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.
* --------------------------------------------------------------------------- */
#include "los_bitmap.h"
#include "los_toolchain.h"
#ifdef __cplusplus
#if __cplusplus
extern "C" {
#endif /* __cplusplus */
#endif /* __cplusplus */
#define OS_BITMAP_MASK 0x1FU//位图的掩码,与数据进行与操作得到低五位的信息
VOID LOS_BitmapSet(UINT32 *bitmap, UINT16 pos)
{
if (bitmap == NULL) {
return;
}
*bitmap |= 1U << (pos & OS_BITMAP_MASK);
}
VOID LOS_BitmapClr(UINT32 *bitmap, UINT16 pos)
{
if (bitmap == NULL) {
return;
}
*bitmap &= ~(1U << (pos & OS_BITMAP_MASK));
}
UINT16 LOS_HighBitGet(UINT32 bitmap)
{
if (bitmap == 0) {
return LOS_INVALID_BIT_INDEX;
}
return (OS_BITMAP_MASK - CLZ(bitmap));
}
UINT16 LOS_LowBitGet(UINT32 bitmap)
{
if (bitmap == 0) {
return LOS_INVALID_BIT_INDEX;
}
return CTZ(bitmap);
}
#ifdef __cplusplus
#if __cplusplus
}
#endif /* __cplusplus */
#endif /* __cplusplus */