incubator-nuttx/include/nuttx/fdcheck.h

103 lines
3.4 KiB
C

/****************************************************************************
* include/nuttx/fdcheck.h
*
* Licensed to the Apache Software Foundation (ASF) under one or more
* contributor license agreements. See the NOTICE file distributed with
* this work for additional information regarding copyright ownership. The
* ASF licenses this file to you under the Apache License, Version 2.0 (the
* "License"); you may not use this file except in compliance with the
* License. You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
* WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
* License for the specific language governing permissions and limitations
* under the License.
*
****************************************************************************/
#ifndef __INCLUDE_NUTTX_FDCHECK_H
#define __INCLUDE_NUTTX_FDCHECK_H
/****************************************************************************
* Included Files
****************************************************************************/
#include <nuttx/config.h>
/****************************************************************************
* Public Function Prototypes
****************************************************************************/
#ifdef __cplusplus
#define EXTERN extern "C"
extern "C"
{
#else
#define EXTERN extern
#endif
#ifdef CONFIG_FDCHECK
/****************************************************************************
* Name: fdcheck_restore
*
* Description: Obtain original fd information
*
* Val carries the tag and fd information.
* The original fd information is stored in high bit of val.
* The tag information is stored in the low bit of val.
* For ease of understanding, let's give an example where
* the following information is represented in 32-bit binary format
*
* val 00000000 00000000 10001010 00000001
* fd 00000000 00000000 00000000 10001010
* tag 00000000 00000000 00000000 00000001
*
* In this function, we also check tag information is correct.
* If there is an error, it will panic.
*
* Input Parameters:
* val - this val carrying tag and original fd information
*
* Returned Value: The original fd is returned.
*
****************************************************************************/
int fdcheck_restore(int val);
/****************************************************************************
* Name: fdcheck_protect
*
* Description: Obtain the combined value of fd and tag
*
* the return value carries the tag and fd information.
* The original fd information is stored in low bit of val.
* The tag information is stored in high bit of val.
* For ease of understanding, let's give an example where
* the following information is represented in 32-bit binary format
*
* fd 00000000 00000000 00000000 10001010
* tag 00000000 00000000 00000000 00000001
* val 00000000 00000000 10001010 00000001
*
* Input Parameters:
* fd - original fd
*
* Returned Value: the combined value of fd and tag
*
****************************************************************************/
int fdcheck_protect(int fd);
#undef EXTERN
#ifdef __cplusplus
}
#endif
#endif
#endif /* __INCLUDE_NUTTX_FDCHECK_H */