fs/vfs/lock.h

/****************************************************************************
 * fs/vfs/lock.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 __FS_VFS_LOCK_H
#define __FS_VFS_LOCK_H

/****************************************************************************
 * Included Files
 ****************************************************************************/

#include <fcntl.h>

/****************************************************************************
 * Pre-processor Definitions
 ****************************************************************************/

#if CONFIG_FS_LOCK_BUCKET_SIZE == 0
#  define file_initlk()
#  define file_closelk(filep)
#  define file_getlk(filep, flock) ((void)flock, -ENOSYS)
#  define file_setlk(filep, flock, nonblock) ((void)flock, -ENOSYS)
#else

/****************************************************************************
 * Public Function Prototypes
 ****************************************************************************/

/****************************************************************************
 * Name: file_initlk
 *
 * Description:
 *   Initializing file locks
 *
 ****************************************************************************/

void file_initlk(void);

/****************************************************************************
 * Name: file_closelk
 *
 * Description:
 *   Remove all locks associated with the filep when call close is applied.
 *
 * Input Parameters:
 *   filep - The filep that corresponds to the shutdown.
 *
 ****************************************************************************/

void file_closelk(FAR struct file *filep);

/****************************************************************************
 * Name: file_getlk
 *
 * Description:
 *   Attempts to lock the region (not a real lock), and if there is a
 *   conflict then returns information about the conflicting locks
 *
 * Input Parameters:
 *   filep - File structure instance
 *   flock - Lock types to be converted
 *
 * Returned Value:
 *   The resulting 0 on success. A errno value is returned on any failure.
 *
 ****************************************************************************/

int file_getlk(FAR struct file *filep, FAR struct flock *flock);

/****************************************************************************
 * Name: file_setlk
 *
 * Description:
 *   Actual execution of locking and unlocking behaviors
 *
 * Input Parameters:
 *   filep    - File structure instance
 *   flock    - Lock types to be converted
 *   nonblock - Waiting for lock
 *
 * Returned Value:
 *   The resulting 0 on success. A errno value is returned on any failure.
 *
 ****************************************************************************/

int file_setlk(FAR struct file *filep, FAR struct flock *flock,
               bool nonblock);

#endif /* CONFIG_FS_LOCK_BUCKET_SIZE */
#endif /* __FS_VFS_LOCK_H */