mirror of
https://github.com/oliverschmidt/contiki.git
synced 2024-11-05 04:05:34 +00:00
135 lines
4.2 KiB
C
135 lines
4.2 KiB
C
/**
|
|
* \file
|
|
* Argument buffer for passing arguments when starting processes
|
|
* \author Adam Dunkels <adam@dunkels.com>
|
|
*/
|
|
|
|
/**
|
|
* \addtogroup sys
|
|
* @{
|
|
*/
|
|
|
|
/**
|
|
* \defgroup arg Argument buffer
|
|
* @{
|
|
*
|
|
* The argument buffer can be used when passing an argument from an
|
|
* exiting process to a process that has not been created yet. Since
|
|
* the exiting process will have exited when the new process is
|
|
* started, the argument cannot be passed in any of the processes'
|
|
* addres spaces. In such situations, the argument buffer can be used.
|
|
*
|
|
* The argument buffer is statically allocated in memory and is
|
|
* globally accessible to all processes.
|
|
*
|
|
* An argument buffer is allocated with the arg_alloc() function and
|
|
* deallocated with the arg_free() function. The arg_free() function
|
|
* is designed so that it can take any pointer, not just an argument
|
|
* buffer pointer. If the pointer to arg_free() is not an argument
|
|
* buffer, the function does nothing.
|
|
*/
|
|
|
|
/*
|
|
* Copyright (c) 2003, Adam Dunkels.
|
|
* All rights reserved.
|
|
*
|
|
* 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. The name of the author may not be used to endorse or promote
|
|
* products derived from this software without specific prior
|
|
* written permission.
|
|
*
|
|
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``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 AUTHOR 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.
|
|
*
|
|
* This file is part of the Contiki desktop OS
|
|
*
|
|
* $Id: arg.c,v 1.2 2006/08/14 23:39:23 oliverschmidt Exp $
|
|
*
|
|
*/
|
|
|
|
#include "contiki.h"
|
|
#include "sys/arg.h"
|
|
|
|
/**
|
|
* \internal Structure used for holding an argument buffer.
|
|
*/
|
|
struct argbuf {
|
|
char buf[128];
|
|
char used;
|
|
};
|
|
|
|
static struct argbuf bufs[1];
|
|
|
|
/*-----------------------------------------------------------------------------------*/
|
|
/**
|
|
* \internal Initalizer, called by the dispatcher module.
|
|
*/
|
|
/*-----------------------------------------------------------------------------------*/
|
|
void
|
|
arg_init(void)
|
|
{
|
|
bufs[0].used = 0;
|
|
}
|
|
/*-----------------------------------------------------------------------------------*/
|
|
/**
|
|
* Allocates an argument buffer.
|
|
*
|
|
* \param size The requested size of the buffer, in bytes.
|
|
*
|
|
* \return Pointer to allocated buffer, or NULL if no buffer could be
|
|
* allocated.
|
|
*
|
|
* \note It currently is not possible to allocate argument buffers of
|
|
* any other size than 128 bytes.
|
|
*
|
|
*/
|
|
/*-----------------------------------------------------------------------------------*/
|
|
char *
|
|
arg_alloc(char size)
|
|
{
|
|
if(bufs[0].used == 0) {
|
|
bufs[0].used = 1;
|
|
return bufs[0].buf;
|
|
}
|
|
return 0;
|
|
}
|
|
/*-----------------------------------------------------------------------------------*/
|
|
/**
|
|
* Deallocates an argument buffer.
|
|
*
|
|
* This function deallocates the argument buffer pointed to by the
|
|
* parameter, but only if the buffer actually is an argument buffer
|
|
* and is allocated. It is perfectly safe to call this function with
|
|
* any pointer.
|
|
*
|
|
* \param arg A pointer.
|
|
*/
|
|
/*-----------------------------------------------------------------------------------*/
|
|
void
|
|
arg_free(char *arg)
|
|
{
|
|
if(arg == bufs[0].buf) {
|
|
bufs[0].used = 0;
|
|
}
|
|
}
|
|
/*-----------------------------------------------------------------------------------*/
|
|
/** @} */
|
|
/** @} */
|