From 2973d0c78e9b8eed3c5af239927c6bd36af64604 Mon Sep 17 00:00:00 2001 From: "B. Watson" Date: Wed, 13 Mar 2019 02:50:42 -0400 Subject: initial commit --- uip/lib/memb.c | 104 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 104 insertions(+) create mode 100644 uip/lib/memb.c (limited to 'uip/lib/memb.c') diff --git a/uip/lib/memb.c b/uip/lib/memb.c new file mode 100644 index 0000000..777b52f --- /dev/null +++ b/uip/lib/memb.c @@ -0,0 +1,104 @@ +/* + * Copyright (c) 2004, Swedish Institute of Computer Science. + * 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. Neither the name of the Institute 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 INSTITUTE 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 INSTITUTE 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. + * + * This file is part of the uIP TCP/IP stack + * + * Author: Adam Dunkels + * + * $Id: memb.c,v 1.1 2006/06/12 08:21:43 adam Exp $ + */ + +/** + * \addtogroup memb + * @{ + */ + + /** + * \file + * Memory block allocation routines. + * \author Adam Dunkels + */ +#include + +#include "memb.h" + +/*---------------------------------------------------------------------------*/ +void +memb_init(struct memb_blocks *m) +{ + memset(m->count, 0, m->num); + memset(m->mem, 0, m->size * m->num); +} +/*---------------------------------------------------------------------------*/ +void * +memb_alloc(struct memb_blocks *m) +{ + int i; + + for(i = 0; i < m->num; ++i) { + if(m->count[i] == 0) { + /* If this block was unused, we increase the reference count to + indicate that it now is used and return a pointer to the + memory block. */ + ++(m->count[i]); + return (void *)((char *)m->mem + (i * m->size)); + } + } + + /* No free block was found, so we return NULL to indicate failure to + allocate block. */ + return NULL; +} +/*---------------------------------------------------------------------------*/ +char +memb_free(struct memb_blocks *m, void *ptr) +{ + int i; + char *ptr2; + + /* Walk through the list of blocks and try to find the block to + which the pointer "ptr" points to. */ + ptr2 = (char *)m->mem; + for(i = 0; i < m->num; ++i) { + + if(ptr2 == (char *)ptr) { + /* We've found to block to which "ptr" points so we decrease the + reference count and return the new value of it. */ + if(m->count[i] > 0) { + /* Make sure that we don't deallocate free memory. */ + --(m->count[i]); + } + return m->count[i]; + } + ptr2 += m->size; + } + return -1; +} +/*---------------------------------------------------------------------------*/ + +/** @} */ -- cgit v1.2.3