libcsupport/src/rtems_heap_sbrk_greedy.c

0001 /* SPDX-License-Identifier: BSD-2-Clause */
0002
0003 /**
0004  * @file
0005  *
0006  * @brief Greedy Allocate that Empties the sbrk system call
0007  *
0008  * @ingroup MallocSupport
0009  *
0010  * @brief Greedy allocation os sbrk system call memory
0011  *
0012  * The call consumes all the avialable sbrk memory extending
0013  * the supplied heap with it. There is no free as sbrk memory
0014  * is only ever allocated.
0015  */
0016
0017 /*
0018  * Copyright (c) 2021 Chris Johns.  All rights reserved.
0019  *
0020  * Redistribution and use in source and binary forms, with or without
0021  * modification, are permitted provided that the following conditions
0022  * are met:
0023  * 1. Redistributions of source code must retain the above copyright
0024  *    notice, this list of conditions and the following disclaimer.
0025  * 2. Redistributions in binary form must reproduce the above copyright
0026  *    notice, this list of conditions and the following disclaimer in the
0027  *    documentation and/or other materials provided with the distribution.
0028  *
0029  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
0030  * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
0031  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
0032  * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
0033  * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
0034  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
0035  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
0036  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
0037  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
0038  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
0039  * POSSIBILITY OF SUCH DAMAGE.
0040  */
0041
0042 #ifdef HAVE_CONFIG_H
0043 #include "config.h"
0044 #endif
0045
0046 #include "malloc_p.h"
0047
0048 void rtems_heap_sbrk_greedy_allocate(
0049   Heap_Control *heap,
0050   size_t alloc_size
0051 )
0052 {
0053   while ( alloc_size > 0 ) {
0054     void *p = (*rtems_malloc_extend_handler)( heap, alloc_size );
0055     if ( p == NULL ) {
0056       alloc_size >>= 1;
0057     } else {
0058       if ( rtems_malloc_dirty_helper != NULL ) {
0059     (*rtems_malloc_dirty_helper)( p, alloc_size );
0060       }
0061     }
0062   }
0063 }