diff options
Diffstat (limited to 'nuttx/mm/mm_free.c')
| -rw-r--r-- | nuttx/mm/mm_free.c | 153 |
1 files changed, 0 insertions, 153 deletions
diff --git a/nuttx/mm/mm_free.c b/nuttx/mm/mm_free.c deleted file mode 100644 index b34b8a459..000000000 --- a/nuttx/mm/mm_free.c +++ /dev/null @@ -1,153 +0,0 @@ -/**************************************************************************** - * mm/mm_free.c - * - * Copyright (C) 2007, 2009 Gregory Nutt. All rights reserved. - * Author: Gregory Nutt <gnutt@nuttx.org> - * - * 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 NuttX 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 COPYRIGHT HOLDERS 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 - * COPYRIGHT OWNER 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. - * - ****************************************************************************/ - -/**************************************************************************** - * Included Files - ****************************************************************************/ - -#include <assert.h> - -#include "mm_environment.h" -#include "mm_internal.h" - -/**************************************************************************** - * Pre-processor Definitions - ****************************************************************************/ - -/**************************************************************************** - * Private Functions - ****************************************************************************/ - -/**************************************************************************** - * Public Functions - ****************************************************************************/ - -/**************************************************************************** - * Name: free - * - * Description: - * Returns a chunk of memory into the list of free nodes, merging with - * adjacent free chunks if possible. - * - ****************************************************************************/ - -void free(FAR void *mem) -{ - FAR struct mm_freenode_s *node; - FAR struct mm_freenode_s *prev; - FAR struct mm_freenode_s *next; - - mvdbg("Freeing %p\n", mem); - - /* Protect against attempts to free a NULL reference */ - - if (!mem) - { - return; - } - - /* We need to hold the MM semaphore while we muck with the - * nodelist. - */ - - mm_takesemaphore(); - - /* Map the memory chunk into a free node */ - - node = (FAR struct mm_freenode_s *)((char*)mem - SIZEOF_MM_ALLOCNODE); - node->preceding &= ~MM_ALLOC_BIT; - - /* Check if the following node is free and, if so, merge it */ - - next = (FAR struct mm_freenode_s *)((char*)node + node->size); - if ((next->preceding & MM_ALLOC_BIT) == 0) - { - FAR struct mm_allocnode_s *andbeyond; - - /* Get the node following the next node (which will - * become the new next node). We know that we can never - * index past the tail chunk because it is always allocated. - */ - - andbeyond = (FAR struct mm_allocnode_s*)((char*)next + next->size); - - /* Remove the next node. There must be a predecessor, - * but there may not be a successor node. - */ - - DEBUGASSERT(next->blink); - next->blink->flink = next->flink; - if (next->flink) - { - next->flink->blink = next->blink; - } - - /* Then merge the two chunks */ - - node->size += next->size; - andbeyond->preceding = node->size | (andbeyond->preceding & MM_ALLOC_BIT); - next = (FAR struct mm_freenode_s *)andbeyond; - } - - /* Check if the preceding node is also free and, if so, merge - * it with this node - */ - - prev = (FAR struct mm_freenode_s *)((char*)node - node->preceding); - if ((prev->preceding & MM_ALLOC_BIT) == 0) - { - /* Remove the node. There must be a predecessor, but there may - * not be a successor node. - */ - - DEBUGASSERT(prev->blink); - prev->blink->flink = prev->flink; - if (prev->flink) - { - prev->flink->blink = prev->blink; - } - - /* Then merge the two chunks */ - - prev->size += node->size; - next->preceding = prev->size | (next->preceding & MM_ALLOC_BIT); - node = prev; - } - - /* Add the merged node to the nodelist */ - - mm_addfreechunk(node); - mm_givesemaphore(); -} |