source: rtems/cpukit/score/src/heap.c @ 1d486eff

4.104.114.84.95
Last change on this file since 1d486eff was 3127180, checked in by Ralf Corsepius <ralf.corsepius@…>, on 03/29/04 at 12:51:43

2004-04-29 Ralf Corsepius <ralf_corsepius@…>

  • score/src/Unlimited.txt, score/src/chain.c, score/src/coremsg.c, score/src/coremsgbroadcast.c, score/src/coremsgclose.c, score/src/coremsgflush.c, score/src/coremsgflushsupp.c, score/src/coremsgseize.c, score/src/coremsgsubmit.c, score/src/coremutex.c, score/src/coremutexflush.c, score/src/coresem.c, score/src/coresemflush.c, score/src/coretod.c, score/src/coretodtickle.c, score/src/coretodtoseconds.c, score/src/coretodvalidate.c, score/src/heap.c, score/src/heapallocate.c, score/src/heapextend.c, score/src/heapfree.c, score/src/heapsizeofuserarea.c, score/src/interr.c, score/src/iterateoverthreads.c, score/src/mpci.c, score/src/object.c, score/src/objectallocate.c, score/src/objectallocatebyindex.c, score/src/objectclearname.c, score/src/objectcomparenameraw.c, score/src/objectcomparenamestring.c, score/src/objectcopynameraw.c, score/src/objectcopynamestring.c, score/src/objectextendinformation.c, score/src/objectfree.c, score/src/objectget.c, score/src/objectgetbyindex.c, score/src/objectgetisr.c, score/src/objectgetnoprotection.c, score/src/objectidtoname.c, score/src/objectinitializeinformation.c, score/src/objectmp.c, score/src/objectnametoid.c, score/src/objectshrinkinformation.c, score/src/thread.c, score/src/threadcreateidle.c, score/src/threadget.c, score/src/threadidlebody.c, score/src/threadinitialize.c, score/src/threadmp.c, score/src/threadq.c, score/src/threadqdequeuepriority.c, score/src/threadqenqueuepriority.c, score/src/threadqfirstpriority.c, score/src/threadqflush.c, score/src/threadreset.c, score/src/threadrestart.c, score/src/threadsettransient.c, score/src/threadstackallocate.c, score/src/threadstart.c, score/src/userext.c, score/src/watchdoginsert.c, score/src/wkspace.c: Convert to using c99 fixed size types.
  • Property mode set to 100644
File size: 2.8 KB
Line 
1/*
2 *  Heap Handler
3 *
4 *  COPYRIGHT (c) 1989-1999.
5 *  On-Line Applications Research Corporation (OAR).
6 *
7 *  The license and distribution terms for this file may be
8 *  found in the file LICENSE in this distribution or at
9 *  http://www.rtems.com/license/LICENSE.
10 *
11 *  $Id$
12 */
13
14
15#include <rtems/system.h>
16#include <rtems/score/sysstate.h>
17#include <rtems/score/heap.h>
18
19/*PAGE
20 *
21 *  _Heap_Initialize
22 *
23 *  This kernel routine initializes a heap.
24 *
25 *  Input parameters:
26 *    the_heap         - pointer to heap header
27 *    starting_address - starting address of heap
28 *    size             - size of heap
29 *    page_size        - allocatable unit of memory
30 *
31 *  Output parameters:
32 *    returns - maximum memory available if RTEMS_SUCCESSFUL
33 *    0       - otherwise
34 *
35 *    This is what a heap looks like in memory immediately
36 *    after initialization:
37 *
38 *            +--------------------------------+
39 *     0      |  size = 0      | status = used |  a.k.a.  dummy back flag
40 *            +--------------------------------+
41 *     4      |  size = size-8 | status = free |  a.k.a.  front flag
42 *            +--------------------------------+
43 *     8      |  next     = PERM HEAP_TAIL     |
44 *            +--------------------------------+
45 *    12      |  previous = PERM HEAP_HEAD     |
46 *            +--------------------------------+
47 *            |                                |
48 *            |      memory available          |
49 *            |       for allocation           |
50 *            |                                |
51 *            +--------------------------------+
52 *  size - 8  |  size = size-8 | status = free |  a.k.a.  back flag
53 *            +--------------------------------+
54 *  size - 4  |  size = 0      | status = used |  a.k.a.  dummy front flag
55 *            +--------------------------------+
56 */
57
58uint32_t   _Heap_Initialize(
59  Heap_Control        *the_heap,
60  void                *starting_address,
61  uint32_t             size,
62  uint32_t             page_size
63)
64{
65  Heap_Block        *the_block;
66  uint32_t           the_size;
67
68  if ( !_Heap_Is_page_size_valid( page_size ) ||
69       (size < HEAP_MINIMUM_SIZE) )
70    return 0;
71
72  the_heap->page_size = page_size;
73  the_size = size - HEAP_OVERHEAD;
74
75  the_block             = (Heap_Block *) starting_address;
76  the_block->back_flag  = HEAP_DUMMY_FLAG;
77  the_block->front_flag = the_size;
78  the_block->next       = _Heap_Tail( the_heap );
79  the_block->previous   = _Heap_Head( the_heap );
80
81  the_heap->start          = the_block;
82  the_heap->first          = the_block;
83  the_heap->permanent_null = NULL;
84  the_heap->last           = the_block;
85
86  the_block             = _Heap_Next_block( the_block );
87  the_block->back_flag  = the_size;
88  the_block->front_flag = HEAP_DUMMY_FLAG;
89  the_heap->final       = the_block;
90
91  return ( the_size - HEAP_BLOCK_USED_OVERHEAD );
92}
93
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