ratufacoat/src/sjmercnm.c

   1 /* -*- Mode: C; indent-tabs-mode: t; tab-width: 4 -*-
   2 // ---------------------------------------------------------------------------
   3 // SquirrelJME
   4 //     Copyright (C) Stephanie Gawroriski <xer@multiphasicapps.net>
   5 // ---------------------------------------------------------------------------
   6 // SquirrelJME is under the GNU General Public License v3+, or later.
   7 // See license.mkd for licensing and copyright information.
   8 // --------------------------------------------------------------------------*/
   9
  10 /**
  11  * Native memory functions.
  12  *
  13  * @since 2019/06/25
  14  */
  15
  16 /* Palm OS Functions. */
  17 #if defined(__palmos__)
  18         #include <MemoryMgr.h>
  19         #include <MemGlue.h>
  20 #endif
  21
  22 #include "sjmerc.h"
  23
  24 /** Allocates the given number of bytes. */
  25 void* sjme_malloc(sjme_jint size)
  26 {
  27         void* rv;
  28
  29         /* These will never allocate. */
  30         if (size <= 0)
  31                 return NULL;
  32
  33         /* Round size and include extra 4-bytes for size storage. */
  34         size = ((size + SJME_JINT_C(3)) & (~SJME_JINT_C(3))) + SJME_JINT_C(4);
  35
  36         /* Exceeds maximum permitted allocation size? */
  37         if (sizeof(sjme_jint) > sizeof(size_t) && size > (sjme_jint)SIZE_MAX)
  38                 return NULL;
  39
  40 #if defined(__palmos__)
  41         /* Palm OS, use glue to allow greater than 64K. */
  42         rv = MemGluePtrNew(size);
  43 #else
  44         /* Use standard C function otherwise. */
  45         rv = calloc(1, size);
  46 #endif
  47
  48         /* Did not allocate? */
  49         if (rv == NULL)
  50                 return NULL;
  51
  52 #if defined(__palmos__)
  53         /* Clear memory on Palm OS. */
  54         MemSet(rv, size, 0);
  55 #endif
  56
  57         /* Store the size into this memory block for later free. */
  58         *((sjme_jint*)rv) = size;
  59
  60         /* Return the adjusted pointer. */
  61         return SJME_POINTER_OFFSET_LONG(rv, 4);
  62 }
  63
  64 /** Frees the given pointer. */
  65 void sjme_free(void* p)
  66 {
  67         void* basep;
  68
  69         /* Ignore null pointers. */
  70         if (p == NULL)
  71                 return;
  72
  73         /* Base pointer which is size shifted. */
  74         basep = SJME_POINTER_OFFSET_LONG(p, -4);
  75
  76 #if defined(__palmos__)
  77         /* Use Palm OS free. */
  78         MemPtrFree(basep);
  79 #else
  80         /* Use Standard C free. */
  81         free(basep);
  82 #endif
  83 }