manes/mem_alloc.cpp

   1 /* Quarn OS
   2  *
   3  * C++ memory allocation functions
   4  *
   5  * Copyright (C) 2008-2009 Pawel Dziepak
   6  *
   7  * This program is free software; you can redistribute it and/or modify
   8  * it under the terms of the GNU General Public License as published by
   9  * the Free Software Foundation; either version 2 of the License, or
  10  * (at your option) any later version.
  11  *
  12  * This program is distributed in the hope that it will be useful,
  13  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  14  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  15  * GNU General Public License for more details.
  16  *
  17  * You should have received a copy of the GNU General Public License along
  18  * with this program; if not, write to the Free Software Foundation, Inc.,
  19  * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
  20  *
  21  */
  22
  23 /* Functions that makes it possible to allocate more memory using operators
  24  * new and delete. After booting they uses static part of memory, but then
  25  * they change to the memory allocator.
  26  */
  27
  28 #include "services/kernel_state.h"
  29 #include "manec.h"
  30 #include "error.h"
  31 #include "manes/component.h"
  32 #include "resources/buffer.h"
  33
  34 using namespace manes;
  35 using namespace resources;
  36
  37 static const int _static_mem_amount = 0x5000;
  38 char _static_mem[_static_mem_amount];
  39 int _static_mem_ptr = 0;
  40 bool _static_mem_off = false;
  41
  42 unsigned int allocated_memory = 0;
  43
  44 void *operator new(unsigned int size) {
  45         allocated_memory += size;
  46         if (!_static_mem_off) {
  47                 int begin = _static_mem_ptr;
  48                 _static_mem_ptr += size;
  49                 if (_static_mem_ptr >= _static_mem_amount)
  50                         critical("mem_alloc: not enough space on static heap to allocate more memory");
  51                 char *buf = (char*)&(_static_mem[begin]);
  52                 for (unsigned int i = 0; i < size; i++)
  53                         buf[i] = 0;
  54                 return (void*)buf;
  55         }
  56         char *buf = (char*)manec::state()->get_memalloc()->allocate_space(size);
  57         for (unsigned int i = 0; i < size; i++)
  58                 buf[i] = 0;
  59         return (void*)buf;
  60 }
  61
  62 void *operator new(unsigned int size, int align) {
  63         void *ptr = new char[size + align];
  64         int add = align - (int)ptr % align;
  65         ptr = (void*)((int)ptr + add);
  66
  67 #if DEBUG_MODE == CONF_YES
  68         if ((int)ptr & (align - 1))
  69                 __asm__("cli\nhlt"::"a"(ptr));
  70 #endif
  71
  72         return ptr;
  73 }
  74
  75 void *operator new[](unsigned int size) {
  76         return operator new(size);
  77 }
  78
  79 void *operator new[](unsigned int size, int align) {
  80         return operator new(size, align);
  81 }
  82
  83 void operator delete(void *ptr) {
  84         if ((unsigned int)ptr < (unsigned int)_static_mem + _static_mem_ptr)
  85                 return;
  86         if (!_static_mem_off)
  87                 return;
  88         manec::state()->get_memalloc()->deallocate_space(ptr);
  89 }
  90
  91 void operator delete[](void *ptr) {
  92         operator delete(ptr);
  93 }