src/kits/app/ServerMemoryAllocator.cpp

   1 /*
   2  * Copyright 2006-2012, Haiku, Inc. All Rights Reserved.
   3  * Distributed under the terms of the MIT License.
   4  *
   5  * Authors:
   6  *              Axel Dörfler, axeld@pinc-software.de
   7  */
   8
   9
  10 /*!     Note, this class don't provide any locking whatsoever - you are
  11         supposed to have a BPrivate::AppServerLink object around which
  12         does the necessary locking.
  13         However, this is not enforced in the methods here, you have to
  14         take care for yourself!
  15 */
  16
  17
  18 #include "ServerMemoryAllocator.h"
  19
  20 #include <new>
  21
  22 #ifndef HAIKU_TARGET_PLATFORM_LIBBE_TEST
  23 #       include <syscalls.h>
  24 #endif
  25
  26
  27 static const size_t kReservedSize = 128 * 1024 * 1024;
  28 static const size_t kReserveMaxSize = 32 * 1024 * 1024;
  29
  30
  31 namespace BPrivate {
  32
  33
  34 struct area_mapping {
  35         area_id server_area;
  36         area_id local_area;
  37         uint8*  local_base;
  38 };
  39
  40
  41 ServerMemoryAllocator::ServerMemoryAllocator()
  42         :
  43         fAreas(4)
  44 {
  45 }
  46
  47
  48 ServerMemoryAllocator::~ServerMemoryAllocator()
  49 {
  50         for (int32 i = fAreas.CountItems(); i-- > 0;) {
  51                 area_mapping* mapping = (area_mapping*)fAreas.ItemAt(i);
  52
  53                 delete_area(mapping->local_area);
  54                 delete mapping;
  55         }
  56 }
  57
  58
  59 status_t
  60 ServerMemoryAllocator::InitCheck()
  61 {
  62         return B_OK;
  63 }
  64
  65
  66 status_t
  67 ServerMemoryAllocator::AddArea(area_id serverArea, area_id& _area,
  68         uint8*& _base, size_t size, bool readOnly)
  69 {
  70         area_mapping* mapping = new (std::nothrow) area_mapping;
  71         if (mapping == NULL || !fAreas.AddItem(mapping)) {
  72                 delete mapping;
  73                 return B_NO_MEMORY;
  74         }
  75
  76         status_t status = B_ERROR;
  77         uint32 addressSpec = B_ANY_ADDRESS;
  78         void* base;
  79 #ifndef HAIKU_TARGET_PLATFORM_LIBBE_TEST
  80         if (!readOnly && size < kReserveMaxSize) {
  81                 // Reserve 128 MB of space for the area, but only if the area
  82                 // is smaller than 32 MB (else the address space waste would
  83                 // likely to be too large)
  84                 base = (void*)0x60000000;
  85                 status = _kern_reserve_address_range((addr_t*)&base, B_BASE_ADDRESS,
  86                         kReservedSize);
  87                 addressSpec = status == B_OK ? B_EXACT_ADDRESS : B_BASE_ADDRESS;
  88         }
  89 #endif
  90
  91         mapping->local_area = clone_area(readOnly
  92                         ? "server read-only memory" : "server_memory", &base, addressSpec,
  93                 B_READ_AREA | (readOnly ? 0 : B_WRITE_AREA), serverArea);
  94         if (mapping->local_area < B_OK) {
  95                 status = mapping->local_area;
  96
  97                 fAreas.RemoveItem(mapping);
  98                 delete mapping;
  99
 100                 return status;
 101         }
 102
 103         mapping->server_area = serverArea;
 104         mapping->local_base = (uint8*)base;
 105
 106         _area = mapping->local_area;
 107         _base = mapping->local_base;
 108
 109         return B_OK;
 110 }
 111
 112
 113 void
 114 ServerMemoryAllocator::RemoveArea(area_id serverArea)
 115 {
 116         for (int32 i = fAreas.CountItems(); i-- > 0;) {
 117                 area_mapping* mapping = (area_mapping*)fAreas.ItemAt(i);
 118
 119                 if (mapping->server_area == serverArea) {
 120                         // we found the area we should remove
 121                         delete_area(mapping->local_area);
 122                         delete mapping;
 123                         fAreas.RemoveItem(i);
 124                         break;
 125                 }
 126         }
 127 }
 128
 129
 130 status_t
 131 ServerMemoryAllocator::AreaAndBaseFor(area_id serverArea, area_id& _area,
 132         uint8*& _base)
 133 {
 134         // TODO: why not use a map?
 135         for (int32 i = fAreas.CountItems(); i-- > 0;) {
 136                 area_mapping* mapping = (area_mapping*)fAreas.ItemAt(i);
 137
 138                 if (mapping->server_area == serverArea) {
 139                         _area = mapping->local_area;
 140                         _base = mapping->local_base;
 141                         return B_OK;
 142                 }
 143         }
 144
 145         return B_ERROR;
 146 }
 147
 148
 149 }       // namespace BPrivate