haiku/src/kits/app/ServerMemoryAllocator.cpp

151 lines
3.1 KiB
C++

/*
* Copyright 2006-2012, Haiku, Inc. All Rights Reserved.
* Distributed under the terms of the MIT License.
*
* Authors:
* Axel Dörfler, axeld@pinc-software.de
*/
/*! Note, this class don't provide any locking whatsoever - you are
supposed to have a BPrivate::AppServerLink object around which
does the necessary locking.
However, this is not enforced in the methods here, you have to
take care for yourself!
*/
#include "ServerMemoryAllocator.h"
#include <new>
#ifndef HAIKU_TARGET_PLATFORM_LIBBE_TEST
# include <syscalls.h>
#endif
static const size_t kReservedSize = 128 * 1024 * 1024;
static const size_t kReserveMaxSize = 32 * 1024 * 1024;
namespace BPrivate {
struct area_mapping {
area_id server_area;
area_id local_area;
uint8* local_base;
};
ServerMemoryAllocator::ServerMemoryAllocator()
:
fAreas(4)
{
}
ServerMemoryAllocator::~ServerMemoryAllocator()
{
for (int32 i = fAreas.CountItems(); i-- > 0;) {
area_mapping* mapping = (area_mapping*)fAreas.ItemAt(i);
delete_area(mapping->local_area);
delete mapping;
}
}
status_t
ServerMemoryAllocator::InitCheck()
{
return B_OK;
}
status_t
ServerMemoryAllocator::AddArea(area_id serverArea, area_id& _area,
uint8*& _base, size_t size, bool readOnly)
{
area_mapping* mapping = new (std::nothrow) area_mapping;
if (mapping == NULL || !fAreas.AddItem(mapping)) {
delete mapping;
return B_NO_MEMORY;
}
status_t status = B_ERROR;
uint32 addressSpec = B_ANY_ADDRESS;
void* base;
#ifndef HAIKU_TARGET_PLATFORM_LIBBE_TEST
if (!readOnly && size < kReserveMaxSize) {
// Reserve 128 MB of space for the area, but only if the area
// is smaller than 32 MB (else the address space waste would
// likely to be too large)
base = (void*)0x60000000;
status = _kern_reserve_address_range((addr_t*)&base, B_BASE_ADDRESS,
kReservedSize);
addressSpec = status == B_OK ? B_EXACT_ADDRESS : B_BASE_ADDRESS;
}
#endif
mapping->local_area = clone_area(readOnly
? "server read-only memory" : "server_memory", &base, addressSpec,
B_CLONEABLE_AREA | B_READ_AREA | (readOnly ? 0 : B_WRITE_AREA),
serverArea);
if (mapping->local_area < B_OK) {
status = mapping->local_area;
fAreas.RemoveItem(mapping);
delete mapping;
return status;
}
mapping->server_area = serverArea;
mapping->local_base = (uint8*)base;
_area = mapping->local_area;
_base = mapping->local_base;
return B_OK;
}
void
ServerMemoryAllocator::RemoveArea(area_id serverArea)
{
for (int32 i = fAreas.CountItems(); i-- > 0;) {
area_mapping* mapping = (area_mapping*)fAreas.ItemAt(i);
if (mapping->server_area == serverArea) {
// we found the area we should remove
delete_area(mapping->local_area);
delete mapping;
fAreas.RemoveItem(i);
break;
}
}
}
status_t
ServerMemoryAllocator::AreaAndBaseFor(area_id serverArea, area_id& _area,
uint8*& _base)
{
// TODO: why not use a map?
for (int32 i = fAreas.CountItems(); i-- > 0;) {
area_mapping* mapping = (area_mapping*)fAreas.ItemAt(i);
if (mapping->server_area == serverArea) {
_area = mapping->local_area;
_base = mapping->local_base;
return B_OK;
}
}
return B_ERROR;
}
} // namespace BPrivate