16ce982290
git-svn-id: file:///srv/svn/repos/haiku/trunk/current@4568 a95241bf-73f2-0310-859d-f6bbb57e9c96
151 lines
4.3 KiB
C++
151 lines
4.3 KiB
C++
/*
|
|
* Copyright (c) 2003 Marcus Overhagen
|
|
*
|
|
* Permission is hereby granted, free of charge, to any person obtaining a
|
|
* copy of this software and associated documentation files (the "Software"),
|
|
* to deal in the Software without restriction, including without limitation
|
|
* the rights to use, copy, modify, merge, publish, distribute, sublicense,
|
|
* and/or sell copies of the Software, and to permit persons to whom the
|
|
* Software is furnished to do so, subject to the following conditions:
|
|
*
|
|
* The above copyright notice and this permission notice shall be included in
|
|
* all copies or substantial portions of the Software.
|
|
*
|
|
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
|
|
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
|
|
* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
|
|
* AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
|
|
* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
|
|
* FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
|
|
* DEALINGS IN THE SOFTWARE.
|
|
*/
|
|
|
|
#include <BlockCache.h>
|
|
#include <Debug.h>
|
|
#include <string.h>
|
|
#include <stdlib.h>
|
|
#include <new>
|
|
|
|
#define MAGIC1 0x9183f4d9
|
|
#define MAGIC2 0xa6b3c87d
|
|
|
|
struct BBlockCache::_FreeBlock {
|
|
DEBUG_ONLY( uint32 magic1; )
|
|
_FreeBlock *next;
|
|
DEBUG_ONLY( uint32 magic2; )
|
|
};
|
|
|
|
|
|
// The requirements set by the BeBook's description of the destructor,
|
|
// as well as Get() function, allowing the caller to dispose of the
|
|
// memory, do not allow to allocate one large block to be used as pool.
|
|
// Thus we need to create multiple small ones.
|
|
// We maintain a list of free blocks.
|
|
|
|
BBlockCache::BBlockCache(uint32 blockCount,
|
|
size_t blockSize,
|
|
uint32 allocationType)
|
|
: fFreeList(0),
|
|
fBlockSize(blockSize),
|
|
fFreeBlocks(0),
|
|
fBlockCount(blockCount),
|
|
fLocker("some BBlockCache lock"),
|
|
fAlloc(0),
|
|
fFree(0)
|
|
{
|
|
switch (allocationType) {
|
|
case B_OBJECT_CACHE:
|
|
fAlloc = &operator new[];
|
|
fFree = &operator delete[];
|
|
break;
|
|
case B_MALLOC_CACHE:
|
|
default:
|
|
fAlloc = &malloc;
|
|
fFree = &free;
|
|
break;
|
|
}
|
|
|
|
// To properly maintain a list of free buffers, a buffer must be
|
|
// large enough to contain the _FreeBlock struct that is used.
|
|
if (blockSize < sizeof(_FreeBlock))
|
|
blockSize = sizeof(_FreeBlock);
|
|
|
|
// should have at least one block
|
|
if (blockCount == 0)
|
|
blockCount = 1;
|
|
|
|
// create blocks and put them into the free list
|
|
while (blockCount--) {
|
|
_FreeBlock *block = reinterpret_cast<_FreeBlock *>(fAlloc(blockSize));
|
|
if (!block)
|
|
break;
|
|
fFreeBlocks++;
|
|
block->next = fFreeList;
|
|
fFreeList = block;
|
|
DEBUG_ONLY(block->magic1 = MAGIC1);
|
|
DEBUG_ONLY(block->magic2 = MAGIC2 + (uint32)block->next);
|
|
}
|
|
}
|
|
|
|
BBlockCache::~BBlockCache()
|
|
{
|
|
// walk the free list and deallocate all blocks
|
|
fLocker.Lock();
|
|
while (fFreeList) {
|
|
ASSERT(fFreeList->magic1 == MAGIC1);
|
|
ASSERT(fFreeList->magic2 == MAGIC2 + (uint32)fFreeList->next);
|
|
void *pointer = fFreeList;
|
|
fFreeList = fFreeList->next;
|
|
DEBUG_ONLY(memset(pointer, 0xCC, sizeof(_FreeBlock)));
|
|
fFree(pointer);
|
|
}
|
|
fLocker.Unlock();
|
|
}
|
|
|
|
void *
|
|
BBlockCache::Get(size_t blockSize)
|
|
{
|
|
if (!fLocker.Lock())
|
|
return 0;
|
|
void *pointer;
|
|
if (blockSize == fBlockSize && fFreeList != 0) {
|
|
// we can take a block from the list
|
|
ASSERT(fFreeList->magic1 == MAGIC1);
|
|
ASSERT(fFreeList->magic2 == MAGIC2 + (uint32)fFreeList->next);
|
|
pointer = fFreeList;
|
|
fFreeList = fFreeList->next;
|
|
fFreeBlocks--;
|
|
DEBUG_ONLY(memset(pointer, 0xCC, sizeof(_FreeBlock)));
|
|
} else {
|
|
if (blockSize < sizeof(_FreeBlock))
|
|
blockSize = sizeof(_FreeBlock);
|
|
pointer = fAlloc(blockSize);
|
|
DEBUG_ONLY(if (pointer) memset(pointer, 0xCC, sizeof(_FreeBlock)));
|
|
}
|
|
fLocker.Unlock();
|
|
return pointer;
|
|
}
|
|
|
|
void
|
|
BBlockCache::Save(void *pointer, size_t blockSize)
|
|
{
|
|
if (!fLocker.Lock())
|
|
return;
|
|
if (blockSize == fBlockSize && fFreeBlocks < fBlockCount) {
|
|
// the block needs to be returned to the cache
|
|
_FreeBlock *block = reinterpret_cast<_FreeBlock *>(pointer);
|
|
block->next = fFreeList;
|
|
fFreeList = block;
|
|
fFreeBlocks++;
|
|
DEBUG_ONLY(block->magic1 = MAGIC1);
|
|
DEBUG_ONLY(block->magic2 = MAGIC2 + (uint32)block->next);
|
|
} else {
|
|
DEBUG_ONLY(memset(pointer, 0xCC, sizeof(_FreeBlock)));
|
|
fFree(pointer);
|
|
}
|
|
fLocker.Unlock();
|
|
}
|
|
|
|
void BBlockCache::_ReservedBlockCache1() {}
|
|
void BBlockCache::_ReservedBlockCache2() {}
|