replicant-frameworks_native/include/binder/MemoryDealer.h

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/*
* Copyright (C) 2007 The Android Open Source Project
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
#ifndef ANDROID_MEMORY_DEALER_H
#define ANDROID_MEMORY_DEALER_H
#include <stdint.h>
#include <sys/types.h>
#include <binder/IMemory.h>
#include <utils/threads.h>
#include <binder/MemoryHeapBase.h>
namespace android {
// ----------------------------------------------------------------------------
class String8;
/*
* interface for implementing a "heap". A heap basically provides
* the IMemoryHeap interface for cross-process sharing and the
* ability to map/unmap pages within the heap.
*/
class HeapInterface : public virtual BnMemoryHeap
{
public:
// all values must be page-aligned
virtual sp<IMemory> mapMemory(size_t offset, size_t size) = 0;
HeapInterface();
protected:
virtual ~HeapInterface();
};
// ----------------------------------------------------------------------------
/*
* interface for implementing an allocator. An allocator provides
* methods for allocating and freeing memory blocks and dumping
* its state.
*/
class AllocatorInterface : public RefBase
{
public:
enum {
PAGE_ALIGNED = 0x00000001
};
virtual size_t allocate(size_t size, uint32_t flags = 0) = 0;
virtual status_t deallocate(size_t offset) = 0;
virtual size_t size() const = 0;
virtual void dump(const char* what, uint32_t flags = 0) const = 0;
virtual void dump(String8& res,
const char* what, uint32_t flags = 0) const = 0;
AllocatorInterface();
protected:
virtual ~AllocatorInterface();
};
// ----------------------------------------------------------------------------
/*
* concrete implementation of HeapInterface on top of mmap()
*/
class SharedHeap : public HeapInterface, public MemoryHeapBase
{
public:
SharedHeap();
SharedHeap(size_t size, uint32_t flags = 0, char const * name = NULL);
virtual ~SharedHeap();
virtual sp<IMemory> mapMemory(size_t offset, size_t size);
};
// ----------------------------------------------------------------------------
/*
* A simple templatized doubly linked-list implementation
*/
template <typename NODE>
class LinkedList
{
NODE* mFirst;
NODE* mLast;
public:
LinkedList() : mFirst(0), mLast(0) { }
bool isEmpty() const { return mFirst == 0; }
NODE const* head() const { return mFirst; }
NODE* head() { return mFirst; }
NODE const* tail() const { return mLast; }
NODE* tail() { return mLast; }
void insertAfter(NODE* node, NODE* newNode) {
newNode->prev = node;
newNode->next = node->next;
if (node->next == 0) mLast = newNode;
else node->next->prev = newNode;
node->next = newNode;
}
void insertBefore(NODE* node, NODE* newNode) {
newNode->prev = node->prev;
newNode->next = node;
if (node->prev == 0) mFirst = newNode;
else node->prev->next = newNode;
node->prev = newNode;
}
void insertHead(NODE* newNode) {
if (mFirst == 0) {
mFirst = mLast = newNode;
newNode->prev = newNode->next = 0;
} else {
insertBefore(mFirst, newNode);
}
}
void insertTail(NODE* newNode) {
if (mLast == 0) insertBeginning(newNode);
else insertAfter(mLast, newNode);
}
NODE* remove(NODE* node) {
if (node->prev == 0) mFirst = node->next;
else node->prev->next = node->next;
if (node->next == 0) mLast = node->prev;
else node->next->prev = node->prev;
return node;
}
};
/*
* concrete implementation of AllocatorInterface using a simple
* best-fit allocation scheme
*/
class SimpleBestFitAllocator : public AllocatorInterface
{
public:
SimpleBestFitAllocator(size_t size);
virtual ~SimpleBestFitAllocator();
virtual size_t allocate(size_t size, uint32_t flags = 0);
virtual status_t deallocate(size_t offset);
virtual size_t size() const;
virtual void dump(const char* what, uint32_t flags = 0) const;
virtual void dump(String8& res,
const char* what, uint32_t flags = 0) const;
private:
struct chunk_t {
chunk_t(size_t start, size_t size)
: start(start), size(size), free(1), prev(0), next(0) {
}
size_t start;
size_t size : 28;
int free : 4;
mutable chunk_t* prev;
mutable chunk_t* next;
};
ssize_t alloc(size_t size, uint32_t flags);
chunk_t* dealloc(size_t start);
void dump_l(const char* what, uint32_t flags = 0) const;
void dump_l(String8& res, const char* what, uint32_t flags = 0) const;
static const int kMemoryAlign;
mutable Mutex mLock;
LinkedList<chunk_t> mList;
size_t mHeapSize;
};
// ----------------------------------------------------------------------------
class MemoryDealer : public RefBase
{
public:
enum {
READ_ONLY = MemoryHeapBase::READ_ONLY,
PAGE_ALIGNED = AllocatorInterface::PAGE_ALIGNED
};
// creates a memory dealer with the SharedHeap and SimpleBestFitAllocator
MemoryDealer(size_t size, uint32_t flags = 0, const char* name = 0);
// provide a custom heap but use the SimpleBestFitAllocator
MemoryDealer(const sp<HeapInterface>& heap);
// provide both custom heap and allocotar
MemoryDealer(
const sp<HeapInterface>& heap,
const sp<AllocatorInterface>& allocator);
virtual ~MemoryDealer();
virtual sp<IMemory> allocate(size_t size, uint32_t flags = 0);
virtual void deallocate(size_t offset);
virtual void dump(const char* what, uint32_t flags = 0) const;
sp<IMemoryHeap> getMemoryHeap() const { return heap(); }
sp<AllocatorInterface> getAllocator() const { return allocator(); }
private:
const sp<HeapInterface>& heap() const;
const sp<AllocatorInterface>& allocator() const;
class Allocation : public BnMemory {
public:
Allocation(const sp<MemoryDealer>& dealer,
ssize_t offset, size_t size, const sp<IMemory>& memory);
virtual ~Allocation();
virtual sp<IMemoryHeap> getMemory(ssize_t* offset, size_t* size) const;
private:
sp<MemoryDealer> mDealer;
ssize_t mOffset;
size_t mSize;
sp<IMemory> mMemory;
};
sp<HeapInterface> mHeap;
sp<AllocatorInterface> mAllocator;
};
// ----------------------------------------------------------------------------
}; // namespace android
#endif // ANDROID_MEMORY_DEALER_H