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1 /*
2  * Copyright (C) 2007 The Android Open Source Project
3  *
4  * Licensed under the Apache License, Version 2.0 (the "License");
5  * you may not use this file except in compliance with the License.
6  * You may obtain a copy of the License at
7  *
8  *      http://www.apache.org/licenses/LICENSE-2.0
9  *
10  * Unless required by applicable law or agreed to in writing, software
11  * distributed under the License is distributed on an "AS IS" BASIS,
12  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13  * See the License for the specific language governing permissions and
14  * limitations under the License.
15  */
16 
17 #ifndef ANDROID_HIDL_MEMORY_DEALER_H
18 #define ANDROID_HIDL_MEMORY_DEALER_H
19 
20 #include <android/hidl/memory/1.0/IMemory.h>
21 #include <android/hidl/memory/block/1.0/types.h>
22 #include <stdint.h>
23 #include <sys/types.h>
24 namespace android {
25 namespace hardware {
26 
27 class SimpleBestFitAllocator;
28 
29 // MemoryDealer allocates/deallocates blocks from a continuous memory region.
30 // It operates on size and offset and does not depend on any specific data types.
31 class MemoryDealer : public RefBase {
32    public:
33     /// Allocate a block with size. The allocated block is identified with an
34     /// offset. For example:
35     /// ssize_t K = dealer->allocateOffset(size);
36     /// On success, K is positive and points to a subregion K ~ (K+size-1) in the heap.
37     /// It's negative if the allocation fails.
38     virtual ssize_t allocateOffset(size_t size);
39     /// @param offset It points to the block that allocated with allocateOffset previously.
40     virtual void deallocate(size_t offset);
41     /// @param tag a string tag used to mark the dump message
42     virtual void dump(const char* tag) const;
43 
44     // allocations are aligned to some value. return that value so clients can account for it.
45     static size_t getAllocationAlignment();
46 
47     MemoryDealer(size_t size);
48     virtual ~MemoryDealer();
49 
50    protected:
51     SimpleBestFitAllocator* mAllocator;
52 };
53 
54 // It extends the generic MemoryDealer and uses
55 //  - sp<IMemory> to represent the main memory region.
56 //  - MemoryBlock to represent the the block to allocate/deallocate
57 class HidlMemoryDealer : public MemoryDealer {
58     using IMemory = ::android::hidl::memory::V1_0::IMemory;
59     using IMemoryToken = ::android::hidl::memory::token::V1_0::IMemoryToken;
60     using MemoryBlock = ::android::hidl::memory::block::V1_0::MemoryBlock;
61 
62    public:
63     static bool isOk(const MemoryBlock& memblk);
64     /// @param memory The memory size must align to 4096 bytes
65     static sp<HidlMemoryDealer> getInstance(const hidl_memory& memory);
66     virtual MemoryBlock allocate(size_t size);
67     virtual sp<IMemory> heap();
68 
69    protected:
70     /// @param heap It must be acquired with mapMemory(memory) with its
71     /// argument corresponds to the 2nd argument passed to HidlMemoryDealer.
72     HidlMemoryDealer(sp<IMemory> heap, const hidl_memory& memory);
73     sp<IMemory> mHeap;
74     sp<IMemoryToken> mToken;
75 };
76 
77 };  // namespace hardware
78 };  // namespace android
79 
80 #endif  // ANDROID_HIDL_MEMORY_DEALER_H
81