gfx/skia/trunk/src/core/SkTObjectPool.h@deefc01c0e14 (annotated)
gfx/skia/trunk/src/core/SkTObjectPool.h
Thu, 15 Jan 2015 21:03:48 +0100
- author
- Michael Schloh von Bennewitz <michael@schloh.com>
- date
- Thu, 15 Jan 2015 21:03:48 +0100
- branch
- TOR_BUG_9701
- changeset 11
- deefc01c0e14
- permissions
- -rw-r--r--
Integrate friendly tips from Tor colleagues to make (or not) 4.5 alpha 3;
This includes removal of overloaded (but unused) methods, and addition of
a overlooked call to DataStruct::SetData(nsISupports, uint32_t, bool.)
| michael@0 | 1 | /* |
| michael@0 | 2 | * Copyright 2014 Google Inc. |
| michael@0 | 3 | * |
| michael@0 | 4 | * Use of this source code is governed by a BSD-style license that can be |
| michael@0 | 5 | * found in the LICENSE file. |
| michael@0 | 6 | */ |
| michael@0 | 7 | |
| michael@0 | 8 | #ifndef SkFreeList_DEFINED |
| michael@0 | 9 | #define SkFreeList_DEFINED |
| michael@0 | 10 | |
| michael@0 | 11 | #include "SkTInternalSList.h" |
| michael@0 | 12 | |
| michael@0 | 13 | /** |
| michael@0 | 14 | * An implementation of a self growing pool of objects. |
| michael@0 | 15 | * It maintains a pool of fully initialized objects. If an attempt is made to |
| michael@0 | 16 | * acquire one, and there are none left, it makes some more. |
| michael@0 | 17 | * It does not automatically reclaim them, they have to be given back to it. |
| michael@0 | 18 | * Constructors will be called on objects allocated by the pool at allocation |
| michael@0 | 19 | * time. |
| michael@0 | 20 | * All allocated objects will be destroyed and memory will be reclaimed when |
| michael@0 | 21 | * the pool is destroyed, so the pool must survive longer than you are using |
| michael@0 | 22 | * any item taken from it. |
| michael@0 | 23 | */ |
| michael@0 | 24 | template<typename T, int numItemsPerBlock = 4096/sizeof(T)> class SkTObjectPool { |
| michael@0 | 25 | public: |
| michael@0 | 26 | SkTObjectPool() {} |
| michael@0 | 27 | ~SkTObjectPool() { |
| michael@0 | 28 | while (!fBlocks.isEmpty()) { |
| michael@0 | 29 | SkDELETE(fBlocks.pop()); |
| michael@0 | 30 | } |
| michael@0 | 31 | } |
| michael@0 | 32 | |
| michael@0 | 33 | /** |
| michael@0 | 34 | * Get an item from the pool. |
| michael@0 | 35 | * If the pool has no free items, it will allocate and construct some more. |
| michael@0 | 36 | * The returned item is only valid as long as the pool has not been |
| michael@0 | 37 | * destroyed, at that point all memory allocated by grow will have been |
| michael@0 | 38 | * reclaimed. |
| michael@0 | 39 | * This method is *not* thread safe. |
| michael@0 | 40 | */ |
| michael@0 | 41 | T* acquire() { |
| michael@0 | 42 | if (fAvailable.isEmpty()) { |
| michael@0 | 43 | grow(); |
| michael@0 | 44 | } |
| michael@0 | 45 | return fAvailable.pop(); |
| michael@0 | 46 | } |
| michael@0 | 47 | |
| michael@0 | 48 | /** |
| michael@0 | 49 | * Release an item into the pool. |
| michael@0 | 50 | * The item does not have to have come from the pool, but if it did not |
| michael@0 | 51 | * it must have a lifetime greater than the pool does. |
| michael@0 | 52 | * This method is *not* thread safe. |
| michael@0 | 53 | */ |
| michael@0 | 54 | void release(T* entry) { |
| michael@0 | 55 | fAvailable.push(entry); |
| michael@0 | 56 | } |
| michael@0 | 57 | |
| michael@0 | 58 | /** |
| michael@0 | 59 | * Takes all the items from an SkTInternalSList and adds them back to this |
| michael@0 | 60 | * pool. The other list will be left empty. |
| michael@0 | 61 | */ |
| michael@0 | 62 | void releaseAll(SkTInternalSList<T>* other) { |
| michael@0 | 63 | fAvailable.pushAll(other); |
| michael@0 | 64 | } |
| michael@0 | 65 | |
| michael@0 | 66 | /** |
| michael@0 | 67 | * Returns the number of items immediately available without having to |
| michael@0 | 68 | * construct any new ones. |
| michael@0 | 69 | */ |
| michael@0 | 70 | int available() const { return fAvailable.getCount(); } |
| michael@0 | 71 | |
| michael@0 | 72 | /** |
| michael@0 | 73 | * Returns the number of blocks of items the pool has allocated so far. |
| michael@0 | 74 | */ |
| michael@0 | 75 | int blocks() const { return fBlocks.getCount(); } |
| michael@0 | 76 | |
| michael@0 | 77 | private: |
| michael@0 | 78 | /** |
| michael@0 | 79 | * The type for a new block of entries for the list. |
| michael@0 | 80 | */ |
| michael@0 | 81 | struct Block { |
| michael@0 | 82 | T entries[numItemsPerBlock]; |
| michael@0 | 83 | SK_DECLARE_INTERNAL_SLIST_INTERFACE(Block); |
| michael@0 | 84 | }; |
| michael@0 | 85 | SkTInternalSList<Block> fBlocks; |
| michael@0 | 86 | SkTInternalSList<T> fAvailable; |
| michael@0 | 87 | |
| michael@0 | 88 | /** |
| michael@0 | 89 | * When the free list runs out of items, this method is called to allocate |
| michael@0 | 90 | * a new block of them. |
| michael@0 | 91 | * It calls the constructors and then pushes the nodes into the available |
| michael@0 | 92 | * list. |
| michael@0 | 93 | */ |
| michael@0 | 94 | void grow() { |
| michael@0 | 95 | Block* block = SkNEW(Block); |
| michael@0 | 96 | fBlocks.push(block); |
| michael@0 | 97 | for(int index = 0; index < numItemsPerBlock; ++index) { |
| michael@0 | 98 | fAvailable.push(&block->entries[index]); |
| michael@0 | 99 | } |
| michael@0 | 100 | } |
| michael@0 | 101 | |
| michael@0 | 102 | }; |
| michael@0 | 103 | |
| michael@0 | 104 | #endif |
