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Diffstat (limited to 'gfx/angle/src/compiler/translator/PoolAlloc.h')
| -rwxr-xr-x | gfx/angle/src/compiler/translator/PoolAlloc.h | 303 |
1 files changed, 303 insertions, 0 deletions
diff --git a/gfx/angle/src/compiler/translator/PoolAlloc.h b/gfx/angle/src/compiler/translator/PoolAlloc.h new file mode 100755 index 000000000..f15b3e05d --- /dev/null +++ b/gfx/angle/src/compiler/translator/PoolAlloc.h @@ -0,0 +1,303 @@ +// +// Copyright (c) 2002-2010 The ANGLE Project Authors. All rights reserved. +// Use of this source code is governed by a BSD-style license that can be +// found in the LICENSE file. +// + +#ifndef COMPILER_TRANSLATOR_POOLALLOC_H_ +#define COMPILER_TRANSLATOR_POOLALLOC_H_ + +#ifdef _DEBUG +#define GUARD_BLOCKS // define to enable guard block sanity checking +#endif + +// +// This header defines an allocator that can be used to efficiently +// allocate a large number of small requests for heap memory, with the +// intention that they are not individually deallocated, but rather +// collectively deallocated at one time. +// +// This simultaneously +// +// * Makes each individual allocation much more efficient; the +// typical allocation is trivial. +// * Completely avoids the cost of doing individual deallocation. +// * Saves the trouble of tracking down and plugging a large class of leaks. +// +// Individual classes can use this allocator by supplying their own +// new and delete methods. +// +// STL containers can use this allocator by using the pool_allocator +// class as the allocator (second) template argument. +// + +#include <stddef.h> +#include <string.h> +#include <vector> + +// If we are using guard blocks, we must track each indivual +// allocation. If we aren't using guard blocks, these +// never get instantiated, so won't have any impact. +// + +class TAllocation { +public: + TAllocation(size_t size, unsigned char* mem, TAllocation* prev = 0) : + size(size), mem(mem), prevAlloc(prev) { + // Allocations are bracketed: + // [allocationHeader][initialGuardBlock][userData][finalGuardBlock] + // This would be cleaner with if (guardBlockSize)..., but that + // makes the compiler print warnings about 0 length memsets, + // even with the if() protecting them. +#ifdef GUARD_BLOCKS + memset(preGuard(), guardBlockBeginVal, guardBlockSize); + memset(data(), userDataFill, size); + memset(postGuard(), guardBlockEndVal, guardBlockSize); +#endif + } + + void check() const { + checkGuardBlock(preGuard(), guardBlockBeginVal, "before"); + checkGuardBlock(postGuard(), guardBlockEndVal, "after"); + } + + void checkAllocList() const; + + // Return total size needed to accomodate user buffer of 'size', + // plus our tracking data. + inline static size_t allocationSize(size_t size) { + return size + 2 * guardBlockSize + headerSize(); + } + + // Offset from surrounding buffer to get to user data buffer. + inline static unsigned char* offsetAllocation(unsigned char* m) { + return m + guardBlockSize + headerSize(); + } + +private: + void checkGuardBlock(unsigned char* blockMem, unsigned char val, const char* locText) const; + + // Find offsets to pre and post guard blocks, and user data buffer + unsigned char* preGuard() const { return mem + headerSize(); } + unsigned char* data() const { return preGuard() + guardBlockSize; } + unsigned char* postGuard() const { return data() + size; } + + size_t size; // size of the user data area + unsigned char* mem; // beginning of our allocation (pts to header) + TAllocation* prevAlloc; // prior allocation in the chain + + // Support MSVC++ 6.0 + const static unsigned char guardBlockBeginVal; + const static unsigned char guardBlockEndVal; + const static unsigned char userDataFill; + + const static size_t guardBlockSize; +#ifdef GUARD_BLOCKS + inline static size_t headerSize() { return sizeof(TAllocation); } +#else + inline static size_t headerSize() { return 0; } +#endif +}; + +// +// There are several stacks. One is to track the pushing and popping +// of the user, and not yet implemented. The others are simply a +// repositories of free pages or used pages. +// +// Page stacks are linked together with a simple header at the beginning +// of each allocation obtained from the underlying OS. Multi-page allocations +// are returned to the OS. Individual page allocations are kept for future +// re-use. +// +// The "page size" used is not, nor must it match, the underlying OS +// page size. But, having it be about that size or equal to a set of +// pages is likely most optimal. +// +class TPoolAllocator { +public: + TPoolAllocator(int growthIncrement = 8*1024, int allocationAlignment = 16); + + // + // Don't call the destructor just to free up the memory, call pop() + // + ~TPoolAllocator(); + + // + // Call push() to establish a new place to pop memory too. Does not + // have to be called to get things started. + // + void push(); + + // + // Call pop() to free all memory allocated since the last call to push(), + // or if no last call to push, frees all memory since first allocation. + // + void pop(); + + // + // Call popAll() to free all memory allocated. + // + void popAll(); + + // + // Call allocate() to actually acquire memory. Returns 0 if no memory + // available, otherwise a properly aligned pointer to 'numBytes' of memory. + // + void* allocate(size_t numBytes); + + // + // There is no deallocate. The point of this class is that + // deallocation can be skipped by the user of it, as the model + // of use is to simultaneously deallocate everything at once + // by calling pop(), and to not have to solve memory leak problems. + // + + // Catch unwanted allocations. + // TODO(jmadill): Remove this when we remove the global allocator. + void lock(); + void unlock(); + + private: + size_t alignment; // all returned allocations will be aligned at + // this granularity, which will be a power of 2 + size_t alignmentMask; + +#if !defined(ANGLE_TRANSLATOR_DISABLE_POOL_ALLOC) + friend struct tHeader; + + struct tHeader { + tHeader(tHeader* nextPage, size_t pageCount) : + nextPage(nextPage), + pageCount(pageCount) +#ifdef GUARD_BLOCKS + , lastAllocation(0) +#endif + { } + + ~tHeader() { +#ifdef GUARD_BLOCKS + if (lastAllocation) + lastAllocation->checkAllocList(); +#endif + } + + tHeader* nextPage; + size_t pageCount; +#ifdef GUARD_BLOCKS + TAllocation* lastAllocation; +#endif + }; + + struct tAllocState { + size_t offset; + tHeader* page; + }; + typedef std::vector<tAllocState> tAllocStack; + + // Track allocations if and only if we're using guard blocks + void* initializeAllocation(tHeader* block, unsigned char* memory, size_t numBytes) { +#ifdef GUARD_BLOCKS + new(memory) TAllocation(numBytes, memory, block->lastAllocation); + block->lastAllocation = reinterpret_cast<TAllocation*>(memory); +#endif + // This is optimized entirely away if GUARD_BLOCKS is not defined. + return TAllocation::offsetAllocation(memory); + } + + size_t pageSize; // granularity of allocation from the OS + size_t headerSkip; // amount of memory to skip to make room for the + // header (basically, size of header, rounded + // up to make it aligned + size_t currentPageOffset; // next offset in top of inUseList to allocate from + tHeader* freeList; // list of popped memory + tHeader* inUseList; // list of all memory currently being used + tAllocStack mStack; // stack of where to allocate from, to partition pool + + int numCalls; // just an interesting statistic + size_t totalBytes; // just an interesting statistic + +#else // !defined(ANGLE_TRANSLATOR_DISABLE_POOL_ALLOC) + std::vector<std::vector<void *>> mStack; +#endif + + TPoolAllocator& operator=(const TPoolAllocator&); // dont allow assignment operator + TPoolAllocator(const TPoolAllocator&); // dont allow default copy constructor + bool mLocked; +}; + + +// +// There could potentially be many pools with pops happening at +// different times. But a simple use is to have a global pop +// with everyone using the same global allocator. +// +extern TPoolAllocator* GetGlobalPoolAllocator(); +extern void SetGlobalPoolAllocator(TPoolAllocator* poolAllocator); + +// +// This STL compatible allocator is intended to be used as the allocator +// parameter to templatized STL containers, like vector and map. +// +// It will use the pools for allocation, and not +// do any deallocation, but will still do destruction. +// +template<class T> +class pool_allocator { +public: + typedef size_t size_type; + typedef ptrdiff_t difference_type; + typedef T* pointer; + typedef const T* const_pointer; + typedef T& reference; + typedef const T& const_reference; + typedef T value_type; + + template<class Other> + struct rebind { + typedef pool_allocator<Other> other; + }; + pointer address(reference x) const { return &x; } + const_pointer address(const_reference x) const { return &x; } + + pool_allocator() { } + + template<class Other> + pool_allocator(const pool_allocator<Other>& p) { } + + template <class Other> + pool_allocator<T>& operator=(const pool_allocator<Other>& p) { return *this; } + +#if defined(__SUNPRO_CC) && !defined(_RWSTD_ALLOCATOR) + // libCStd on some platforms have a different allocate/deallocate interface. + // Caller pre-bakes sizeof(T) into 'n' which is the number of bytes to be + // allocated, not the number of elements. + void* allocate(size_type n) { + return getAllocator().allocate(n); + } + void* allocate(size_type n, const void*) { + return getAllocator().allocate(n); + } + void deallocate(void*, size_type) {} +#else + pointer allocate(size_type n) { + return reinterpret_cast<pointer>(getAllocator().allocate(n * sizeof(T))); + } + pointer allocate(size_type n, const void*) { + return reinterpret_cast<pointer>(getAllocator().allocate(n * sizeof(T))); + } + void deallocate(pointer, size_type) {} +#endif // _RWSTD_ALLOCATOR + + void construct(pointer p, const T& val) { new ((void *)p) T(val); } + void destroy(pointer p) { p->T::~T(); } + + bool operator==(const pool_allocator& rhs) const { return true; } + bool operator!=(const pool_allocator& rhs) const { return false; } + + size_type max_size() const { return static_cast<size_type>(-1) / sizeof(T); } + size_type max_size(int size) const { return static_cast<size_type>(-1) / size; } + + TPoolAllocator& getAllocator() const { return *GetGlobalPoolAllocator(); } +}; + +#endif // COMPILER_TRANSLATOR_POOLALLOC_H_ |