Merge "Tune LA's initial size better"

// The ideal size of a page allocation (these need to be multiples of 8)

#define INITIAL_PAGE_SIZE ((size_t)4096) // 4kb

#define INITIAL_PAGE_SIZE ((size_t)512) // 512b

#define MAX_PAGE_SIZE ((size_t)131072) // 128kb

// The maximum amount of wasted space we can have per page

// If this is too low, we will malloc too much

// Too high, and we may waste too much space

// Must be smaller than INITIAL_PAGE_SIZE

#define MAX_WASTE_SIZE ((size_t)1024)

#define MAX_WASTE_RATIO (0.5f)

#if ALIGN_DOUBLE

#define ALIGN_SZ (sizeof(double))

LinearAllocator::LinearAllocator()

    : mPageSize(INITIAL_PAGE_SIZE)

    , mMaxAllocSize(MAX_WASTE_SIZE)

    , mMaxAllocSize(INITIAL_PAGE_SIZE * MAX_WASTE_RATIO)

    , mNext(0)

    , mCurrentPage(0)

    , mPages(0)

    if (mCurrentPage && mPageSize < MAX_PAGE_SIZE) {

        mPageSize = min(MAX_PAGE_SIZE, mPageSize * 2);

        mMaxAllocSize = mPageSize * MAX_WASTE_RATIO;

        mPageSize = ALIGN(mPageSize);

    }

    mWastedSpace += mPageSize;