Function LFAllocImpl

library/cpp/lfalloc/lf_allocX64.h:1512–1577

/////////////////////////////////////////////////////////////////////

//////////////////////////////////////////////////////////////////////////
static Y_FORCE_INLINE void* LFAllocImpl(size_t _nSize) {
#if defined(LFALLOC_DBG)
    size_t size = _nSize;
    _nSize += sizeof(TAllocHeader);
#endif

    IncrementCounter(CT_USER_ALLOC, _nSize);

    int nSizeIdx;
    if (_nSize > 512) {
        if (_nSize > N_MAX_FAST_SIZE) {
            void* ptr = LargeBlockAlloc(_nSize, CT_LARGE_ALLOC);
#if defined(LFALLOC_DBG)
            ptr = TrackAllocation(ptr, size, N_SIZES);
#endif
            return ptr;
        }
        nSizeIdx = size2idxArr2[(_nSize - 1) >> 8];
    } else
        nSizeIdx = size2idxArr1[1 + (((int)_nSize - 1) >> 3)];

    IncrementCounter(CT_SMALL_ALLOC, nSizeIdxToSize[nSizeIdx]);

    // check per thread buffer
    TThreadAllocInfo* thr = pThreadInfo;
    if (!thr) {
        AllocThreadInfo();
        thr = pThreadInfo;
        if (!thr) {
            void* ptr = LFAllocNoCache(nSizeIdx, MEM_DEFRAG);
#if defined(LFALLOC_DBG)
            ptr = TrackAllocation(ptr, size, nSizeIdx);
#endif
            return ptr;
        }
    }
    {
        int& freePtrIdx = thr->FreePtrIndex[nSizeIdx];
        if (freePtrIdx < THREAD_BUF) {
            void* ptr = thr->FreePtrs[nSizeIdx][freePtrIdx++];
#if defined(LFALLOC_DBG)
            ptr = TrackAllocation(ptr, size, nSizeIdx);
#endif
            return ptr;
        }

        // try to alloc from global free list
        char* buf[FL_GROUP_SIZE];
        int count = TakeBlocksFromGlobalFreeList(nSizeIdx, buf);
        if (count == 0) {
            count = LFAllocNoCacheMultiple(nSizeIdx, buf);
            if (count == 0) {
                NMalloc::AbortFromCorruptedAllocator("no way LFAllocNoCacheMultiple() can fail");
            }
        }
        char** dstBuf = thr->FreePtrs[nSizeIdx] + freePtrIdx - 1;
        for (int i = 0; i < count - 1; ++i)
            dstBuf[-i] = buf[i];