Method ialloc

libCacheSim/dataStructure/sparsepp/spp_dlalloc.h:3416–3541

Common support for independent_X routines, handling all of the combinations that can result. The opts arg has: bit 0 set if all elements are same size (using sizes[0]) bit 1 set if elements should be zeroed */

    bit 1 set if elements should be zeroed
*/
void** malloc_state::ialloc(size_t n_elements, size_t* sizes, int opts,
                            void* chunks[])
{

    size_t    element_size;   // chunksize of each element, if all same
    size_t    contents_size;  // total size of elements
    size_t    array_size;     // request size of pointer array
    void*     mem;            // malloced aggregate space
    mchunkptr p;              // corresponding chunk
    size_t    remainder_size; // remaining bytes while splitting
    void**    marray;         // either "chunks" or malloced ptr array
    mchunkptr array_chunk;    // chunk for malloced ptr array
    flag_t    was_enabled;    // to disable mmap
    size_t    size;
    size_t    i;

    mparams.ensure_initialization();
    // compute array length, if needed
    if (chunks != 0)
    {
        if (n_elements == 0)
            return chunks; // nothing to do
        marray = chunks;
        array_size = 0;
    }
    else
    {
        // if empty req, must still return chunk representing empty array
        if (n_elements == 0)
            return (void**)internal_malloc(0);
        marray = 0;
        array_size = request2size(n_elements * (sizeof(void*)));
    }

    // compute total element size
    if (opts & 0x1)
    {
        // all-same-size
        element_size = request2size(*sizes);
        contents_size = n_elements * element_size;
    }
    else
    {
        // add up all the sizes
        element_size = 0;
        contents_size = 0;
        for (i = 0; i != n_elements; ++i)
            contents_size += request2size(sizes[i]);
    }

    size = contents_size + array_size;

    /*
      Allocate the aggregate chunk.  First disable direct-mmapping so
      malloc won't use it, since we would not be able to later
      free/realloc space internal to a segregated mmap region.
    */
    was_enabled = use_mmap();