#include "moar.h"

void * MVM_region_alloc(MVMThreadContext *tc, MVMRegionAlloc *al, size_t bytes) {

    char *result = NULL;

#if !defined(MVM_CAN_UNALIGNED_INT64) || !defined(MVM_CAN_UNALIGNED_NUM64)

    /* Round up size to next multiple of 8, to ensure alignment. */

    bytes = (bytes + 7) & ~7;

#endif

    if (al->block != NULL && (al->block->alloc + bytes) < al->block->limit) {

        result = al->block->alloc;

        al->block->alloc += bytes;

    } else {

        /* No block, or block was full. Add another. */

        MVMRegionBlock *block = MVM_malloc(sizeof(MVMRegionBlock));

        size_t buffer_size = al->block == NULL

            ? MVM_REGIONALLOC_FIRST_MEMBLOCK_SIZE

            : MVM_REGIONALLOC_MEMBLOCK_SIZE;

        if (buffer_size < bytes)

            buffer_size = bytes;

        block->buffer = MVM_calloc(1, buffer_size);

        block->alloc  = block->buffer;

        block->limit  = block->buffer + buffer_size;

        block->prev   = al->block;

        al->block     = block;

        /* Now allocate out of it. */

        result = block->alloc;

        block->alloc += bytes;

    }

    return result;

}

void MVM_region_destroy(MVMThreadContext *tc, MVMRegionAlloc *alloc) {

    MVMRegionBlock *block = alloc->block;

    /* Free all of the allocated memory. */

    while (block) {

        MVMRegionBlock *prev = block->prev;

        MVM_free(block->buffer);

        MVM_free(block);

        block = prev;

    }

    alloc->block = NULL;

}