static void
init_heap_space(size_t min_size, size_t max_size)
{
size_t pagesize, alloc_size, reserve_size, freesize_pre, freesize_post;
unsigned int min_num_segments, max_num_segments, bitmap_bits;
void *p;
pagesize = GetPageSize();
if (SEGMENT_SIZE % pagesize != 0)
sml_fatal(0, "SEGMENT_SIZE is not aligned in page size.");
alloc_size = ALIGNSIZE(min_size, SEGMENT_SIZE);
reserve_size = ALIGNSIZE(max_size, SEGMENT_SIZE);
if (alloc_size < SEGMENT_SIZE)
alloc_size = SEGMENT_SIZE;
if (reserve_size < alloc_size)
reserve_size = alloc_size;
min_num_segments = alloc_size / SEGMENT_SIZE;
max_num_segments = reserve_size / SEGMENT_SIZE;
p = ReservePage(HEAP_BEGIN_ADDR, SEGMENT_SIZE + reserve_size);
if (p == ReservePageError)
sml_fatal(0, "failed to alloc virtual memory.");
freesize_post = (uintptr_t)p & (SEGMENT_SIZE - 1);
if (freesize_post == 0) {
ReleasePage(p + reserve_size, SEGMENT_SIZE);
} else {
freesize_pre = SEGMENT_SIZE - freesize_post;
ReleasePage(p, freesize_pre);
p = (char*)p + freesize_pre;
ReleasePage(p + reserve_size, freesize_post);
}
heap_space.begin = p;
heap_space.end = (char*)p + reserve_size;
heap_space.min_num_segments = min_num_segments;
heap_space.max_num_segments = max_num_segments;
heap_space.num_committed = 0;
heap_space.extend_step = min_num_segments > 0 ? min_num_segments : 1;
bitmap_bits = ALIGNSIZE(max_num_segments, BITPTR_WORDBITS);
heap_space.bitmap = xmalloc(bitmap_bits / CHAR_BIT);
memset(heap_space.bitmap, 0, bitmap_bits / CHAR_BIT);
extend_heap(min_num_segments);
}
//------------------------------------------------------------------------------
void stPlainDiskPageManager::DisposePage(stPage * page){
stPageID * next;
// Append to free list
next = (stPageID *)page->GetData();
*next = header->Available;
header->Available = page->GetPageID();
WritePage(page);
// Update header
header->UsedPages--;
WriteHeaderPage(headerPage);
// Free resources
ReleasePage(page);
}//end stPlainDiskPageManager::DisposePage
void
sml_heap_free()
{
ReleasePage(heap_space.begin,
(char*)heap_space.end - (char*)heap_space.begin);
}
