void *malloc(int size)
{
t_header *tmp;
int total_size;
if (size <= 0)
return (NULL);
lock_thread();
if ((size % sizeof(int)) != 0)
size += (sizeof(int) - (size % sizeof(int)));
if ((tmp = (t_header *)findFreeBlock(size)) == NULL)
tmp = (t_header *)getMoreMem(size + sizeof(*tmp));
else
{
if (tmp->size - size >= THRESHOLD)
{
total_size = tmp->size + sizeof(*tmp);
tmp->size = size;
split_mid(tmp, total_size);
}
deleteFromFreeList(tmp);
}
unlock_thread();
if (tmp == NULL)
return (NULL);
return ((void *)((int)tmp + sizeof(*tmp)));
}
///
/// Given a size, traverse the arena from the start while looking for
/// a free chunk of memory that can satisfy the allocation
/// request. The arena free list is updated as the traversal is
/// performed.
///
void *PArena::allocFromUpdatedFreeList(
size_t sz, bool does_need_cache_line_alignment, bool does_need_logging)
{
#ifdef _FORCE_FAIL
fail_program();
#endif
// TODO: add support for cache line alignment
if (does_need_cache_line_alignment) return nullptr;
size_t actual_sz = PMallocUtil::get_actual_alloc_size(sz);
char *mem = static_cast<char*>(StartAddr_);
while (mem < (char*)CurrAllocAddr_)
{
size_t mem_sz = PMallocUtil::get_requested_alloc_size_from_mem(mem);
size_t actual_mem_sz = PMallocUtil::get_actual_alloc_size(mem_sz);
if (!PMallocUtil::is_mem_allocated(mem))
{
if (actual_sz > actual_mem_sz)
{
// This address may be in the free list already. But the
// implementation ensures no duplicates are added.
insertToFreeList(
PMallocUtil::get_bin_number(
*(reinterpret_cast<size_t*>(mem))),
mem);
mem += actual_mem_sz;
continue;
}
void *carved_mem = nullptr;
if (actual_sz + PMallocUtil::get_smallest_actual_alloc_size() <=
actual_mem_sz)
carved_mem = carveExtraMem(mem, actual_sz, actual_mem_sz);
else assert(actual_sz == actual_mem_sz);
// If we fail here, the above carving does not take effect
*(reinterpret_cast<size_t*>(mem)) = sz;
// If we fail here or anywhere above, no memory is leaked
#ifndef _DISABLE_ALLOC_LOGGING
if (does_need_logging) nvm_log_alloc(mem + sizeof(size_t));
#endif
*(reinterpret_cast<size_t*>(mem + sizeof(size_t))) = true;
// The above metadata updates are to the same cache line
NVM_FLUSH(mem);
// If we fail here, the above allocated memory may be leaked
deleteFromFreeList(PMallocUtil::get_bin_number(mem_sz), mem);
if (carved_mem)
insertToFreeList(
PMallocUtil::get_bin_number(
*(reinterpret_cast<size_t*>(carved_mem))),
carved_mem);
incrementActualAllocedStats(actual_sz);
return static_cast<void*>(mem + PMallocUtil::get_metadata_size());
}
mem += actual_mem_sz;
}
return nullptr;
}