Files
snmalloc/src/pal/pal_open_enclave.h
2019-11-26 15:50:22 +00:00

65 lines
1.5 KiB
C++

#pragma once
#include "pal_plain.h"
#ifdef OPEN_ENCLAVE
extern "C" const void* __oe_get_heap_base();
extern "C" const void* __oe_get_heap_end();
extern "C" void* oe_memset(void* p, int c, size_t size);
extern "C" void oe_abort();
namespace snmalloc
{
class PALOpenEnclave
{
std::atomic<void*> oe_base;
public:
/**
* Bitmap of PalFeatures flags indicating the optional features that this
* PAL supports.
*/
static constexpr uint64_t pal_features = AlignedAllocation;
static void error(const char* const str)
{
UNUSED(str);
oe_abort();
}
template<bool committed>
void* reserve(size_t* size, size_t align) noexcept
{
if (oe_base == 0)
{
void* dummy = NULL;
oe_base.compare_exchange_strong(
dummy, const_cast<void*>(__oe_get_heap_base()));
}
void* old_base = oe_base;
void* old_base2 = old_base;
void* next_base;
auto end = __oe_get_heap_end();
do
{
old_base2 = old_base;
auto new_base = pointer_align_up(old_base, align);
next_base = pointer_offset(new_base, *size);
if (next_base > end)
error("Out of memory");
} while (oe_base.compare_exchange_strong(old_base, next_base));
*size = pointer_diff(old_base2, next_base);
return old_base;
}
template<bool page_aligned = false>
void zero(void* p, size_t size) noexcept
{
oe_memset(p, 0, size);
}
};
}
#endif