blob: 3e3e9107ba431eb345841aaf57f546508b0d9f8f [file] [log] [blame]
//===------------------------ memory.cpp ----------------------------------===//
//
// The LLVM Compiler Infrastructure
//
// This file is dual licensed under the MIT and the University of Illinois Open
// Source Licenses. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
#include "memory"
_LIBCPP_BEGIN_NAMESPACE_STD
namespace
{
template <class T>
inline T
increment(T& t)
{
return __sync_add_and_fetch(&t, 1);
}
template <class T>
inline T
decrement(T& t)
{
return __sync_add_and_fetch(&t, -1);
}
} // namespace
const allocator_arg_t allocator_arg = allocator_arg_t();
bad_weak_ptr::~bad_weak_ptr() throw() {}
const char*
bad_weak_ptr::what() const throw()
{
return "bad_weak_ptr";
}
__shared_count::~__shared_count()
{
}
void
__shared_count::__add_shared()
{
increment(__shared_owners_);
}
bool
__shared_count::__release_shared()
{
if (decrement(__shared_owners_) == -1)
{
__on_zero_shared();
return true;
}
return false;
}
__shared_weak_count::~__shared_weak_count()
{
}
void
__shared_weak_count::__add_shared()
{
__shared_count::__add_shared();
}
void
__shared_weak_count::__add_weak()
{
increment(__shared_weak_owners_);
}
void
__shared_weak_count::__release_shared()
{
if (__shared_count::__release_shared())
__release_weak();
}
void
__shared_weak_count::__release_weak()
{
if (decrement(__shared_weak_owners_) == -1)
__on_zero_shared_weak();
}
__shared_weak_count*
__shared_weak_count::lock()
{
long object_owners = __shared_owners_;
while (object_owners != -1)
{
if (__sync_bool_compare_and_swap(&__shared_owners_,
object_owners,
object_owners+1))
{
__add_weak();
return this;
}
object_owners = __shared_owners_;
}
return 0;
}
#ifndef _LIBCPP_NO_RTTI
const void*
__shared_weak_count::__get_deleter(const type_info&) const
{
return 0;
}
#endif // _LIBCPP_NO_RTTI
void
declare_reachable(void*)
{
}
void
declare_no_pointers(char*, size_t)
{
}
void
undeclare_no_pointers(char*, size_t)
{
}
pointer_safety
get_pointer_safety()
{
return pointer_safety::relaxed;
}
void*
__undeclare_reachable(void* p)
{
return p;
}
void*
align(size_t alignment, size_t size, void*& ptr, size_t& space)
{
void* r = nullptr;
if (size <= space)
{
char* p1 = static_cast<char*>(ptr);
char* p2 = (char*)((size_t)(p1 + (alignment - 1)) & -alignment);
ptrdiff_t d = p2 - p1;
if (d <= space - size)
{
r = p2;
ptr = r;
space -= d;
}
}
return r;
}
_LIBCPP_END_NAMESPACE_STD