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Diffstat (limited to 'contrib/libc++/src/memory.cpp')
-rw-r--r-- | contrib/libc++/src/memory.cpp | 215 |
1 files changed, 215 insertions, 0 deletions
diff --git a/contrib/libc++/src/memory.cpp b/contrib/libc++/src/memory.cpp new file mode 100644 index 0000000..3884a2b --- /dev/null +++ b/contrib/libc++/src/memory.cpp @@ -0,0 +1,215 @@ +//===------------------------ 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. +// +//===----------------------------------------------------------------------===// + +#define _LIBCPP_BUILDING_MEMORY +#include "memory" +#include "mutex" +#include "thread" + +_LIBCPP_BEGIN_NAMESPACE_STD + +namespace +{ + +template <class T> +inline T +increment(T& t) _NOEXCEPT +{ + return __sync_add_and_fetch(&t, 1); +} + +template <class T> +inline T +decrement(T& t) _NOEXCEPT +{ + return __sync_add_and_fetch(&t, -1); +} + +} // namespace + +const allocator_arg_t allocator_arg = allocator_arg_t(); + +bad_weak_ptr::~bad_weak_ptr() _NOEXCEPT {} + +const char* +bad_weak_ptr::what() const _NOEXCEPT +{ + return "bad_weak_ptr"; +} + +__shared_count::~__shared_count() +{ +} + +void +__shared_count::__add_shared() _NOEXCEPT +{ + increment(__shared_owners_); +} + +bool +__shared_count::__release_shared() _NOEXCEPT +{ + if (decrement(__shared_owners_) == -1) + { + __on_zero_shared(); + return true; + } + return false; +} + +__shared_weak_count::~__shared_weak_count() +{ +} + +void +__shared_weak_count::__add_shared() _NOEXCEPT +{ + __shared_count::__add_shared(); +} + +void +__shared_weak_count::__add_weak() _NOEXCEPT +{ + increment(__shared_weak_owners_); +} + +void +__shared_weak_count::__release_shared() _NOEXCEPT +{ + if (__shared_count::__release_shared()) + __release_weak(); +} + +void +__shared_weak_count::__release_weak() _NOEXCEPT +{ + if (decrement(__shared_weak_owners_) == -1) + __on_zero_shared_weak(); +} + +__shared_weak_count* +__shared_weak_count::lock() _NOEXCEPT +{ + long object_owners = __shared_owners_; + while (object_owners != -1) + { + if (__sync_bool_compare_and_swap(&__shared_owners_, + object_owners, + object_owners+1)) + return this; + object_owners = __shared_owners_; + } + return 0; +} + +#ifndef _LIBCPP_NO_RTTI + +const void* +__shared_weak_count::__get_deleter(const type_info&) const _NOEXCEPT +{ + return 0; +} + +#endif // _LIBCPP_NO_RTTI + +#if __has_feature(cxx_atomic) + +static const std::size_t __sp_mut_count = 16; +static mutex mut_back[__sp_mut_count]; + +_LIBCPP_CONSTEXPR __sp_mut::__sp_mut(void* p) _NOEXCEPT + : _(p) +{ +} + +void +__sp_mut::lock() _NOEXCEPT +{ + mutex& m = *static_cast<mutex*>(_); + unsigned count = 0; + while (!m.try_lock()) + { + if (++count > 16) + { + m.lock(); + break; + } + this_thread::yield(); + } +} + +void +__sp_mut::unlock() _NOEXCEPT +{ + static_cast<mutex*>(_)->unlock(); +} + +__sp_mut& +__get_sp_mut(const void* p) +{ + static __sp_mut muts[__sp_mut_count] + { + &mut_back[ 0], &mut_back[ 1], &mut_back[ 2], &mut_back[ 3], + &mut_back[ 4], &mut_back[ 5], &mut_back[ 6], &mut_back[ 7], + &mut_back[ 8], &mut_back[ 9], &mut_back[10], &mut_back[11], + &mut_back[12], &mut_back[13], &mut_back[14], &mut_back[15] + }; + return muts[hash<const void*>()(p) & (__sp_mut_count-1)]; +} + +#endif // __has_feature(cxx_atomic) + +void +declare_reachable(void*) +{ +} + +void +declare_no_pointers(char*, size_t) +{ +} + +void +undeclare_no_pointers(char*, size_t) +{ +} + +pointer_safety +get_pointer_safety() _NOEXCEPT +{ + 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); + size_t d = static_cast<size_t>(p2 - p1); + if (d <= space - size) + { + r = p2; + ptr = r; + space -= d; + } + } + return r; +} + +_LIBCPP_END_NAMESPACE_STD |