libcxx initial import

git-svn-id: https://llvm.org/svn/llvm-project/libcxx/trunk@103490 91177308-0d34-0410-b5e6-96231b3b80d8

src/memory.cpp

@@ -0,0 +1,201 @@
+//===------------------------ memory.cpp ----------------------------------===//
+//
+// <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+
+#include "memory"
+#include <libkern/OSAtomic.h>
+
+_LIBCPP_BEGIN_NAMESPACE_STD
+
+namespace
+{
+
+template <class T>
+inline
+typename enable_if
+<
+    sizeof(T) * __CHAR_BIT__ == 32,
+    T
+>::type
+increment(T& t)
+{
+    return OSAtomicIncrement32Barrier((volatile int32_t*)&t);
+}
+
+template <class T>
+inline
+typename enable_if
+<
+    sizeof(T) * __CHAR_BIT__ == 32,
+    T
+>::type
+decrement(T& t)
+{
+    return OSAtomicDecrement32Barrier((volatile int32_t*)&t);
+}
+
+#ifndef __ppc__
+
+template <class T>
+inline
+typename enable_if
+<
+    sizeof(T) * __CHAR_BIT__ == 64,
+    T
+>::type
+increment(T& t)
+{
+    return OSAtomicIncrement64Barrier((volatile int64_t*)&t);
+}
+
+template <class T>
+inline
+typename enable_if
+<
+    sizeof(T) * __CHAR_BIT__ == 64,
+    T
+>::type
+decrement(T& t)
+{
+    return OSAtomicDecrement64Barrier((volatile int64_t*)&t);
+}
+
+#endif
+
+}  // 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_);
+}
+
+void
+__shared_count::__release_shared()
+{
+    if (decrement(__shared_owners_) == -1)
+        __on_zero_shared();
+}
+
+__shared_weak_count::~__shared_weak_count()
+{
+}
+
+void
+__shared_weak_count::__add_shared()
+{
+    __shared_count::__add_shared();
+    __add_weak();
+}
+
+void
+__shared_weak_count::__add_weak()
+{
+    increment(__shared_weak_owners_);
+}
+
+void
+__shared_weak_count::__release_shared()
+{
+    __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 (OSAtomicCompareAndSwapLongBarrier(object_owners,
+                                              object_owners+1,
+                                              &__shared_owners_))
+        {
+            __add_weak();
+            return this;
+        }
+        object_owners = __shared_owners_;
+    }
+    return 0;
+}
+
+const void*
+__shared_weak_count::__get_deleter(const type_info&) const
+{
+    return 0;
+}
+
+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