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Updated documentation

pull/211/merge
Jeffrey Walton 2016-07-03 01:53:55 -04:00
parent 739c8e5c14
commit 0f8871c9c9
1 changed files with 7 additions and 6 deletions
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13
misc.h
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@ -219,10 +219,11 @@ struct NewObject
//! \brief A memory barrier
//! \details MEMORY_BARRIER attempts to ensure reads and writes are completed
//! in the absence of a language synchronization point. It is used by the
//! Singleton class if the compiler supports it. The use is provided at the
//! customary check points in a double-checked initialization.
//! \details Internally, MEMORY_BARRIER uses <tt>intrinsic(_ReadWriteBarrier)</tt>,
//! <tt>_ReadWriteBarrier()</tt> or <tt>__asm__("" ::: "memory")</tt>.
//! Singleton class if the compiler supports it. The barrier is provided at the
//! customary places in a double-checked initialization.
//! \details Internally, MEMORY_BARRIER uses <tt>std::atomic_thread_fence</tt> if
//! C++11 atomics are available. Otherwise, <tt>intrinsic(_ReadWriteBarrier)</tt>,
//! <tt>_ReadWriteBarrier()</tt> or <tt>__asm__("" ::: "memory")</tt> is used.
#define MEMORY_BARRIER ...
#else
#if defined(CRYPTOPP_CXX11_ATOMICS)
@ -246,8 +247,8 @@ struct NewObject
//! \details This class safely initializes a static object in a multithreaded environment. For C++03
//! and below it will do so without using locks for portability. If two threads call Ref() at the same
//! time, they may get back different references, and one object may end up being memory leaked. This
//! is by design. For C++11 and above, a standard double-checked locking pattern with memory fences
//! is used. The locks and fences are standard and do not hinder portability.
//! is by design. For C++11 and above, a standard double-checked locking pattern with thread fences
//! are used. The locks and fences are standard and do not hinder portability.
//! \sa <A HREF="http://preshing.com/20130930/double-checked-locking-is-fixed-in-cpp11/">Double-Checked Locking is Fixed In C++11</A>
template <class T, class F = NewObject<T>, int instance=0>
class Singleton