Mercurial > octave
diff liboctave/util/oct-refcount.h @ 27447:396996f1dad0
use std::atomic to implement refcount class
* oct-atomic.h, oct-atomic.c: New files.
* liboctave/util/module.mk: Update.
* dim-vector.h (dim_vector::increment_count,
dim_vector::decrement_count): New functions. Use them instead of
OCTAVE_ATOMIC_INCREMENT and OCTAVE_ATOMIC_DECREMENT macros.
* Array.h (Array<T>::jit_ref_count): Return int, not pointer. Change
all uses.
* jit-typeinfo.h, jit-typeinfo.cc (jit_array::m_ref_count): Store
integer, not pointer. Change all uses.
* oct-refcount.h (OCTAVE_ATOMIC_INCREMENT, OCTAVE_ATOMIC_DECREMENT,
OCTAVE_ATOMIC_POST_INCREMENT, OCTAVE_ATOMIC_POST_DECREMENT):
Delete macros.
(refcount::m_count): Now std::atomic<T> instead of T.
(refcount::operator++, refcount::operator--): Define using std::atomic
operators instead of increment macros.
(refcount::get): Delete.
(class refcount): Explicitly delete assignment operator and copy
constructor. Explicitly use default destructor. Eliminate all uses
of assignment as directly setting the reference count value apart from
initialization should not be needed.
| author | John W. Eaton <jwe@octave.org> |
|---|---|
| date | Wed, 25 Sep 2019 17:57:08 -0400 |
| parents | 8498dccc15c7 |
| children | b442ec6dda5c |
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--- a/liboctave/util/oct-refcount.h Thu Sep 26 11:32:52 2019 -0400 +++ b/liboctave/util/oct-refcount.h Wed Sep 25 17:57:08 2019 -0400 @@ -25,48 +25,10 @@ #include "octave-config.h" -#if (defined (OCTAVE_ENABLE_ATOMIC_REFCOUNT) \ - && (defined (__GNUC__) || defined (_MSC_VER))) - -# if defined (__GNUC__) - -# define OCTAVE_ATOMIC_INCREMENT(x) __sync_add_and_fetch (x, 1) -# define OCTAVE_ATOMIC_DECREMENT(x) __sync_add_and_fetch (x, -1) -# define OCTAVE_ATOMIC_POST_INCREMENT(x) __sync_fetch_and_add (x, 1) -# define OCTAVE_ATOMIC_POST_DECREMENT(x) __sync_fetch_and_add (x, -1) - -# elif defined (_MSC_VER) - -# include <intrin.h> - -# define OCTAVE_ATOMIC_INCREMENT(x) \ - _InterlockedIncrement (static_cast<long *> (x)) - -# define OCTAVE_ATOMIC_DECREMENT(x) \ - _InterlockedDecrement (static_cast<long *> (x)) - -# define OCTAVE_ATOMIC_POST_INCREMENT(x) \ - _InterlockedExchangeAdd (static_cast<long *> (x)) - -# define OCTAVE_ATOMIC_POST_DECREMENT(x) \ - _InterlockedExchangeAdd (static_cast<long *> (x)) - -# endif - -#else - -// Generic non-locking versions - -# define OCTAVE_ATOMIC_INCREMENT(x) ++(*(x)) -# define OCTAVE_ATOMIC_DECREMENT(x) --(*(x)) -# define OCTAVE_ATOMIC_POST_INCREMENT(x) (*(x))++ -# define OCTAVE_ATOMIC_POST_DECREMENT(x) (*(x))-- - -#endif +#include <atomic> namespace octave { - // Encapsulates a reference counter. template <typename T> @@ -80,30 +42,36 @@ : m_count (initial_count) { } + refcount (const refcount&) = delete; + + refcount& operator = (const refcount&) = delete; + + ~refcount (void) = default; + // Increment/Decrement. int is postfix. count_type operator++ (void) { - return OCTAVE_ATOMIC_INCREMENT (&m_count); + return ++m_count; } count_type operator++ (int) { - return OCTAVE_ATOMIC_POST_INCREMENT (&m_count); + return m_count++; } count_type operator-- (void) { - return OCTAVE_ATOMIC_DECREMENT (&m_count); + return --m_count; } count_type operator-- (int) { - return OCTAVE_ATOMIC_POST_DECREMENT (&m_count); + return m_count--; } count_type value (void) const { - return static_cast<count_type const volatile&> (m_count); + return m_count.load (); } operator count_type (void) const @@ -111,14 +79,9 @@ return value (); } - count_type * get (void) - { - return &m_count; - } - private: - count_type m_count; + std::atomic<T> m_count; }; }