atomicity.h File Reference

#include <bits/c++config.h>
#include <bits/gthr.h>
#include <bits/atomic_word.h>

Go to the source code of this file.

Macros
#define	_GLIBCXX_READ_MEM_BARRIER   __asm __volatile ("":::"memory")
#define	_GLIBCXX_WRITE_MEM_BARRIER   __asm __volatile ("":::"memory")

Functions
namespace __gnu_cxx	_GLIBCXX_VISIBILITY (default)

Detailed Description

This file is a GNU extension to the Standard C++ Library.

Macro Definition Documentation

#define _GLIBCXX_READ_MEM_BARRIER   __asm __volatile ("":::"memory")

#define _GLIBCXX_WRITE_MEM_BARRIER   __asm __volatile ("":::"memory")

Function Documentation

namespace __gnu_cxx _GLIBCXX_VISIBILITY

(

default

)

{
_GLIBCXX_BEGIN_NAMESPACE_VERSION

  // Functions for portable atomic access.
  // To abstract locking primitives across all thread policies, use:
  // __exchange_and_add_dispatch
  // __atomic_add_dispatch
#ifdef _GLIBCXX_ATOMIC_BUILTINS
  static inline _Atomic_word 
  __exchange_and_add(volatile _Atomic_word* __mem, int __val)
  { return __atomic_fetch_add(__mem, __val, __ATOMIC_ACQ_REL); }

  static inline void
  __atomic_add(volatile _Atomic_word* __mem, int __val)
  { __atomic_fetch_add(__mem, __val, __ATOMIC_ACQ_REL); }
#else
  _Atomic_word
  __attribute__ ((__unused__))
  __exchange_and_add(volatile _Atomic_word*, int) throw ();

  void
  __attribute__ ((__unused__))
  __atomic_add(volatile _Atomic_word*, int) throw ();
#endif

  static inline _Atomic_word
  __exchange_and_add_single(_Atomic_word* __mem, int __val)
  {
    _Atomic_word __result = *__mem;
    *__mem += __val;
    return __result;
  }

  static inline void
  __atomic_add_single(_Atomic_word* __mem, int __val)
  { *__mem += __val; }

  static inline _Atomic_word
  __attribute__ ((__unused__))
  __exchange_and_add_dispatch(_Atomic_word* __mem, int __val)
  {
#ifdef __GTHREADS
    if (__gthread_active_p())
      return __exchange_and_add(__mem, __val);
    else
      return __exchange_and_add_single(__mem, __val);
#else
    return __exchange_and_add_single(__mem, __val);
#endif
  }

  static inline void
  __attribute__ ((__unused__))
  __atomic_add_dispatch(_Atomic_word* __mem, int __val)
  {
#ifdef __GTHREADS
    if (__gthread_active_p())
      __atomic_add(__mem, __val);
    else
      __atomic_add_single(__mem, __val);
#else
    __atomic_add_single(__mem, __val);
#endif
  }

_GLIBCXX_END_NAMESPACE_VERSION
} // namespace