stl.h

用c++包装好的线程库,直接拿来使用,提高效率.

// Threading support -*- C++ -*-

// This file is part of C++ threads, and provides threading
// support for the standard template library.
//

#ifndef GCC_VERSION
#define GCC_VERSION ( __GNUC__ * 1000 + __GNUC_MINOR__ )
#endif

#if (GCC_VERSION < 3000)

# include <threads/alloc.h>

#else

/*
 * Copyright (c) 1997-1999
 * Silicon Graphics Computer Systems, Inc.
 *
 * Permission to use, copy, modify, distribute and sell this software
 * and its documentation for any purpose is hereby granted without fee,
 * provided that the above copyright notice appear in all copies and
 * that both that copyright notice and this permission notice appear
 * in supporting documentation.  Silicon Graphics makes no
 * representations about the suitability of this software for any
 * purpose.  It is provided "as is" without express or implied warranty.
 */

#ifndef __SGI_STL_INTERNAL_THREADS_H
#define __SGI_STL_INTERNAL_THREADS_H

#define __STL_THREADS

#include <threads/spinlock.h>

extern "C" {

# include <sys/types.h>

};

namespace std
{

  // Class _Refcount_Base provides a type, _RC_t, a data member,
  // _M_ref_count, and member functions _M_incr and _M_decr, which perform
  // atomic preincrement/predecrement.  The constructor initializes 
  // _M_ref_count.
  
  struct _Refcount_Base
  {
    typedef size_t _RC_t;
    volatile _RC_t _M_ref_count;
    mutex_t _M_ref_count_lock;

    _Refcount_Base(_RC_t __n) : _M_ref_count(__n) {};

    void _M_incr() 
    {
      mutex_lock(&_M_ref_count_lock);
      ++_M_ref_count;
      mutex_unlock(&_M_ref_count_lock);
    }

    _RC_t _M_decr() 
    {
      mutex_lock(&_M_ref_count_lock);
      volatile _RC_t __tmp = --_M_ref_count;
      mutex_unlock(&_M_ref_count_lock);
      return __tmp;
    }
  };

  // We use a template here only to get a unique initialized instance.
  template<int __dummy>
  struct _Swap_lock_struct {
    static mutex_t _S_swap_lock;
  };

  template<int __dummy>
  mutex_t _Swap_lock_struct<__dummy>::_S_swap_lock = DEFAULTMUTEX;

  // This should be portable, but performance is expected
  // to be quite awful.  This really needs platform specific
  // code.
  inline unsigned long _Atomic_swap(unsigned long * __p, unsigned long __q) 
    {
      mutex_lock(&_Swap_lock_struct<0>::_S_swap_lock);
      unsigned long __result = *__p;
      *__p = __q;
      mutex_unlock(&_Swap_lock_struct<0>::_S_swap_lock);
      return __result;
    }

  // Locking class.  Note that this class *does not have a constructor*.
  // It must be initialized either statically, with __STL_MUTEX_INITIALIZER,
  // or dynamically, by explicitly calling the _M_initialize member function.
  // (This is similar to the ways that a pthreads mutex can be initialized.)
  // There are explicit member functions for acquiring and releasing the lock.

  // There is no constructor because static initialization is essential for
  // some uses, and only a class aggregate (see section 8.5.1 of the C++
  // standard) can be initialized that way.  That means we must have no
  // constructors, no base classes, no virtual functions, and no private or
  // protected members.

  // Helper struct.  This is a workaround for various compilers that don't
  // handle static variables in inline functions properly.
  template <int __inst>
    struct _STL_mutex_spin {
      enum { __low_max = 30, __high_max = 1000 };
      // Low if we suspect uniprocessor, high for multiprocessor.

      static unsigned __max;
      static unsigned __last;
    };

  template <int __inst>
    unsigned _STL_mutex_spin<__inst>::__max = _STL_mutex_spin<__inst>::__low_max;

  template <int __inst>
    unsigned _STL_mutex_spin<__inst>::__last = 0;

  struct _STL_mutex_lock
  {
    mutex_t _M_lock;

    void _M_initialize()   { _M_lock = DEFAULTMUTEX; };
    void _M_acquire_lock() { mutex_lock(&_M_lock);   };
    void _M_release_lock() { mutex_unlock(&_M_lock); };
  };

# define __STL_MUTEX_INITIALIZER = { DEFAULTMUTEX }

  // A locking class that uses _STL_mutex_lock.  The constructor takes a
  // reference to an _STL_mutex_lock, and acquires a lock.  The
  // destructor releases the lock.  It's not clear that this is exactly
  // the right functionality.  It will probably change in the future.

  struct _STL_auto_lock
  {
    _STL_mutex_lock& _M_lock;
  
    _STL_auto_lock(_STL_mutex_lock& __lock) : _M_lock(__lock)
    { _M_lock._M_acquire_lock(); }
    ~_STL_auto_lock() { _M_lock._M_release_lock(); }

    private:
    void operator=(const _STL_auto_lock&);
    _STL_auto_lock(const _STL_auto_lock&);
  };

} // namespace std

#endif /* __SGI_STL_INTERNAL_THREADS_H */


#endif // GCC_VERSION