Atomic.h

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//     ____   ______ __
//    / __ \ / ____// /
//   / /_/ // /    / /
//  / ____// /___ / /___   PixInsight Class Library
// /_/     \____//_____/   PCL 2.8.4
// ----------------------------------------------------------------------------
// pcl/Atomic.h - Released 2024-12-23T11:32:56Z
// ----------------------------------------------------------------------------
// This file is part of the PixInsight Class Library (PCL).
// PCL is a multiplatform C++ framework for development of PixInsight modules.
//
// Copyright (c) 2003-2024 Pleiades Astrophoto S.L. All Rights Reserved.
//
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// modification, is permitted provided that the following conditions are met:
//
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// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
// TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
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// ----------------------------------------------------------------------------
 
#ifndef __PCL_Atomic_h
#define __PCL_Atomic_h
 
 
#include <pcl/Defs.h>
 
#ifdef __PCL_WINDOWS
# include <intrin.h>
# pragma intrinsic (_InterlockedIncrement)
# pragma intrinsic (_InterlockedDecrement)
# pragma intrinsic (_InterlockedCompareExchange)
# pragma intrinsic (_InterlockedExchange)
# pragma intrinsic (_InterlockedExchangeAdd)
#endif
 
namespace pcl
{
 
// ----------------------------------------------------------------------------
 
class PCL_CLASS AtomicInt
{
public:
 
   AtomicInt( int value = 0 )
      : m_value( value )
   {
      // ### N.B.:
      // The default zero initialization is *critical* - DO NOT change it.
   }
 
   AtomicInt( const AtomicInt& ) = default;
 
   AtomicInt& operator =( const AtomicInt& ) = default;
 
   operator int() const
   {
      return m_value;
   }
 
   bool operator !() const
   {
      return m_value == 0;
   }
 
   bool operator ==( int x ) const
   {
      return m_value == x;
   }
 
   bool operator !=( int x ) const
   {
      return m_value != x;
   }
 
   AtomicInt& operator =( int x )
   {
      m_value = x;
      return *this;
   }
 
   int Load()
   {
      return FetchAndAdd( 0 );
   }
 
   void Store( int newValue )
   {
      (void)FetchAndStore( newValue );
   }
 
   void Increment()
   {
#ifdef __PCL_WINDOWS
      (void)_InterlockedIncrement( &m_value );
#else
      asm volatile( "lock\n\t"
                    "incl %0\n"
                     : "=m" (m_value)
                     : "m" (m_value)
                     : "memory", "cc" );
#endif
   }
 
   void Decrement()
   {
#ifdef __PCL_WINDOWS
      (void)_InterlockedDecrement( &m_value );
#else
      asm volatile( "lock\n\t"
                    "decl %0\n"
                     : "=m" (m_value)
                     : "m" (m_value)
                     : "memory", "cc" );
#endif
   }
 
   bool Reference()
   {
#ifdef __PCL_WINDOWS
      return _InterlockedIncrement( &m_value ) != 0;
#else
      uint8 result;
      asm volatile( "lock\n\t"
                    "incl %0\n\t"
                    "setnz %1\n"
                     : "=m" (m_value), "=qm" (result)
                     : "m" (m_value)
                     : "memory", "cc" );
      return result != 0;
#endif
   }
 
   bool Dereference()
   {
#ifdef __PCL_WINDOWS
      return _InterlockedDecrement( &m_value ) != 0;
#else
      uint8 result;
      asm volatile( "lock\n\t"
                    "decl %0\n\t"
                    "setnz %1\n"
                     : "=m" (m_value), "=qm" (result)
                     : "m" (m_value)
                     : "memory", "cc" );
      return result != 0;
#endif
   }
 
   bool TestAndSet( int expectedValue, int newValue )
   {
#ifdef __PCL_WINDOWS
      return _InterlockedCompareExchange( &m_value, newValue, expectedValue ) == expectedValue;
#else
      uint8 result;
      asm volatile( "lock\n\t"
                    "cmpxchgl %3,%2\n\t"
                    "setz %1\n"
                     : "=a" (newValue), "=qm" (result), "+m" (m_value)
                     : "r" (newValue), "0" (expectedValue)
                     : "memory", "cc" );
      return result != 0;
#endif
   }
 
   int FetchAndStore( int newValue )
   {
#ifdef __PCL_WINDOWS
      return _InterlockedExchange( &m_value, newValue );
#else
      asm volatile( "xchgl %0,%1\n"
                     : "=r" (newValue), "+m" (m_value)
                     : "0" (newValue)
                     : "memory" );
      return newValue;
#endif
   }
 
   int FetchAndAdd( int valueToAdd )
   {
#ifdef __PCL_WINDOWS
      return _InterlockedExchangeAdd( &m_value, valueToAdd );
#else
      asm volatile( "lock\n\t"
                    "xaddl %0,%1\n"
                     : "=r" (valueToAdd), "+m" (m_value)
                     : "0" (valueToAdd)
                     : "memory", "cc" );
      return valueToAdd;
#endif
   }
 
private:
 
#ifdef _MSC_VER
   __declspec(align(4)) volatile long m_value;
#else
   volatile int m_value __attribute__ ((aligned (4)));
#endif
};
 
// ----------------------------------------------------------------------------
 
// ----------------------------------------------------------------------------
 
class AutoReentrancyGuard
{
public:
 
   AutoReentrancyGuard( AtomicInt& guard )
      : m_guard( guard )
   {
      m_guarded = m_guard.TestAndSet( 0, 1 );
   }
 
   ~AutoReentrancyGuard()
   {
      if ( m_guarded )
         m_guard.Store( 0 );
   }
 
   operator bool() const volatile
   {
      return m_guarded;
   }
 
private:
 
   AtomicInt& m_guard;
   bool       m_guarded = false;
};
 
#define PCL_REENTRANCY_GUARDED_BEGIN                                          \
   {                                                                          \
      static pcl::AtomicInt __r_g__( 0 );                                     \
      volatile pcl::AutoReentrancyGuard __a_r_g__( __r_g__ );                 \
      if ( __a_r_g__ )                                                        \
      {
 
#define PCL_REENTRANCY_GUARDED_END                                            \
      }                                                                       \
   }
 
#define PCL_CLASS_REENTRANCY_GUARD                                            \
   mutable pcl::AtomicInt __pcl_guard__;
 
#define PCL_CLASS_REENTRANCY_GUARDED_BEGIN                                    \
   {                                                                          \
      volatile pcl::AutoReentrancyGuard __a_r_g__( __pcl_guard__ );           \
      if ( __a_r_g__ )                                                        \
      {
 
#define PCL_MEMBER_REENTRANCY_GUARD( member )                                 \
   mutable pcl::AtomicInt __pcl_guard_##member##__;
 
#define PCL_MEMBER_REENTRANCY_GUARDED_BEGIN( member )                         \
   {                                                                          \
      volatile pcl::AutoReentrancyGuard __a_r_g__( __pcl_guard_##member##__ );\
      if ( __a_r_g__ )                                                        \
      {
 
// ----------------------------------------------------------------------------
 
} // pcl
 
#endif  // __PCL_Atomic_h
 
// ----------------------------------------------------------------------------
// EOF pcl/Atomic.h - Released 2024-12-23T11:32:56Z