geode-client-native/src/tests/fwklib/PaceMeter.hpp

/*=========================================================================
* Copyright (c) 2002-2014 Pivotal Software, Inc. All Rights Reserved.
 * This product is protected by U.S. and international copyright
 * and intellectual property laws. Pivotal products are covered by
 * more patents listed at http://www.pivotal.io/patents.
* All Rights Reserved.
*=========================================================================
*/

#ifndef __PaceMeter_hpp__
#define __PaceMeter_hpp__

#include "fwklib/FwkLog.hpp"
#include <ace/Time_Value.h>
#include <ace/OS.h>


#ifdef WIN32
#include <windows.h>
#else
#include <sys/time.h>
#include <sys/types.h>
#include <unistd.h>
#endif

namespace gemfire {
namespace testframework {
  
class Waiter {
  public:
  Waiter() {}
  void waitUntil( ACE_Time_Value * until ) {
    ACE_Time_Value now = ACE_OS::gettimeofday();
    if ( *until < now ) {
      return;
    }
    ACE_Time_Value interval = *until - now;
#ifdef WIN32
    WaitForSingleObject( GetCurrentThread(), interval.msec() );
#else
    struct timeval tv;
    tv.tv_sec = interval.sec();
    tv.tv_usec = interval.usec();
    select( 1, NULL, NULL, NULL, &tv );
#endif
  }
};
  
class PaceMeter {
  private:
  int32_t m_opsLimit;
  int32_t m_current;
  int32_t m_waitSeconds;
  int32_t m_waitMicros;
  ACE_Time_Value m_timeLimit;
  
  public:
  PaceMeter( int32_t ops, int32_t seconds = 1 ) :
    m_opsLimit( 0 ),
    m_current( 0 ),
    m_waitSeconds( 0 ),
    m_waitMicros( 0 ),
    m_timeLimit( 0 ) {
    if ( ( ops <= 0 ) || ( seconds <= 0 ) ) {
      return;
    }
    
    double os = ( double )ops / ( double )seconds;
    
    if ( ( ops / seconds ) < 1 ) { // This is for the "seconds per op" case
      double dsec = 1 / os;
      m_opsLimit = 1;
      m_waitSeconds = ( int32_t )dsec;
      dsec -= m_waitSeconds;
      m_waitMicros = ( int32_t )( dsec * 1000000 );
    }
    else {
      int32_t ios = ops / seconds;
      m_waitSeconds = 0;
      
      if ( ios < 4 ) {
        m_opsLimit = ios;
        m_waitSeconds = 1;
        m_waitMicros = 0;
      }
      else {
        if ( ( ios % 3 ) >= ( ios % 4 ) ) {
          m_opsLimit = ios / 4;
          m_waitMicros = 250000;
        }
        else {
          m_opsLimit = ios / 3;
          m_waitMicros = 333333;
        }
      }
    }
//    FWKINFO( "Args: " << ops << ", " << seconds << "     Ops: " << m_opsLimit << "  Seconds: " << m_waitSeconds << "   Micros: " << m_waitMicros ); 
  }
  
  void checkPace() {
    if ( m_opsLimit == 0 ) {
      return;
    }
    if ( m_current == 0 ) {
//      FWKINFO( "Setting time limit to Seconds: " << m_waitSeconds << "   Micros: " << m_waitMicros ); 
      m_timeLimit = ACE_OS::gettimeofday() + ACE_Time_Value( m_waitSeconds, m_waitMicros ); 
    }
    if ( ++m_current >= m_opsLimit ) {
//      FWKINFO( "m_current is: " << m_current << "  waiting." ); 
      m_current = 0;
      Waiter waiter;
      waiter.waitUntil( &m_timeLimit );
    }
  }
};

} // namespace testframework
} // namespace gemfire

#endif // __PaceMeter_hpp__