firebird-mirror/extern/libcds/cds/os/aix/timer.h

// Copyright (c) 2006-2018 Maxim Khizhinsky
//
// Distributed under the Boost Software License, Version 1.0. (See accompanying
// file LICENSE or copy at http://www.boost.org/LICENSE_1_0.txt)

#ifndef CDSLIB_OS_AIX_TIMER_H
#define CDSLIB_OS_AIX_TIMER_H

// Source: http://publib16.boulder.ibm.com/doc_link/en_US/a_doc_lib/libs/basetrf2/read_real_time.htm

#ifndef CDSLIB_OS_TIMER_H
#   error "<cds/os/timer.h> must be included"
#endif

#include <sys/time.h>
#include <sys/systemcfg.h>

//@cond none
namespace cds { namespace OS {
    inline namespace Aix {

        // High resolution timer
        class Timer {
            timebasestruct_t    m_tmStart;

        protected:
            static unsigned long long nano( native_timer_type const& nStart, native_timer_type const& nEnd )
            {
                return (((unsigned long long) (nEnd.tb_high - nStart.tb_high)) << 32) + (nEnd.tb_low - nStart.tb_low);
            }

        public:
            typedef timebasestruct_t    native_timer_type;
            typedef long long            native_duration_type;

            Timer() : m_tmStart( current()) {}

            static native_timer_type    current()
            {
                native_timer_type tm;
                current( &tm );
                return tm;
            }
            static void current( native_timer_type& tmr )
            {
                read_real_time( &tmr, sizeof(tmr));
                time_base_to_time( &tmr, sizeof(tmr ));
            }

            double reset()
            {
                native_timer_type tt;
                current( tt );
                double ret = nano( m_tmStart, tt ) / 1.0E9;
                m_tmStart = tt;
                return ret;
            }

            double duration( native_duration_type dur )
            {
                return double( dur ) / 1.0E9;
            }

            double duration()
            {
                return duration( native_duration());
            }

            native_duration_type    native_duration()
            {
                return native_duration( m_tmStart, current());
            }

            static native_duration_type    native_duration( native_timer_type const & nStart, native_timer_type const & nEnd )
            {
                return nano( nStart, nEnd );
            }

            static unsigned long long random_seed()
            {
                native_timer_type tmr;
                read_real_time( &tmr, sizeof(tmr));
                return ( ((unsigned long long)(tmr.tb_hight)) << 32 ) + tmr.tb_low;
            }
        };
    }    // namespace Aix

}}   // namespace cds::OS
//@endcond

#endif // #ifndef CDSLIB_OS_AIX_TIMER_H