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openmpi/opal/mca/timer/darwin/timer_darwin.h
2015-06-23 20:59:57 -07:00

77 строки
2.4 KiB
C

/*
* Copyright (c) 2004-2005 The Trustees of Indiana University and Indiana
* University Research and Technology
* Corporation. All rights reserved.
* Copyright (c) 2004-2014 The University of Tennessee and The University
* of Tennessee Research Foundation. All rights
* reserved.
* Copyright (c) 2004-2005 High Performance Computing Center Stuttgart,
* University of Stuttgart. All rights reserved.
* Copyright (c) 2004-2005 The Regents of the University of California.
* All rights reserved.
* $COPYRIGHT$
*
* Additional copyrights may follow
*
* $HEADER$
*/
#ifndef OPAL_MCA_TIMER_DARWIN_TIMER_DARWIN_H
#define OPAL_MCA_TIMER_DARWIN_TIMER_DARWIN_H
#include "opal_config.h"
#include <mach/mach_time.h>
typedef uint64_t opal_timer_t;
/* frequency in mhz */
OPAL_DECLSPEC extern opal_timer_t opal_timer_darwin_freq;
OPAL_DECLSPEC extern mach_timebase_info_data_t opal_timer_darwin_info;
OPAL_DECLSPEC extern opal_timer_t opal_timer_darwin_bias;
/**
* Use the pragmatic solution proposed at
* http://stackoverflow.com/questions/23378063/how-can-i-use-mach-absolute-time-without-overflowing/23378064#23378064
*/
static inline opal_timer_t
opal_timer_base_get_cycles(void)
{
uint64_t now = mach_absolute_time();
if( opal_timer_darwin_info.denom == 0 ) {
(void)mach_timebase_info(&opal_timer_darwin_info);
if( opal_timer_darwin_info.denom > 1024 ) {
double frac = (double)opal_timer_darwin_info.numer/opal_timer_darwin_info.denom;
opal_timer_darwin_info.denom = 1024;
opal_timer_darwin_info.numer = opal_timer_darwin_info.denom * frac + 0.5;
}
opal_timer_darwin_bias = now;
}
/* this is basically a wrapper around the "right" assembly to convert
the tick counter off the PowerPC Time Base into nanos. */
return (now - opal_timer_darwin_bias) * opal_timer_darwin_info.numer / opal_timer_darwin_info.denom;
}
static inline opal_timer_t
opal_timer_base_get_usec(void)
{
/* freq is in Hz, so this gives usec */
return opal_timer_base_get_cycles() / 1000;
}
static inline opal_timer_t
opal_timer_base_get_freq(void)
{
return opal_timer_darwin_freq;
}
#define OPAL_TIMER_CYCLE_NATIVE 0
#define OPAL_TIMER_CYCLE_SUPPORTED 1
#define OPAL_TIMER_USEC_NATIVE 1
#define OPAL_TIMER_USEC_SUPPORTED 1
#endif