Viewing file:  timer.h (3.35 KB) -rw-r--r--
Select action/file-type:
 (+) |  (+) |  (+) | Code (+) | Session (+) |  (+) | SDB (+) |  (+) |  (+) |  (+) |  (+) |  (+) |
/* -*- Mode: C; c-basic-offset:4 ; indent-tabs-mode:nil -*- */
/*
* Copyright (c) 2004-2005 The Trustees of Indiana University and Indiana
* University Research and Technology
* Corporation. All rights reserved.
* Copyright (c) 2004-2005 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 (c) 2015 Los Alamos National Security, LLC. All rights
* reserved.
* $COPYRIGHT$
*
* Additional copyrights may follow
*
* $HEADER$
*/
/**
* @file
*
* High resolution timer / cycle counter
*
* High resolution timer / cycle counter interface. This interface is
* intended to hide the system-dependent nature of timers that provide
* higher resolution and lower calling cost than gettimeofday().
* Unlike most component interfaces, there should only ever be one
* component available to be built on a particular platform.
* Therefore, a number of #defines are available to determine how well
* the platform supports high resolution timers:
*
* <UL>
* <LI><PRE>OPAL_TIMER_CYCLE_NATIVE</PRE> Whether
* opal_timer_base_get_cycle() is implemented directly or computed
* from some other data (such as a high res timer)</LI>
* <LI><PRE>OPAL_TIMER_CYCLE_SUPPORTED</PRE> Whether
* opal_timer_base_get_cycle() is supported on the current
* platform.</LI>
* <LI><PRE>OPAL_TIMER_USEC_SUPPORTED</PRE> Whether
* opal_timer_base_get_usec() is supported on the current
* platform or implemented on top of gettimeofday(), which
* may be unsuitable for some uses.
* </UL>
*
* The cycle count may not be the cycle count of the CPU itself, if
* there is another sufficiently close counter with better behavior
* characteristics (like the Time Base counter on many Power/PowerPC
* platforms). The function opal_timer_base_get_freq() returns the
* frequency of the cycle counter in use, *NOT* the frequency of the
* main CPU.
*
* Unless otherwise noted, no attempt is made to cope with the the
* differences in counters on SMP machines. If your process switches
* CPUs, your timer results may change.
*
* Build time priorities are allocated as follows:
*
* - 0 gettimeofday() wrapper
* - 10 Assembly timers with bad frequency search (Linux)
* - 20 NIC software stack (QSNet, Myrinet?)
* - 30 Operating systems with native interfaces
*/
#ifndef OPAL_MCA_TIMER_TIMER_H
#define OPAL_MCA_TIMER_TIMER_H
#include "opal_config.h"
#include "opal/mca/mca.h"
#include "opal/mca/base/base.h"
/**
* Structure for timer components.
*/
struct opal_timer_base_component_2_0_0_t {
/** MCA base component */
mca_base_component_t timerc_version;
/** MCA base data */
mca_base_component_data_t timerc_data;
};
/**
* Convenience typedef
*/
typedef struct opal_timer_base_component_2_0_0_t opal_timer_base_component_2_0_0_t;
/*
* Macro for use in components that are of type timer
*/
#define OPAL_TIMER_BASE_VERSION_2_0_0 \
OPAL_MCA_BASE_VERSION_2_1_0("timer", 2, 0, 0)
#endif /* OPAL_MCA_TIMER_TIMER_H */
|