wtime.c

mpi并行计算的c++代码 可用vc或gcc编译通过 可以用来搭建并行计算试验环境

/* -*- Mode: C; c-basic-offset:4 ; -*- */
/*  $Id: wtime.c,v 1.11 2005/10/28 15:54:12 gropp Exp $
 *
 *  (C) 2001 by Argonne National Laboratory.
 *      See COPYRIGHT in top-level directory.
 */

#include "mpiimpl.h"
/* -- Begin Profiling Symbol Block for routine MPI_Wtime */
#if defined(HAVE_PRAGMA_WEAK)
#pragma weak MPI_Wtime = PMPI_Wtime
#elif defined(HAVE_PRAGMA_HP_SEC_DEF)
#pragma _HP_SECONDARY_DEF PMPI_Wtime  MPI_Wtime
#elif defined(HAVE_PRAGMA_CRI_DUP)
#pragma _CRI duplicate MPI_Wtime as PMPI_Wtime
#endif
/* -- End Profiling Symbol Block */

/* Define MPICH_MPI_FROM_PMPI if weak symbols are not supported to build
   the MPI routines */
#ifndef MPICH_MPI_FROM_PMPI
#define MPI_Wtime PMPI_Wtime
#endif

#undef FUNCNAME
#define FUNCNAME MPI_Wtime

/*@
  MPI_Wtime - Returns an elapsed time on the calling processor

  Return value:
  Time in seconds since an arbitrary time in the past.

  Notes:
  This is intended to be a high-resolution, elapsed (or wall) clock.
  See 'MPI_WTICK' to determine the resolution of 'MPI_WTIME'.
  If the attribute 'MPI_WTIME_IS_GLOBAL' is defined and true, then the
  value is synchronized across all processes in 'MPI_COMM_WORLD'.  

  Notes for Fortran:
  This is a function, declared as 'DOUBLE PRECISION MPI_WTIME()' in Fortran.

.see also: MPI_Wtick, MPI_Comm_get_attr, MPI_Attr_get
@*/
double MPI_Wtime( void )
{
    double d;
    MPID_Time_t t;
    MPID_MPI_STATE_DECL(MPID_STATE_MPI_WTIME);

    MPIR_ERRTEST_INITIALIZED_ORDIE();

    MPID_CS_ENTER();
    MPID_MPI_FUNC_ENTER(MPID_STATE_MPI_WTIME);
    MPID_Wtime( &t );
    MPID_Wtime_todouble( &t, &d );
    MPID_MPI_FUNC_EXIT(MPID_STATE_MPI_WTIME);
    MPID_CS_EXIT();
    return d;
}