text: /*
   * Copyright (c) 2004-2007 The Trustees of Indiana University and Indiana
   *                         University Research and Technology
   *                         Corporation.  All rights reserved.
   * Copyright (c) 2004-2018 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) 2006-2022 Cisco Systems, Inc.  All rights reserved
   * Copyright (c) 2015      Research Organization for Information Science
   *                         and Technology (RIST). All rights reserved.
   * Copyright (c) 2017      IBM Corporation.  All rights reserved.
   * Copyright (c) 2017      Los Alamos National Security, LLC. All rights
   *                         reserved.
   * $COPYRIGHT$
   *
   * Additional copyrights may follow
   *
   * $HEADER$
   */
  #include "ompi_config.h"
  
  #ifdef HAVE_SYS_TIME_H
  #include <sys/time.h>
  #endif
  #include <stdio.h>
  #ifdef HAVE_TIME_H
  #include <time.h>
  #endif  /* HAVE_TIME_H */
  
  #include "ompi/mpi/c/bindings.h"
  #include "ompi/runtime/mpiruntime.h"
  #include "ompi/runtime/ompi_spc.h"
  
  #include "opal/util/clock_gettime.h"
  
  #if OMPI_BUILD_MPI_PROFILING
  #if OPAL_HAVE_WEAK_SYMBOLS
  #pragma weak MPI_Wtime = PMPI_Wtime
  #endif
  #define MPI_Wtime PMPI_Wtime
  /**
   * Have a base time set on the first call to wtime, to improve the range
   * and accuracy of the user visible timer.
   * More info: https://github.com/mpi-forum/mpi-issues/issues/77#issuecomment-369663119
   */
  struct timespec ompi_wtime_time_origin = {.tv_sec = 0};
  #else  /* OMPI_BUILD_MPI_PROFILING */
  extern struct timespec ompi_wtime_time_origin;
  #endif
  
  double MPI_Wtime(void)
  {
      double wtime;
  
      SPC_RECORD(OMPI_SPC_WTIME, 1);
  
      // We intentionally don't use the OPAL timer framework here.  See
      // https://github.com/open-mpi/ompi/issues/3003 for more details.
      struct timespec tp;
      (void) opal_clock_gettime(&tp);
      if (OPAL_UNLIKELY(0 == ompi_wtime_time_origin.tv_sec)) {
          ompi_wtime_time_origin = tp;
      }
      wtime  = (double)(tp.tv_nsec - ompi_wtime_time_origin.tv_nsec)/1.0e+9;
      wtime += (tp.tv_sec - ompi_wtime_time_origin.tv_sec);
  
      return wtime;
  }
  