MPI_Wtick/MPI_Wtime: use opal_clock_get*() wrappers

Update MPI_Wtick and MPI_Wtime to use the portable wrappers
opal_clock_gettime() and opal_clock_getres().

Signed-off-by: Jeff Squyres <jsquyres@cisco.com>

Author: jsquyres

ompi/mpi/c/wtick.c

@@ -9,7 +9,7 @@
  *                         University of Stuttgart.  All rights reserved.
  * Copyright (c) 2004-2005 The Regents of the University of California.
  *                         All rights reserved.
- * Copyright (c) 2007-2014 Cisco Systems, Inc.  All rights reserved.
+ * Copyright (c) 2007-2022 Cisco Systems, Inc.  All rights reserved
  * Copyright (c) 2015-2016 Research Organization for Information Science
  *                         and Technology (RIST). All rights reserved.
  * Copyright (c) 2017      IBM Corporation.  All rights reserved.
@@ -31,10 +31,11 @@
 #include <time.h>
 #endif
 
-#include MCA_timer_IMPLEMENTATION_HEADER
 #include "ompi/mpi/c/bindings.h"
 #include "ompi/runtime/mpiruntime.h"
 
+#include "opal/util/clock_gettime.h"
+
 #if OMPI_BUILD_MPI_PROFILING
 #if OPAL_HAVE_WEAK_SYMBOLS
 #pragma weak MPI_Wtick = PMPI_Wtick
@@ -44,38 +45,15 @@
 
 double MPI_Wtick(void)
 {
-    /*
-     * See https://github.com/open-mpi/ompi/issues/3003
-     * to get an idea what's going on here.
-     */
-#if 0
-#if OPAL_TIMER_CYCLE_NATIVE
-    {
-        opal_timer_t freq = opal_timer_base_get_freq();
-        if (0 == freq) {
-            /* That should never happen, but if it does, return a bogus value
-             * rather than crashing with a division by zero */
-            return (double)0.0;
-        }
-        return (double)1.0 / (double)freq;
-    }
-#elif OPAL_TIMER_USEC_NATIVE
-    return 0.000001;
-#endif
-#else
-#if defined(__linux__) && OPAL_HAVE_CLOCK_GETTIME
+    // We intentionally don't use the OPAL timer framework here.  See
+    // https://github.com/open-mpi/ompi/issues/3003 for more details.
     struct timespec spec;
     double wtick = 0.0;
-    if (0 == clock_getres(CLOCK_MONOTONIC, &spec)){
+    if (0 == opal_clock_getres(&spec)){
         wtick =  spec.tv_sec + spec.tv_nsec * 1.0e-09;
     } else {
         /* guess */
         wtick = 1.0e-09;
     }
     return wtick;
-#else
-    /* Otherwise, we already return usec precision. */
-    return 0.000001;
-#endif
-#endif
 }

ompi/mpi/c/wtime.c

@@ -9,7 +9,7 @@
  *                         University of Stuttgart.  All rights reserved.
  * Copyright (c) 2004-2005 The Regents of the University of California.
  *                         All rights reserved.
- * Copyright (c) 2006-2014 Cisco Systems, Inc.  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.
@@ -31,11 +31,12 @@
 #include <time.h>
 #endif  /* HAVE_TIME_H */
 
-#include MCA_timer_IMPLEMENTATION_HEADER
 #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
@@ -46,17 +47,9 @@
  * and accuracy of the user visible timer.
  * More info: https://github.com/mpi-forum/mpi-issues/issues/77#issuecomment-369663119
  */
-#if defined(__linux__) && OPAL_HAVE_CLOCK_GETTIME
 struct timespec ompi_wtime_time_origin = {.tv_sec = 0};
-#else
-struct timeval ompi_wtime_time_origin = {.tv_sec = 0};
-#endif
 #else  /* OMPI_BUILD_MPI_PROFILING */
-#if defined(__linux__) && OPAL_HAVE_CLOCK_GETTIME
 extern struct timespec ompi_wtime_time_origin;
-#else
-extern struct timeval ompi_wtime_time_origin;
-#endif
 #endif
 
 double MPI_Wtime(void)
@@ -65,36 +58,15 @@ double MPI_Wtime(void)
 
     SPC_RECORD(OMPI_SPC_WTIME, 1);
 
-    /*
-     * See https://github.com/open-mpi/ompi/issues/3003 to find out
-     * what's happening here.
-     */
-#if 0
-#if OPAL_TIMER_CYCLE_NATIVE
-    wtime = ((double) opal_timer_base_get_cycles()) / opal_timer_base_get_freq();
-#elif OPAL_TIMER_USEC_NATIVE
-    wtime = ((double) opal_timer_base_get_usec()) / 1000000.0;
-#endif
-#else
-#if defined(__linux__) && OPAL_HAVE_CLOCK_GETTIME
+    // 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) clock_gettime(CLOCK_MONOTONIC, &tp);
-    if( OPAL_UNLIKELY(0 == ompi_wtime_time_origin.tv_sec) ) {
+    (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);
-#else
-    /* Fall back to gettimeofday() if we have nothing else */
-    struct timeval tv;
-    gettimeofday(&tv, NULL);
-    if( OPAL_UNLIKELY(0 == ompi_wtime_time_origin.tv_sec) ) {
-        ompi_wtime_time_origin = tv;
-    }
-    wtime  = (double)(tv.tv_usec - ompi_wtime_time_origin.tv_usec) / 1.0e+6;
-    wtime += (tv.tv_sec - ompi_wtime_time_origin.tv_sec);
-#endif
-#endif
 
     return wtime;
 }