From 7f86924279a899f0d1722f6857cf0550499b8c38 Mon Sep 17 00:00:00 2001
From: Jeff Curtis <jcurtis2@illinois.edu>
Date: Wed, 2 Oct 2024 12:37:08 -0500
Subject: [PATCH] change timing to use system_clock

---
 src/partmc.F90   |  4 +++-
 src/run_part.F90 | 10 +++++++---
 2 files changed, 10 insertions(+), 4 deletions(-)

diff --git a/src/partmc.F90 b/src/partmc.F90
index bf3fca3ad..542270322 100644
--- a/src/partmc.F90
+++ b/src/partmc.F90
@@ -338,6 +338,7 @@ subroutine partmc_part(file)
     character(len=PMC_MAX_FILENAME_LEN) :: restart_filename
     integer :: dummy_index, dummy_i_repeat
     real(kind=dp) :: n_part
+    integer(kind=8) :: clock_count, clock_count_rate
 
     !> \page input_format_particle Input File Format: Particle-Resolved Simulation
     !!
@@ -486,7 +487,8 @@ subroutine partmc_part(file)
     call pmc_rand_finalize()
     call pmc_srand(rand_init, pmc_mpi_rank())
 
-    call cpu_time(run_part_opt%t_wall_start)
+    call system_clock(clock_count, clock_count_rate)
+    run_part_opt%t_wall_start = real(clock_count, kind=dp) / clock_count_rate
 
     do i_repeat = 1,run_part_opt%n_repeat
        run_part_opt%i_repeat = i_repeat
diff --git a/src/run_part.F90 b/src/run_part.F90
index 5f907927e..69497194f 100644
--- a/src/run_part.F90
+++ b/src/run_part.F90
@@ -89,7 +89,7 @@ module pmc_run_part
      integer :: i_repeat
      !> Total number of repeats.
      integer :: n_repeat
-     !> Cpu_time() of start.
+     !> Wall clock time of start.
      real(kind=dp) :: t_wall_start
      !> Whether to record particle removal information.
      logical :: record_removals
@@ -160,6 +160,7 @@ subroutine run_part(scenario, env_state, aero_data, aero_state, gas_data, &
     integer :: global_n_nuc
     logical :: do_output, do_state, do_state_netcdf, do_progress, did_coag
     real(kind=dp) :: t_start, t_wall_now, t_wall_elapsed, t_wall_remain
+    integer(kind=8) :: clock_count, clock_count_rate
     type(env_state_t) :: old_env_state
     integer :: n_time, i_time, pre_i_time
     integer :: i_state, i_state_netcdf, i_output
@@ -222,7 +223,8 @@ subroutine run_part(scenario, env_state, aero_data, aero_state, gas_data, &
           t_wall_elapsed = 0d0
           t_wall_remain = 0d0
        else
-          call cpu_time(t_wall_now)
+          call system_clock(clock_count, clock_count_rate)
+          t_wall_now = real(clock_count, kind=dp) / clock_count_rate
           prop_done = real(run_part_opt%i_repeat - 1, kind=dp) &
                / real(run_part_opt%n_repeat, kind=dp)
           t_wall_elapsed = t_wall_now - run_part_opt%t_wall_start
@@ -807,6 +809,7 @@ subroutine run_part_timestep(scenario, env_state, aero_data, aero_state, &
     integer :: global_n_nuc
     logical :: do_output, do_state, do_state_netcdf, do_progress
     real(kind=dp) :: t_wall_now, t_wall_elapsed, t_wall_remain, time
+    integer(kind=8) :: clock_count, clock_count_rate
     type(env_state_t) :: old_env_state
 #ifdef PMC_USE_CAMP
     type(camp_state_t), pointer :: camp_state
@@ -948,7 +951,8 @@ subroutine run_part_timestep(scenario, env_state, aero_data, aero_state, &
           call pmc_mpi_reduce_sum_integer(progress_n_nuc, global_n_nuc)
           if (pmc_mpi_rank() == 0) then
              ! progress only printed from root process
-             call cpu_time(t_wall_now)
+             call system_clock(clock_count, clock_count_rate)
+             t_wall_now = real(clock_count, kind=dp) / clock_count_rate
              prop_done = (real(run_part_opt%i_repeat - 1, kind=dp) &
                   + time / run_part_opt%t_max) &
                   / real(run_part_opt%n_repeat, kind=dp)