HELPERS: Add functions to enable/disable I/O flush and sync.

This change introduces the logical flag 'noflush' to control the flushing
and synchronization of I/O buffers. Subsequently, subroutines
'enable_flush_and_sync' and 'disable_flush_and_sync' were added to enable
and disable the flushing and synchronization, respectively.

The 'flush_and_sync' subroutine was modified to respect the noflush flag.

Additionally, this change updates 'statistics.F90' to read
the 'enable_io_flush' parameter and call the appropriate subroutine
('enable_flush_and_sync' or 'disable_flush_and_sync') based on its value.

Signed-off-by: Grzegorz Kowal <grzegorz@amuncode.org>

sources/helpers.F90

@@ -49,11 +49,13 @@ module helpers
     module procedure print_message_msg
   end interface
 
+  logical :: noflush = .true.
+
   private
 
   public :: print_welcome, print_section, print_parameter, print_message
   public :: uppercase, lowercase
-  public :: flush_and_sync
+  public :: enable_flush_and_sync, disable_flush_and_sync, flush_and_sync
 
 !- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
 !
@@ -551,10 +553,53 @@ module helpers
 !
 !===============================================================================
 !
+! subroutine ENABLE_FLUSH_AND_SYNC:
+! --------------------------------
+!
+!   This function enables flushing and synchronization of I/O buffers.
+!
+!===============================================================================
+!
+  subroutine enable_flush_and_sync()
+
+    implicit none
+
+!-------------------------------------------------------------------------------
+!
+    noflush = .false.
+
+!-------------------------------------------------------------------------------
+!
+  end subroutine enable_flush_and_sync
+!
+!===============================================================================
+!
+! subroutine DISABLE_FLUSH_AND_SYNC:
+! ---------------------------------
+!
+!   This function disables flushing and synchronization of I/O buffers.
+!
+!===============================================================================
+!
+  subroutine disable_flush_and_sync()
+
+    implicit none
+
+!-------------------------------------------------------------------------------
+!
+    noflush = .true.
+
+!-------------------------------------------------------------------------------
+!
+  end subroutine disable_flush_and_sync
+!
+!===============================================================================
+!
 ! subroutine FLUSH_AND_SYNC:
 ! -------------------------
 !
-!   Function flushes and fsyncs the I/O buffers.
+!   This function performs a flush of the I/O buffers and ensures that all
+!   changes are synchronized to the storage device using fsync.
 !
 !   Arguments:
 !
@@ -584,6 +629,8 @@ module helpers
 
 !-------------------------------------------------------------------------------
 !
+    if (noflush) return
+
     call flush(iounit)
 
 #ifdef __GFORTRAN__

sources/statistics.F90

@@ -104,6 +104,7 @@ module statistics
     use equations  , only : pvars, nf
     use evolution  , only : error_control
     use forcing    , only : forcing_enabled
+    use helpers    , only : enable_flush_and_sync, disable_flush_and_sync
     use mpitools   , only : master
 #ifdef MPI
     use mpitools   , only : nprocs
@@ -124,6 +125,15 @@ module statistics
 !
     status = 0
 
+    stmp = "off"
+    call get_parameter("enable_io_flush", stmp)
+    select case(trim(stmp))
+    case ("on", "ON", "t", "T", "y", "Y", "true", "TRUE", "yes", "YES")
+      call enable_flush_and_sync
+    case default
+      call disable_flush_and_sync
+    end select
+
     stmp = "on"
     call get_parameter("enable_conservation", stmp)
     select case(trim(stmp))