system_cpu_time Subroutine

public subroutine system_cpu_time(total, user, system)

NAME

    system_cpu_time(3f) - [M_system] get processor time by calling times(3c)
    (LICENSE:PD)

SYNOPSIS

    subroutine system_cpu_time(c_user, c_system, c_total)

     real,intent(out) :: c_total
     real,intent(out) :: c_user
     real,intent(out) :: c_system

DESCRIPTION

OUTPUT

     c_total   total processor time ( c_user + c_system )
     c_user    processor user time
     c_system  processor system time

ERRORS

    No errors are defined.

EXAMPLES

Sample program:

program demo_system_cpu_time

use M_system, only : system_cpu_time
use ISO_C_BINDING, only : c_float
implicit none
real    :: user_start, system_start, total_start
real    :: user_finish, system_finish, total_finish
integer :: i
integer :: itimes=1000000
real    :: value

   call system_cpu_time(total_start,user_start,system_start)

   value=0.0
   do i=1,itimes
      value=sqrt(real(i)+value)
   enddo
   write(10,*)value
   flush(10)
   write(*,*)'average sqrt value=',value/itimes
   call system_cpu_time(total_finish,user_finish,system_finish)
   write(*,*)'USER ......',user_finish-user_start
   write(*,*)'SYSTEM ....',system_finish-system_start
   write(*,*)'TOTAL .....',total_finish-total_start

end program demo_system_cpu_time

Typical Results:

Arguments

Type IntentOptional Attributes Name
real, intent(out) :: total
real, intent(out) :: user
real, intent(out) :: system

Contents

Source Code

system_cpu_time

Source Code

subroutine system_cpu_time(total,user,system)

real,intent(out)   :: user,system,total
real(kind=c_float) :: c_user,c_system,c_total

interface
   subroutine c_cpu_time(c_total,c_user,c_system) bind (C,NAME='my_cpu_time')
      import c_float
      real(kind=c_float) :: c_total,c_user,c_system
   end subroutine c_cpu_time
end interface

call c_cpu_time(c_total,c_user,c_system)
user=c_user
system=c_system
total=c_total
end subroutine system_cpu_time