SYSTEM_CLOCK(3I) Last changed: 1-8-98
NAMESYSTEM_CLOCK - Returns integer data from a real-time clock
SYNOPSIS
CALL SYSTEM_CLOCK ([[COUNT=]count] [,[COUNT_RATE=]count_rate]
[,[COUNT_MAX=count_max])
IMPLEMENTATION
UNICOS, UNICOS/mk, and IRIX systems
STANDARDS
Fortran 90
DESCRIPTION
The SYSTEM_CLOCK intrinsic subroutine returns information gathered
from the real-time clock. SYSTEM_CLOCK accepts the following
arguments:
count Must be type default integer. If count is present, it is
set to a machine-specific value based on the current value
of the machine's clock. If there is no clock, it is set to
-HUGE(0). The machine-specific value is incremented by one
for each clock count until the value count_max is reached;
it is reset to 0 at the next count. If there is a clock, it
lies in the range 0 to count_max.
count_rate
Must be type default integer. If count_rate is present, it
is set to the number of clock counts per second. If there
is no clock, it is set to 0.
count_max Must be type default integer. If count_max is present, it
is set to the maximum value that count can have. If there
is no clock, it is set to 0.
The arguments to SYSTEM_CLOCK cannot be declared with a nondefault
kind type. For information on default integer kind types, see section
4.3 of the Fortran Language Reference Manual, Volume 1, publication
SR-3902.
The name of this intrinsic cannot be passed as an argument.
Hardware counter values from the syssgi(2) system call are used on
IRIX systems. The real-time clock is used on UNICOS and UNICOS/mk
systems.
Due to the hardware characteristics of UNICOS systems, the values
returned in count and count_max are 64-bit values on these systems.
SEE ALSOSYSCLOCK(3F)gettimeofday(2) in the UNICOS System Calls Reference Manual,
publication SR-2012
Intrinsic Procedures Reference Manual, publication SR-2138, for the
printed version of this man page.
