clock(3C)                      DG/UX R4.11MU05                     clock(3C)


NAME
       clock - report CPU time used

SYNOPSIS
       #include <time.h>

       clockt clock (void);

DESCRIPTION
       clock returns the amount of CPU time (in microseconds) used since the
       first call to clock by the calling process.  The time reported is the
       sum of the user and system times of the calling process and its
       terminated child processes for which it has executed the wait(2)
       system call, the pclose(3S) function, or the system(3S) function.

       Dividing the value returned by clock by the constant CLOCKSPERSEC,
       defined in the time.h header file, will give the time in seconds.

       The resolution of the clock is 10 milliseconds on Data General
       processors.


   Considerations for Threads Programming
                     +---------+-----------------------------+
                     |         |                      async- |
                     |function | reentrant   cancel   cancel |
                     |         |             point     safe  |
                     +---------+-----------------------------+
                     |clock    |     Y         N        N    |
                     +---------+-----------------------------+

SEE ALSO
       times(2), wait(2), reentrant(3), popen(3S), system(3S).

NOTES
       The value returned by clock is defined in microseconds for
       compatibility with systems that have CPU clocks with much higher
       resolution.  Because of this, the value returned will wrap around
       after accumulating only 2147 seconds of CPU time (about 36 minutes).
       If the process time used is not available or cannot be represented,
       clock returns the value (clockt)-1.


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