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@c

@c COPYRIGHT (c) 1988-2002.

@c On-Line Applications Research Corporation (OAR).

@c All rights reserved.

@c

@c clock.t,v 1.6 2002/01/17 21:47:45 joel Exp

@c

@chapter Clock Manager

@section Introduction

The clock manager ...

The directives provided by the clock manager are:

@itemize @bullet

@item @code{clock_gettime} - Obtain Time of Day

@item @code{clock_settime} - Set Time of Day

@item @code{clock_getres} - Get Clock Resolution

@item @code{sleep} - Delay Process Execution

@item @code{nanosleep} - Delay with High Resolution

@item @code{gettimeofday} - Get the Time of Day

@item @code{time} - Get time in seconds

@end itemize

@section Background

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@section Operations

There is currently no text in this section.

@section Directives

This section details the clock manager's directives.

A subsection is dedicated to each of this manager's directives

and describes the calling sequence, related constants, usage,

and status codes.

@subsection clock_gettime -Obtain Time of Day

@findex clock_gettime

@cindex obtain time of day

@subheading CALLING SEQUENCE:

@example

#include 

int clock_gettime(

  clockid_t        clock_id,

  struct timespec *tp

);

@end example

@subheading STATUS CODES:

On error, this routine returns -1 and sets errno to one of the following:

@table @b

@item EINVAL

The tp pointer parameter is invalid.

@item EINVAL

The clock_id specified is invalid.

@end table

@subheading DESCRIPTION:

@subheading NOTES:

NONE

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@page

@subsection clock_settime - Set Time of Day

@findex clock_settime

@cindex  set time of day

@subheading CALLING SEQUENCE:

@example

#include 

int clock_settime(

  clockid_t              clock_id,

  const struct timespec *tp

);

@end example

@subheading STATUS CODES:

On error, this routine returns -1 and sets errno to one of the following:

@table @b

@item EINVAL

The tp pointer parameter is invalid.

@item EINVAL

The clock_id specified is invalid.

@item EINVAL

The contents of the tp structure are invalid.

@end table

@subheading DESCRIPTION:

@subheading NOTES:

NONE

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@page

@subsection clock_getres - Get Clock Resolution

@findex clock_getres

@cindex  get clock resolution

@subheading CALLING SEQUENCE:

@example

#include 

int clock_getres(

  clockid_t        clock_id,

  struct timespec *res

);

@end example

@subheading STATUS CODES:

On error, this routine returns -1 and sets errno to one of the following:

@table @b

@item EINVAL

The res pointer parameter is invalid.

@item EINVAL

The clock_id specified is invalid.

@end table

@subheading DESCRIPTION:

@subheading NOTES:

If res is NULL, then the resolution is not returned.

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@page

@subsection sleep - Delay Process Execution

@findex sleep

@cindex  delay process execution

@subheading CALLING SEQUENCE:

@example

#include 

unsigned int sleep(

  unsigned int seconds

);

@end example

@subheading STATUS CODES:

This routine returns the number of unslept seconds.

@subheading DESCRIPTION:

The @code{sleep()} function delays the calling thread by the specified

number of @code{seconds}.

@subheading NOTES:

This call is interruptible by a signal.

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@page

@subsection nanosleep - Delay with High Resolution

@findex nanosleep

@cindex  delay with high resolution

@subheading CALLING SEQUENCE:

@example

#include 

int nanosleep(

  const struct timespec *rqtp,

  struct timespec       *rmtp

);

@end example

@subheading STATUS CODES:

On error, this routine returns -1 and sets errno to one of the following:

@table @b

@item EINTR

The routine was interrupted by a signal.

@item EAGAIN

The requested sleep period specified negative seconds or nanoseconds.

@item EINVAL

The requested sleep period specified an invalid number for the nanoseconds

field.

@end table

@subheading DESCRIPTION:

@subheading NOTES:

This call is interruptible by a signal.

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@page

@subsection gettimeofday - Get the Time of Day

@findex gettimeofday

@cindex  get the time of day

@subheading CALLING SEQUENCE:

@example

#include 

#include 

int gettimeofday(

  struct timeval  *tp,

  struct timezone *tzp

);

@end example

@subheading STATUS CODES:

On error, this routine returns -1 and sets @code{errno} as appropriate.

@table @b

@item EPERM

@code{settimeofdat} is called by someone other than the superuser.

@item EINVAL

Timezone (or something else) is invalid.

@item EFAULT

One of @code{tv} or @code{tz} pointed outside your accessible address

space

@end table

@subheading DESCRIPTION:

This routine returns the current time of day in the @code{tp} structure.

@subheading NOTES:

Currently, the timezone information is not supported. The @code{tzp}

argument is ignored.

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@page

@subsection time - Get time in seconds

@findex time

@cindex  get time in seconds

@subheading CALLING SEQUENCE:

@example

#include 

int time(

  time_t *tloc

);

@end example

@subheading STATUS CODES:

This routine returns the number of seconds since the Epoch.

@subheading DESCRIPTION:

@code{time} returns the time since 00:00:00 GMT, January 1, 1970,

measured in seconds

If @code{tloc} in non null, the return value is also stored in the

memory pointed to by @code{t}.

@subheading NOTES:

NONE