diff options
Diffstat (limited to 'doc/user/clock.t')
| -rw-r--r-- | doc/user/clock.t | 22 |
1 files changed, 19 insertions, 3 deletions
diff --git a/doc/user/clock.t b/doc/user/clock.t index f27748d4e3..be61b9651a 100644 --- a/doc/user/clock.t +++ b/doc/user/clock.t @@ -42,7 +42,9 @@ The clock facilities of the clock manager operate upon calendar time. These directives utilize the following date and time @value{STRUCTURE} for the native time and date format: + @ifset is-C +@findex rtems_time_of_day @example struct rtems_tod_control @{ rtems_unsigned32 year; /* greater than 1987 */ @@ -108,6 +110,8 @@ seconds since the RTEMS epoch of January 1, 1988. @subsection Clock Tick and Timeslicing +@cindex timeslicing + Timeslicing is a task scheduling discipline in which tasks of equal priority are executed for a specific period of time before control of the CPU is passed to another task. It is @@ -129,6 +133,8 @@ ready task of equal priority. @subsection Delays +@cindex delays + A sleep timer allows a task to delay for a given interval or up until a given time, and then wake and continue execution. This type of timer is created automatically by the @@ -140,6 +146,8 @@ sleep timer at a time. @subsection Timeouts +@cindex timeouts + Timeouts are a special type of timer automatically created when the timeout option is used on the @code{@value{DIRPREFIX}message_queue_receive}, @@ -190,8 +198,12 @@ the number of seconds since the RTEMS epoch, the number of ticks since the executive was initialized, and the number of ticks per second. The information returned by the @code{@value{DIRPREFIX}clock_get} directive is -dependent on the option selected by the caller. The following -options are available: +dependent on the option selected by the caller. This +is specified using one of the following constants +associated with the enumerated type +@code{@value{DIRPREFIX}clock_get_options}: + +@findex rtems_clock_get_options @itemize @bullet @item @code{@value{RPREFIX}CLOCK_GET_TOD} - obtain native style date and time @@ -325,8 +337,12 @@ The caller can always obtain the number of ticks per second (option is ticks since the executive was initialized option is @code{@value{RPREFIX}CLOCK_GET_TICKS_SINCE_BOOT}). -The data type expected for time_buffer is indicated below: +The @code{option} argument may taken on any value of the enumerated +type @code{rtems_clock_get_options}. The data type expected for +@code{time_buffer} is based on the value of @code{option} as +indicated below: +@findex rtems_clock_get_options @ifset is-C @itemize @bullet @item @code{@value{RPREFIX}CLOCK_GET_TOD} - (rtems_time_of_day *) |