diff options
Diffstat (limited to 'doc/user/timer.t')
| -rw-r--r-- | doc/user/timer.t | 58 |
1 files changed, 33 insertions, 25 deletions
diff --git a/doc/user/timer.t b/doc/user/timer.t index 2f4538a12b..bdfb6d1801 100644 --- a/doc/user/timer.t +++ b/doc/user/timer.t @@ -65,10 +65,11 @@ A clock tick is required to support the functionality provided by this manager. A timer is an RTEMS object which allows the application to schedule operations to occur at specific times in the future. User supplied timer service routines are invoked by -the clock_tick directive when the timer fires. Timer service -routines may perform any operations or directives which normally +the @code{@value{DIRPREFIX}clock_tick} directive +when the timer fires. Timer service routines may perform +any operations or directives which normally would be performed by the application code which invoked the -clock_tick directive. +@code{@value{DIRPREFIX}clock_tick} directive. The timer can be used to implement watchdog routines which only fire to denote that an application error has @@ -131,7 +132,7 @@ service routine. The argument user_data may be NULL. @end ifinfo @subsection Creating a Timer -The timer_create directive creates a timer by +The @code{@value{DIRPREFIX}timer_create} directive creates a timer by allocating a Timer Control Block (TMCB), assigning the timer a user-specified name, and assigning it a timer ID. Newly created timers do not have a timer service routine associated with them @@ -145,55 +146,58 @@ and are not active. When a timer is created, RTEMS generates a unique timer ID and assigns it to the created timer until it is deleted. The timer ID may be obtained by either of two methods. -First, as the result of an invocation of the timer_create +First, as the result of an invocation of the +@code{@value{DIRPREFIX}timer_create} directive, the timer ID is stored in a user provided location. -Second, the timer ID may be obtained later using the timer_ident -directive. The timer ID is used by other directives to -manipulate this timer. +Second, the timer ID may be obtained later using the +@code{@value{DIRPREFIX}timer_ident} directive. The timer ID +is used by other directives to manipulate this timer. @ifinfo @node Initiating an Interval Timer, Initiating a Time of Day Timer, Obtaining Timer IDs, Timer Manager Operations @end ifinfo @subsection Initiating an Interval Timer -The timer_fire_after directive initiates a timer to +The @code{@value{DIRPREFIX}timer_fire_after} directive initiates a timer to fire a user provided timer service routine after the specified number of clock ticks have elapsed. When the interval has elapsed, the timer service routine will be invoked from the -clock_tick directive. +@code{@value{DIRPREFIX}clock_tick} directive. @ifinfo @node Initiating a Time of Day Timer, Canceling a Timer, Initiating an Interval Timer, Timer Manager Operations @end ifinfo @subsection Initiating a Time of Day Timer -The timer_fire_when directive initiates a timer to +The @code{@value{DIRPREFIX}timer_fire_when} directive initiates a timer to fire a user provided timer service routine when the specified time of day has been reached. When the interval has elapsed, -the timer service routine will be invoked from the clock_tick -directive. +the timer service routine will be invoked from the +@code{@value{DIRPREFIX}clock_tick} directive. @ifinfo @node Canceling a Timer, Resetting a Timer, Initiating a Time of Day Timer, Timer Manager Operations @end ifinfo @subsection Canceling a Timer -The timer_cancel directive is used to halt the +The @code{@value{DIRPREFIX}timer_cancel} directive is used to halt the specified timer. Once canceled, the timer service routine will not fire unless the timer is reinitiated. The timer can be -reinitiated using the timer_reset, timer_fire_after, and -timer_fire_when directives. +reinitiated using the @code{@value{DIRPREFIX}timer_reset}, +@code{@value{DIRPREFIX}timer_fire_after}, and +@code{@value{DIRPREFIX}timer_fire_when} directives. @ifinfo @node Resetting a Timer, Deleting a Timer, Canceling a Timer, Timer Manager Operations @end ifinfo @subsection Resetting a Timer -The timer_reset directive is used to restore an +The @code{@value{DIRPREFIX}timer_reset} directive is used to restore an interval timer initiated by a previous invocation of -timer_fire_after to its original interval length. If the +@code{@value{DIRPREFIX}timer_fire_after} to +its original interval length. If the timer has not been used or the last usage of this timer -was by a timer_fire_when directive, then an error is +was by a @code{@value{DIRPREFIX}timer_fire_when} directive, then an error is returned. The timer service routine is not changed or fired by this directive. @@ -202,7 +206,7 @@ fired by this directive. @end ifinfo @subsection Deleting a Timer -The timer_delete directive is used to delete a timer. +The @code{@value{DIRPREFIX}timer_delete} directive is used to delete a timer. If the timer is running and has not expired, the timer is automatically canceled. The timer's control block is returned to the TMCB free list when it is deleted. A timer can be @@ -352,8 +356,9 @@ procedure Timer_Cancel ( @subheading DESCRIPTION: This directive cancels the timer id. This timer will -be reinitiated by the next invocation of timer_reset, -timer_fire_after, or timer_fire_when with id. +be reinitiated by the next invocation of @code{@value{DIRPREFIX}timer_reset}, +@code{@value{DIRPREFIX}timer_fire_after}, or +@code{@value{DIRPREFIX}timer_fire_when} with id. @subheading NOTES: @@ -537,15 +542,18 @@ procedure Timer_Reset ( This directive resets the timer associated with id. This timer must have been previously initiated with a -timer_fire_after directive. If active the timer is canceled, +@code{@value{DIRPREFIX}timer_fire_after} +directive. If active the timer is canceled, after which the timer is reinitiated using the same interval and -timer service routine which the original timer_fire_after +timer service routine which the original +@code{@value{DIRPREFIX}timer_fire_after} directive used. @subheading NOTES: If the timer has not been used or the last usage of this timer -was by a timer_fire_when directive, then the NOT_DEFINED error is +was by a @code{@value{DIRPREFIX}timer_fire_when} +directive, then the @code{@value{RPREFIX}NOT_DEFINED} error is returned. Restarting a cancelled after timer results in the timer being |