From f027b909c92629e6de83cc217c3499ab99ca1060 Mon Sep 17 00:00:00 2001 From: Joel Sherrill Date: Thu, 7 Sep 2006 18:08:25 +0000 Subject: 2006-09-07 Ken Peters PR 1171/doc * user/timer.t: Correct documentation for rtems_timer_initiate_server. --- doc/user/timer.t | 10 +++++++--- 1 file changed, 7 insertions(+), 3 deletions(-) (limited to 'doc/user/timer.t') diff --git a/doc/user/timer.t b/doc/user/timer.t index 421fc4f032..88c59d7306 100644 --- a/doc/user/timer.t +++ b/doc/user/timer.t @@ -60,7 +60,8 @@ sometimes referred to as a "keep alive" or a "deadman" timer. The Timer Server task is responsible for executing the timer service routines associated with all task-based timers. This task executes at a priority higher than any RTEMS application -task and thus can be viewed logically as the lowest priority interrupt. +task, and is created non-preemptible, and thus can be viewed logically as +the lowest priority interrupt. By providing a mechanism where timer service routines execute in task rather than interrupt space, the application is @@ -70,7 +71,9 @@ can be configured to have a floating point context in which case it would be save to perform floating point operations from a task-based timer. Most of the time, executing floating point instructions from an interrupt service routine -is not considered safe. +is not considered safe. However, since the Timer Server task +is non-preemptible, only directives allowed from an ISR can be +called in the timer service routine. The Timer Server is designed to remain blocked until a task-based timer fires. This reduces the execution overhead @@ -512,7 +515,8 @@ preempted. @findex rtems_timer_initiate_server @example rtems_status_code rtems_timer_initiate_server( - unsigned32 stack_size, + rtems_unsigned32 priority, + rtems_unsigned32 stack_size, rtems_attribute attribute_set ) ); -- cgit v1.2.3