Hardware Reference
In-Depth Information
Creation
A kernel operation that allocates and initializes all data structures neces-
sary for the management of the object being created (such as task, resource, com-
munication channel, and so on).
Critical instant
The time at which the release of a job produces the largest response
time.
Critical section
A code segment subject to a mutual exclusion.
Critical zone
The interval between a critical instant of a job and its corresponding
finishing time.
Cumulative value
The sum of the task values gained by a scheduling algorithm after
executing a task set.
Deadline
The time within which a real-time task should complete its execution.
Deadlock
A situation in which two or more processes are waiting indefinitely for
events that will never occur.
Direct blocking
A form of blocking due to the attempt of accessing an exclusive
resource, held by another task.
Dispatching
A kernel operation consisting in the assignment of the processor to the
task having highest priority.
Domino effect
A phenomenon in which the arrival of a new task causes all previ-
ously guaranteed tasks to miss their deadlines.
Dynamic scheduling
A scheduling method in which all active jobs are reordered
every time a new job enters the system or a new event occurs.
Event
An occurrence that requires a system reaction.
Exceeding time
The interval of time in which a job stays active after its deadline. It
is also called
tardiness
.
Exclusive resource
A shared resource that cannot be accessed by more than one
task at a time.
Search WWH ::
Custom Search