The worst-case execution time is the utmost length of time to compile a specific
calculation task on a unique platform. Task completion on time is an
important aspect in real time systems as we cannot afford large delays. To
ensure perfection and correctness of a system, every real time task should be
accomplished within the allocated time of period. For this purpose, it is
mandatory to calculate or analyze worst case execution time of every task.
Computing worst case execution time of every task is
itself a quite challenging task as if we only test the tasks in general, it
could not be efficient enough to identify the omission of errors. Some of the most
commonly found issues in worst case execution time analysis are:
It is quite ugly
approach to test a task by again and again calculating the time of a particular
task and also not much safe typically. Moreover, to prove all the conditions
fulfilled while identifying maximum execution time is most often nearly impossible
and itself a much difficult task to be accomplished.
Mostly in latest components
of processor such as pipelines and caches makes it difficult and complex job of
calculating worst case execution time with a great pace. Due to which a single
instruction of task might depends on various instructions or history of
Worst case execution time analysis methods mostly
do not ponder cache and pipeline behavior
with respect to magnitude which resultantly leads towards considerable wastage of hardware resources.
To encounter all the above mentioned
issues, below mentioned are some of the solutions to the problems:
aiT worst case execution time
analyzers provided the solution in which they stated that they qualitatively
analyzed a task’s intrinsic
cache and pipeline behavior which depends upon pipelines models and formal
cache. This supports correct and narrow upper limits to be calculated for the
worst-case execution time.
Red line :Volvo’s
line : aiT analysis results
black line : measured WCET
aiT calculated limits
are very tightly bounded which
is resultantly projects the real performance of the system.
aiT calculated ranges
are perfect for all the inputs and every time compilation of a task.
Binary executables are
directly analyzes in aiT. It is highly independent of the compiler and programming
language used for source code.