Cheddar Release 3.x user's guide

All Cheddar analysis tools are called from the "Tools" menu. This section gives a short description of them. Some of them compute
tasks parameters, and then are composed of two submenus : "Compute and update tasks set"
and "Compute and display".

File Menu :
1. New sub-menu : creates a new XML project.
2. Open sub-menu : loads a XML project file into the editor.
3. Save sub-menu : saves the current XML project into a file with the current XML project file name.
4. Save as sub-menu : saves the current XML project into a file with a new XML project file name.
5. AADL sub-menu : provides ane features related to AADL specifications.
  1. AADL import : reads an AADL specification into Cheddar.
  2. AADL export : translates a Cheddar specification towards an AADL specification.
  3. Export property sets used by Cheddar : writes the Cheddar's property sets into files of the current directory.
  4. Export standard AADL property set : writes the standard AADL property set into files of the current directory.
  5. Customize how AADL services work : allows the user to set some options related to the AADL services provided by Cheddar.
6. Exit sub-menu : Quit the Cheddar's editor.
Edit menu : creates/updates/deletes entities of the current architecture to analyse (entities of the current XML project). Entities can be a processor, a task, a message, a buffer, a network or an event analyzer.
Tools menu :
1. Clear work space sub-menu : cleans the working area (main window). Does not change anything on the project itself.
2. Scheduling sub-menu :
  1. Customized scheduling simulation sub-menu : computes and draws scheduling simulation. This sub-menu allows the user to customize the way the scheduling is computed.
  2. Customized scheduling feasibility sub-menu : computes some basics feasibility tests on all processors. The feasibility tests computed there are the utilization factor test and the response time test.
  3. Set priorities according to Rate Monotonic sub-menu : change the task priority according to its period (Tasks with the smallest period become tasks with the highest priority).
  4. Set priorities according to Deadline Monotonic sub-menu : changes the task priority according to its deadline (Tasks with the smallest deadline become tasks with the highest priority).
  5. Partition sub-menu : provides some services to assign tasks on a set of processors.
    1. With Best Fit sub-sub-menu : assigns tasks on the set of processors according to the Best Fit algorithm.
    2. With General Task sub-sub-menu : assigns tasks on the set of processors according to the General Task algorithm.
    3. With Next Fit sub-sub-menu : assigns tasks on the set of processors according to the Next Fit algorithm.
    4. With First Fit sub-sub-menu : assigns tasks on the set of processors according to the First Fit algorithm.
    5. With Small Task sub-sub-menu : assigns tasks on the set of processors according to the Small Task algorithm.
  6. Event table services sub-menu : provides some basic services on event tables.
    1. Compute scheduling and generate event table sub-sub-menu :computes the scheduling and produces the event table.
    2. Draw time line from event table sub-sub-menu : draws time line from the last computed or loaded scheduling/event table.
    3. Run analysis on event table sub-sub-menu : performs analysis on the last computed or loaded scheduling/event table.
    4. Export event table sub-sub-menu : saves the last scheduling/event table into a file with a XML format.
  7. Options sub-menu : describes how the scheduling simulation will be carried out.
3. Resource sub-menu :
  1. Bound on blocking time sub-sub-menu : computes bound on shared resources blocking time according to PCP and PIP protocols without computing the scheduling
  2. Looking for priority inversion from simulation sub-sub-menu : runs analysis on a previously computed scheduling to look for high priority tasks blocked by lower priority task at shared resource access.
  3. Looking for priority inversion from simulation sub-sub-menu : runs analysis on a previously computed scheduling to look for tasks blocked forever on shared resources.
4. Buffer sub-menu : this submenu can help you to study buffers shared by tasks.
  1. Buffer simulation sub-sub-menu : computes buffer utilization factor and message waiting time from a given scheduling simulation.
  2. Buffer feasibility tests sub-sub-menu : computes bound on buffer utilization factor and message waiting time without computing scheduling.
5. Precedency sub-menu : . You will find here some heuristics/algorithms that can schedule or check feasibility of a tasks set with dependencies.
  1. Chetto/Blazewicz modifications on priorities sub-sub-menu : This service creates an independent task set from a dependent task set by modifying task priorities according to precedency constraints.
  2. Chetto/Blazewicz modifications on deadlines sub-sub-menu : This service creates an independent task set from a dependent task set by modifying task deadlines according to precedency constraints.
  3. End to End response time : computes response time from a set of task (which have precendency relationships) with the Holistic method.
6. Random sub-menu : this submenu should provide necessary tools to carry out simulations with random events.
  1. Compute response time density sub-menu : compute statistic distribution of task response time from a scheduling simulation.
Help Menu :
1. About Cheddar sub-menu : provides version number of the Cheddar's binaries.
2. Manual sub-menu : contains the text given in this section.
3. Scheduling references sub-menu : gives all paper references used to compute feasibility tests and simulation results.

X. Summary of Cheddar's editor menus and sub-menus