CarLinO Processes Manager and Performance Monitoring

Processes Manager

All CarLinO applications and standard Linux application that use CarLinO_wrapper class, must be registered to CarLinO_core using classes CarLinO_process / CarLinO_leash.
The CarLinO_core class has a pool of CarLinO_process classes to receive application register requests and to manage the processes. Every CarLinO native applications must istantiate a class (app_leash), derived from CarLinO_leash, to implement the comunication protocol with CarLinO_core.
During this registration the application sends to CarLinO core a structure called CarLinO_process_attr with informations about:

• Process memory requirement
  
• Process CPU usage requirement
  
• CarLinO resource requests (number of child threads, number of child processes, graphic objects, ...)
  

CarLinO_process will use this informations to control the process behavior and performances.

                   |                                                     |
 CarLinO_core      |                                                     | Application
                   |                                                     |
  _________________|                           _______________           |___________
 |                 |   Register CarLinO app  |               |  Inehrit  |           |
 | CarLinO_process | <---------------------- | CarLinO_leash | . . . . . | app_leash |
 |                 |                         |               |           |           |
 |                 |    messages / alerts    |   control     |           |           |
 |                 | ------------------------|---------------|---------> |  ---.     |
 |                 |                         |       |       |           |     |     |
 |                 |                         |     action    |           |  action   |
 |                 |         response        |       |       |           |     |     |
 |                 | <-----------------------|---------------|---------- | <---'     |
 |_________________|                         |_______________|           |___________|
                   |                                                     |
                   |                                                     |
                   |                                                     |

Performance Monitoring and Controls

During normal operations, CarLinO_process send messages periodically to monitor and to control the processes behavior. This messages are:

• PING message for keepalive check
  
• Warning message for policy changing
  
• Control message to modify the process's behavior
  

The app_leash class must act and responding properly at all PING/warning messages to avoid control action from CarLinO. CarLinO use a black list to put into the disobedient processes and it will apply policies to tame they.

Messages for performance monitoring and controls

The messages send from CarLinO_process class to CarLinO_leash and his derived class (called my_leash in the follow) are:

• CarlinoMsgPing: my_leash have to responde with CarlinoMsgPong
  
• ... work in progress ...

This messages are received in the Dispach method of CarLinO_leash classe. This method is a pure virtual method and have to be implemented in the derived class of CarLinO_leash. A CarLinO native application have to use this class to allow the CarLinO_core managing. If it doesn't do it CarLinO_core could discared this application.

Todo:

• CarLinO_process / CarLinO_leash messages exchange
• CarLinO_core process policies: black list