Notes.txt

class: utility, classify events
classtab: a table
debie (6.2): entry point
health: health monitoring task (periodic), in HandleHealthMonitoring resp. HealthMonitoringTask
hw_if: init of hardware?
measure: aquisition 
msg_ctrl: WaitMail OS functionality (wait for mailbox message, simulated)
su_ctrl: Sensor Unit Control (simulated)
taskctrl: Task scheduling control (simulated)
tc_hand: Telecommand ISR
telem: Telemetry ISR

6.3. DAS: task and interrupt management; triggers 
  Triggers (ISR)
    TcHandler <=> tc_hand . TC_InterruptService (fills mailbox using Send_ISR_Mail)
    TmHandler <=> telem . TM_InterruptService (fills mailbox using Send_ISR_Mail),
  HitTriggerTask (waits for hit-trigger interrupt event using WaitInterrupt) <=> measure     
  TelecommandExecutionTask (waits for mail from T[cm]Handler using WaitMail) <=> tc_hand . TelecommandExecutionTask
  HealthMonitoringTask (period) <=> health
  AquisitionTask (waits for mail from HitTriggerTask using WaitMail) <=> measure
  
JOP Model (rough idea, for now put everything in Runnables):
  TcHandler: Runnable registered as interrupt handler for TC Interrupt
  TmHandler: Runnable registered as interrupt handler for TM Interrupt
  HtHandler: triggers particle hit software event
  HitTriggerTask: SwEvent (HT Interrupt, similar to BoundAsyncEventHandler, see RtThreadImpl#blockForEvent)
  TelecommandExecutionTask: SwEvent (MailBox)
  AquisitionTask: SwEvent (MailBox)
  HealthMonitoringTask: RtThread (periodic)

General Notes on problematic translation steps:
  * We have no unsigned data type in Java, and therefore need to carefully
    check whether taking the signed variant (for byte/int) is correct.
    As a consequence, the translation of primitive types is not an automated
    task; depending on whether we want to save memory, and whether overflow may
    occur (or not), different choices are preferable.

Mailbox implementation:
  * public abstract class debie.support.Mailbox
  	* sendTaskMail(message, timeout)
	  * Changes to C implementation: mailbox id is implicit
	* waitMail()
	  * Changes to C implementation: fields from incoming_mail_t *message are implicit
	* fields from incoming_mail_t
  * public class debie.harness.HarnessMailbox extends Mailbox
    * uses same (static) mechanisms as C implementation

EventRecord implementation:
  * computing checksums and copying records needs A LOT of code if each field is 
  addressed seperately. Maybe we should use some internal magic for this stuff.
  Maybe ask the SCJ Gurus?
    
EventQueue (Telecommand) implementation:
  * RecordEvent: in C, interrupts are disabled here; for now, no thread safety
    in Java. Eventually, we should use monitors.

ScienceData:
	* Science Data is shared data; access needs to be protected (e.g., by monitors).
	  In the Java version all data in 'ordinary' memory (that is, we
	  do not distinguish between internal/external memory).

Telecommand implementation: