T-Kernel Specification (1.B0.02)

278 CHAPTER 6. T-KERNEL/DS FUNCTIONS
td hoc dsp
Define Task Dispatch Hook Routine
[C Language Interface]
ER ercd = td_hok_dsp ( TD_HDSP *hdsp ) ;
[Parameters]
TD HDSP hdsp Hook routine definition information
hdsp detail:
FP exec Hook routine when execution starts
FP stop Hook routine when execution stops
[Return Parameters]
ER ercd Error code
[Description]
Sets hook routines in the task dispatcher. A hook routine is canceled by setting NULL in hdsp.
The hook routines are called in dispatch disabled state. The hook routines must not invoke T-Kernel/OS
system calls (tk_—) or extended SVC. T-Kernel/DS service calls (td_—) may be invoked.
void exec( ID tskid, INT lsid )
tskid Task ID of the started or resumed task
lsid Logical ID of the task designated in tskid
This is called when the designated task starts execution or resumes. At the time exec() is called,
the task designated in tskid is already in RUN state and logical space has been switched. However,
execution of the tskid task program code occurs after the return from exec().
void stop( ID tskid, INT lsid, UINT tskstat )
tskid Task ID of the executed or stopped task
lsid Logical ID of the task designated in tskid
tskstat State of the task designated in tskid
This is called when the designated task executes or stops. tskstat indicates the task state after stopping,
as one of the following states.
TTS RDY READY state
TTS WAI WAIT state
TTS SUS SUSPEND state
TTS WAS WAIT-SUSPEND state
TTS DM TDORMANT state
0 NON-EXISTENT state
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T-Kernel 1.B0.02