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Service_StartFiler
Programmer's Reference Manuals
» Part 16 – Service Calls?
» Service_StartFiler
Service_StartFiler
(Service &4B)
| Entry | |
|---|---|
| R0 | Task handle of Filer |
| R1 | 75 (&4B) |
| Exit | |
|---|---|
| R0 | Pointer to command start module, else preserved to pass on |
| R1 | 0 to claim service, else preserved to pass on |
Use
This service is issued by the Filer to start up resident filer module tasks by passing the returned command to Wimp_StartTask.
Notes
Module tasks which wish to start should claim this service, passing their start command in R0. The Filer will re-issue this service until no more modules claim it.
To prevent infinite loops if an error occurs in starting a task, modules should:
- Set their taskhandle to 0 on;
- Initialise (see Module Initialisation Code?)
- Service_PostReset
- Service_StartedFiler
- Only claim this service if their taskhandle is zero (i.e. they are not already running, and not attempting to re-start)
- Set their taskhandle to a flag value (-1) when they claim this service
- Do either;
- Set their taskhandle based on the return result of Wimp_Initialise if their command is called,
- or set their taskhandle back to 0 on Service_StartedFiler (failed to initialise)
- Set their taskhandle back to 0 when they quit using Wimp_CloseDown
Filer tasks should also check for Service_FilerDying, and close down if they receive it.
See also
- Module Initialisation Code?
- Service Calls
- Service_FilerDying
- Service_PostReset
- Service_StartedFiler
- Wimp_CloseDown
- Wimp_Initialise