Datatypes functions crash

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Sat, 2021-12-04 00:04
#1
walkero
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Last seen: 3 months 3 weeks ago
Joined: 2009-05-03 16:54
Datatypes functions crash

I need to check if an image is supported by the installed datatypes, before I use it in GUI. So I thought to use the NewDTObject, and I wrote the checkImageDatatype() method to test it. Below you can see the code.

Although that this works great on AmigaOS 3 68k code, the AmigaOS 4 PPC version crashes the system at the NewDTObject() line.

  1. BOOL check_path_exists(char *path)
  2. {
  3. 	const BPTR lock = Lock(path, SHARED_LOCK);
  4. 	if (lock) {
  5. 		UnLock(lock);
  6. 		return TRUE;
  7. 	}
  8.  
  9. 	return FALSE;
  10. }
  11.  
  12. BOOL checkImageDatatype(STRPTR filename)
  13. {
  14. 	if (check_path_exists(filename))
  15. 	{
  16. 		Object *dtObj;
  17.  
  18. 		dtObj = NewDTObject(filename,
  19. 				DTA_SourceType,		DTST_FILE,
  20. 				DTA_GroupID,		GID_PICTURE,
  21. 				TAG_DONE);
  22.  
  23. 		if (dtObj)
  24. 		{
  25. 			DisposeDTObject (dtObj);
  26. 			return TRUE;
  27. 		}
  28. 	}
  29.  
  30. 	return FALSE;
  31. }

Then I tried to change the method with the following, but unfortunately, on AmigaOS 4 PPC version it crashes at the ObtainDataType() line again.

  1. BOOL checkImageDatatype(STRPTR filename)
  2. {
  3. 	BOOL result = FALSE;
  4. 	BPTR lock;
  5. 	struct DataType *dtn;
  6.  
  7. 	if((lock = Lock(filename, SHARED_LOCK)))
  8. 	{
  9. 		if((dtn = ObtainDataType(DTST_FILE, (APTR) lock, TAG_END)))
  10. 		{
  11. 			const struct DataTypeHeader *dth = dtn->dtn_Header;
  12. 			printf("Description: %s\n", dth->dth_Name);
  13. 			printf("      Group: %s\n", GetDTString(dth->dth_GroupID));
  14.  
  15. 			if (dth->dth_GroupID == GID_PICTURE)
  16. 			{
  17. 				result = TRUE;
  18. 			}
  19.  
  20. 			ReleaseDataType(dtn);
  21. 		}
  22. 		UnLock(lock);
  23. 	}
  24. 	return result;
  25. }

Any idea why the above works fine on AmigaOS 3 but crashes on AmigaOS 4? Anything I could check?

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Sat, 2021-12-04 01:20
walkero
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Last seen: 3 months 3 weeks ago
Joined: 2009-05-03 16:54
Re: Datatypes functions crash

The issue is solved. I forgot to register the DataTypesIFace, that's why it was crashing only on OS4.
Found that issue thanks to Andy Broad who was kind to point me that way. Thanks Andy.

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