Read lines from a file and split int variables.
The iterationStart() method is used to set up each set of values.
By default, the same file is shared between all threads
(and other thread groups, if they use the same file name).
The shareMode can be set to:
- All threads - default, as described above
- Current thread group
- Current thread
- Identifier - all threads sharing the same identifier
The class uses the FileServer alias mechanism to provide the different share modes.
For all threads, the file alias is set to the file name.
Otherwise, a suffix is appended to the filename to make it unique within the required context.
For current thread group, the thread group identityHashcode is used;
for individual threads, the thread hashcode is used as the suffix.
Or the user can provide their own suffix, in which case the file is shared between all
threads with the same suffix.