Hello. I'm afraid objectscript does not have the exact equivalent of the Java/C# LOCK command.

As far as re-entrant in the same process goes: there is no need, as objectscript has no ability to parallel process in one process. It's a "simple", interpreted language with effectively one thread (though the interpreter itself is another matter).

What is worse (maybe) is the way programmers prevent problems with concurrency is "by convention only". Our lock command puts entries in a shared "lock table", and that is then available for other processors to read to see if something else is using it. But it can be ignored, unlike in Java. See  https://docs.intersystems.com/iris20251/csp/docbook/DocBook.UI.Page.cls?KEY=GCOS_lockbasics#GCOS_lockbasics_uses_activity_blocking

(By the way, I personally think there's no need to use "device opening" these days as modern systems usually make a good job of cleaning up the lock table when something goes wrong.)

Hi everyone,

That stored procedure solution looks great, and may work, but I'd just like to point out that you have no control over what order the rows are in when the method is called. That's going to be decided by the compiler.

If you've done "ORDER BY Date DESC" then it could build a temporary index by date and then run through that to extract the output, so row 4 would be processed first and the call to the method will return "New" instead of "Old".

Putting in the required order in the query might work, but even then, you have no certainty what the compiler will do. You either need a subquery, or calculate the column outside of SQL when you pull the rows (in the right order).

Regards,

Mike

Assuming all the classes are identical in both namespaces, then I think you can just copy over the underlying global arrays that hold the table data. You'll need to know a bit about the naming rules, etc. to find the globals, and a bit of programming to clear them out in the target beforehand. (The classes could be copied over separately.) If the namespaces are on the same network, and the tables small, then Merge commands could be used.

The documentation examples all have <sequence> blocks around the calls and sync. Your code only has a <scope> block in the bit we can see. Maybe try adding a <sequence>... </sequence>?

Actually, thinking about it, the behaviour is as if you had in the sync an attribute:
type='any' 
but I can see you have:
type='all'
Maybe try changing the "type"? or removing it completely, as the default is "all"?

All I can think of is the timeout setting. The documentation says it should be in seconds, i.e. an integer, but you have "PT30S" which might be treated as zero?

Hi,

After many years of development and support I've become wary of one-line requests. 🤔 I wonder why you need this (Five whys - Wikipedia). For example, if you are trying to debug a mysterious state in a background job then maybe you just need "D LOG^%ETN" to store the variables in the error log. Or, at least you could look in there for ways to use $ORDER and $QUERY  to scan local variables without involving ^SPOOL (or, as we once did, opening a file to ZW to, closing, and then reading it back).

Hi Julian,

As I put in a reply to the discussion that @Mary George  linked to, you can easily get a Service to only run once at the start of each scheduled period by setting the CallInterval to a very large number so it never does a second call.  /Mike

Hi. Not entirely sure what you mean, but I usually write a noddy test routine to clear variables, set up objects and properties, run methods, display, compare results, etc. Have it open in Studio alongside the classes being edited. Then call from terminal. Note that to save typing <ctrl>P can be used to get the previous entries at the command line (and <ctrl>N for next) and allow editing. Alternatively, for repeated test cases I often just copy and paste code from Word or OneNote. / Mike

Hi. You say the codebase is over 30 years old. Well, I have a solution from 1991...

The PAS system I (still) work on has some standard search and display ("code list") software that has to return all codes "starting with", but it's not pretty. As the starting point for the $O() it does this:

	; Return a string immediately preceding input in collating sequence (returns null if input is null)
	; ABC becomes ABB||, -1 becomes -1.0000000001, -.1 becomes .1000000001, 0 becomes -.0000000001, .1 becomes .0999999999, 1 becomes 0.9999999999
SEED(A)	Q:A="" ""  ; null string
	I '$$NUMERIC(A) S LEN=$L(A),T=$E(A,1,LEN-1)_$C($A($E(A,LEN))-1)_"||" Q T
	Q A-(1E-10)

Since you know your target global only has non-numeric subscripts, you won't need to see the 5 lines of nastiness that is the NUMERIC call. :-) The end of your S SEED=$O(@CLGREF@(SEED)) is either the usual "", or ZIN'=$E(SEED,1,$L(ZIN))  (again ignoring the horrible code dealing with numeric values).

Apologies for the ancient coding style (not mine, but I wrote similar back then).  / Mike

Hi. If you mean the ODBC driver, then it gets installed when you install Cache. So, any Cache install file for that version has it. I don't know if you can select to only install the driver and nothing else as I always want the full lot on my PC.

(... just tried and a "custom" setup allows you to remove everything but the ODBC driver, but it's fiddly.)

Have you tried the old trick of running your code inside an execute (X) command? (I sometimes do that for code that only works in non-cache platforms, like DSM, to stop the cache compiler complaining.)

Hi. Interesting topic.

Why did you choose to become a software engineer / developer?

- Always had an interest in science and tech growing up. Introduced to programming at school and enjoyed it. When looking for a job, there was a programming one, so I chose it. And never looked back.

How and when did you start to generate a "flow state of mind" during your career?

- Again, always had it, I think. Give me a good programming problem and I can lose hours without noticing.

What are recommend habits inside and outside, during you own time and during your work time, to be focused during you coding session and daily tasks?

- As I'm lucky and it "just happens" I'm not sure I'm a good source of ideas on this. But at work I find it helps to try to stop other things breaking my concentration. So I will "clear the decks": very little in my email in tray (it all goes into "later" or is set up as a task, or done, or deleted) and all big things to do are recorded as tasks, and scheduled, so that I don't have that "I must remember to do x" popping into my head.

The hard part is avoiding interruptions like new emails and chats from colleagues. Sometimes I just don't notice them, though, as I'm in "flow". So the problem is the other way around: missing important, urgent stuff! Best to find/allocate time when I'm not expected to respond quickly. Often I split my day into two: first I'll do all the other stuff like emails, admin, training, meetings, etc. and as a reward, play with code later. :-)

Hi. Label printers are a pain. :-) In the application I worked on, the printing was originally to matrix/line printers via a "driver" that knew the escape codes to use. But then along came the "thermal" printers using things like ZPL, and squeezing that into a line by line driver was not easy. Had to keep track of a virtual print head "position".

Using a tool to build a template and just providing the field data from IRIS sounds like a much easier route. I think you can save templates in the printer memory, if you don't want to store the text in IRIS.

If you do want to build the printer commands yourself, I recommend hiding them behind a class that stores a virtual label, and have methods to add the commands that take sensible inputs like x and y in mm (or inches), rotation in degrees, font in points, etc. Then internal functions can convert to dots, replace special characters, work out font to use, etc. And then have a final "print" method that writes the whole set of label commands out.

Have fun,

Mike

When we've had license problems in the past, the WRC have supplied us with a routine that watches for the limit warnings and then does a one-off dump of what processes are running for later investigation. We also wrote our own code to do a snapshot of license usage to a file, which is called by the Caché task manager at regular intervals so that we can analyze license usage over time. Helps when trying to see if the site needs more, or sometimes less, licenses. There's nothing like a good graph to prove your point. :-)

I'm no particular fan of this aspect of the language, but changing it as an "option" (by namespace?, routine?) would be a nightmare for maintenance. :-) Only recently fell foul of it with code like: IF type="X"!type="Y" ... that can never be true.

You could argue that it is at least very simple to understand. Just one rule to remember - left to right, except for brackets - rather than a precedence order for every single operation you might use!