I have written awful.util.spawn("vncviewer") in rc.lua. But this results in two vncviewer instances (windows) in the startup. What is the reason?
Without more details, my guess is as good as yours. However the odds are that you put the line in a signal callback that gets called twice (like for each screen or something).
Can you pastebin your rc.lua in a comment so I can update my message with a more accurate answer?
Related
I have encountered an issue recently while processing a CICS transaction. My CICS transaction is calling a chain of dynamically linked COBOL modules. The transaction runs fine for the first time after the PGM-A load is new copied into the region. When I try to process the transaction for the second time, I keep getting CEE3DD abend saying the module not found for PGM-B which is being called from PGM-A. IF I do a new copy for PGM-A in CICS, the transaction again runs fine.
Something is wrong with the CICS setup or memory but I am not able to figure it out. PGM-A is working fine in batch processing. PGM-B has no issues when it is called from any other PGMs except PGM-A.
Can someone share some thoughts on what may be wrong with this?
To invoke your program via CICS, it must be compiled with the NODYNAM option.
It admittedly seems counter-intuitive, but using the DYNAM option will cause CICS stubs to be loaded, instead of your intended programs, and result in the CEE3501S condition.
So, compile your programs with the NODYNAM option to avoid this error condition.
See the following links for additional info:
https://www.ibm.com/support/knowledgecenter/en/SSGMCP_5.3.0/com.ibm.cics.ts.applicationprogramming.doc/topics/dfhp3_cobol_subprog_rules.html
http://www-01.ibm.com/support/docview.wss?uid=swg21054079
Does PGM-A use "CALL VARIABLE" to invoke PGM-B? If so check the contents of VARIABLE on the second run (the contents of that variable will probably be reported in the error message. The contents of the variable may be overwritten by a bug in PGM-A. That might explain why the program always fails after the (seemingly) succesful run and after a newcopy.
Converting this from dynamic to static worked. But the question remains why it was not working with dynamic linking.
I am writing a small IDE with Single Steps using the Debugdemo.
Now I need an Event before and after a line is executed.
I would like to disable my Editor while the current Line is executed.
I found the OnLine Event but did not find out in what cases it is fired or how I can use it.
Any hints are welcome.
Greetings Klaus
The OnLine event is meant to alter the interpretation of code.
It is not meant for debugging purposes.
If you want to do that use the BreakPoints in TPSScriptDebugger.
Put a breakpoint on the line and after the line.
Now you will get a signal before and after the line is executed.
I recently started taking an interest in Lua programming with a Minecraft addon called Computercraft, which involves console-based GUIs to control computers and other things with Lua. However, I seem to be randomly getting an error where the code requires something called an "eof". I have searched multiple manuals and how-tos, and none mention this particular error. In fact, I am having trouble finding anything with an error list. I am fairly new to programming, but have had basic Python experience. Could anyone explain what "eof" is?
An eof is do or then.
Usually eof means you have too many (or not enough) end statements. Paste code maybe?
Suppose I create a file with one too many end statements:
> edit test.lua
for i = 1, 10 do
print(i)
end
end
When I run it, and lua encounters that extra end statement on the last line where there is no code block still open, you'll get an error like:
> test.lua
bios: 337: [string "test.lua"]: 4: '<eof>' expected
(from a quick test in CCDesk pr7.1.1)
Problems with the basic structure of the blocks of lua code show up with bios on the left rather than your file name; the part of bios that loads lua files will usually tell you where it was at in the file when couldn't make sense of the code anymore (like line 4: here). Sometimes it might be a bit of a puzzle to work your way from the scene of the accident back to where things got off track. =)
Using ESPlorer there is a difference between "uploading" a script and "sending" a script. Use "Upload".
This is not the same issue as the one reported, but as searching landed me here...
I'm trying to do something a little fancy here, but the docs suggest it should be possible. Maybe LLDB is still too new, but I'm getting a lot of debugger crashes / deadlocks and even when that doesn't happen it does't seem to work like I expected.
I'm trying to put together a debug wrapper around all selector calls, to extract the message call graph inside a certain chunk of code. (I could explain why if you really want to know, but it isn't really relevant to the debugger issue.)
I start out with an Xcode breakpoint on the line where I want to start tracking things (for bonus points, this is happening on a secondary thread, but before you ask, no, nothing on any other thread is doing any accesses to this object or anything in its property subgraph):
[myObject startProcessing];
The breakpoint triggers, and I run "bt", just to extract:
* thread #5: tid = 0x2203, 0x000277d2 .........
I then do something mildly evil: I put a breakpoint in objc_msgSend, right at the instruction where it calls out to the real object selector. objc_msgSend looks like:
libobjc.A.dylib`objc_msgSend:
...(instructions)...
0x37babfa4: bx r12
...(more instructions)...
(Actually there are two bx calls but let's keep things simple.) I run:
breakpoint set -a 0x37babfa4 -t 0x2203
(TID included because I'm having enough trouble tracking this one thread and I don't need irrelevant stuff interfering.)
Here's where the scripting comes in. The setup described above works exactly as I'd like it to. If I resume execution until the breakpoint triggers, I can run:
frame select 0
thread step-inst -m this-thread 5
frame info
continue
and the effect will be that the debugger:
moves to the objc_msgSend frame
steps by one instruction, advancing it into the object selector frame it was pointing at
displays relevant details (object type, selector called)
resumes execution
at which point I can keep pasting in those four commands over and over and copying the output until I hate myself.
If, on the other hand, I run:
breakpoint command add -s command
and paste in those exact same commands, everything breaks. It does not advance to the object selector frame. It doesn't show the frame details, or at least not the correct ones -- depending on various tweaks (see below), it may or may not show "objc_msgSend" as being the current function. It doesn't resume execution.
In this case, if I could get that example working, I'd be mostly happy. But for even more bonus points, I've also tried this with python, which I would prefer because it would allow for much more sophisticated logging:
breakpoint command add -s python
> thread = frame.GetThread()
> thread.StepInstruction(1)
> newFrame = thread.GetFrameAtIndex(0)
> print " " * thread.GetNumFrames() + newFrame.GetFunctionName()
> process = thread.GetProcess()
> process.Continue()
> DONE
Again no good. Again depending on tiny details, this may or may not print something (usually objc_msgSend), but it never prints the correct thing. It never steps the instruction forward. It never resumes execution afterwards.
And again, the python version works fine if I do it by hand: if I wait till the breakpoint fires, then run "script" and enter those exact same lines, it works as expected. Some parts will even work in isolation, e.g. if I remove everything except the parts that get the process and call process.Continue() and trigger those automatically, that "works" (meaning I see the lldb prompt flashing rapidly as it suspends and resumes execution. Usually I regret this because it becomes unresponsive and crashes shortly after.)
So: Any ideas? Is the technology Not Ready Yet, or am I just missing some clever piece of the puzzle that will fix everything? Or should I give up entirely and just live with the fact that there are some parts of object internals that I will never understand?...
Breakpoint commands cannot resume execution and then get control back again, at least today. There are a lot of unresolved questions about what would happen if breakpoint 1 is running the process and then breakpoint 2 is hit. Besides the whole question of whether the code base can really handle nested breakpoints correctly (it was designed to...), what does it mean if breakpoint 2 decides execution should stop? Is breakpoint 1's state thrown away?
It seems a little esoteric to worry about a breakpoint hitting another breakpoint while stepping the inferior process but unless all the details have been worked out, it's easy for the user to shoot themselves in the foot. So for today, breakpoint commands can either stop when the breakpoint is hit or continue to run - but there isn't any ability to run a little bit and do more processing. I know this would be a really useful capability for certain tasks but there are a lot of gotchas that need to be thought out before it could be done.
For some cases, it is possible to handle it the other way around ... if you want to stop in function parser() only when it has been called by function lexer(), it is easy to put a breakpoint on lexer() with some a few python commands to go one stack frame up the stack and see what the calling function is. If it's not lexer(), continue. I don't think this will apply to what you're trying to do, though.
What's the best way to do the semantic equivalent of the traditional sleep() system call from within an Informix SPL routine? In other words, simply "pause" for N seconds (or milliseconds or whatever, but seconds are fine). I'm looking for a solution that does not involve linking some new (perhaps written by me) C code or other library into the Informix server. This has to be something I can do purely from SPL. A solution for IDS 10 or 11 would be fine.
#RET - The "obvious" answer wasn't obvious to me! I didn't know about the SYSTEM command. Thank you! (And yes, I'm the guy you think I am.)
Yes, it's for debugging purposes only. Unfortunately, CURRENT within an SPL will always return the same value, set at the entry to the call:
"any call to CURRENT from inside the SPL function that an EXECUTE FUNCTION (or EXECUTE PROCEDURE) statement invokes returns the value of the system clock when the SPL function starts."
—IBM Informix Guide to SQL
Wrapping CURRENT in its own subroutine does not help. You do get a different answer on the first call to your wrapper (provided you're using YEAR TO FRACTION(5) or some other type with high enough resolution to show the the difference) but then you get that same value back on every single subsequent call, which ensures that any sort of loop will never terminate.
There must be some good reason you're not wanting the obvious answer:
SYSTEM "sleep 5". If all you're wanting is for the SPL to pause while you check various values etc, here are a couple of thoughts (all of which are utter hacks, of course):
Make the TRACE FILE a named pipe (assuming Unix back-end), so it blocks until you choose to read from it, or
Create another table that your SPL polls for a particular entry from a WHILE loop, and insert said row from elsewhere (horribly inefficient)
Make SET LOCK MODE your friend: execute "SET LOCK MODE TO WAIT n" and deliberately requery a table you're already holding a cursor open on. You'll need to wrap this in an EXCEPTION handler, of course.
Hope that is some help (and if you're the same JS of Ars and Rose::DB fame, it's the least I could do ;-)
I'm aware that the answer is too late. However I've recently encountered the same problem and this site shows as the first one. So it is beneficial for other people to place new anwser here.
Perfect solution was found by Eric Herber and published in April 2012 here: How to sleep (or yield) for a fixed time in a stored procedure
Unfortunately this site is down.
His solution is to use following function:
integer sysadmin:yieldn( integer nseconds )
I assume that you want this "pause" for debugging purposes, otherwise think about it, you'll always have some better tasks to do for your server than sleep ...
A suggestion: Maybe you could get CURRENT, add it a few seconds ( let mytimestamp ) then in a while loop select CURRENT while CURRENT <= mytimestamp . I've no informix setup around my desk to try it, so you'll have to figure the correct syntax. Again, do not put such a hack on a production server. You've been warned :D
Then you'll have to warp CURRENT in another function that you'll call from the first (but this is a hack on the previous hack ...).