Potential uninitialized variable?

Similar Questions

• Initialization of a local Variable (variable uninitialized perhaps, but it is initialized?)

  I have behaviors very weird with my code. Some error messages complaining about reference uninitialized variables has led me to search around and found out that the shareware I use has very little initialization of local variables. CVI gives warning of the compiler on these variables, and I don't think he has caught even near each other. I went through the whole file and initialized everything myself.

  Even after that I booted my variables, however, the compiler always indicates they are unitialized, and my code still does not work. I've attached a screen of warnings from the compiler as well as one of the problem functions. Note that in the first warning (36, 9 WARNING: variable '(*tw1).i' maybe is not initialized when used here) there two notes under it, the one who told me where the variable is declared and who says "1, 1 Note: Add initialization to silence this warning. When I double-click on that note, he points to the top of the file, as if he says me to initialize the variable outside the function.

  I also found a very similar post about this but the user has said they were defining the structure twice.

  http://forums.NI.com/T5/LabWindows-CVI/local-array-initializations-not-recognized/m-p/2638119/highli...

  In addition, I understand that the screenshot I've not yet initialized the members of the struct, which I intend to do once that I get rid of these warnings.

  What should I do to remove this error? Any help is greatly appreciated, I've been messing around with this for too long. Thank you!

  emoser,

  I think that the strange warning is due to a bug in the analysis of the variables uninitialized in the compiler. The inaccurate diagnostic tests is issued at the line where you set a variable of local pointer to structure kiss_fft_cpx. It seems that the warning is caused during the pointer variable declaration is immediately followed by a local declaration of a structure of the same type:

  kiss_fft_cpx * tw1 = NULL;

  kiss_fft_cpx t;

  Basically, the incorrect diagnosis will happen:

  1. If a local pointer to a typedef struct variable is followed by a statement of the same variable type.
  2. If the second local variable declaration is not initialized.
  3. It doesn't matter if the pointer variable is initialized or not.

  The bug can come because the compiler can guess that the region of memory in the data segment continues from the pointer variable through the definition of the second variable, because they are of the same base type. A possible workaround in your case would be to go to the declaration of the variables of the same type (in your case, the declaration of the variable t) before the declaration of the pointer:

  kiss_fft_cpx t;

  kiss_fft_cpx * tw1 = NULL;

  Fortunately, this problem is fixed in the latest version of 2015 LabWindows/CVI.

  I hope this helps. I would like to know if the workaround works for you.

  Best regards!

  -Johannes

• Test variables in built-in workflows...

  I've included a simple package with 2 workflow...

  the 'test' workflow is just a block of custom decision-making returning true or false on the length of the string 'test'... it works fine if you run it directly.

  "the 'parentTest' workflow is just a workflow that runs the workflow 'test' and fails with: ' TypeError: cannot read property 'length' is null"

  Obviously, this is a simplistic example, but what would be the right way to do it?

  Thank you
  Deric

  Definitely a bug.

  What happens is that when you put a workflow in a workflow there is a stacking complex variables managed by the same wf (if that makes sense for you) and you have here a special case where the type of the attribute cannot be determined since it was not initalized in the first place (the empty chain box has not initialized the variable).

  If you try to add you decision System.log (System.getObjectClassName (testString)) box, you'll see when you run the wf, he knows it's a chain and during the execution of the parent, he does not know (the same way, he wouldn't know what an uninitialized variable.

  To simulate this, you can perform in a box containing a script:

  var testString;

  System.log (System.getObjectClassName (testString));

  To resolve this problem, you have 2 solutions.

  First is to initialize your variable with the addition of a box containing a script before the decision one with:

  string test = "";

  An alternative withou touching the void workflows is to add it to the workflow parent as a workflow that is nested as a suborkflow.

  The nested workflow is executed in a separate workflow context. Workflow will work you exactly as if you would have it run separately.

  I had opened a similar bug but I would need to check with engineering, if it's quite similar and that this will be fixed by the next update.

  You will have to annoy me with this again in a few days since I'm on vacation tonight!

  Christophe.

• Provide the output

  Hi all

  DECLARE
  SYSDATE DATE ;
  START
  SYSDATE := SYSDATE ;
  DBMS_OUTPUT . Put_line ('Date is ' || SYSDATE );
  END ;

  Can you please provide the o/p?

  Thank you

  Do not use function names Oracle integrated variables.

  What is happening here is that you declare SYSDATE as an uninitialized variable, SYSDATE then: = SYSDATE assigns NULL to SYSDATE. Where the output for SYSDATE is NULL.

• Error in documentation of PL/SQL on multidimensional holdings?

  Hello
  
  It is a small issue, but I think that the following PL/SQL reference 11.2 (http://docs.oracle.com/cd/E11882_01/appdev.112/e25519/composites.htm#BABIBDDG), is to the wrong tables nested data types (and variables created of these types).
  Surely, no matter where you see "INDEX BY...» ', it is an associative array. Therefore, ntb1 is an associative array of associative arrays, and ntb2 is an associative array of varrays. Am I wrong?
  
  Thank you
  Jason
  

  Example 5–13 Nested Tables of Associative Arrays and Varrays of Strings
  DECLARE
    TYPE tb1 IS TABLE OF INTEGER INDEX BY PLS_INTEGER; -- associative arrays
    v4 tb1;
    v5 tb1;
    TYPE ntb1 IS TABLE OF tb1 INDEX BY PLS_INTEGER; -- nested table of
    v2 ntb1; -- associative arrays
    TYPE va1 IS VARRAY(10) OF VARCHAR2(20); -- varray of strings
    v1 va1 := va1('hello', 'world');
    TYPE ntb2 IS TABLE OF va1 INDEX BY PLS_INTEGER; -- nested table of varrays
    v3 ntb2;
  BEGIN
    v4(1) := 34; -- populate associative array 
    v4(2) := 46456;
    v4(456) := 343;
    v2(23) := v4; -- populate nested table of associative arrays
    v3(34) := va1(33, 456, 656, 343); -- populate nested table of varrays
    v2(35) := v5; -- assign empty associative array to v2(35)
    v2(35)(2) := 78;
  END;
  /

  >
  It is a small issue, but I think that the following PL/SQL reference 11.2 (http://docs.oracle.com/cd/E11882_01/appdev.112/e25519/composites.htm#BABIBDDG), is to the wrong tables nested data types (and variables created of these types).
  Surely, no matter where you see "INDEX BY...» ', it is an associative array. Therefore, ntb1 is an associative array of associative arrays, and ntb2 is an associative array of varrays. Am I wrong?
  >
  Yes - the documentation is wrong on this point.

  One of the main differences between an associative array and a nested table is how they are treated after creation if they have not yet been met. The table is considered to be EMPTY, while the nested table is treated as UNITIALIZED.

  The doc says so
  >
  As a database, an associative array:

  Is empty (but not zero) until that fill you
  . . .
  An uninitialized variable nested table is a collection of zero. You must initialize, either by making empty or by assigning a value not NULL.
  >
  You can see this particular difference with this code example.

  DECLARE
    TYPE array_test1 IS table of VARCHAR2(15) index by PLS_INTEGER;
    my_array1 array_test1;
  
    TYPE nt_test1 IS TABLE OF VARCHAR2(15);  -- nested table type
  
    my_nt1 nt_test1;
  BEGIN
  --  dbms_output.put_line('array 1 [' || my_array1(0) || '].');
  
    dbms_output.put_line('nt 1 [' || my_nt1(0) || '].');
  
  END;
  

  The foregoing will give this exception:
  >
  ORA-06531: Reference to an uninitialized collection
  ORA-06512: at line 11 level
  >
  If "uncomment you" the first line and comment on the second, you will get a different exception:
  >
  ORA-01403: no data found
  ORA-06512: at line 9 level

• dates of Research Forum

  Searching the forum seems to love at 17:00 on December 31, 1969, very well this new forum is a REAL MESS

  

  If you click on "All in Photoshop Lightroom search results", you will get a complete list of search results showing the correct dates.

  Clearly a bug - December 31, 1969 at 16:00 is January 1, 1970 00:00:00 UTC, a magic date in many operating systems and the programming languages that is represented by the integer 0 (i.e. an uninitialized variable date).

  You could this repost in the Forum comments forum:

  Comments from the Forum

  Personal Adobe has an active interest in these things.  (However, the main problems with this update of the forum seem to be outside of their control - everyone seems to agree that it's a total mess.)

• VARRAY ORA-06533: Subscript beyond County

  Hi all
  I stated in my package body

  create or replace package body mng_res_pack
  is
  ------------------------------------------------------
  TYPE rest_ans_type IS VARRAY(5) OF NUMBER(1);
  rest_ans rest_ans_type:=rest_ans_type();
  -----------------------------------------------------
  PROCEDURE fetch_rest_data
   IS
   rest_rec restore_users%ROWTYPE;
   MONE NUMBER :=0;
   BEGIN 
   FOR I IN 1..5
   LOOP 
   DBMS_OUTPUT.PUT_LINE ('HERE'||' '||rest_ans(i));
   END LOOP;
  .
  .
  .
  end fetch_rest_data;
  end mng_res_pack;

  When I run the procedure, I get the error
  ERROR on line 1:
  ORA-06533: index beyond County
  -----------------------------------------------------
  ORA-06512: at "MNG_RES_PACK", line 46
  Why?
  the size of the varray is 5, and I've also initialized?
  Help, please
  Thanks in advance
  Naama

  >
  even if I does not initialize the varray with numbers, I stil I declare it as a size of 5.
  I still don't understand why he wrote that it out of bounds. NULL is only the value, not the size of the varray.
  He must have made loops 5 times and display null, no?
  >
  No - the VARRAY itself is EMPTY - meaning there is no entry for access. You cannot browse entries because there isn't any.
  The declared 5 size is simply the maximum number of entries that the VARRAY can ever - but it does not all entries; You must do.

  See Varrays in the doc of the PL/SQL language
  http://docs.Oracle.com/CD/E11882_01/AppDev.112/e17126/composites.htm#CHDEIJHD
  >
  An uninitialized variable varray is a collection of nowhere. You must initialize, either by making empty or by assigning a value not NULL. For more information, see 'Constructors of Collection' and "Assign values to the Variables Collection".

• Addition of new global variables

  I change code that uses one or more global variables in a global folder of vi. I would like to add a few variables more and potentially change what exists and ask them to be in the same globals vi. I can easily add a variable of the same type by copying and pasting a variable of the same type on the Panel before the globals vi, but I can't add variables of different types.

  This post comes closest: http://forums.ni.com/t5/LabVIEW/how-to-associate-existing-global-variables/m-p/1079535/highlight/tru... but I did not understand this line:

  • Add FP (there may be several elements in a global variable VI)

  I read some of the warnings against the use of global variables as it can cause race conditions / lead to General illegibility. I'm curious what is recommended if global variables are used as the constants that are defined at the beginning of the program. In general, my LabVIEW code gets pretty unreadable if I have a lot of threads for all of these constants. Is there something better?

  Thank you!

  Kristen

  Hello kllurie,

  The scenario you mentioned (using globals to replace duplicate constants) is probably the best use cases for them - conditions of race etc. problems arise when they are used to the stream or in several scenarios of the writer.  Readability is perhaps a matter of concern, because it is not immediately clear what could be reading from or writing to a global when a thread would suffice.

  With regard to the modification of the globals vi, all you need to do is drop objects on the front of the range of controls (right click).

  Kind regards

• Functional Global Variables: an indicator can be used instead of a shift register?

  It is a simple question, but I can't find an answer to it. The model agreed to a functional Global Variable is to use an uninitialized as in this example shift register:

  

  ('Référence IN' and ' Reference to "is actually a pile of references.) There is also a "Se Refnum" case, which comes the straight through the tunnels shift register.

  My question is, why can't we do store the indicator data? It is much simpler to use a shift register (IMHO a non obvious way to store global data!):

  

  The case "Se Refnum" does absolutely nothing. Other functions such as erasure of data can be implemented just as easily. The advantage of the FGV to help avoid race conditions is maintained because you always use the VI to access the data.

  JonP says:

  
  

  Not so much, the Inidicator can happily live outside the case structure, together and Clear would be just assign different values.

  If you have only a case structure, the indicator could not live outside of it.  In order to maintain the indicator data, your design requires that it is not written in for a case of Get.  If you have an exterior structure deal that decides on 'Get' or 'set or clear' and (in the case of "Set or clear") contains the terminal of the indicator and a classiquee case that decides on 'Set' or 'clear '.  However, I would consider this a design below using the standard template of the FGV.

  The difficulty with retrieving the value if you want to do a read operation / writing change. But LV provides many ways to retrieve data from an indicator (one you don't mention is the 'Value' property), do you mean that's all "incorrect"?

  Yes (I mean that they are all incorrect).

  You could hack your way around the design to work with a single structure of matter and the terminal of the indicator being outside using a method to read the value of the indicator and through a tunnel to the structure of the case through wiring for the tunnel of writing indicator in the case of 'Get '.  However, who will require a local Variable or value of property node.  As I said, these (I only mentioned the local Variable originally) are not good choices for performance and scalability.  If you are not aware of the functional differences between the terminals, local Variables and nodes of property value, refer to this article (obviously advantages/disadvantages such as redraw objects on the front panel are not relevant here).

  I guess you could say that indicators should only be written, but it is difficult to be pure!

  No, it's not, just use the classic design of the FGV!

• How can I create an event listener for the change of variable shared or similar?

  Hello

  I have a 'big' 6 devices communicating measurement system via the TCP protocol. The system is designed to use REST (the representative State transfer) with JSON (JavaScript object notation).

  Now, I need to add labview program to this environment. I've implemented a solution to 'work' with the help of this forum. Thank you for this! Now, I need to do better (currently no timestamps, large delays, etc.).

  I currently have a web service deployed using http-get as input. My web service .vi is just passing the web entrance to shared variables that are then questioned in real measurement program. Reason is that when I put the measurement program directly to the web service, it does not (something about rights and dependencies). Measurement program includes one third of the owners (Instron) drivers. Also I would not direct access via the network to our mechanical testing device potentially dangerous.

  Now, I want to change the message from the web services .vi commensurate .vi. Currently I have a loop of 10ms to query for changes in the shared variable. Is there a better way to do this? I thought create a listener to the shared variable change events.

  In addition, if you have any ideas (preferably, working code example) how to make the interface between labview and TCP-JSON I would really appreciate it.

  BR,

  Juha

  Currently in LabVIEW, the only way to create an event listener or event NSV is to use the DSC toolkit.  Most of the time the DSC is a very expensive tool that simply encapsulates the functionality that is built into the motor of the PSP and OAS and which is accessible to anyone who can program in LabWindows/CVI.

  http://zone.NI.com/reference/en-XX/help/370051P-01/CVI/libref/cvicnvcreatesubscriber/

  If you want to collaborate, I would like to create a small library of LV that would create a base SV events using a vi LV reminder or possibly passing return user LV event which is how works the DSC toolkit.  I asked OR several times to explain how do this and they're very tight discreet about it.  I guess that they do not want to give users LV less reason to buy the DSC.

• How the shared variable affects determinism RT?

  I continue to read again and again that ' If you activate the FIFO in real-time to a shared variable, you can deterministically share data active without affecting the determinism of the screws on an RT target. "

  Could someone help me understand how shared variable affects RT determisim and how FIFO variable sharing does not work.

  Thank you!

  If you send something comes the RT to the host, you use the network, which is inherently not deterministic.

  To use an SV to maintain determinism, you want to stay on target to RT.  You would use this to pass the latest value of a loop to the other.  If you enable the FIFO, you create separate read and write the points so that you have not the same access point in both your curls deterministic and non-deterministic.  With this, you are able to maintain the determinism to nondeterministic loops the last value of a variable.

  The idea is that do not break the determinism of your deterministic loop while accessing these data elsewhere.  If you do not select the FIFO, you have a shared resource that may eventually block the deterministic loop and could potentially go beyond your jitter related.

• FOR loop does not update the local Variable

  I am newer to labview, and I can't wrap the head around why not a habit of local variable to update in the code if it updates on the dashboard. Anything im missing?

  Assume that you are talking about the local variable of the 'State of the cell. The terminal updates every 500ms in the small top loop, the local variable indicates simply that the indicator and thus updates also.

  The problem is "dataflow" and you need to familiarize yourself with the concept!

  Once the while loop starts, the local variable is reading and inside the loop begins. Most likely, the local variable is read before it is updated in the small loop, so most likely returns the value of a fade on the first iteration of the while loop. Now the small loop continues to go twice per second for about five seconds. Only after the loop FOR (and everything else inside the while loop) completed, the while loop will go to the next iteration, date on which the local variable is read once more, this time with the last value of the last for loop iteration of the previous iteration of the while loop.

  In summary, the local variable updates very well, it's just that the code does not read the new value around most of the time.

  Your VI is full also potential competition conditions caused by the over-use of the local variable. You need to respect the proper execution order by eliminating local variables.

  So what is the solution? Hard to say without knowing what the VI is supposed to do. Most likely, you will need to remove the inside OF the loop and use it outside while loop for everything.

• Allocation of buffer in functional variable drives me crazy

  Hello

  I have a functional variable that holds 16 waveforms. You attends waveforms of theses in time. For more efficient memory, I try to use the data tables pre-allocating (say that 300000 double rooms).

  But it seems that there is a new allowance of buffer in the shift register and it is slowing down my app time.

  Since I'm pre-allocating and using inplace structure, I do not see why LabVIEW is a duplication of all waveforms.

  Any idea to achieve functional variable effectiveness?

  Here is the code of my functional variable.

  Thanks in advance!

  Vincent

  

  I don't think that that dot allocation memory buffer is your problem. Which will appear on a register to offset uninitialized and is just the LV medium to tell you it's going to store data.

  To improve performance, I would like to add a new folder named Get Data that displays the waveform buffer, rather than having the shift register directly connected to an indicator of output. Forcing all LV to make a copy of the whole buffer each time this FG is called, even just to write or initialize the data. The case of the Get Data would be the thread of the fork offset register and send it to an output. Select use the default value for this output to the output terminal, so that other cases (writing, initialization, etc) out just an empty array of waveforms, which allows to make very effectively LV.

• LV/CVI how can I access variables 'unique process' shared by his name?

  LabviewCVI 9.0, how can I access a variable shared 'unique process' by his name?

  Hi jenstl,

  If you are referring to a LabVIEW shared variable project unique process, then I don't think that you can access it (directly) from the CVI. As its name suggests, the variable is related to a single process, i.e., LabVIEW.

  If you want to share a variable between LabVIEW and CVI, you could try a shared Variable of published network. Not only is it really easy to convert a process unique to a network shared Variable shared Variable, but there is also an example on their share between LabVIEW and CVI.

  Community: CVI and LabVIEW shared Variables published network

  For more information on Variables shared:

  Developer Zone tutorial: use the LabVIEW shared Variable

  Also, I originally said that you cannot use a single shared Variable directly from the ICB process. I added the 'directly' in there because in all likelihood, you might happen to a (potentially convoluted) workaround involving the use of ActiveX to call the LabVIEW ActiveX Server and communicate to the Variable shared in this way.

  Hope that helps!

• Why not add a URL variable custom for the publishing options?

  This program is ideal for animating with, but freakin ' EXTREMELY FRUSTRANT to implement. Much of this could be mitigated if the options 'release' allow me to specify a URL to the level of the host (or better yet a FTP protocol that I could download my work, while I dream).  In this way, the code can reference the folder I put in on my existing Web site and save me the javascript editing and declaring a variable and redirect each asset it EVERY SINGLE TIME I've updated the stupid thing, because in case you were not able to tell from MY LETTERS CAPITALS angry I had problems with getting my edge animations to display , and when they do they are HORRIBLEMENT CASE (they work in previews and not where elsewhere) and there only seems to be a lot of support here I had problems.

  Oh wow has completely neglected the CAN, it's great! Thank you.

  Not sure if you understood the "file management". We are not to seek a new method to download files or create a site, we are looking for a variable set a path root in the media of edge for when direct sound. How does dreamweaver or other tools limit making temporary edit > push variables in the stacks of jQuery edge? I do not think they do... which puts the logic of full circle manual edition edge to js changes at a level exceeding the ordinary people. We had to manually make a new variable "rtdir" and change the variables "im", then add all the paths manually to make it work. Looks like native support for it asking a lot too many other tools, especially considering that they have no role in 'construction' files still have to change them a bit. Also, there is a great chance to other tools to hang at this level, edge variables would cause too many paths to corrupted files.

  Whereas edge built "im" and has the potential to do the same for "rtdir", it would be really difficult to integrate an entry box where you type in the URL path button... then this path is crushed in XXXXX_edge.js and XXXXX_edgePreload.js when it is published. The directory of the song is already functional like the structure of the existing files. The question is it leaves in a non-specific overview of the State... example: / MyFolder/project1. This breaks every URL its used on as its adding/myfolder/project1 after any link whatsoever