Inconsistent output in project values. Possible race condition.

Similar Questions

• Autofocus TextField when the user presses the keys (and possible race condition)

  Someone tried to implement a device by which a TextField (or text box, I guess) automatically gets the focus when a user starts to type anything? It is very convenient to have something, at least with a phone model Qwerty, in certain situations. (A use case is where a list that is too long for the useful shortcuts, but the TextField object is used to implement a filtering mechanism that can reduce the data set to a reasonable size, and the user can then scroll just to find a target element).

  I've set up something using a KeyListener (calling requestFocus() for the TextField object) attached to the container Page, but there are problems with it.

  It's a question that the first keystroke does not render in the TextField object, since it has not a focus when the key was first struck.

  To solve that you can enter the key (event.unicode) and that insert into the TextField object, and then the following keys go on the field you want... but there is also a problem with that.

  If you type two or three buttons in quick succession, probably less than 50ms between them, you can see that even if the KeyListener gets each of them, the TextField object receives the second or, sometimes, the third, even if you can check that by the time second keyPressed/output signal arrives in your earpiece the TextField claims to have developed (TextField.focused is true).

  This seems like a bug, but maybe it's just a case of corner cascading who is inevitable, given its design... I'm not sure.

  If anyone can reproduce it, thanks for posting here. I'll do a test case to prove and will report it as a bug if you do.

  If anyone has a reliable and quality approach, please post here too! :-)

  P.S. for a good laugh, a code here that I did for my particular case, which seeks to avoid the race condition. As you can see, this is a great hack, but it works 100% reliable for me so far with a fairly comprehensive test (including the tests with the movement of the cursor, copy/paste, etc.). It's too complicated to analyze and ensure that it is really robust, however, but feel free to use... If you care enough. ;-)  http://pastebin.com/r2VUtPJC

  Have you tried setting the primaryKeyTarget it's inputRoute?

  https://developer.BlackBerry.com/native/reference/Cascades/bb__cascades__inputrouteproperties.html

  Has been added to the 10.1, which should do what you want.

  You can also achieve the same messing around with pre FocusPolicy 10.1, but it is much simpler.

• Having a very bad Friday afternoon, no idea how I can eliminate a possible race condition?  I have a working script intermittently :(

  I have a script that seems to work intermittently, usually it fails on the line of characters 1 128 (in bold below) I think that the VC will not return with information and therefore the script fails on the capture...

  on the other

  {

  Write-Host "space is insufficient on the target data store. Please increase the space to continue.

  Write-Output "space is insufficient on the target data store. Please increase the space to continue"> > $logfile

  Write-Host "Exiting with code 1.

  Write-Output "exit with code 1" > > $logfile

  Send-MailMessage-to $From-$To-CC $Cc - subject $Subject '

  -Body $BodyFailure1 - SmtpServer $SMTPServer - port $SMTPPort

  Output 1

  The architect suggested it might be a race condition, can someone with a lot more experience than me (it's pretty anyone) suggests an alteration that may well solve this problem?  I guess I could put breaks in but I'm not 100% where would be the best place to do so or if maybe it's the mickey mouse method?

  Error

  # ==============================================================================================

  # NAME: CloneVMs

  #

  # AUTHOR: Luc

  # DATE: 10/09/2015

  #

  # COMMENT: Creates a clone/backup of virtual machines described in the text and names using the

  # past param.  Virtual MACHINE will be appointed in accordance with the following VM1-12345678 example

  #

  #

  #

  # * Software dependencies: *.

  # - Microsoft PowerShell *.

  # - VMWare PowerCLI *.

  # ==============================================================================================

  # Parameters

  # ==============================================================================================

  # Below is provided by Control-M parameter refers to the prefix point cycle and restoration,

  # the date can be added automatically, however, this feature has been disabled.

  Param ([string] $CYRPYYMMDD)

  # ==============================================================================================

  # Functions

  # ==============================================================================================

  #Function for you to check if a command is responsible

  Function Check-Command ($cmdname)

  {

  return [bool] (Get-Command - Name $cmdname - ErrorAction SilentlyContinue)

  }

  # ==============================================================================================

  # Varibles

  # ==============================================================================================

  # Add the snap of vmware for powershell

  # Add - PSSnapin VMware.VimAutomation.Core

  # Add the snap of vmware for powershell (keeps see you error messages)

  If (control "Connect-VIServer")

  {

  Write-Host "already automation tool for".

  }

  on the other

  {

  #If not already loaded load the snap

  Write-Host "loading automation tools.

  Add-PSSnapin VMware.VimAutomation.Core

  }

  backup of # = true adds date; false creates a clone with the same name.

  $backup = 'True '.

  debugging of #-true: clones not vm. FALSE will clone the virtual machine.

  $debug = "FALSE".

  # Target Datastore

  $targetdatastore = "LUN9_BASIC_MATADM_ONLY".

  Check the #Refers the percentage of free space for space DS

  $freePerc = 10

  # Target location - folder existing in vcenter structure, where the clones will be held

  $targetlocation = "DMAT DNT for Cycles compatibleM BackUp.

  # Set a date

  $datestart = (get-date - uformat %Y %m %d)

  # Name a log file to record the results.

  $logfile = $datestart + "_VMClones_bulk.txt".

  #

  Write-output "new journal ($datestart) - ($logfile)" > > $logfile

  # Gets the list of virtual machines from the file associated with this script

  $VmFileList = get-Content VmsToCloneList.list | Select-Object - jump 3

  #

  $ds = get-Datastore-name $targetdatastore

  #Email varibles

  $From = «»

  $To = «»

  $Cc = «»

  #$Attachment = "C:\temp\Some random file.txt".

  $Subject = «!» DMAT TEST createRP TEST! »

  $BodySuccess = "A DMAT VM has correctly saved to the specified folder of destination organizational data store and inventory in vSphere"

  $BodyFailure1 = "the combined use of VMDK put in service of the virtual machine is greater than the capacity of the destination database or the datstore does not exist, coming out with code 1"

  $BodyFailure2 = "there is not enough space on the target data store, increase the space to continue, exit with code 1"

  $BodyFailure3 = "a virtual machine with the specified name is not found maybe it does not exist? Exit with code 1 "

  $SMTPServer = «»

  $SMTPPort = "25".

  # Connect

  $Creds = get-VICredentialStoreItem-Host 127.0.0.1 - folder C:\Users\matadm\PS_ITC_BAS.xml

  SE connect-VIServer 127.0.0.1-$ username-password Creds.User $Creds.Password

  # Gets the total ProvisionedSpaceGB of VM for all s VM in the list.

  # Ensures whitespace and hashes are effectively ignored

  # create a clean list that calculates / creates the variable required for the validation check 1

  $vmCleanedList = New-Object system. Collections.ArrayList

  # Loop through our VM file list and own is in place, check for incorrectly specified VM

  ForEach ($vmname to $VmFileList)

  {

  If ([string]: IsNullOrWhiteSpace ($vmname) - or $vmname.) StartsWith("#"))

  {

  writing-host("Invalid machine name-$vmname")

  }

  on the other

  {

  #Should trim vmname to ensure that we have no spaces before or the end

  $vm = get - VM $vmname

  $vmCleanedList.Add ($vmname)

  $TotalRequiredGB += $vm. ProvisionedSpaceGB

  }

  Write-Host "Total needed = $TotalRequiredGB.

  }

  # ==============================================================================================

  # Validation checks before launching the clone script

  # ==============================================================================================

  # Updates the prior to storage data store information.

  $ds. ExtensionData.RefreshDatastoreStorageInfo)

  # Validation check 1, check if the combined usage of VMDK put into service of the virtual machine is greater than the capacity of the destination database?

  If (($ds.)) FreeSpaceGB - gt $TotalRequiredGB))

  {

  Write-Host 'continue with your script.

  }

  on the other

  {

  Write-Host "space is insufficient on the target data store. Please increase the space to continue.

  Write-Output "space is insufficient on the target data store. Please increase the space to continue"> > $logfile

  Write-Host "Exiting with code 1.

  Write-Output "exit with code 1" > > $logfile

  Send-MailMessage-to $From-$To-CC $Cc - subject $Subject '

  -Body $BodyFailure1 - SmtpServer $SMTPServer - port $SMTPPort

  Output 1

  }

  $ds = get-Datastore-name $targetdatastore

  # 2 validation control, you have X % datatstorespace free?

  If ((($ds.)) FreeSpaceGB / $ds. CapacityGB) * 100)-ge $freePerc)

  {

  Write-Host 'continue with your script.

  }

  on the other

  {

  Write-Host "there is less than X % of free space on the data store. Please increase the space to continue.

  Write-Output "there less than X % of free space on the data store. Please increase the space to continue"> > $logfile

  Write-Host "Exiting with code 2.

  Write-Output 'output with code 2' > > $logfile

  Send-MailMessage-to $From-$To-CC $Cc - subject $Subject '

  -Body $BodyFailure2 - SmtpServer $SMTPServer - port $SMTPPort

  Output 2

  }

  #Hack + of the duplication of efforts

  #$VmListFile = get-Content VmsToCloneList.list | Select-Object - jump 3

  ForEach ($vmname to $vmCleanedList)

  {

  # The virtual computer object

  $vm = get-VM-name $vmname

  # Target host - use the same host as the current VM (it's faster than the cloning on hosts).

  $targethost = $vm.vmhost.name

  # Target VM name - name if the BACKUP is FALSE

  $vmtarget = $vmname

  #

  $datastore = get-datastore $targetdatastore - vmhost $targethost

  # ==============================================================================================

  # Start the real clone script

  # ==============================================================================================

  If ($vm - no $null)

  {

  Write-Host "a virtual machine named $VM exists. From clone "

  Write-output "a virtual machine named $VM exists. From clone"> > $logfile

  }

  on the other

  {

  Write-Host "a virtual machine with the specified name is not found maybe it does not exist?

  Write-Output "a virtual machine with the specified name is not found there is perhaps no?" > > $logfile

  Write-Host "Exiting with code 3.

  Write-Output "output with code 3" > > $logfile

  Send-MailMessage-to $From-$To-CC $Cc - subject $Subject '

  -Body $BodyFailure3 - SmtpServer $SMTPServer - port $SMTPPort

  exit 3

  }

  If ($backup - eq "TRUE")

  {

  # Clone the virtual machine for backup_vmname_todaysdate

  $vmtarget = $vmtarget + '-' + $CYRPYYMMDD #+ '-' + $datestart

  }

  beautiful colors # if you look at the script runs

  write-host - foregroundcolor green 'cloning $vm to $vmtarget.

  Write-output - foregroundcolor green 'Cloning $vm to $vmtarget' > > $logfile

  new-vm-name $vmtarget - vm $vm vmhost - $targethost - $datastore - $targetlocation location data store - slim DiskStorageFormat

  Send-MailMessage-to $From-$To-CC $Cc - subject $Subject '

  -Body $BodySuccess - SmtpServer $SMTPServer - port $SMTPPort

  }

  Write-Host "complete."

  Exit 0

  # COMPLETED

  Have you ever tried to test if $ds-eq $null before you call the RefreshDatastoreStorageInfo method?

  In the error message, it looks like $ds contains $null, no idea why when the data store 'LUN9_BASIC_MATADM_ONLY' exists in the environment in which you are conencted.

  In fact, you could test immediately after the Get-data store.

  Ah, but wait, you seem to be doing the first Get-Datastore (there are two in the script, but I guess you know) before the connect-VIServer, it won't work.

  Unless I'm missing something here

• Table of only clusters during initialization or Possible Race Conditions

  Hi all

  I worked on a fairly complex project for work, and I have not worked with before Labview. Unfortunately, nobody in my office really has experience with it so I'm on my own. I especially the working draft and it might be a little heavy, but if it works it is fine.

  Essentially, it is a temperature control device and I made sure it's extensible, so the bunches and berries everywhere.

  My question is this. I have an array of clusters showing the status of all the plates in the system. When I start the VI for the first time, they did not initialize. They are still just Gray, but when I stop and start again, it will work every time. I think it's strange behavior. I heard racing conditions and while I tried to make sure that c ELA is not the case, he could be without noticing me.

  I tried to put a table initialize block in the first call while loop and that does nothing, and if I remove the initializer in the registry to offset in the while loop top which stops them being initalized altogether.

  I guess I was hoping someone might have an idea of what is the cause, or could possible give my code the time. The gist of it is at the top of the code, but there are many small manifestations taking care of type GUI stuff.

  I have included all the source code. It might be a bit much, but I didn't start shooting it hand if I don't know what is happening.

  Thanks in advance.

  Chris.

  
  

• How to avoid race conditions?

  Hi, ive done Labview for a dozen years. And this is the first time ive met or its made my code. I have a lot of code that runs at the same time. And for years, good practice in order to avoid it never repeated?

  Stu

  I spent an entire course on the race conditions and concurency in higher education, and to avoid race conditions, understand why they occur.

  Race conditions occur when several parallel processes or competitor access to a shared resource.  Furthurmore, this is especially annoying when 2 or more threads or processes are seen change a resource.  Then all first identify candidates for this when the architecture of your application.  If you only have one thread, you must be sure (although it gets more blurry since it has the ability to run in parallel).  Is it then all variables/resources that are needed in the 2 wires at the same time, and if so, you change the value in one or more threads.  If so, you have to deal with synchronization.

  Traditionally, you talk semaphors, locks and mutexes.  All methods of locking critical code (ie the resources that are sources of possible race condition).

  BUT WE ARE IN LABVIEW.  LabVIEW has a simple method which could be easier to use, functional overall.

  screws that are not marked for reentrancy is essentially a great way for the protection of data and your locking critacal sections.  That only one thread can access and or modify the data stored in the vi, at the same time.  Other threads will be blocked and wait on the resource.

  It was much more difficult to implement in c.

  Anyway the way you deal with racing conditions is to

  1. identify critical sections and resources which can cause race conditions (usually shared resources with multiple writers)

  2 lock the resource until cooked (avoid deadlocks by per se - but that is another debate)

  Unlike traditional bugs, bugs competitor are more random and very difficult to reproduce/test for so you will have to deal with them in the design of architecture.

• Update only one item in the cluster while avoiding race conditions

  I have a cluster called "Inputs" that has a bunch of data within all kinds of data types.

  I have several loops in the code I want each of them to update a specific element within the cluster.

  I have to get the cluster use this Bundle by name on the specific item and then rewrite in the cluster.

  This way I have racing conditions because two loops can 'be' the cluster at the same time, but when they rewrite a wiil overwrites the other.

  How can I avoid these race conditions?

  I am familiar with Globals functional if it is connected to a possible solution (I have the feeling that it is..)

  Thank you!

  I still think that my suggestion to use the value of data references would be easier. The structure of the International preliminary examination will block the concurrent access to the data cluster: no race condition.

  

  The last loop (option) shows how to query the State of the heap of data.

• Control vs control tree string: "changed value" calendar race?

  I develop a configuration dialog box that uses a tree control and a tabbed pane and I have problems with the timing of the event. The tree control presents the structure of the connected equipment and the tabs pane shows the configuration for the selected node. The tree control is used as a tabbed pane may not have additional tabs created during execution, and the connected equipment vary from installation to installation. Rather than write a pane tabs hardcoded for each deployment, I use a flexible class structure that allows an "m x n' configuration - m zones with n channels per area, but n varies by area. By selecting a node in the tree fills the tab corresponding to the values of the node. The number of zones is limited the number of configured system views (discrete monitors) and the total number of channels is limited to the number of installed channels A/D. To capture the configuration data, each control in the tabs pane is a 'value changing' event, which sets the value of the element in the class.

  Now that you know what it is supposed to do, here's the problem: it only works if you do not click on the tree after a value is changed. For example if you enter in a new 'ladder' and then click elsewhere on the tabbed pane, the value is correctly associated with the node. If you click another node in the tree before leaving the field, the value is assigned to the node clicked instead. I looked at the timestamps for events and field "changed value" fires first, so the value of the tree should still be the original node. On the contrary, the tree seems to update before the event to "change the value" of the field is managed, even if the event of the field were pulled everything first. I read the value of the tree inside the event handler for the field, but there is no way to get the 'previous' value is the field control in the tabs pane.

  So where should I go from here? Is this a legitimate race condition, or am I just not processing events properly? I prefer not to post the code because it is pretty heavy with all its dependencies, but I can try to do a simple example.

  

  Cranky wrote:

  It seems that it is not an event filter for the change of the tree: value.

  This kind of surprises me.  But I couldn't find either.

  My other thought (like Altenbach) would store in a shift of the currently selected item register.  Since the change in value of the tree that happens after change in the value of the parameter, you read the registry value of offset for the change of setting and then update the registry to offset with the change in value of tree.  Do not forget to connect the values directly but for any event except the change in value of tree.

• Locking access to Global Variables to avoid race conditions?

  Hi all

  I'm developing an application where 'control' Subvi accesses a Subvi 'action '. The Subvi action is actually limited by a number of different high-level subVIs to I really need to use globals.

  I wrote the next part of the code and was struck that it could lead to a race condition. Essentially my Subvi control runs two loops in parallel. Each loop reads the global increments a different value in each of them, wait a while and then returns to its previous value.

  I wrote this piece of code to demo what I mean. The table of waveform takes the place of the Subvi 'action '. Running this code resulted in a competitive situation (one of the values goes from 0 to 5 range to the range of 5-10) after its loading into memory using a second time usually allows it to operate for a long time.

  

  I modified the VI to exaggerate the effect of the condition of competition for demonstration. I've also implemented a solution using a local variable to stop the globals accessed at the same time. However, it is far more elegent and I don't think it will work for more than two loops. Finally, I need to use three loops.

  I have attached my demo/exaggerated solution. If you can suggest a better way to solve this problem, I would be very grateful.

  Thank you

  Dave

  DeltaJ wrote:

  I'm just out of the laboratory for a bit of fresh air--after watching this problem for hours - and he hit me. If I write access to my Globals in a Subvi - what I can do - and do the reentrant VI will not program only be able to access the globals in the order and avoid the condtion race in this way?

  A reentrant VI uses its own separate for each instance memory space, so it means it can be called in parallel with another instance. In other words, it gives you just the same situation as what you currently have.

  Or do you mean I can access to the global queue - I'm able to do it without a huge rewrite!

  No, I wasn't talking about the queue access globally. I was talking to store the data in a queue.

  Encapsulation of the value in a Subvi refresh, it's what you would do with a motor of Action. Note that you want an 'update' action so the write occurs inside the engine of Action VI.  This will give you as close to an atomic operation that you can get.

• ... Is sorting on a given value possible in oracle?

  Hello
  I have a table that contains a column titled 'level' (values possible sont0, 1, 2, 3, 4, 5) and a second column, 'createTime' (date of entry is created).
  I want to display the sorted lines in this way:
  -First level = 5
  -Then the other levels (in any order, but ordered by crateTime).
  -For 2 categories, I want the results sorted by crateTime.
  
  In mysql, I could do:
  SELECT createTime level, FROM table order by desc level = 5, createTime asc;
  
  In Oracle "level = 5 order" is not accepted."
  Is there a way to do this?
  
  Thank you.

  That's what you're looking for:

  SELECT * FROM my_table
  ORDER BY (CASE WHEN level = 5 THEN 0 ELSE 1 END), createtime
  /
  

  Published by: AP on October 11, 2010 05:07

• Race condition with data value reference?

  I'm having a problem that presents itself as a condition using DVR to pass data through a VI.  I had heard that the DVR has blocked concurrent access to the data reference.  I have a DVR from two places in my code, 1) I write a new value to the DVR, what happens when a user event and fires rarely and 2) that I read the DVR to access data and display them graphically in an update of loop at 2 Hz.  The DVR stores a large cluster of the elements, and in this case I can only access one of the cluster using the structure of the element 'In Place'.  I'm in trouble that on some occasions the DVR reads the old data, rather than the new set of data by the user event.  I've attached screenshots of the access screw and I use a Get/Set configuration that allows me to read/write an element unique cluster of the DVR.

  I'd appreciate comments on structure I use, traps, or am I misunderstanding of the use of the RECORDER.

  Thank you
  Dan

  To protect what is inside the structure of inplace DVR. Once outside, the Paris are open.

  Sounds like you want a queue where there is only a value if send it awaiting it upward.

  Ben

• reset all outputs the initial values

  Hello

  in our case, a project VeriStand is running on a machine RT with cRIO-I/O.

  Is there a possibility to reset all outputs to the initial value, while the project is running? (I don't want to restart the system in real time or deploy the project to new because who consumes too much time).

  Hello

  You can create an alarm that calls a reset procedure. The alarm can be mapped on a Boolean button in the workspace. Or you can call a Sequenze RT to reset your values.

  Best regards

  Philippe

• Satellite 1415: Two outputs screen is not possible?

  I would like to use the coaxial video output as a second screen. Is this possible? An explanation, in the cases where I'm being unclear. In essence, I would like to use the coaxial output as a second monitor as seen with computers with two monitors and the office is stretched between the two (the half being on one monitor, the other half is on the other monitor).

  Reason being, I want to configure my laptop as a karaoke station. I would have to open the Windows Explorer and mediaplayer playlist on my laptop, while having the words "full screen" on television. Someone knows how can I do this?

  Thanks for any help you can provide!
  Art

  Satellite 1415 seems to be designed for an American market. I didn t see in Europe or on the European sites.
  Anyway, your description is clear and I think you want to use the extended desktop option. I use this too. It s very useful for someone who uses different applications together.

  But it takes something cleat. Video out port (coaxial cable output) to play video DVDs on a projector or TV. It s not for external monitor connection.
  The device also supports a RGB port (near parallel port) and this interface allows to connect an external monitor.

  The extended desktop, you can turn on in the properties of the graphics card. Simply right-click on the desktop and select Properties.

• Ignore test values if the condition is empty

  I'm going through a spreadsheet of Excel to numbers. I manage not to come with a formula of workaround for some table formulas in the Excel worksheet. In total, there are 16 array formulas, but they all follow a format similar to this:

  {= SUM (IF ((B: B = M7) + (M7 = ' '), F:F)}))}

  Basically, I want to add up the values in column F when the B column matches the value specified in M7 and if M7 is empty, so I want to do the sum of each row, effectively without taking into account the State.

  I'm not an Excel guru and hacked this together years ago and it worked fine. I don't know if it was the best way to do it in the first place, but ideas to do the same thing in numbers would be appreciated.

  Thank you.

  I think that's what you want:

  

  = IF ($M$ 7 = "", SUM ($F), SUMIF ($B, $M$ 7, F))

  In my example, line 10 is defined as a footer line.

  As you use numbers more you can break things up into separate tables.  Usually you can avoid having a condition like M7 completely cell our there by himself in a sea of cells.  Recommend to have a look at the patterns to queue > New.

  SG

• Extensometer - project value

  Hello!

  I use extensometer to measure the deformation of an axis in brass. I installed an extensometer via connector 9944 to NI 9237 tends in NI 9162 carrier (or NI 9174, I think that no matter what carrier I use).

  It works very well, but every now and then when I run the program I get "project of value." For example, when I start the program, the value is 0.020, but then it starts to write in + or - although I do not move or bend axis. So the values can change from 0.020 to 1,200. I can't find the reason for this error.

  Then I start to reset the card or program and change the cable ports several times until it stops, it can take 20 minutes or more.

  Help is needed, thank you!

  
  

• Avoid race Conditions, using Variables of network w / RT

  SYSTEM:
  I use a cRIO system connected to a host via ethernet PC.
  One of the parts of my system of cRIO with that I'm having a problem using CAN.

  BACKGROUND:
  FPGA waits for a reading, and when a message is received (U8 table format), he shoves every element in a target-to-Host U8 FIFO.
  RT sees the message in the FIFO, it collects and it integrates an array 2D U8 (in the case where more than one message is received) and adds to a growing range of U8 2D.

  PROBLEM:
  Originally, I was misleading this table 2D to the host computer via a Variable network and display on the façade of the host machine.  This works, except over time, this table 2D-U8 gets huge-especially if I use an echo.

  Ultimately, I want the host to display entire history, but including the RT rewrite this entire variable each time and send them over the network it slows down.

  FAILED ATTEMPTS:
  I expect to change to a queue, but apparently it is accessible by other elements in the host (in this case, the Module LabVIEW RT.)

  Writing an empty array in the network Variable after reading it obviously causes problems of condition Whitneys.

  QUESTION:
  Any suggestions on how to transmit these data to the host without losing data?

  Is it possible to have something similar to a queue or FIFO on the network?

  Thank you

  ~ Andrew

  (There are two routes that you might go: 1) for broadcast continues to the host network streams gives the effect of the queue on the network but it requires something to transmitted data namely hard if you need connect/disconnect your host. (2) stick with static variables, but your RT code will be expected to handle the buffer. For example, you can set up a circular buffer of the last samples n that is written to the variable. Based on what you say, I'd go with 2 though, so he can give that a complete history is difficult.