object of class of access in multiple threads

Similar Questions

• Berkeley DB Java Edition - multiple threads accessing the database

  Hello
  
  I would like to access (read & write) a Berkeley DB of multiple threads (process/FMV anyway).
  
  Can I use a single com.sleepycat.je.Database object for all threads, or should I create an instance of each?
  
  Or is there another way to do it?
  
  Thank you

  The object database can be used by multiple threads, you can use a single instance or multiple ones, as suits you best. Of http://docs.oracle.com/cd/E17277_02/html/java/com/sleepycat/je/Database.html.

  The database handles are free of threads and can be used simultaneously by multiple threads. '

  If you read the javadoc, you can find any other comments on the use of the classes from multiple threads.

  Kind regards

  Linda

• concurrent writes to a logfile from multiple threads (Java 7)?

  Hello everyone

  I have a multi-threaded Java 7 (jar file) program that uses JDBC to perform work (he uses a fixed pool of threads).

  The program works very well and it records things that it moves the console command shell window (System.out.printf ()) starting from multiple concurrent threads.

  In addition to the release of the console, I also need to add the capability of this program write in a single flat ASCII text file journal - starting from multiple threads.

  The output volume is low, the file will be relatively low because it is not a data file, a log file.

  Can you please suggest a relatively simple and good to achieve design/approach using Java 7 features (I have not yet Java 8)?

  The code examples would also be appreciated.

  Thank you very much

  I have a multi-threaded Java 7 (jar file) program that uses JDBC to perform work (he uses a fixed pool of threads).

  The program works very well and it records things that it moves the console command shell window (System.out.printf ()) starting from multiple concurrent threads.

  In addition to the release of the console, I also need to add the capability of this program write in a single flat ASCII text file journal - starting from multiple threads.

  The output volume is low, the file will be relatively low because it is not a data file, a log file.

  Can you please suggest a relatively simple and good to achieve design/approach using Java 7 features (I have not yet Java 8)?

  The code examples would also be appreciated.

  Use a dedicated thread for logging and a queue to source it. See the "queue implementations of the trails in the Java tutorials for the use of queues and the code example that works.

  https://docs.Oracle.com/javase/tutorial/collections/implementations/queue.html

  Java has several classes of queue synchronized you can use if those in this tutorial are not suitable for your use case. Here's just one:

  https://docs.Oracle.com/javase/7/docs/API/Java/util/concurrent/ConcurrentLinkedQueue.html

  Unlimited thread-safe queue based on linked nodes. This queue orders elements FIFO (first-in-first-out). The head of the queue is this element which remained the longest the queue. The tail of the queue is this element that has been on the queue as quickly as possible. New elements are inserted at the tail of the queue, and get the recovery operations of the queue of the elements at the head of the queue. At ConcurrentLinkedQueue is a good choice when the number of threads will share access to a common collection. Like most other concurrent collection implementations, this class does not allow the use of null elements.

  Using a queue your current code can add recording which is FAST because it is add an instance of the class to a collection rather interact with the file system. And your current code requires NO knowledge of the functioning of the system of newspaper, that it connects or when and where it connects.

  For your use case use you a synchronized queue and edit each of your worker threads to add their log data to the master queue used by the newspaper for the logging thread.

  You shouldn't have multiple threads trying to write directly in the same file.

  The entire point of the modular and multi-processing programming is to BREAK dependencies between modules of code.

  The logging system must be INDEPENDENT of the other code and your current code must NOT have ANY need or knowledge of the file system or OF the specificity of the way where, or when the data is actually stored.

  Your code must run simple and minimal logging by adding its data to a queud. Once the log data was added to the queue and then, as far as your code is concerned, that data has been noted. It should be ONLY module log to determine the LOCATION to save the data, HOW to record data and even WHAT information to log.

  You can add the larger newspapers in the future: newspapers, paper 1) different levels of 2) to a remote server or the database 3 send some events in the log.

  I suggest you create a SIMPLE D.O. (data object) to maintain the log info (attributes like gravity, time/date, type of exception stack, error, etc.). Then create a class of SIMPLE log with several overloaded methods: a method that takes a single parameter, with two, etc. Javas is owner of exception classes have some simple examples of both simple and complex, nested exception handling.

  These methods journal would take care to fill in the NEWSPAPER to DO correctly and then placing the instance of the D.O. to the journal queue. In this way, you can use a parameter of a simple newspaper just pass an error message and the log class method will add a default severity level (which can vary from thread if you want), time (which can range from wire) and other necessary data.

  The goal is to keep the journal interface use you in your existing code as SIMPLE as possible while keeping as independent as possible of the actual logging mechanism.

  The result is a mechanism of simple logging that is versatile and scalable and can then be used for your PROJECTS that require a registration (file, database, e-mail).

  Do not make the mistake to hardcode the mechinism journal in your existing code.

  DO not continue independent, modular architecture that you already use.

• AppleScriptObjC and multiple threads

  Hello again people.

  I read some old threads here to have multiple threads in a Cocoa-AppleScript application, but I have not found any that I think that would work for my particular use case.

  Here's my situation: I have a method that expects that the user say a phrase and then runs another method when he hears the phrase. Here is the code that I currently use:

  on listenForQuery()
  set query to ""
          try
              tell application "/System/Library/PrivateFrameworks/SpeechObjects.framework/Versions/A/SpeechRecognitionServer.app"
                  set query to listen for {"Hello"} giving up after 5
              end tell
          end try
          if query as text is equal to "Hello" then my newQuery_(null)
          performSelector_withObject_afterDelay_("listenForQuery", missing value, 2.0) -- do it again every two seconds
      end listenForQuery
  

  AppleScriptObjC is not multi-threaded, but it seems that you forgot that it can use many of the classes and methods of cocoa.  Instead to use AppleScript to control another application, take a look at aid NSSpeechRecognizer in yours - you can give it a list of commands to listen and to define a delegate method that is called when something is recognized.

• SQL Toolkit crashing with multiple threads

  Hello everyone and happy new year!

  I was hoping someone might be able to shed some light on this problem. I update an older application to use multiple threads. In fact, the thread that is causing a problem now is created by using an asynchronous timer.

  I use CVI 2010, and I think the SQL Toolbox is version 2.2.

  If I execute a SQL statement from the main thread, there is no problem.

  stat = DBInit (DB_INIT_MULTITHREADED);
  
  hdbc = DBConnect( "Provider=Microsoft.Jet.OLEDB.4.0;Data Source=sample.mdb;Mode=ReadWrite|Share Deny None" );
  hstmt = DBActivateSQL( hdbc, "SELECT * FROM SAMPLES" );
  
  DBDeactivateSQL(hstmt);
  DBDisconnect(hdbc);
  

  If I add code to perform the same duties in a reminder of the timer, it causes a stack overflow error.

  .. Start the main thread

  stat = DBInit (DB_INIT_MULTITHREADED);
  
  NewAsyncTimer (5.0, -1, 1, &gfn_quicktest, 0);
  

  .. end of main thread

  .. and then the reminder of the timer

  int CVICALLBACK gfn_quicktest (int reserved, int timerId, int event,  void *callbackData, int eventData1, int eventData2)
  {
    {
      int hdbc = DBConnect( "Provider=Microsoft.Jet.OLEDB.4.0;Data Source=params\\sample.mdb;Mode=ReadWrite|Share Deny None" );
      int hstmt = DBActivateSQL( hdbc, "SELECT * FROM SAMPLES" );
  
     DBDeactivateSQL(hstmt);
      DBDisconnect(hdbc);
    }
  
    return 0;
  }
  

  The program crashes with a stack overflow error when the DBActivateSQL statement is called.

  I understand that the Access ODBC driver can not support multithreaded, but I only connect to this base starting from the same thread with these 2 statements only so it should be good?

  Any idea would be appreciated,
  Thank you
  Ed.

  I just tried this using the sample provided with CVI access database. It uses a DSN instead of mdb. It has worked out well. I see that no reason multithreading would be a problem here, if you open and close the connection in the same segment of code. I see that you use params in the asynchronous callback connection string. Where did this come from? Maybe try to use the database and see if it works.

• kb2596615 causes ade to failure, error was 459: object or class does not support the set of events

  A couple of my users started getting our application error messages ade grown after you apply this update. Everything is well after its withdrawal. First mistake was 459: object or class does not support the set of events. Basically, no event has worked. Why is this update break my application? It should be removed from the queue of the update.

  Okay, I've worked on it with Microsoft, and the actual cause turns out to be:

  MS12-060 security update affects the functionality of Access database
  http://support.Microsoft.com/kb/2748410

  This article updated fingers MS12-060, specifically KB 2687441, as the culprit.

  It turned out that ActiveX controls on the form (specifically the Microsoft Common Controls 6.0 Toolbar), caused the failure.

  The solution was simple: on a patched machine, open each form with an ActiveX control in design mode, compile and save it. It worked for me. Ignore the details of the solution that I wrote in the previous post!

  You may need to resave MSCOMCTL. OCX, as suggested in the article, to get your databases to work.

  -Ken

• Violation of unique constraint in JPA in multiple threads

  I get the following error message when you use APP to create a record in my database:
  # < 14 October 2009 10:13:14 AM CDT > < Info > < EJB > < lharding pc > < AdminServer > < ExecuteThread [ASSET]: '3' for queue: '(self-adjusting) weblogic.kernel.Default' > < < anonymous > > < BEA1 003262EA920A3057A4BD > <>< 1255533194632 > < BEA-010227 > < EJB Exception occurred during invocation of home or business: weblogic.ejb.container.internal.StatelessEJBHomeImpl@589d49 threw the exception : javax.persistence.PersistenceException: Exception [EclipseLink-4002] (Eclipse - 1.1.0.r3338 - M8 persistence Services): org.eclipse.persistence.exceptions.DatabaseException
  Inner exception: java.sql.SQLIntegrityConstraintViolationException: ORA-00001: unique constraint (BDSS. CONN_USER_DOMAIN_STATE_PK) violated
  
  Error code: 1
  Call: INSERT INTO USER_CONTEXT_STATES (ID, TEMP_FLG, STATE_INDEX, LAST_SYNC_TS, USER_CONTEXT_ID) VALUES (?,?,?,?,?)
  link = > [12701, 100003, T, null, null]
  Query: InsertObjectQuery (oracle.bdss.datamodel.UserContextStates@a4af11) >
  
  
  I do the work of an EJB on Weblogic Server and I used the JDev "Entities of Tables" Wizard to generate the code for each table.
  
  The code works fine most of the time. However when there are multiple threads using the EJB, I think that the allocation of the sequence becomes the same set IDS on different threads. The Session Cache for my persistence has the default "(soft low)".
  
  Everyone seems it before and you know a solution?
  
  The annotations that I use for the generation of PK for the ID column (where the unique constraint is violated) are:
  
  @Id
  @Column (nullable = false)
  @TableGenerator (name = "UserContextStatesSeq", table = "SÉQUENCE",
  scheme = "SDE", pkColumnName = "SEQ_NAME,"
  valueColumnName = "SEQ_COUNT"
  pkColumnValue = "BDSS. USER_CONTEXT_STATES «(, allocationSize = 50).
  @GeneratedValue (strategy = GenerationType.TABLE,
  generator = "UserContextStatesSeq")
  Private Long id;
  
  
  The code for the EJB is shown below (only the relevant parts):
  
  
  @Stateless (name = "RuntimeEJBBean")
  @Local
  public class RuntimeEJBBean
  implements RuntimeEJBLocal
  {
  @PersistenceContext (unitName = "persist")
  Private EntityManager em;
  
  public RuntimeEJBBean()
  {
  }
  
  Private Sub createNewContextState()
  throws the Exception
  {
  NewState UserContextStates = null;
  Try
  {
  newState = new UserContextStates();
  EM. Persist (newState);
  ...
  EM. Flush();
  catch (System.Exception e)
  {
  ...
  }
  }

  According to your annotation you use table named SEQUENCE to generate the id I suggest switching to sequence if you use Oracle.

  So instead of

  @TableGenerator (name = "UserContextStatesSeq", table = "SÉQUENCE",
  scheme = "SDE", pkColumnName = "SEQ_NAME,"
  valueColumnName = "SEQ_COUNT"
  pkColumnValue = "BDSS. USER_CONTEXT_STATES «(, allocationSize = 50).
  @GeneratedValue (strategy = GenerationType.TABLE,
  generator = "UserContextStatesSeq")

  use

  @SequenceGenerator (name = "UserContextStatesSeq", sequenceName = "USER_CONTEXT_STATES_ID", allocationSize = 1)
  @GeneratedValue (generator = "UserContextStatesSeq")

  and db to create sequences:

  CREATE THE SER_CONTEXT_STATES_ID MINVALUE SEQUENCE 1 WITH AN INCREMENT BY 1 1 COVER 50 ALL;

  allocationSize = 1 in @SequenceGenerator with CACHE 50 in phrase makes any id generation caching done at Oracle no ORM.

  If go to the sequence isn't an option, I would check if all error a bind ID with values such as XXXX01 or XXXX51. If Yes, then taking into account the fact that you have allocationSize = 50, it would mean that EclipseLink does not correctly synchronize award of the new id if that's the case then maybe change allocationSize 1 would help.

• Fill a table from multiple threads

  Hello

  I tried to find the mechanism that I could use to fill an array of strings of multiple threads (a little and loops with different times, within a single process) in an asynchronous way.

  I went to create--> property/Invoke Nodes-> (...) but I could not find any properties/methods that I could use. Did I miss something?

  For example how programmatically insert item in array to the x position?

  I will use so semaphores or FGV would be enough?

  K

  
  

• Problem with multiple threads

  I have a program that interacts with an ESX 3.5 server using the VIX API, written in c#. I'm from multiple threads in c# program with each thread running an automation process which creates a connection to a virtual machine on the ESX Server, some automated process, and then disconnects. I'm having problems with this. When I call Disconnect() from one of the threads, it seems to cause problems with my other son if they have not yet disconnected. I connect to an another VM on the server in each thread. The problem is if I don't call disconnect, I get errors, but if I call disconnect in a thread it causes errors. Y at - it something similar? Any suggestions on how to make this run smoothly? Thank you!

  This sounds a lot like you are getting hurt by the host sharing of handle.  If HostConnect() is called with the same parameters, the handle of the host gets reused.  HostDisconnect() will clean this handle, even if his commune.  It's actually documented behaivior.  We have also decided that there may problems like the one you have reached, so it will be removed in a future release.

  So your application will share the handful of host among all discussions, and as soon as we call disconnection, the host handles in other countries also becomes invalid.

  Make a unique HostConnect() and share this handle inside threads is a way to avoid this.  HostConnect() is generally quite expensive, so we recommend in all cases.

• problem between objects of class

  well, I'm a huge refactoring ActionScript file and so tried to move some functions in their own classes.  Why does this work?  I have a function in my primary class:

  // ...

  
  

  private var testBlock:Sprite;

  
  

  public Function testingINT() {}

  testBlock = new Sprite();

  var TB = new TAPATTesting();

  testBlock = TB.makeTestBlock ();

  TAPATContainer.addChild (testBlock);

  }

  ... testingINT() is called away

  and then, the class TAPATTesting is here:

  package com.bpi.tapat

  {

  import flash.display. *;

  import flash.text.TextField;

  import flash.text.TextFieldAutoSize;

  import flash.text.TextFormat;

  public class TAPATTesting { }

            

  public var testBlock:Sprite;

  public var test1TXT:TextField;

  public var test2TXT:TextField;

  public var test3TXT:TextField;

  public var test4TXT:TextField;

  public var test5TXT:TextField;

  public var test6TXT:TextField;

  public var test7TXT:TextField;

            

  public function TAPATTesting ():void {}

                 

            }

            

  public function makeTestBlock (): Sprite {}

                 

  var formatTest: TextFormat = new TextFormat();

  formatTest.font = "Monaco";

  formatTest.color = 0xCCCCCC;

  formatTest.size = 10;

                 

  testBlock = new Sprite();

                 //

                 var textX = 50;

                 var textY = 270;

  test1TXT = new TextField();

  test1TXT.autoSize = TextFieldAutoSize.LEFT;

  test1TXT.defaultTextFormat = formatTest;

  test1TXT.x = textX;

  test1TXT.y = textY;

  testBlock.addChild (test1TXT);

                 //

  test2TXT = new TextField();

  test2TXT.autoSize = TextFieldAutoSize.LEFT;

  test2TXT.defaultTextFormat = formatTest;

  test2TXT.x = textX;

  test2TXT.y = textY + 20;

  testBlock.addChild (test2TXT);

                 //

  test3TXT = new TextField();

  test3TXT.autoSize = TextFieldAutoSize.LEFT;

  test3TXT.defaultTextFormat = formatTest;

  test3TXT.x = textX;

  test3TXT.y = textY + 40.

  testBlock.addChild (test3TXT);

                 //

  test4TXT = new TextField();

  test4TXT.autoSize = TextFieldAutoSize.LEFT;

  test4TXT.defaultTextFormat = formatTest;

  test4TXT.x = textX

  test4TXT.y = textY + 60;

  testBlock.addChild (test4TXT);

                 //

  test5TXT = new TextField();

  test5TXT.autoSize = TextFieldAutoSize.LEFT;

  test5TXT.defaultTextFormat = formatTest;

  test5TXT.x = textX;

  test5TXT.y = textY + 90;

  testBlock.addChild (test5TXT);

                 //

  test6TXT = new TextField();

  test6TXT.autoSize = TextFieldAutoSize.LEFT;

  test6TXT.defaultTextFormat = formatTest;

  test6TXT.x = textX;

  test6TXT.y = textY + 110;

  testBlock.addChild (test6TXT);

                 //

  test7TXT = new TextField();

  test7TXT.autoSize = TextFieldAutoSize.LEFT;

  test7TXT.defaultTextFormat = formatTest;

  test7TXT.x = textX;

  test7TXT.y = textY + 140;

  testBlock.addChild (test7TXT);

                 

                 return testBlock;

            }

       }

  }

  So, therefore, I would that testBlock in the primary class would have the Sprite testBlock of the TAPATTesting passed to him.  The problem arises here in another function of the primary class:

  private Function testReport() {}

                      

  testBlock.test1TXT.text = ' # effect: " + currentStim + ' / ' + numberStims;"»

  testBlock.test2TXT.text = ' stem length: " + stimDuration;"»

  testBlock.test3TXT.text = ' inter-stim int: " + interStimInterval;"»

  testBlock.test4TXT.text = "target freq:" + targetFrequency; "»

       //

  testBlock.test5TXT.text = ' stem angle: " + stimAngle;"»

  testBlock.test6TXT.text = ' stim dist: ' + stimDistance;

       //

  testBlock.test7TXT.text = ' user evaluation: " + userResponseTime + "ms";". "

  }

  I get this same error on each of these lines:

  Several markers to this line:

  -1119: access to property may be undefined test7TXT through a reference with static type flash.display:Sprite.

  Why can't I access the Sprite testBlock children?

  That's because TestBlock is a Sprite, and a Sprite is not a property named "test7TXT".

  You can still access them by doing something like the following:

  -Give the textfield object a name

  test7TXT = new TextField();

  test7TXT.name = "test7TXT";

  test7TXT.AutoSize = TextFieldAutoSize.LEFT;

  test7TXT.defaultTextFormat = formatTest;

  test7TXT.x = textX;

  test7TXT.y = textY + 140;

  testBlock.addChild (test7TXT);

  -Access to the textfield object using its name

  TextField (TestBlock.getChildByName ('test7TXT')) .text = "assessment of users...". » ;

  Note that getChildByName returns the object as a DisplayObject, you will need to cast to a TextField.

  I hope this helps.

• Passing an object of class SolidColor()

  Hello! I want to move an object in the SolidColor class in a single sentence (object), but I get an error: object expected.

  I think I'm passing an object... but I don't know what the problem is: S

  as:

  var color = new SolidColor()

  Color.RGB = {'red': 255, 'green': 255, 'blue': 255}; < -.

  app.backgroundColor = color;

  Instead of:

  var color = new SolidColor()

  Color.RGB.Red = 255;

  Color.RGB.Green = 255;

  Color.RGB.Blue = 255;

  app.backgroundColor = color;

  Thank you!!!

  The only way to do it in one line is:

  app.backgroundColor.rgb.hexValue = "FFFFFF";

• objc [250]: object of class 0x15e509ce0 NSRunningApplication autoreleased with no pool in place

  Hello

  After Effects is running extremely slow. I can't really work...

  The Console on Mac gives the following information:

  objc [250]: break 0x15e509ce0 of class NSRunningApplication autoreleased object with no pool in place - just a leak - on objc_autoreleaseNoPool() to debug

  No idea how I could fix this? I'm desperate...

  Thanks for the help!

  I use After Effects on the Mac Pro CS6 following:

  processor 2 x 2.93 GHz 6 - Core Intel Xeon

  memory 12 GB 1333 MHz DDR3 ECC

  Graphics  ATI Radeon HD 5870 1024 MB

  software  OS X 10.8.5 (12F37)

  
  

  the solution from the support of the aja...

  What could happen is 2 AJA AE plug-ins are activated at the same time.

  The first AE AJA plug-ins comes with the driver. You will find in the AE preferences-> preview video: output device value set to AJA and output mode in Kona RGBA video format which corresponds to the composition.

  The other comes with the Adobe plug-ins, AJA.  To check if it is installed: in the menu bar AE-> windows-> overview of AJA.

  Make sure a single AE plugin is enabled.

  To disable the plugin first AE AJA: go to preferences-> video preview-> on-screen computer output device only AE.

  To disable the second AJA AE plugin: go to the overview of AJA and tick the disable box.

  .. It worked in my case

• Objects of scheme of access without having to specify the user.

  I just created a role in a scheme and assigned to certain privileges. Then, I created a user and granted the role to him. But as the newly created user is not the owner of the schema when I say a query select simle like this:
  
  SELECT EMLOYEENAME FROM EMPLOYEES
  
  I get the error "table or view does not exist. Is there a way I can wirte to refer to objects in this schema without having to identify the owner. For example, instead of writing to SCOTUS. I want to write just the EMPLOYEES EMPLOYEES.

  >
  So, I create SYNONYMS for all objects in the right of the schema? And also, I have to use these synonyms in all procedures, functions and views rather than their real names?
  >
  Yes, if the procedures are not owned by the user who owns objects.
  A procedure created by SCOTT didn't need to use the synonym to access the objects belonging to SCOTT.

  Then, if you issue

  GRANT EXECUTE ON scottProcedure1 TO DAVID
  

  Then the user DAVID can perform the Procedure1 scott without the need to have privileges on scott objects used by the procedure.

     EXEC SCOTT.PROCEDURE1;
  

  DAVID must use the schema to perform the procedure, unless you create a synonym for the procedure.

• Correct handling of the objects of classes FX

  Quick simple question. If I write a class that is extended to one of the classes of JavaFX, do I need to make changes of State that were not part of the original on the FX Application thread class? In my case, I created a class of signal that is basically a path, but there some other information which are defined by other threads, as the next value that will be added to the path. Obviously, I need to make adding this value the path on the FX Application thread. But if my Signal is extended by the path, and I have a nextValue field and a receiveValue method, it would be safe to call me receiveValue on another thread? Coordinate it to add the path would create later this value on the FX Application thread. Thank you!
  -Jean

  You can call your own methods of any thread you like. As soon as you interact with the properties that would have upset the scene however, you will need to be on the thread of FX.

  I express the JavaFX containers all the time in my project and I am very pleased with how that works.

• Move the object of class position

  Hello

  I'm looking for how to move an object from its current position to a coordinate _x designated.  I want a current position to a variable which followed where he is currently and travel automatically without having to say move from 24.7 to 35.8, for example. I am usuing tweener mx base classes and would like to keep it this way.  Basically, I create a nav where a point flies in the selection of nav. So the end result is I want the code that says travel to this coordinate _x wherever you are currently.

  Thank you!

  1. it is not the tweener class.  It's the tween class.

  2. you can put all of these on a single line if statements and use an interpolation function:

  navHome.onRelease = function() {     if (navBullet._y == -360 || navBullet._y==-319||navBullet._y==-279||navBullet._y==-237||navBullet._y==-196) {          bulletTween = new Tween(navBullet, _y, Back.easeOut, navBullet._y, -402, 1.5, true);     }};