Search Results

Search found 15087 results on 604 pages for 'python multithreading'.

Page 270/604 | < Previous Page | 266 267 268 269 270 271 272 273 274 275 276 277  | Next Page >

• Castle ActiveRecord: session error search and access to lazy loading property in different threads

  - by sc911

  Hi *, I've got a problem with an multi-threaded desktop application using Castle ActiveRecord in C#: To keep the GUI alive while searching for the objects based on userinput I'm using the BackgroundWorker for the search-function. Some of the properties of the objects, especially some HasMany-Relations, are marked as Lazy. Now, when the search is finished and the user selects an resulting object, some of the properties of this object should be displayed. But as the search was done by the BackgroundWorker in a different thread, accessing the properties fails as the session for the lazy-access is no longer available. What will be the best way to do the search in an extra thread to keep the GUI alive and to access all properties correctly including those marked as lazy? Thanks for any advise! Regards sc911

  Read the article

• Is it possible to prevent out-of-order execution by using single volatile

  - by Yan Cheng CHEOK

  By referring article, it is using a pair of volatile to prevent out-of-order execution. I was wondering, is it possible to prevent it using single volatile? void fun_by_thread_1() { this.isNuclearFactory = true; this.factory = new NuclearFactory(); } void fun_by_thread_2() { Factory _factory = this.factory; if (this.isNuclearFactory) { // Do not operate nuclear factory!!! return; } // If out-of-order execution happens, _factory might // be NuclearFactory instance. _factory.operate(); } Factory factory = new FoodFactory(); volatile boolean isNuclearFactory = false; The reason I ask, is because I have a single guard flag (similar to isNuclearFactory flag), to guard against multiple variables (similar to many Factory). I do not wish to mark all the Factory as volatile. Or, shall I fall into the following solution? void fun_by_thread_1() { try { writer.lock(); this.isNuclearFactory = true; this.factory = new NuclearFactory(); } finally { writer.unlock(); } } void fun_by_thread_2() { try { reader.lock(); Factory _factory = this.factory; if (this.isNuclearFactory) { // Do not operate nuclear factory!!! return; } } finally { reader.unlock(); } _factory.operate(); } Factory factory = new FoodFactory(); boolean isNuclearFactory = false; P/S: I know instanceof. Factory is just an example to demonstrate of out-of-order problem.

  Read the article

• JTextArea thread safe?

  - by Dhaivat Pandya

  Hello everyone, I have some code that does some initialization (including making a JTextArea object), starts three seperate threads, and then these threads try to update the JTextArea (i.e. append() to it), but its not working at all. Nothing shows up on the JTextArea (however, during the initialzation, I print some test lines onto it, and that works fine). What's going on? How can I fix this? Also, each of those threads sleeps a random amount of time every time it has to update the JTextArea. Sorry I haven't provided any code, its all spread out over several files.

  Read the article

• How does static code run with multiple threads?

  - by Krisc

  I was reading http://stackoverflow.com/questions/1511798/threading-from-within-a-class-with-static-and-non-static-methods and I am in a similar situation. I have a static method that pulls data from a resource and creates some runtime objects based on the data. static class Worker{ public static MyObject DoWork(string filename){ MyObject mo = new MyObject(); // ... does some work return mo; } } The method takes awhile (in this case it is reading 5-10mb files) and returns an object. I want to take this method and use it in a multiple thread situation so I can read multiple files at once. Design issues / guidelines aside, how would multiple threads access this code? Let's say I have something like this... class ThreadedWorker { public void Run() { Thread t = new Thread(OnRun); t.Start(); } void OnRun() { MyObject mo = Worker.DoWork("somefilename"); mo.WriteToConsole(); } } Does the static method run for each thread, allowing for parallel execution?

  Read the article

• Cumulative +1/-1 Cointoss crashes on 1000 iterations. Please advise; c++ boost random libraries

  - by user1731972

  following some former advice Multithreaded application, am I doing it right? I think I have a threadsafe number generator using boost, but my program crashes when I input 1000 iterations. The output .csv file when graphed looks right, but I'm not sure why it's crashing. It's using _beginthread, and everyone is telling me I should use the more (convoluted) _beingthreadex, which I'm not familiar with. If someone could recommend an example, I would greatly appreciate it. Also... someone pointed out I should be applying a second parameter to my _beginthread for the array counting start positions, but I have no idea how to pass more than one parameter, other than attempting to use a structure, and I've read structure's and _beginthread don't get along (although, I could just use the boost threads...) #include <process.h> #include <windows.h> #include <iostream> #include <fstream> #include <time.h> #include <random> #include <boost/random.hpp> //for srand48_r(time(NULL), &randBuffer); which doesn't work #include <stdio.h> #include <stdlib.h> //#include <thread> using namespace std; using namespace boost; using namespace boost::random; void myThread0 (void *dummy ); void myThread1 (void *dummy ); void myThread2 (void *dummy ); void myThread3 (void *dummy ); //for random seeds void initialize(); //from http://stackoverflow.com/questions/7114043/random-number-generation-in-c11-how-to-generate-how-do-they-work uniform_int_distribution<> two(1,2); typedef std::mt19937 MyRNG; // the Mersenne Twister with a popular choice of parameters uint32_t seed_val; // populate somehow MyRNG rng1; // e.g. keep one global instance (per thread) MyRNG rng2; // e.g. keep one global instance (per thread) MyRNG rng3; // e.g. keep one global instance (per thread) MyRNG rng4; // e.g. keep one global instance (per thread) //only needed for shared variables //CRITICAL_SECTION cs1,cs2,cs3,cs4; // global int main() { ofstream myfile; myfile.open ("coinToss.csv"); int rNum; long numRuns; long count = 0; int divisor = 1; float fHolder = 0; long counter = 0; float percent = 0.0; //? //unsigned threadID; //HANDLE hThread; initialize(); HANDLE hThread[4]; const int size = 100000; int array[size]; printf ("Runs (uses multiple of 100,000) "); cin >> numRuns; for (int a = 0; a < numRuns; a++) { hThread[0] = (HANDLE)_beginthread( myThread0, 0, (void*)(array) ); hThread[1] = (HANDLE)_beginthread( myThread1, 0, (void*)(array) ); hThread[2] = (HANDLE)_beginthread( myThread2, 0, (void*)(array) ); hThread[3] = (HANDLE)_beginthread( myThread3, 0, (void*)(array) ); //waits for threads to finish before continuing WaitForMultipleObjects(4, hThread, TRUE, INFINITE); //closes handles I guess? CloseHandle( hThread[0] ); CloseHandle( hThread[1] ); CloseHandle( hThread[2] ); CloseHandle( hThread[3] ); //dump array into calculations //average array into fHolder //this could be split into threads as well for (int p = 0; p < size; p++) { counter += array[p] == 2 ? 1 : -1; //cout << array[p] << endl; //cout << counter << endl; } //this fHolder calculation didn't work //fHolder = counter / size; //so I had to use this cout << counter << endl; fHolder = counter; fHolder = fHolder / size; myfile << fHolder << endl; } } void initialize() { //seed value needs to be supplied //rng1.seed(seed_val*1); rng1.seed((unsigned int)time(NULL)); rng2.seed(((unsigned int)time(NULL))*2); rng3.seed(((unsigned int)time(NULL))*3); rng4.seed(((unsigned int)time(NULL))*4); }; void myThread0 (void *param) { //EnterCriticalSection(&cs1); //aquire the critical section object int *i = (int *)param; for (int x = 0; x < 25000; x++) { //doesn't work, part of merssene twister //i[x] = next(); i[x] = two(rng1); //original srand //i[x] = rand() % 2 + 1; //doesn't work for some reason. //uint_dist2(rng); //i[x] = qrand() % 2 + 1; //cout << i[x] << endl; } //LeaveCriticalSection(&cs1); // release the critical section object } void myThread1 (void *param) { //EnterCriticalSection(&cs2); //aquire the critical section object int *i = (int *)param; for (int x = 25000; x < 50000; x++) { //param[x] = rand() % 2 + 1; i[x] = two(rng2); //i[x] = rand() % 2 + 1; //cout << i[x] << endl; } //LeaveCriticalSection(&cs2); // release the critical section object } void myThread2 (void *param) { //EnterCriticalSection(&cs3); //aquire the critical section object int *i = (int *)param; for (int x = 50000; x < 75000; x++) { i[x] = two(rng3); //i[x] = rand() % 2 + 1; //cout << i[x] << endl; } //LeaveCriticalSection(&cs3); // release the critical section object } void myThread3 (void *param) { //EnterCriticalSection(&cs4); //aquire the critical section object int *i = (int *)param; for (int x = 75000; x < 100000; x++) { i[x] = two(rng4); //i[x] = rand() % 2 + 1; //cout << i[x] << endl; } //LeaveCriticalSection(&cs4); // release the critical section object }

  Read the article

• Where can I find a good tutorial for py2exe?

  - by Manzabar

  Can somebody point me at a good tutorial for py2exe? I've read over the official tutorial but it is rather light on details, compared to all the options one can use when building an executable out of a python script. For the record, my python script uses Python 2.5.2, wxPython/wxWidgets 2.8 and MySQLdb 1.2.2; so if you have specific tips for py2exe with those packages that would be much appreciated (and yes, I've seen the Py2EXE and wxPython page).

  Read the article

• Why .NET does not allow cross-thread operations?

  - by RHaguiuda

  This question is not about what is a cross-thread operation, and how to avoid it, but why internal mechanics of .NET framework does not allow a cross-thread operation. I can`t understand why a SerialPort DataReceived event cannot update a simple text box on my form and why using delegates this is possible?

  Read the article

• Is thread-safe to use the 'yield' operator inside a static method'?

  - by SDReyes

  Is a static method using yield thread-safe? For example: public static T Select<T>( this IDataReader reader, Func<IDataReader, T> convertString ) { { while( reader.Read( ) ) yield return convertString( reader ); } }

  Read the article

• For Loop help In a Hash Cracker Homework.

  - by aaron burns

  On the homework I am working on we are making a hash cracker. I am implementing it so as to have my cracker. java call worker.java. Worker.java implements Runnable. Worker is to take the start and end of a list of char, the hash it is to crack, and the max length of the password that made the hash. I know I want to do a loop in run() BUT I cannot think of how I would do it so it would go to the given max pasword length. I have posted the code I have so far. Any directions or areas I should look into.... I thought there was a way to do this with a certain way to write the loop but I don't know or can't find the correct syntax. Oh.. also. In main I divide up so x amount of threads can be chosen and I know that as of write now it only works for an even number of the 40 possible char given. package HashCracker; import java.util.*; import java.security.MessageDigest; import java.security.NoSuchAlgorithmException; public class Cracker { // Array of chars used to produce strings public static final char[] CHARS = "abcdefghijklmnopqrstuvwxyz0123456789.,-!".toCharArray(); public static final int numOfChar=40; /* Given a byte[] array, produces a hex String, such as "234a6f". with 2 chars for each byte in the array. (provided code) */ public static String hexToString(byte[] bytes) { StringBuffer buff = new StringBuffer(); for (int i=0; i<bytes.length; i++) { int val = bytes[i]; val = val & 0xff; // remove higher bits, sign if (val<16) buff.append('0'); // leading 0 buff.append(Integer.toString(val, 16)); } return buff.toString(); } /* Given a string of hex byte values such as "24a26f", creates a byte[] array of those values, one byte value -128..127 for each 2 chars. (provided code) */ public static byte[] hexToArray(String hex) { byte[] result = new byte[hex.length()/2]; for (int i=0; i<hex.length(); i+=2) { result[i/2] = (byte) Integer.parseInt(hex.substring(i, i+2), 16); } return result; } public static void main(String args[]) throws NoSuchAlgorithmException { if(args.length==1)//Hash Maker { //create a byte array , meassage digestand put password into it //and get out a hash value printed to the screen using provided methods. byte[] myByteArray=args[0].getBytes(); MessageDigest hasher=MessageDigest.getInstance("SHA-1"); hasher.update(myByteArray); byte[] digestedByte=hasher.digest(); String hashValue=Cracker.hexToString(digestedByte); System.out.println(hashValue); } else//Hash Cracker { ArrayList<Thread> myRunnables=new ArrayList<Thread>(); int numOfThreads = Integer.parseInt(args[2]); int charPerThread=Cracker.numOfChar/numOfThreads; int start=0; int end=charPerThread-1; for(int i=0; i<numOfThreads; i++) { //creates, stores and starts threads. Runnable tempWorker=new Worker(start, end, args[1], Integer.parseInt(args[1])); Thread temp=new Thread(tempWorker); myRunnables.add(temp); temp.start(); start=end+1; end=end+charPerThread; } } } import java.util.*; public class Worker implements Runnable{ private int charStart; private int charEnd; private String Hash2Crack; private int maxLength; public Worker(int start, int end, String hashValue, int maxPWlength) { charStart=start; charEnd=end; Hash2Crack=hashValue; maxLength=maxPWlength; } public void run() { byte[] myHash2Crack_=Cracker.hexToArray(Hash2Crack); for(int i=charStart; i<charEnd+1; i++) { Cracker.numOfChar[i]////// this is where I am stuck. } } }

  Read the article

• SQLserver multithreaded locking with TABLOCKX

  - by WilfriedVS

  I have a table "tbluser" with 2 fields: userid = integer (autoincrement) user = nvarchar(100) I have a multithreaded/multi server application that uses this table. I want to accomplish the following: Guarantee that field user is unique in my table Guarantee that combination userid/user is unique in each server's memory I have the following stored procedure: CREATE PROCEDURE uniqueuser @user nvarchar(100) AS BEGIN BEGIN TRAN DECLARE @userID int SET nocount ON SET @userID = (SELECT @userID FROM tbluser WITH (TABLOCKX) WHERE [user] = @user) IF @userID <> '' BEGIN SELECT userID = @userID END ELSE BEGIN INSERT INTO tbluser([user]) VALUES (@user) SELECT userID = SCOPE_IDENTITY() END COMMIT TRAN END Basically the application calls the stored procedure and provides a username as parameter. The stored procedure either gets the userid or insert the user if it is a new user. Am I correct to assume that the table is locked (only one server can insert/query)?

  Read the article

• Java Parallel Programming

  - by user578524

  Dear All, I need to parallelize a CPU intensive Java application on my multicore desktop but I am not so comfortable with threads programming. I looked at Scala but this would imply learning a new language which is really time consuming. I also looked at Ateji PX Java parallel extensions which seem very easy to use but did not have a chance yet to evaluate it. Would anyone recommend it? Other suggestions welcome. Thanks in advance for your help Bill

  Read the article

• Bluetooth in Java Mobile: Handling connections that go out of range

  - by Albus Dumbledore

  I am trying to implement a server-client connection over the spp. After initializing the server, I start a thread that first listens for clients and then receives data from them. It looks like that: public final void run() { while (alive) { try { /* * Await client connection */ System.out.println("Awaiting client connection..."); client = server.acceptAndOpen(); /* * Start receiving data */ int read; byte[] buffer = new byte[128]; DataInputStream receive = client.openDataInputStream(); try { while ((read = receive.read(buffer)) > 0) { System.out.println("[Recieved]: " + new String(buffer, 0, read)); if (!alive) { return; } } } finally { System.out.println("Closing connection..."); receive.close(); } } catch (IOException e){ e.printStackTrace(); } } } It's working fine for I am able to receive messages. What's troubling me is how would the thread eventually die when a device goes out of range? Firstly, the call to receive.read(buffer) blocks so that the thread waits until it receives any data. If the device goes out of range, it would never proceed onward to check if meanwhile it has been interrupted. Secondly, it would never close the connection, i.e. the server would not accept the device once it goes back in range. Thanks! Any ideas would be highly appreciated! Merry Christmas!

  Read the article

• cache-coherence MOESI protocol

  - by Yaron

  processor A owns a cache line which is shared with processor B. what happens when B tries to write to that line? also, if it was 'invalid' instead of 'shared' would it make any difference? thank you.

  Read the article

• Grails/Spring HttpServletRequest synchronization

  - by Jeff Storey

  I was writing a simple Grails app and I have a spot in a gsp where one of my java beans in modified. <g:each in="${myList}" status="i" var="myVar"> // if the user performs some view action, update one of the myVar elements </g:each> This works, but I don't think it's quite threadsafe. myList is an http request variable but in cases of pages that use ajax (or other client side manipulations), it is possible for two threads to be modifying the same request scope variable The Spring AbstractController class provides a setSynchronizeOnSession method. Does grails provide any equivalent functionality? If not, what's the best way to protect this non-threadsafe mutation? thanks, Jeff

  Read the article

• Java - when to use notify or notifyAll?

  - by mdma

  Why does java.lang.Object have two notify methods - notify and notifyAll? It seems that notifyAll does at least everything notify does, so why not just use notifyAll all the time? If notifyAll is used instead of notify, is the program still correct, and vice versa? What influences the choice between these two methods?

  Read the article

• OCCI createEnvironment Blocks My Thread

  - by sahs

  Hello, I'm writing a multi-threaded application, where there is a main thread which distributes tasks to the worker threads. According to the task, a worker thread creates a connection, by using a global occi environment. When a worker thread completes its task, it closes the connection (I'm sure, there is no exception thrown while termination). My problem is that after a while(sometimes 5 mins, sometimes 5 hours) the threads cannot get connection from the environment, and they get blocked there. What can be the problem?

  Read the article

• How do you pass a BitmapImage from a background thread to the UI thread in WPF?

  - by DanM

  I have a background thread that generates a series of BitmapImage objects. Each time the background thread finishes generating a bitmap, I would like to show this bitmap to the user. The problem is figuring out how to pass the BitmapImage from the background thread to the UI thread. This is an MVVM project, so my view has an Image element: <Image Source="{Binding GeneratedImage}" /> My view-model has a property GeneratedImage: private BitmapImage _generatedImage; public BitmapImage GeneratedImage { get { return _generatedImage; } set { if (value == _generatedImage) return; _generatedImage= value; RaisePropertyChanged("GeneratedImage"); } } My view-model also has the code that creates the background thread: public void InitiateGenerateImages(List<Coordinate> coordinates) { ThreadStart generatorThreadStarter = delegate { GenerateImages(coordinates); }; var generatorThread = new Thread(generatorThreadStarter); generatorThread.ApartmentState = ApartmentState.STA; generatorThread.IsBackground = true; generatorThread.Start(); } private void GenerateImages(List<Coordinate> coordinates) { foreach (var coordinate in coordinates) { var backgroundThreadImage = GenerateImage(coordinate); // I'm stuck here...how do I pass this to the UI thread? } } I'd like to somehow pass backgroundThreadImage to the UI thread, where it will become uiThreadImage, then set GeneratedImage = uiThreadImage so the view can update. I've looked at some examples dealing with the WPF Dispatcher, but I can't seem to come up with an example that addresses this issue. Please advise.

  Read the article

• How do I use SDl_Threads properly?

  - by Anoymonous

  I am new to threads,SDL and how graphic work in general. I've been looking through all of LazyFoo's SDL tutorials, and had helped me greatly. But in his tutorials about multi threading, he commented that you should never use video functions in separate threads, or might cause problem. I am curious how it should be done, as I still have a vague understanding of graphics and threads. As one of my projects is a shoot'em up, I was wondering if I should create one thread that displays all the graphics, one threads receives all the player input for his ship, and another thread for the enemy AI. If this is NOT how it should be done, (I think it's wrong) does anyone have any advice of how graphics should be implemented with user input and enemy AI with threads? For the Lazyfoo's tutorials, this is the link: http://lazyfoo.net/SDL_tutorials/

  Read the article

• Using static mutex in a class

  - by Dmitry Yudakov

  I have a class that I can have many instances of. Inside it creates and initializes some members from a 3rd party library (that use some global variables) and is not thread-safe. I thought about using static boost::mutex, that would be locked in my class constructor and destructor. Thus creating and destroying instances among my threads would be safe for the 3rd party members. class MyClass { static boost::mutex mx; // 3rd party library members public: MyClass(); ~MyClass(); }; MyClass::MyClass() { boost::mutex::scoped_lock scoped_lock(mx); // create and init 3rd party library stuff } MyClass::~MyClass() { boost::mutex::scoped_lock scoped_lock(mx); // destroy 3rd party library stuff } I cannot link because I receive error: undefined reference to `MyClass::mx` Do I need some special initialization of such static member? Is the whole conception of static mutex wrong?

  Read the article

• Class initialization and synchronized class method

  - by nybon

  Hi there, In my application, there is a class like below: public class Client { public synchronized static print() { System.out.println("hello"); } static { doSomething(); // which will take some time to complete } } This class will be used in a multi thread environment, many threads may call the Client.print() method simultaneously. I wonder if there is any chance that thread-1 triggers the class initialization, and before the class initialization complete, thread-2 enters into print method and print out the "hello" string? I see this behavior in a production system (64 bit JVM + Windows 2008R2), however, I cannot reproduce this behavior with a simple program in any environments. In Java language spec, section 12.4.1 (http://java.sun.com/docs/books/jls/second_edition/html/execution.doc.html), it says: A class or interface type T will be initialized immediately before the first occurrence of any one of the following: T is a class and an instance of T is created. T is a class and a static method declared by T is invoked. A static field declared by T is assigned. A static field declared by T is used and the reference to the field is not a compile-time constant (§15.28). References to compile-time constants must be resolved at compile time to a copy of the compile-time constant value, so uses of such a field never cause initialization. According to this paragraph, the class initialization will take place before the invocation of the static method, however, it is not clear if the class initialization need to be completed before the invocation of the static method. JVM should mandate the completion of class initialization before entering its static method according to my intuition, and some of my experiment supports my guess. However, I did see the opposite behavior in another environment. Can someone shed me some light on this? Any help is appreciated, thanks.

  Read the article

• Thread-safe data structure design

  - by Inso Reiges

  Hello, I have to design a data structure that is to be used in a multi-threaded environment. The basic API is simple: insert element, remove element, retrieve element, check that element exists. The structure's implementation uses implicit locking to guarantee the atomicity of a single API call. After i implemented this it became apparent, that what i really need is atomicity across several API calls. For example if a caller needs to check the existence of an element before trying to insert it he can't do that atomically even if each single API call is atomic: if(!data_structure.exists(element)) { data_structure.insert(element); } The example is somewhat awkward, but the basic point is that we can't trust the result of "exists" call anymore after we return from atomic context (the generated assembly clearly shows a minor chance of context switch between the two calls). What i currently have in mind to solve this is exposing the lock through the data structure's public API. This way clients will have to explicitly lock things, but at least they won't have to create their own locks. Is there a better commonly-known solution to these kinds of problems? And as long as we're at it, can you advise some good literature on thread-safe design? EDIT: I have a better example. Suppose that element retrieval returns either a reference or a pointer to the stored element and not it's copy. How can a caller be protected to safely use this pointer\reference after the call returns? If you think that not returning copies is a problem, then think about deep copies, i.e. objects that should also copy another objects they point to internally. Thank you.

  Read the article

• Java threadpool functionality

  - by cpf

  Hi stackoverflow, I need to make a program with a limited amount of threads (currently using newFixedThreadPool) but I have the problem that all threads get created from start, filling up memory at alarming rate. I wish to prevent this. Threads should only be created shortly before they are executed. e.g.: I call the program and instruct it to use 2 threads in the pool. The program should create & launch the first 2 Threads immediately (obviously), create the next 2 to wait for the previous 2, and at that point wait until one or both of the first 2 ended executing. I thought about extending executor or FixedThreadPool or such. However I have no clue on how to start there and doubt it is the best solution. Easiest would have my main Thread sleeping on intervals, which is not really good either... Thanks in advance!

  Read the article

• How to approach parallel processing of messages?

  - by Dan

  I am redesigning the messaging system for my app to use intel threading building blocks and am stumped trying to decide between two possible approaches. Basically, I have a sequence of message objects and for each message type, a sequence of handlers. For each message object, I apply each handler registered for that message objects type. The sequential version would be something like this (pseudocode): for each message in message_sequence <- SEQUENTIAL for each handler in (handler_table for message.type) apply handler to message <- SEQUENTIAL The first approach which I am considering processes the message objects in turn (sequentially) and applies the handlers concurrently. Pros: predictable ordering of messages (ie, we are guaranteed a FIFO processing order) (potentially) lower latency of processing each message Cons: more processing resources available than handlers for a single message type (bad parallelization) bad use of processor cache since message objects need to be copied for each handler to use large overhead for small handlers The pseudocode of this approach would be as follows: for each message in message_sequence <- SEQUENTIAL parallel_for each handler in (handler_table for message.type) apply handler to message <- PARALLEL The second approach is to process the messages in parallel and apply the handlers to each message sequentially. Pros: better use of processor cache (keeps the message object local to all handlers which will use it) small handlers don't impose as much overhead (as long as there are other handlers also to be run) more messages are expected than there are handlers, so the potential for parallelism is greater Cons: Unpredictable ordering - if message A is sent before message B, they may both be processed at the same time, or B may finish processing before all of A's handlers are finished (order is non-deterministic) The pseudocode is as follows: parallel_for each message in message_sequence <- PARALLEL for each handler in (handler_table for message.type) apply handler to message <- SEQUENTIAL The second approach has more advantages than the first, but non-deterministic ordering is a big disadvantage.. Which approach would you choose and why? Are there any other approaches I should consider (besides the obvious third approach: parallel messages and parallel handlers, which has the disadvantages of both and no real redeeming factors as far as I can tell)? Thanks!

  Read the article

• Exception calling remote SOAP call from thread

  - by Duncan

  This is an extension / next step of this question I asked a few minutes ago. I've a Delphi application with a main form and a thread. Every X seconds the thread makes a web services request for a remote object. It then posts back to the main form which handles updating the UI with the new information. I was previously using a TTimer object in my thread, and when the TTimer callback function ran, it ran in the context of the main thread (but the remote web services request did work). This rather defeated the purpose of the separate thread, and so I now have a simple loop and sleep routine in my thread's Execute function. The problem is, an exception is thrown when returning from GetIMySOAPService(). procedure TPollingThread.Execute; var SystemStatus : TCWRSystemStatus; begin while not Terminated do begin sleep(5000); try SystemStatus := GetIMySOAPService().GetSystemStatus; PostMessage( ParentHandle, Integer(apiSystemStatus), Integer(SystemStatus), 0 ); SystemStatus.DataContext := nil; LParam(SystemStatus) := 0; except end; end; end; Can anyone advise as to why this exception is being thrown when calling this function from the thread? I'm sure I'm overlooking something fundamental and simple. Thanks, Duncan

  Read the article

• Thread Blocks During Call

  - by user578875

  I have a serious problem, I'm developing an application that mesures on call time during a call; the problem presents when, with the phone on the ear, the thread that the timer has, blocks and no longer responds before taking off my ear. The next log shows the problem. 01-11 16:14:19.607 14558 14566 I Estado : postDelayed Async Service 01-11 16:14:20.607 14558 14566 I Estado : postDelayed Async Service 01-11 16:14:21.607 14558 14566 I Estado : postDelayed Async Service 01-11 16:14:22.597 14558 14566 I Estado : postDelayed Async Service 01-11 16:14:23.608 14558 14566 I Estado : postDelayed Async Service 01-11 16:14:24.017 1106 1106 D iddd : select() < 0, Probably a handled signal: Interrupted system call 01-11 16:14:24.607 14558 14566 I Estado : postDelayed Async Service 01-11 16:18:05.500 1106 1106 D iddd : select() < 0, Probably a handled signal: Interrupted system call 01-11 16:18:06.026 14558 14566 I Estado : postDelayed Async Service 01-11 16:18:06.026 14558 14566 I Estado : postDelayed Async Service 01-11 16:18:06.026 14558 14566 I Estado : postDelayed Async Service 01-11 16:18:06.026 14558 14566 I Estado : postDelayed Async Service 01-11 16:18:06.026 14558 14566 I Estado : postDelayed Async Service 01-11 16:18:06.026 14558 14566 I Estado : postDelayed Async Service I've been trying with Services, Timers, Threads, AyncTasks and they all present the same problem. My Code: @Override public void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); requestWindowFeature(Window.FEATURE_NO_TITLE); getWindow().setFlags(WindowManager.LayoutParams.FLAG_FULLSCREEN, WindowManager.LayoutParams.FLAG_FULLSCREEN); setContentView(R.layout.main); HangUpService.setMainActivity(this); objHangUpService = new Intent(this, HangUpService.class); Runnable rAccion = new Runnable() { public void run() { TelephonyManager tm = (TelephonyManager)getSystemService(TELEPHONY_SERVICE); tm.listen(mPhoneListener, PhoneStateListener.LISTEN_CALL_STATE); objVibrator = (Vibrator) getSystemService(getApplicationContext().VIBRATOR_SERVICE); final ListView lstLlamadas = (ListView) findViewById(R.id.lstFavoritos); final EditText txtMinutos = (EditText) findViewById(R.id.txtMinutos); final EditText txtSegundos = (EditText) findViewById(R.id.txtSegundos); ArrayList<Contacto> cContactos = new ArrayList<Contacto>(); ContactoAdapter caContactos = new ContactoAdapter(HangUp.this, R.layout.row,cContactos); Cursor curContactos = getContentResolver().query( ContactsContract.Contacts.CONTENT_URI, null, null, null, ContactsContract.Contacts.TIMES_CONTACTED + " DESC"); while (curContactos.moveToNext()){ String strNombre = curContactos.getString(curContactos.getColumnIndex(ContactsContract.Contacts.DISPLAY_NAME)); String strID = curContactos.getString(curContactos.getColumnIndex(ContactsContract.Contacts._ID)); String strHasPhone=curContactos.getString(curContactos.getColumnIndex(ContactsContract.Contacts.HAS_PHONE_NUMBER)); String strStarred=curContactos.getString(curContactos.getColumnIndex(ContactsContract.Contacts.STARRED)); if (Integer.parseInt(strHasPhone) > 0 && Integer.parseInt(strStarred) ==1 ) { Cursor CursorTelefono = getContentResolver().query( ContactsContract.CommonDataKinds.Phone.CONTENT_URI, null, ContactsContract.CommonDataKinds.Phone.CONTACT_ID +" = " + strID, null, null); while (CursorTelefono.moveToNext()) { String strTipo=CursorTelefono.getString(CursorTelefono.getColumnIndex(ContactsContract.CommonDataKinds.Phone.TYPE)); String strTelefono=CursorTelefono.getString(CursorTelefono.getColumnIndex(ContactsContract.CommonDataKinds.Phone.NUMBER)); strNumero=strTelefono; String args[]=new String[1]; args[0]=strNumero; Cursor CursorCallLog = getContentResolver().query( android.provider.CallLog.Calls.CONTENT_URI, null, android.provider.CallLog.Calls.NUMBER + "=?", args, android.provider.CallLog.Calls.DATE+ " DESC"); if (Integer.parseInt(strTipo)==2) { caContactos.add( new Contacto( strNombre, strTelefono ) ); } } CursorTelefono.close(); } } curContactos.close(); lstLlamadas.setAdapter(caContactos); lstLlamadas.setOnItemClickListener(new OnItemClickListener() { @Override public void onItemClick(AdapterView a, View v, int position, long id) { Contacto mContacto=(Contacto)lstLlamadas.getItemAtPosition(position); i = new Intent(HangUp.this, Llamada.class); Log.i("Estado","Declaro Intent"); Bundle bundle = new Bundle(); bundle.putString("telefono", mContacto.getTelefono()); i.putExtras(bundle); startActivityForResult(i,SUB_ACTIVITY_ID); Log.i("Estado","Inicio Intent"); blActivo=true; try { String strMinutos=txtMinutos.getText().toString(); String strSegundos=txtSegundos.getText().toString(); if(!strMinutos.equals("") && !strSegundos.equals("")){ int Tiempo = ( (Integer.parseInt(txtMinutos.getText().toString())*60) + Integer.parseInt(txtSegundos.getText().toString()) )* 1000; handler.removeCallbacks(rVibrate); cTime = System.currentTimeMillis(); cTime=cTime+Tiempo; objHangUpAsync = new HangUpAsync(cTime,objVibrator,objPowerManager,objKeyguardLock); objHangUpAsync.execute(); objPowerManager.userActivity(Tiempo+3000, true); objHangUpService.putExtra("cTime", cTime); //startService(objHangUpService); } catch (Exception e) { e.printStackTrace(); } finally { } } }); } }; } AsyncTask: @Override protected String doInBackground(String... arg0) { blActivo = true; mWakeLock = objPowerManager.newWakeLock(PowerManager.FULL_WAKE_LOCK, "My Tag"); objKeyguardLock.disableKeyguard(); Log.i("Estado", "Entro a doInBackground"); timer.scheduleAtFixedRate( new TimerTask() { public void run() { if (blActivo){ if (cTime blActivo=false; objVibrator.vibrate(1000); Log.i("Estado","Vibrar desde Async"); this.cancel(); }else{ try{ mWakeLock.acquire(); mWakeLock.release(); Log.i("Estado","postDelayed Async Service"); }catch(Exception e){ Log.i("Estado","Error: " + e.getMessage()); } } } } }, 0, INTERVAL); return null; }

  Read the article

< Previous Page | 266 267 268 269 270 271 272 273 274 275 276 277  | Next Page >