multithreading

问题 I have a TextBox that's bound to a property that gets modified at a very rapid rate in a background thread. Is data binding in WPF thread safe? Will the data in the property or the TextBox ever get out of sync? Is it necessary (or even possible) to use synchronization on a property that takes part in data binding? I understand that, if the class on which the property resides implements INotifyPropertyChanged, the binding framework automatically marshalls the UI update to the UI thread.

问题 I have a TextBox that's bound to a property that gets modified at a very rapid rate in a background thread. Is data binding in WPF thread safe? Will the data in the property or the TextBox ever get out of sync? Is it necessary (or even possible) to use synchronization on a property that takes part in data binding? I understand that, if the class on which the property resides implements INotifyPropertyChanged, the binding framework automatically marshalls the UI update to the UI thread.

问题 I'm trying to get JSON but I have to do it in AsyncTask , because I get this in logcat AndroidRuntime(18153): Caused by: android.os.NetworkOnMainThreadException . Here is my code: public class LatestAlbums extends Activity { TextView t; // url to make request private static String url = "www.example.com"; // JSON Node names private static final String TAG_ALBUMS = "albums"; private static final String TAG_ID = "id"; private static final String TAG_NAME = "name"; private static final String

问题 Often there is a need for the program to wait for a function to complete its work. Sometimes it is opposite: there is no need for a main program to wait. I've put a simple example. There are four buttons. Clicking each will call the same calculate() function. The only difference is the way the function is called. "Call Directly" button calls calculate() function directly. Since there is a 'Function End' print out it is evident that the program is waiting for the calculate function to complete

问题 I have some troubles trying to compile a program with multi-threading from the standard template library. It return me a obscure error when i try to compile the following program : #include <iostream> #include <thread> void foo() { std::cout << "Thread 1\n"; } int main(int argc, char** argv) { std::thread tr(foo); std::cout << "Main thread\n"; tr.join(); return 0; } I don't understand the error : /tmp/ccE8EtL1.o : In the function « std::thread::thread<void (&)()>(void (&)()) » : file.cpp:(

问题 I have some troubles trying to compile a program with multi-threading from the standard template library. It return me a obscure error when i try to compile the following program : #include <iostream> #include <thread> void foo() { std::cout << "Thread 1\n"; } int main(int argc, char** argv) { std::thread tr(foo); std::cout << "Main thread\n"; tr.join(); return 0; } I don't understand the error : /tmp/ccE8EtL1.o : In the function « std::thread::thread<void (&)()>(void (&)()) » : file.cpp:(

问题 Sample : static void Main(string[] args) { int counter = 0; var t = new System.Timers.Timer(); t.Interval = 3000; t.Elapsed += async (sender, e) => { Debug.WriteLine("Before await - Thread : {0} , Counter : {1}", Thread.CurrentThread.ManagedThreadId, counter); await Task.Delay(1000).ConfigureAwait(true); Debug.WriteLine("Ater await Thread : {0}, Counter : {1} ", Thread.CurrentThread.ManagedThreadId, counter); counter++; if (counter == 2) { Debug.WriteLine("Stop"); t.Stop(); } }; t.Start();

问题 I am creating a custom cache object for data that is relatively static and is periodically updated from the DB. I have chosen to use a strongly-typed DataSet to store the cached data. Now, access for reading and refreshing (clients cannot write to the cache, only refresh it) to the custom cache object is synchronized via ReaderWriterLockSlim. HOWEVER, I want to ensure that clients of the cache cannot corrupt the data (DataTables, DataRows, etc.) within the strongly-typed data set by

问题 I have seen the terms contention and race are used interchangeably when it comes to thread's state(at critical section). Are they same? 回答1: "Contention" usually refers to the situation where two or more threads need to lock the same lock. We say that the lock is "contested" or maybe, "heavily contested," if there is a significant probability of any thread being forced to wait when it tries to acquire the lock. "Race," "Race condition," and "Data race" are phrases whose meanings have changed

问题 I was assigned to create a program that handles three WINAPI threads and reflects the workflow of those in progress bars. I decided to use Qt Widgets for these purposes. I create those threads in suspended state, using CREATE_SUSPENDED creation flag, then i resume it with ResumeThread function upon clicking the button. When I click it, the program crashes with an unhandled exception win32. Why could this happen? My "create" button click slot void MainWindow::on_pb_create_clicked() { hThread[0