thread-safety

问题 i have the following scenario: interface ValueBinding<T> { public void setValue(T input); } public enum FacesBinding { VALUE; public void bindString(ValueBinding<String> fcn, HttpServletRequest req, String param){ try { String val = req.getParameter(param); if( val != null ) fcn.setValue(val); } catch (Exception e) { } } public void bindBoolean(ValueBinding<Boolean> fcn, HttpServletRequest req, String param){ try { fcn.setValue(req.getParameter(param) != null); } catch (Exception e) { } }

问题 i have the following scenario: interface ValueBinding<T> { public void setValue(T input); } public enum FacesBinding { VALUE; public void bindString(ValueBinding<String> fcn, HttpServletRequest req, String param){ try { String val = req.getParameter(param); if( val != null ) fcn.setValue(val); } catch (Exception e) { } } public void bindBoolean(ValueBinding<Boolean> fcn, HttpServletRequest req, String param){ try { fcn.setValue(req.getParameter(param) != null); } catch (Exception e) { } }

问题 I am writing a Python program where in the main thread I am continuously (in a loop) receiving data through a TCP socket, using the recv function. In a callback function, I am sending data through the same socket, using the sendall function. What triggers the callback is irrelevant. I've set my socket to blocking. My question is, is this safe to do? My understanding is that a callback function is called on a separate thread (not the main thread). Is the Python socket object thread-safe? From

问题 I am writing a Python program where in the main thread I am continuously (in a loop) receiving data through a TCP socket, using the recv function. In a callback function, I am sending data through the same socket, using the sendall function. What triggers the callback is irrelevant. I've set my socket to blocking. My question is, is this safe to do? My understanding is that a callback function is called on a separate thread (not the main thread). Is the Python socket object thread-safe? From

问题 I am writing a Python program where in the main thread I am continuously (in a loop) receiving data through a TCP socket, using the recv function. In a callback function, I am sending data through the same socket, using the sendall function. What triggers the callback is irrelevant. I've set my socket to blocking. My question is, is this safe to do? My understanding is that a callback function is called on a separate thread (not the main thread). Is the Python socket object thread-safe? From

问题 I am writing a Python program where in the main thread I am continuously (in a loop) receiving data through a TCP socket, using the recv function. In a callback function, I am sending data through the same socket, using the sendall function. What triggers the callback is irrelevant. I've set my socket to blocking. My question is, is this safe to do? My understanding is that a callback function is called on a separate thread (not the main thread). Is the Python socket object thread-safe? From

问题 Below method is getting used to fill Dataset. if we are calling this method in synchronous way it is working fine. But now we need to call this method in Asynchronous way.so what changes i need to do so that below method should work properly without any issue. public DataSet Filldata(string ProcName, string TableName) { DataSet ds = new DataSet(); try { da = new SqlDataAdapter(ProcName, con); if (con.State != ConnectionState.Open) { con.Open(); } da.SelectCommand.CommandTimeout = 15000; da

问题 I found an interesting behavior yesterday while debugging a Windows Forms application, please refer to this code: bool enter = false; Debugger.Break(); if (enter) // Force to enter the if clause, read next comment { bool a = false; // Bypass previous IF check in debug using 'Set Next Statment (CTRL-SHIFT-F10)' here // Will throw null reference exception // If I don't use invoke everything works fine Invoke(new MethodInvoker(() => { a = true; })); } So if I force to enter an IF clause that was

问题 I use Java 8. I have an event handler that accepts events with a high rate, (n per second) and I want to flush them out to storage when I get so many of them (in this simplified example 1000) Do I have a visibility error on line 25 myCache.get(event.getKey()).add(event.getBean()); ? Should I synchronize on handleEvent() method? public class myClass extends MySimpleEventHanlder { private Map<String, List<MyBean>> myCache; private ScheduledExecutorService scheduler; public void MyClass() {

问题 What are the ways to detect deadlocks in a live multi-threaded application? If we found there is a deadlock, are there any ways to resolve it, without taking down/restarting the application? 回答1: There are two popular ways to detect deadlocks. One is to have threads set checkpoints. For example, if you have a thread that has a work loop, you set a timer at the beginning of doing work that's set for longer than you think the work could possibly take. If the timer fires, you assume the thread