wait

问题 I'm new to Android and Java programming. I created an app for a Coursera class. It has two animations that occur repeatedly. I want them to animate like a drum beat - 1,2,1,2,1,2,1,2,1,2. I wrote two recursive methods that run until the user clicks a Reset button. I tried adding a wait in between the method calls so the second would kick off right after the first one. This is the part of my code that has the wait. mHandler = new Handler(); // .os package class when importing mLeftfoot =

问题 When using Monitor.Wait(object obj) what should one use for the obj? In this article I'm reading on multithreading in .NET the author instantiates a new Object() to be used only as a monitor lock. Is this what you should do in practice, or is it more typical to Monitor the actual variable shared between two or more threads? 回答1: Yes, I normally lock on a new object created specially for that purpose. I also make sure that it is private and static and not a Type object. It's also important to

问题 C program: pid = fork(); if (pid == 0) { execv("Golang Process"); } else (pid > 0) { wait(&status); printf("process %d status: %d\n", pid); } Golang Program: func main() { ...... os.Exit(1) } But, output is: process XXX status: 256 if set os.Exit(2), output is: process XXX status: 512 if set os.Exit(3), output is: process XXX status: 768 Why? 回答1: See wait manual: If status is not NULL, wait() and waitpid() store status information in the int to which it points. This integer can be inspected

问题 I am wondering if it is possible to check the status of a thread, which could possibly be in a waitable state but doesn't have to be and if it is in a waitable state I would like to leave it in that state. Basically, how can I check the status of a thread without changing its (waitable) state. By waitable, I mean if I called wait(pid) it would return properly and not hang. Let me also add that I am tracing a multithreaded program, therefore I cannot change the code of it. Also, I omitted this

问题 I was expecting the second thread in the following example to hang, since it waits on an object with no corresponding notify. Instead, it falls through to the println, presumably due to a spurious wakeup. public class Spurious { public static void main(String[] args) { Thread t1 = new Thread() { public void run() { System.out.println("Hey!"); } }; Thread t2 = new Thread() { public void run() { try { synchronized (t1) { t1.wait(); } } catch (InterruptedException e) { return; } System.out

问题 I was reading about thread synchronisation and wait/notify constructs from the tutorial. It states that When wait is invoked, the thread releases the lock and suspends execution. At some future time, another thread will acquire the same lock and invoke Object.notifyAll, informing all threads waiting on that lock that something important has happened. Some time after the second thread has released the lock, the first thread reacquires the lock and resumes by returning from the invocation of

问题 I am calling a subactivity from main activity. This subactivity should take few numbers from user (i'm using Edit text control to achieve this), save them to static variable in another class and terminate. I want main activity to wait for subactivity but both are just running simultaneously. Even doing sth like that doesn't help: Thread t = new Thread(new Runnable(){ public void run(){ Log.v("==================", "run "+new Date()); startActivityForResult(new Intent(ctx,myCustomSubactivity

问题 Is there any built in feature in bash to wait for 1 out of many processes to finish? And then kill remaining processes? pids="" # Run five concurrent processes for i in {1..5}; do ( longprocess ) & # store PID of process pids+=" $!" done if [ "one of them finished" ]; then kill_rest_of_them; fi I'm looking for "one of them finished" command. Is there any? 回答1: bash 4.3 added a -n flag to the built-in wait command, which causes the script to wait for the next child to complete. The -p option

问题 I'm writing a C++/CX component to be consumed by Window's store Apps. I'm looking for a way to accomplish what Task.Delay(1000) does in C#. 回答1: Old Question, but still unanswered. You can use #include <chrono> #include <thread> std::this_thread::sleep_for(std::chrono::milliseconds(1000)); This will need C++11, which shouldn't be a problem when using C++/CX. 回答2: I'm not going to claim to be a wizard - I'm still fairly new to UWP and C++/CX., but what I'm using is the following: public ref

问题 Having figured out how to use the wait() and notify() in Java application to fetch some data from the Internet, I had to migrate that code into my Android application. As it turns out the code that would've worked in Java app would never had worked within my Android app even with attempts to make it multi-threaded (with Runnable and then ASyncTask). The problem seems that the Android app will hang after a call on Object.wait() and will never continue further. The following is the code of the