wait

Need android activity to wait until GPS location obtained

由 喜欢而已 提交于 2019-12-22 05:35:15
问题 Sorry for my english. I'm trying to get a single location from GPS to put on global variables latitude, longitude. GPS turns on, but the activity goes on before data is retrieved from GPS. My needs in other words... method getCurrentLocation() must finish only if a location has been found and the longitude and latitude variables are filled, so I could use them in other method. I know... user has to wait... I will solve this forward showing something on screen. What should I do? Thank you I

Wait until multiple command line processes complete?

由 坚强是说给别人听的谎言 提交于 2019-12-22 05:01:31
问题 I have a need to execute many command line scripts. They are currently stored in a List . I want to run them all at the same time and proceed with the next step only after all of them have completed. I have tried the approach that I show below, but found it lacking because the last command doesn't necessarily end last. In fact, I found that the last command can even be the first to complete. So, I believe that I need something like WaitForExit() , but which doesn't return until all executing

How is fork() working when children fork?

由 假如想象 提交于 2019-12-21 20:50:37
问题 I have executed a block of code. And it is as shown below: #include<stdio.h> main() { int i=0; fork(); printf("The value of i is:%d\n",++i); fork(); printf("The value of j is:%d\n",++i); fork(); wait(); } And I got following output: The value of i is:1 The value of j is:2 The value of i is:1 The value of j is:2 The value of j is:2 pckoders@ubuntu:~$ The value of j is:2 Can anyone explain to me what role fork() and wait() functions play here? 回答1: The program generates a tree of processes. At

producer - consumer multithreading in Java

由 霸气de小男生 提交于 2019-12-21 17:48:15
问题 I want to write program using multithreading wait and notify methods in Java. This program has a stack (max-length = 5). Producer generate number forever and put it in the stack, and consumer pick it from stack. When stack is full producer must wait and when stack is empty consumers must wait. The problem is that it runs just once, I mean once it produce 5 number it stops but i put run methods in while(true) block to run nonstop able but it doesn't. Here is what i tried so far. Producer class

Wait for signal, then continue execution

由 感情迁移 提交于 2019-12-21 17:37:51
问题 I am trying to make a program that suspends its execution until a signal arrives . Then, after the signal arrives I just want my code to continue its execution from where it was . I don't want it to execute a function handler or whatsoever. Is there a simple way of doing this? I have been struggling for a week or so, reading here and there, and didn't manage to get a fully operative code. In particular, I want the main program to create a thread that waits for some particular event to happen

How to make main window wait until a newly opened window closes in C# WPF?

由 喜欢而已 提交于 2019-12-21 12:18:54
问题 I am new to WPF as well as C#, please bear with me. I have a main window which opens up a new window. Now this new window is a prompt whether or not to overwrite a file, and the main window accesses a public variable in the new window to check for the prompt's result. But I can't get the main window processing to wait until the new window closes. Window1 Win = new Window1(); Win.Show(); if (Win.pr_res == 1) { abc.Text = "File to be overwritten"; File.Delete(_destination); Start(); } else {

消费者、生产者模型

由 纵饮孤独 提交于 2019-12-21 12:11:07
摘自 生产者-消费者的三种实现 wait/notifyAll实现 public class ProductorConsumer { public static void main(String[] args) { LinkedList linkedList = new LinkedList(); ExecutorService service = Executors.newFixedThreadPool(15); for (int i = 0; i < 5; i++) { service.submit(new Productor(linkedList, 8)); } for (int i = 0; i < 10; i++) { service.submit(new Consumer(linkedList)); } } static class Productor implements Runnable { private List<Integer> list; private int maxLength; public Productor(List list, int maxLength) { this.list = list; this.maxLength = maxLength; } @Override public void run() { while (true) {

Are Java wait(), notify() 's implementation significantly different from locks?

由 不打扰是莪最后的温柔 提交于 2019-12-21 10:18:41
问题 Out of curiosity, when Java implements wait() and notify() methods, are they really just using locks? i.e., wait() acquires a mutex, notify() release a mutex, notifyAll() releases all mutexes (in the same object, of course)? Other than being less cumbersome than using locks, are there other advantages of using wait() and notify()? [EDIT] I realized what I confused myself about after Brian's comments: wait doesn't lock, it releases the lock and passes it to someone else who's waiting on a

The difference between wait_queue_head and wait_queue in linux kernel

由 只谈情不闲聊 提交于 2019-12-21 07:39:13
问题 I can find many examples regarding wait_queue_head . It works as a signal, create a wait_queue_head , someone can sleep using it until someother kicks it up. But I can not find a good example of using wait_queue itself, supposedly very related to it. Could someone gives example, or under the hood of them? 回答1: From Linux Device Drivers: The wait_queue_head_t type is a fairly simple structure, defined in <linux/wait.h> . It contains only a lock variable and a linked list of sleeping processes.

fork() and wait() calls

由 試著忘記壹切 提交于 2019-12-21 05:45:16
问题 I have a question about the following code. This is an example found on this page, not my code. The parent process forks 2 child processes, each of them counting to 200 then exiting. What I don't understand is why aren't the children printing their messages immediately after they are forked and they allow their father to enter waiting status? Also, how is the wait system call returning the pid of the child that finishes first? pid = wait(&status); #include <stdio.h> #include <string.h>
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