问题描述
我有我的用户界面和其他线程,那里是循环:
I have my UI and other Thread, where there is loop:
while(true){
}
我检查系统中的字符串值的变化,当变化,我通过pre-打开的套接字将消息发送到服务器。问题是,应用循环的时候,我的应用程序死机,和CPU负载非常高(约90%)。我知道,无限循环不得线程来完成,但你知道如何复制这种行为,没有使用无限循环?
I am checking changes of String value in the system, and when changes, I send message via pre-opened socket to the server. Problem is, when applying loop, my app freezes, and CPU load is very high (about 90 %). I know, infinite loop must not be done in thread, but do you know how to copy this behavior, not using infinite loop?
THX
主要code(onCreate方法):
mProgressDialog = ProgressDialog.show(main.this, "loading","loading", true);
c=new Client(this.getApplicationContext(), "192.168.0.121", 3333);
c.start();
CLIENT_MESSAGE="login user2 user2";
synchronized(c){
c.notify();
}
Client.zHandler.setEmptyMessage(119);
mHandler = new Handler()
{
public void handleMessage(android.os.Message msg)
{
super.handleMessage(msg);
switch (msg.what)
{
case 11:
Log.d("Logged in", "login");
mProgressDialog.dismiss();
break;
case 12:
Log.d("Logged out", "logout and end");
mProgressDialog.dismiss();
finish();
break;
}
}
};
@Override
public boolean onKeyDown(int keyCode, KeyEvent event) {
switch (keyCode) {
case KeyEvent.KEYCODE_BACK:
CLIENT_MESSAGE="logout";
synchronized (c) {
c.notify();
}
Client.zHandler.setEmptyMessage(129)
break;
default:
}
return true;
}
主题code(Client.java):
Thread Code (Client.java):
public Client(Context ctx, String hostname, int port){
this.ctx=ctx;
this.hostname=hostname;
this.port=port;
zHandler = new Handler()
{
public void handleMessage(android.os.Message msg)
{
super.handleMessage(msg);
switch (msg.what)
{
case 119://login
Log.d("119", "case 119");
messageText=DropboxFileClientActivity.CLIENT_MESSAGE;
main.mHandler.sendEmptyMessage(11);
break;
case 129://logout
messageText=DropboxFileClientActivity.CLIENT_MESSAGE;
main.mHandler.sendEmptyMessage(12);
break;
case 100:
break;
}
}
};
}
public void run(){
try {
clientSocket = new Socket(hostname, port);
//inputLine = new BufferedReader(new InputStreamReader(System.in));
os = new ObjectOutputStream (clientSocket.getOutputStream());
is = new ObjectInputStream(clientSocket.getInputStream());
}
catch (UnknownHostException e) {
Log.d("ERROR", "unknown host "+hostname);
}
catch (IOException e) {
Log.d("ERROR2", "no bind"+hostname);
e.printStackTrace();
}
while (!isInterrupted()) {
try{
synchronized (this) {
wait();
}
} catch (InterruptedException e) {
break; // interrupting the thread ends it
}
if (clientSocket != null && os != null && is != null &&!messageText.equals("")) {
messageText="";
//sending message to server, getting reply and displaying it to the screen
}
}//endwhile loop
}
推荐答案
如果你的循环是,事实上,在一个单独的线程中运行,则问题是,它是CPU猪
If your loop is, indeed, running in a separate thread, then the problem is that it is a CPU hog.
而不是轮询,检查更改为字符串
价值,这将是更好(如果你有过相关的code控制)来写一个setter触发来自其他线程的服务器更新(有,比方说,一个等
/ 通知
协议)。
Rather than polling to check for changes to a String
value, it would be much better (if you have control over the relevant code) to write a setter that triggers the server updates from the other thread (with, say, a wait
/notify
protocol).
即使你有轮询,你真的需要在CPU的速度呢?也许等到第二个会做什么?这将让你睡的时间休息。
Even if you have to poll, do you really need to do it at CPU speeds? Perhaps once a second would do? That would let you sleep the rest of the time.
最起码,叫 Thread.yield()
通过循环每次。
At the very least, call Thread.yield()
every time through the loop.
修改基于对信息的评论,你应该在后台线程等待:
EDIT Based on your comment to the post, you should be waiting in the background thread:
在你的后台线程
while (!isInterrupted()) {
synchronized (this) {
wait();
} catch (InterruptedException e) {
break; // interrupting the thread ends it
}
// read string and send it to the server
}
在你的事件处理程序:
public void onSomethingHappened(...) {
// update the string
synchronized (mThread) {
mThread.notify();
}
}
该字符串应标明挥发性除非读取和更新都在同一对象上同步的。
The string should be marked volatile unless the read and update are synchronized on the same object.
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