Hi, I've noticed that on android, the call to pthread_join does not suspend the calling thread. I've a number (6) of new thread created using pthread_create and pthread_join is called on each thread. But It does not suspend the main (calling) thread. I believe this relates to the port of pthread lib to android.
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I need to suspend/resume a thread from another thread in the same process. I tried to look into thread apis,but I couldn't figured out a way to achieve this.Can anyone pls point me some references to look or give a tip to do this.
View 2 Replies View RelatedI am writing an application in which i need to handle messages between the main thread(the deafult UI related thread) and the user created Gamethread.
The requirement is like this.
An activity(say "Activity_X") is setting the view by "setContentView(some "View_Y")". In "Activity_X" i have implemeted "onCreateOptionsMenu()" and "onOptionsItemSelected()" fucntions for creating menus & a switch case for action to be taken on selecting those menus.Menu has items like "resume/pause/zoom/" .
All action to be take on selecting these menus are implemented in "View_Y" in a separate Gamethread by extending "Thread" class.
So whenever a menu is selected in "Activity_X" i need to send a message to "View_Y". And on receiving this ,a particular action/method should be called in View_Y(GameThread).
How can i achieve this using Handlers?Is there any other way of doing this? Please do share with me some code snippets for these.
I have a separate thread running to get data from the internet. After that, I would like to update the ListView in the main thread by calling adapter.notifyDataSetChanged(). But it does not work. Any workaround for that?
View 1 Replies View RelatedThe Android doc says "Like activities and the other components, services run in the main thread of the application process." Is the main thread here the same thing as UI thread?
View 3 Replies View RelatedAre the UI threads for each Activity and Service in an app separate threads, or is there actually 1 underlying UI thread per app that processes the UI message queue for each Activity and Service?
View 2 Replies View RelatedCan someone advise the am command (for adb shell) to run junit tests in the main thread please? The following shows onStart etc running in the test runner thread. am instrument -w -e class co.uk.telesense. tests.MyTest co.uk.telesense.tests/android.test.InstrumentationTestRunner Ewan Benfield ttp://www.telesense.co .uk tel: 0845 643 5691 (+44 845 643 5691) mob: +44 (0) 77859 26477
View 2 Replies View RelatedI was define a new thread for a task, but when task is complete, I must to refresh my listview, however I will get the error for just can use main thread to change view,
View 5 Replies View RelatedThere are a lot of Android SDK APIs where callback handlers are registered. For a concrete example, with MediaPlayer you can set an onCompletionListener callback. Will these callbacks be called from the main (UI) thread? If the answer is "it depends", then I'm looking for some general rules for what callbacks will be called from the main thread versus another thread. The SDK documentation doesn't seem to spell it out. (Maybe I missed it) It seems important to know, because if I'm guaranteed main thread callbacks, then I can skip some thread synchronization on data shared between different places in code. If I'm forced to be pessimistic out of ignorance, then I have to write extra synch block code and worry about deadlocks, data integrity, and reduced performance.
View 4 Replies View RelatedSay that a user clicks on a Button. Is the resulting onClick() function invoked on the main UI thread of the activity?
View 1 Replies View RelatedI want to cancel a Toast to show the next one. This is the description of the behavious I want, when I select one element in the menu i display a toast from the actuel menu element, but if i switch from one element to an other quickly i'm creating a list of Toast to display. So i need to cancel the previous one but i never succed. This is an extract of my code: public class MainActivity extends TabActivity
private Toast toast; private String toastMsg;
private void toast(){ if(toast!=null){ toast.cancel(); } toast = Toast.makeText(MainActivity.this, toastMsg,Toast.LENGTH_SHORT);
toast.show(); } }
I try to make several connection in a class and update the multiple progressbar in the main screen. But I've got the following error trying to use thread in android : Code: 05-06 13:13:11.092: ERROR/ConnectionManager(22854): ERROR:Can't create handler inside thread that has not called Looper.prepare() Here is a small part of my code in the main Activity.
public class Act_Main extends ListActivity
{ private ConnectionManager cm;
public void onCreate(Bundle savedInstanceState)
{ super.onCreate(savedInstanceState);
// Set up the window layout
requestWindowFeature(Window.FEATURE_CUSTOM_TITLE);
setContentView(R.layout.main);
getWindow().setFeatureInt(Window.FEATURE_CUSTOM_TITLE, R.layout.custom_title); }
public void startConnection() { ......
Curious to know the reason behind not allowing updating UI elements from background thread in Android. Will main thread does something more (probably interacting with framework) after updating the UI elements so that changes can be seen on the screen? Is it the same case with other GUI tool kits?
View 1 Replies View RelatedMy program threw a NullPointerException the other day when it tried to use a Handler created on another thread to send that thread a message. The Handler created by the other thread was not yet created, or not yet visible to the calling thread, despite the calling thread having already called start on the other thread. This only happens very rarely. Almost every test run does not get the exception. I was wondering what the best way is to avoid this problem for sure with minimal complication and performance penalty. The program is a game and very performance sensitive, especially once it is running. Therefore I try to avoid using synchronization after setup, for example, and would prefer to avoid spinning on a variable at any time.
View 2 Replies View RelatedI want to display pictures into an ImageSwitcher and change image every 3 seconds. I instanciate a Thread that call the setImageURI(URI) and I schedule it every 3 seconds. It does not update the view and I don't know how to do it. If I call the same code that call the setImageURI() from the OnClickListener of the view it works! Do you know why and how can I make it work?
View 3 Replies View RelatedI am trying to connect to a database, and I understand that it has to be outside of the main thread but i thought that this is what my code was doing...apparently not because i keep getting the error: android.os.NetworkOnMainThreadException.
package com.example.dbtesting;
import java.sql.*;
import android.os.Bundle;
import android.os.Handler;
import android.os.Message;
import android.app.Activity;
import android.view.Menu;
import android.view.View;
import android.widget.EditText;
import android.widget.TextView;
[code]....
Are we guaranteed that Application.onCreate() runs in the UI/main thread? I want to assume so but I can't find any information to make me 100 % sure. When I receive a broadcast I want to post a message onto the UI/main thread. Currently I've added a function in my Application class to return a handler (created in it's onCreate), is this a good solution? If not, what would be a better solution?
View 3 Replies View RelatedMy purpose is very simple : each 1second, I want to redraw an object on different place on background. I do not know where my error on this code below. Here is my code:
public class My_View extends View{ private Bitmap mBackground_img;
private Drawable mMoveObject; private int mObjectw,mObjecth; private int Dx,Dy;
private Handler myHandler = new Handler(); private long lasttime;
public My_View(Context context,AttributeSet ats,int ds) {
super(context,ats,ds); init(context);
} public My_View(Context context,AttributeSet ats) { super(context,ats);
init(context); } public My_View(Context context) { super(context);
init(context); } public void change() { invalidate();
} private void init(Context context) {
Resources res = context.getResources();
mMoveObject = res.getDrawable (R.drawable.lander_firing);
mBackground_img = BitmapFactory.decodeResource(res, R.drawable.my_pic);
mObjectw = mMoveObject.getIntrinsicWidth();
mObjecth = mMoveObject.getIntrinsicHeight();
Dx = Dy = 0; lasttime = System.currentTimeMillis() + 1000;
Thread mthread = new Thread(null,doBackground,"Background");
mthread.start(); } private Runnable doBackground = new Runnable() {
public void run() { long now = System.currentTimeMillis();
if(lasttime < now ) { Dx = Dx + 10; Dy = Dy + 10;
lasttime = now + 1000; myHandler.post(change_view);
} } }; private Runnable change_view = new Runnable() {
public void run() { change();
} };
@Override public void onDraw(Canvas canvas) {
canvas.drawBitmap(mBackground_img,0 ,0 , null);
mMoveObject.setBounds(Dx, Dy, Dx+mObjectw, Dy+mObjecth);
mMoveObject.draw(canvas);
} }
I am trying to start an error-reporting activty if unhandled exception detected. The problem is with exceptions thrown from main thread. Is there any way to start an activity if main thread crashed?
View 3 Replies View RelatedI have an app with a two threads - main and data loader. When data loader finishes it posts a Runnable object to the main thread (as described in the DevGuide), but it never gets delivered and run. Here's the basic code:
class MyApp extends Application{
public void onCreate()
{LoaderThread t = new LoaderThread();
t.start(); }
private class LoaderThread extends Thread {
public void run()
{ SystemClock.sleep(2000);
boolean res = m_handler.post(m_runnable);
if(res)
Log.d(TAG, "Posted Runnable"); } ............
In my game when the user completes a stage, I want the main game thread to pause/sleep/wait and a new activity to be launched called StageClear that displays information about points scored etc. After this has been displayed and the user has pressed continue I want the original game thread to resume where it left off. I have tried to implement this but have so far been unsuccessful, probably because I'm new to dealing with multiple threads and also the idea of synchronizing them. I most recently tried to implement a shared package-visible object that could notify after wait was called on itself, but I am getting errors in eclipse so it won't even compile, I think because though the object is declared public in an inner class, it cannot be seen or recognised by my activity elsewhere in a file in the package. I have already built both activities but my issue is getting the main game one to launch the other, and pause whilst it waits for this activity to finish, before the main game thread continues execution.
View 1 Replies View RelatedI have two activities:
"a" that spawns thread for generating a dynamic array of values inside public void run() function.
"b", graphics activity that will help me draw rectangular pulses based on array values calculated in activity "a" (calculated in a's thread to be precise).
When I am in thread inside "a", how do I pass values of array to activity "b" and
call activity as well.
activity A
CODE:..........
activity B
CODE:..............
Suppose I have code in the onStart() handler of my Service to launch a thread to do some stuff and then call stopSelf().stopSelf() gets called before the thread finishes.What exactly happens?I've tested this out myself and my thread continues to execute until it is finished.Does Android hear the stopSelf() call, but postpone it until the thread is finished?
View 1 Replies View RelatedI have made a game with just one activity.. I just replace the views when I want to change screen. The game runs fine for a really long time inspite of what ever I do within the game.
But once I close the main game, by calling finish on the only activity in the application, and then when I start again, within the next 30 secs it crashes telling VM budget exceeded..
When I don't have a dispose() or a delete method in JAVA.. how the, am I supposed to remove the objects used in memory.. moreover I have android:launchMode="singleInstance" in my manifest
How would I force the current thread to wait until another has finished before continuing. In my program the user selects a MODE from an AlertDialog, I want to halt executing of the program before continuing as the mode holds important configuration for the gameplay.
new AlertDialog.Builder(this)
.setItems(R.array.game_modes, new DialogInterface.OnClickListener() {
public void onClick(DialogInterface dialog, int which) {
switch (which) {
case 0:
setMode(TRAINING_MODE);
case 1:
setMode(QUIZ_MODE);
default:
setMode(TRAINING_MODE);
break; ............
//continue loading the rest of onCreate();
contineOnCreate(); } })
.create().show();
If this is impossible can anyone give a possible solution?
I read somewhere that iPhone UI is so smooth because the thread which renders the UI has the REALTIME priority... so is that possible to mod android's UI thread priority?
View 2 Replies View RelatedI am using an Executor [fixed thread pool] with my own ThreadFactory that adds a Looper:
CODE:...............
I am running a thread that makes network requests but if the network fails I would like a dialog message to be displayed to the user. This process is rather involving since it requires making AND displaying the request in the UI thread. I can wait for the user's response to the dialog by simply adding a Loop to the network thread and wait for a message to be send from the UI thread. This allows me to encapsulate the network requests in a while(tryAgain) thread. All works well except when the Looper.loop() method is called the second time (after a second network error dialog is displayed) and a message is sent by the dialog (in the UI thread) to the network thread's handler:
CODE:.............
In the AlertDialog instance is an OnClickListener:
CODE:...............
I've checked that the thread is still active with handler.getLooper().getThread().isAlive() which always returns true but it still gives me "sending message to a Handler on a dead thread". How is it that the Message/Handler has decided that the thread is dead? Shouldn't it rely on the .isAlive() method? In the end I am trying to avoid replicating the thread management build into the Android OS .
Since I got the original 2.2 update for my Droid, whenever I get a new text message and slide down the notification bar and select the new message, it takes me to the main text message window rather than the actual thread to reply to the person. It is really annoying because it requires an extra step. I figured it would be fixed with the second 2.2 update but it didn't. I called Verizon and they called Motorola and nobody knew of the problem so they shipped me out a new phone and it still does it! I am not sure if I am the only one experiencing this or if its normal. It doesn't do it 100% of the time but closer to 90% probably.
View 1 Replies View RelatedWhile developing an alarm based application, i have stuck in a scenario.
When my alarm is fired, i can receive the event in BroadCastReceiver::onReceive().
Within this function, i want to notify/call a function, which is located on MainActivity.
How to achieve the same?
I've been trying to call a non-static method, located in my main application Class, from the Preferences Class. Because the method I call is not static, I instantiate the main class and then try to call the specific method I want but it's force closing.
Preferences.class (from where I call the method):
Preference sorted = (Preference) findPreference("sortPref");
sorted.setOnPreferenceChangeListener(new Preference.OnPreferenceChangeListener() {
public boolean onPreferenceChange(Preference preference, Object newValue) {
Object d = new Dmarks();
((Dmarks) d).queryBookmarks();
return true;
}});
the Dmarks.class method I call:
public void queryBookmarks() {
Toast.makeText(context, Toast.LENGTH_LONG).show();
//context is not null and the Toast is working if I call it from Dmarks.class }
The Logcat:
E/AndroidRuntime(11718): FATAL EXCEPTION: main
E/AndroidRuntime(11718): java.lang.NullPointerException
E/AndroidRuntime(11718):
at android.content.ContextWrapper.getContentReso
lver(ContextWrapper.java:90)
E/AndroidRuntime(11718):
at android.app.Activity.managedQuery(Activity.ja
va:1520)
E/AndroidRuntime(11718):
at com.droidil.droidmarks.Dmarks.queryBookmarks(
Dmarks.java:101)
E/AndroidRuntime(11718):
at com.droidil.droidmarks.Preferences$2.onPrefer
enceChange(Preferences.java:47)
E/AndroidRuntime(11718):
at android.preference.Preference.callChangeListe
ner(Preference.java:756)
E/AndroidRuntime(11718):
at android.preference.ListPreference.onDialogClo
sed(ListPreference.java:219)
E/AndroidRuntime(11718):
at android.preference.DialogPreference.onDismiss
(DialogPreference.java:384)
E/AndroidRuntime(11718):
at android.app.Dialog$ListenersHandler.handleMes
sage(Dialog.java:1047)
E/AndroidRuntime(11718):
at android.os.Handler.dispatchMessage(Handler.ja
va:99)
E/AndroidRuntime(11718):
at android.os.Looper.loop(Looper.java:123)
E/AndroidRuntime(11718):
at android.app.ActivityThread.main(ActivityThrea
d.java:4627)
E/AndroidRuntime(11718):
at java.lang.reflect.Method.invokeNative(Native
Method)
E/AndroidRuntime(11718):
at java.lang.reflect.Method.invoke(Method.java:5
21)
E/AndroidRuntime(11718):
at com.android.internal.os.ZygoteInit$MethodAndA
rgsCaller.run(ZygoteInit.java:868)
E/AndroidRuntime(11718):
at com.android.internal.os.ZygoteInit.main(Zygot
eInit.java:626)
E/AndroidRuntime(11718):
at dalvik.system.NativeStart.main(Native Method)
D/dalvikvm(11718): GC_FOR_MALLOC freed 4248 objects / 282248 bytes in 40ms
W/ActivityManager( 244): Force finishing activity com.droidil.droidmarks/.Preferences