Performance problem using multi-thread
I am using berkeley db to store a int/double pair, and i randomly get 100,0000 results to check the performance . Using 1 thread, it cost about 1 Mins. But using 4 threads, it costs 4 Mins. More threads, lower performance. Is there Anyone know the reason?
Env flags:
envFlags=DB_CREATE | DB_INIT_MPOOL | DB_THREAD | DB_PRIVATE|DB_INIT_CDB;
DB open flags: DB_THREAD
and i use db->get method to get results.
Berkeley DB 4.8 will be released soon and has features that address CMP/SMP scalability. We would appreciate your feedback on your experiences with it. Once available, please test it and post your results here, I'm sure you'll be pleasently surprised.
regards,
-greg
Similar Messages
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Performance problem using OBJECT tag
I have a performance problem using the java plugin and was wondering if anyone else was has seen the same thing. I have a rather complex applet that interacts with java script in a web page using the LiveConnect API. The applet both calls javascript in the page and is called by java script.
Im using IE6 with the java plugin that ships with the 1.4.2_06 JVM. I have noticed that if I deploy the applet using the OBJECT tags, the application seems the trash everytime I call a java method on the applet from javascript. When I deplot the same applet using the APPLET tag the perfomance is much better. I would like to use the OBJECT tag because it applet bahaves better and I have more control over the caching.
This problem seems to be on the boundaries of IE6, JScript, the JVM and my Applet (and I suppose any could be the real culprit). My application is IE5+ specific so I can not test the applet in isolation from the surround HTML/JavaScript (for example in another browser).
Does anyone have any idea?
thanks in advance.
dennis.I have a performance problem using the java plugin and was wondering if anyone else was has seen the same thing. I have a rather complex applet that interacts with java script in a web page using the LiveConnect API. The applet both calls javascript in the page and is called by java script.
Im using IE6 with the java plugin that ships with the 1.4.2_06 JVM. I have noticed that if I deploy the applet using the OBJECT tags, the application seems the trash everytime I call a java method on the applet from javascript. When I deplot the same applet using the APPLET tag the perfomance is much better. I would like to use the OBJECT tag because it applet bahaves better and I have more control over the caching.
This problem seems to be on the boundaries of IE6, JScript, the JVM and my Applet (and I suppose any could be the real culprit). My application is IE5+ specific so I can not test the applet in isolation from the surround HTML/JavaScript (for example in another browser).
Does anyone have any idea?
thanks in advance.
dennis. -
Using multi threading to access 2 RS232 ports
Hi,
I'm a beginner in multi threading, so this question may be a very basic one....
I'm Using TS3.5 + CVI 8.01 to communicate withs 2 RS232 ports. I thought to use mult threading so I can process 2 steps in parallel rather than in series.
This is what I do:
1) I defined 2 subsequences, each of them call the same CVI function. I use the sub sequence parameters to transfer the com number.
2) My CVI application includes one dll for this specific project and another one, a general dll to handle RS232 functions. The RS232 dll uses one global buffer than collects all the traffic on the com.
QUESTIONS:
1) What happens when 2 seperate threads run the same function in the RS232 dll? (in terms of memory etc...). Does each one use a different buffer (in terms of memory allocation), or, both of them writes to the same buffer? Obviously, if they writes to the same buffer, then, my function will not operate properly.
2) What happens in TestStand after the 2 steps in new threads have finished their execution? does the next step run back in the same threads the sequence run before?
Thanks
RafiRafi,
Glad to hear you were able to make some ground on your application. As for all of your questions, I'll try to answer as many as I can.
First, when you are talking about your global buffer, is it created in TestStand or in the DLL itself? When you use DLLs, global variables or global structures are shared between all threads that call your DLL. On the other hand, if your buffer is declared inside of the DLL it is global for the DLL but not shared and would be a separate buffer for each call.
With your run-time error in TS, it would definitely be helpful to have more information about the error. From what you explained (executing fine on the first call, but failing on future executions), it sounds like the resource is not being released after the first execution.
As far as a specific example for TestStand Multithreading, you'll want to look at the TestStand Development Library and, specifically, Multithreading in TestStand. If you look and browse through the Application Notes and Tutorials section, as well as the Technical Presentations section, you will learn a great deal about multithreading and what options you have in TestStand. For a specific example, you may want to look at This Example. You could also look in the <TestStand>\Examples (where <TestStand> is the directory where TS is installed) at the MultiUUT example for an example of multithreading in TS. These examples may not be exactly what you need, but they should give you a jump start.
As far as making your DLL multithread safe, it is definitely not necessary; however, there are some significant advantages described in this article: Designing Thread-Safe DLLs. It is an MSDN article that focuses on Visual Basic, but it has some helpful information that can apply to C as well.
Hopefully this can help you move further. I have attached a list of links at the end of this post with other helpful links for you as well. Keep us posted with your progress.
Matt Mueller
NI
Links:
General Information on Multithreading for C Programmers
Building Multithreading Applications with LabWindows/CVI
Multithreading in LabWindows/CVI
Easy Multithreading Programming in LabWindows/CVI
Multithreading for Rookies -
How can i use multi threading in labview?
i want to run a Digital storage oscilloscope and an energ ratio meter simultaneously using labview. i am using GPIB interfacing and windows XP. how can i do this using multi threading. Bot the instruments shd run and give data at the same time.
You can't do this - at least not with a single GPIB board. It has nothing to do with threading or LabVIEW. There can only be one talker at a time over the bus. Depending on the instruments, you could probably set them up to take measurements simultaneously but you have to sequentially poll them to get the data.
-
The problem about multi-thread in java application
i have problem with the multi-thread in java application, i don't know how to stop and restart a thread safely, because the function thread.stop(),thread.suspend() are both deprecated.
now what i can only do is making the thread check a flag(true or false) to determine whether to start or to stop, but i think this thread will always be in the memory and maybe it will lower the performance of the system, as the program i am developping is working under realtime enviorement.
please help me about it. thanks !hi,
you can stop a thread by exiting it's run()-method which in terms can be done by checking the interrupted-flag:
public void run(){
while(interrupted()){ //if the thread consists of a loop
or
public void run(){
if(interrupted())return;
if(interrupted())return;
or by the use of the return-statement anywhere withing the run-method. Afterwards, that is when the thread is no longer needed, you clear all the references to the specific thread object by setting them to null:
Thread t;
... //working
t.interrupt(); //interrupting
while(t.isAlive()){
Thread.yield(); //wait till thread t has stopped
t=null;
best regards, Michael -
i know how to do a simple RMI program, but now i want to have a multi-threaded server to support the client. could any one tell me how to do this (using Thread in RMI) ??
thx.
MoWell, you kind of answered your own question.
An RMI server is inherently multi-threaded. This means that each remote request from a client is a separate thread, and can execute simultaneously with requests from other clients. In fact, your biggest problem will probably be to identify the places where access to objects must be synchronized, so that simultaneous requests do not conflict.
So what is it you have to do that RMI doesn't do? -
Hi I'm writing a program like Multi-tap (the text entry before T9 introduced) on mobilephone.
I'm having problem with some of the KEYs. They do not work properly.
As indicated in the code
HERE HERE [3] suppose to function as space button....However whenever the key is pressed before the 'time out' (I use sceduler to implement the time out) it will print half of the previous character instead of space. this key is not related to the scheduler. so i suspect it is something related to multi-thread programming.
HERE HERE [1] function as the caps lock. it can even show the indicator properly.... so i need to settle this b4 i continue.
HEREHERE [2] function as clear button. it doest work too
Someone please help me....
* To change this template, choose Tools | Templates
* and open the template in the editor.
package textEntry;
import javax.microedition.lcdui.game.GameCanvas;
import javax.microedition.lcdui.Graphics;
import javax.microedition.lcdui.*;
import java.util.*;
* @author Ed's
public class MyCanvas extends GameCanvas {
public static final String[] keys =
{".?!,@`-_:;()&\'\"~10�$��+x*/\\|[]=<>#","abc", "def", "ghi", "jkl",
"mno", "pqrs", "tuv", "wxyz"};
public static final String[] capitalKey =
{".?!,@`-_:;()&\'\"~10�$��+x*/\\|[]=<>#","ABC", "DEF", "GHI", "JKL",
"MNO", "PQRS", "TUV", "WXYZ"};
StringBuffer width = new StringBuffer();
Timer keyTimer;
textEntryMain main;
public static char ch;
public boolean keypress=false;
public boolean capital;
public boolean diffrentKey;
String currentIndicator="abc";
int countPress=0;
//int previndex=0;
public int counter=-1;
int index=-1;
int print=0;
int white_space=6;
public StringBuffer sms;
int baseline=10;
int y_axis=12;
int line=1;
char last;
boolean dontPrint=true; //dont print if timer printed or it is at begining
Font font;
Graphics g;
public long time;
int poundHit=0;
String justPressed;
String prevPressed=null;
char prevChar;
//Sms class
Form smsfrm;
TextField smsField ;
//Char Selection speed
public boolean first;
int selection_speed=1500;
//font color (blue)
public int red=0,green=0,blue=255;
//Background color (white)
public int back_red=250,back_green=250,back_blue=250;
Form menu;
public MyCanvas(textEntryMain main){
super(false);
first=true;
this.main=main;
sms=new StringBuffer();
g=getGraphics();
font=Font.getFont(Font.FACE_PROPORTIONAL,Font.STYLE_BOLD,Font.SIZE_LARGE);
keyTimer = new Timer ();
keyTimer.schedule (new task (this), selection_speed, selection_speed);
drawIndicator(currentIndicator);
public void drawIndicator(String indicator){
Font f = Font.getFont(Font.FACE_SYSTEM, Font.STYLE_ITALIC, Font.SIZE_SMALL);
Graphics g = getGraphics();
g.setFont(f);
int x= getWidth()-20;
g.setColor(back_red,back_green,back_blue);
g.fillRect(x,2,15,10);
g.setColor(20,20,20);
g.drawString(indicator, x, 2, g.TOP|g.LEFT);
public void callPaint(char ch){
drawIndicator(currentIndicator);
Graphics g= getGraphics();
g.setColor(back_red,back_green,back_blue);
if(first){
g.fillRect(0,0,getWidth(),getHeight());
reset();
redrawAll();
first=false;
//baseline -1 so that i can cover the pointer
g.fillRect(baseline-1,y_axis,font.charWidth(this.last)+3,font.getHeight());
g.setColor(red,green,blue);
g.setFont(font);
g.drawChar(ch,baseline,line*24,g.LEFT|g.BASELINE);
flushGraphics();
public void showPointer(){
Graphics g = getGraphics();
g.setColor(0,0,0);
g.drawLine(baseline,y_axis,baseline,2*line*12);
flushGraphics();
//pointer appear //pointer disappear-use white line so that it cover the pointer line
public void hidePointer(){
Graphics g = getGraphics();
g.setColor(back_red,back_green,back_blue);
g.drawLine(baseline,y_axis,baseline,2*line*12);
flushGraphics();
//draw the selected
public void ConfirmPaint(char ch){
Graphics g = getGraphics();
sms.append(ch);
g.setColor(red,green,blue);
g.setFont(font);
g.drawChar(ch,baseline,line*24,g.LEFT|g.BASELINE); //draw the selected
baseline+=font.charWidth(ch); // so that the nect letter won't be drawn on the same position
if(baseline>getWidth()-30){ //move to the next line
width.append((char)baseline);
baseline=10;y_axis+=24;
line+=1;
flushGraphics();
public synchronized void deleteChar(){
if(sms.charAt(sms.length()-1)==' '){
baseline-=white_space;
Graphics g= getGraphics();
g.setColor(back_red,back_green,back_blue);
g.fillRect(baseline,y_axis,font.charWidth(sms.charAt(sms.length()-1))+2,font.getHeight());
sms.deleteCharAt(sms.length()-1);
else{
baseline-=font.charWidth(sms.charAt(sms.length()-1));
Graphics g= getGraphics();
g.setColor(back_red,back_green,back_blue);
g.fillRect(baseline,y_axis,font.charWidth(sms.charAt(sms.length()-1))+2,font.getHeight());
sms.deleteCharAt(sms.length()-1);
flushGraphics();
public void redraw(char ch ){
Graphics g= getGraphics();
g.setColor(red,green,blue);
g.setFont(font);
g.drawChar(ch,baseline,line*24,g.LEFT|g.BASELINE);
baseline+=font.charWidth(ch);
if(baseline>getWidth()-30){
width.append((char)baseline);
baseline=10;y_axis+=24;
line+=1;
flushGraphics();
public void reset(){
if(width.length() >0)
width.delete(0,width.length()-1);
line=1;
baseline=10;y_axis=12;
public void redrawAll(){
Graphics g=getGraphics();
g.setColor(back_red,back_green,back_blue);
g.fillRect(0,0,getWidth(),getHeight());
reset();
for(int a=0;a<sms.length();a++)
redraw(sms.charAt(a));
/*public synchronized void keyRepeated (int keyCode) {
int one=1;
/* if(keyCode != KEY_POUND && keyCode != KEY_STAR){
ConfirmPaint((char)keyCode);
if (keyCode == 1){
ConfirmPaint((char)one);
public synchronized void keyPressed (int keyCode) {
justPressed=getKeyName(keyCode);
time=System.currentTimeMillis(); // record the time when the keypress is pressed
if(justPressed.equals("NUM0")){ //caps lock show indicator .............HERE HERE HERE HERE [1]
if(poundHit == 0){
currentIndicator="ABC";
poundHit++;
drawIndicator(currentIndicator);
//set the string buffer to another one
if(poundHit == 1){
currentIndicator="123";
poundHit++;
drawIndicator(currentIndicator);
if(poundHit == 2){
currentIndicator="abc";
poundHit=0;
drawIndicator(currentIndicator);
if(justPressed.equalsIgnoreCase("SEND")){ //send button allocated as clear button ................. HERE HERE HERE [2]
if(sms.length()>0){
hidePointer();
if(baseline<=10){
System.out.println(baseline);
line-=2;
baseline=(int)width.charAt(line);
line++;
y_axis-=24;
deleteChar();
if(justPressed.equals("STAR")){//space ........................................ HERE HERE HERE HERE HERE [3]
hidePointer();
sms.append(" ");
baseline+=white_space;
showPointer();
prevPressed=justPressed;
else{
if(justPressed.equals("NUM1")){index=0;}
if(justPressed.equals("NUM2")){index=1;}
if(justPressed.equals("NUM3")){index=2;}
if(justPressed.equals("NUM4")){index=3;}
if(justPressed.equals("NUM5")){index=4;}
if(justPressed.equals("NUM6")){index=5;}
if(justPressed.equals("NUM7")){index=6;}
if(justPressed.equals("NUM8")){index=7;}
if(justPressed.equals("NUM9")){index=8;}
if(index==0){
keypress=true;
if(justPressed.equalsIgnoreCase(prevPressed) || dontPrint){
if(dontPrint){countPress=35;}
if(countPress<34){
MyCanvas.ch=keys[index].charAt(countPress);
callPaint(MyCanvas.ch);
countPress++;
else{
countPress=0;
MyCanvas.ch=keys[index].charAt(countPress);
callPaint(MyCanvas.ch);
countPress++;
dontPrint=false;
else{ //this is executed when the key is not repeated (prev!=)
ConfirmPaint(last);
countPress=0;
MyCanvas.ch=keys[index].charAt(countPress);
callPaint(MyCanvas.ch);
countPress++;
last=MyCanvas.ch;
prevPressed=justPressed;
if(index==1 || index==2 || index == 3 || index == 4
|| index ==5 || index==7){
keypress=true;
if(justPressed.equalsIgnoreCase(prevPressed) || dontPrint){
if(dontPrint){countPress=4;}
if(countPress<3){
MyCanvas.ch=keys[index].charAt(countPress);
callPaint(MyCanvas.ch);
countPress++;
else{
countPress=0;
MyCanvas.ch=keys[index].charAt(countPress);
callPaint(MyCanvas.ch);
countPress++;
dontPrint = false;
else{ //this is executed when the key is not repeated
ConfirmPaint(last);
countPress=0;
MyCanvas.ch=keys[index].charAt(countPress);
callPaint(MyCanvas.ch);
countPress++;
last=MyCanvas.ch;
prevPressed=justPressed;
if(index==6 || index==8){
keypress=true;
if(justPressed.equalsIgnoreCase(prevPressed)|| dontPrint){
if(dontPrint){countPress=5;}
if(countPress<4){
MyCanvas.ch=keys[index].charAt(countPress);
callPaint(MyCanvas.ch);
countPress++;
else{
countPress=0;
MyCanvas.ch=keys[index].charAt(countPress);
callPaint(MyCanvas.ch);
countPress++;
dontPrint=false;
else{ //this is executed when the key is not repeated
ConfirmPaint(last);
countPress=0;
MyCanvas.ch=keys[index].charAt(countPress);
callPaint(MyCanvas.ch);
countPress++;
last=MyCanvas.ch;
prevPressed=justPressed;
/////////////task class for schedule on constructor
class task extends TimerTask {
public static boolean bool;
MyCanvas canvas;
public task (MyCanvas canvas) {
this.canvas=canvas;
public void run () {
if(canvas.keypress){
if(System.currentTimeMillis()-canvas.time>150){ //compare the time with the time out
canvas.ConfirmPaint(MyCanvas.ch);
canvas.counter=-1;
canvas.keypress=false;
canvas.dontPrint=true;
canvas.showPointer();
}Hi I'm writing a program like Multi-tap (the text entry before T9 introduced) on mobilephone.
I'm having problem with some of the KEYs. They do not work properly.
As indicated in the code
HERE HERE [3] suppose to function as space button....However whenever the key is pressed before the 'time out' (I use sceduler to implement the time out) it will print half of the previous character instead of space. this key is not related to the scheduler. so i suspect it is something related to multi-thread programming.
HERE HERE [1] function as the caps lock. it can even show the indicator properly.... so i need to settle this b4 i continue.
HEREHERE [2] function as clear button. it doest work too
Someone please help me....
* To change this template, choose Tools | Templates
* and open the template in the editor.
package textEntry;
import javax.microedition.lcdui.game.GameCanvas;
import javax.microedition.lcdui.Graphics;
import javax.microedition.lcdui.*;
import java.util.*;
* @author Ed's
public class MyCanvas extends GameCanvas {
public static final String[] keys =
{".?!,@`-_:;()&\'\"~10�$��+x*/\\|[]=<>#","abc", "def", "ghi", "jkl",
"mno", "pqrs", "tuv", "wxyz"};
public static final String[] capitalKey =
{".?!,@`-_:;()&\'\"~10�$��+x*/\\|[]=<>#","ABC", "DEF", "GHI", "JKL",
"MNO", "PQRS", "TUV", "WXYZ"};
StringBuffer width = new StringBuffer();
Timer keyTimer;
textEntryMain main;
public static char ch;
public boolean keypress=false;
public boolean capital;
public boolean diffrentKey;
String currentIndicator="abc";
int countPress=0;
//int previndex=0;
public int counter=-1;
int index=-1;
int print=0;
int white_space=6;
public StringBuffer sms;
int baseline=10;
int y_axis=12;
int line=1;
char last;
boolean dontPrint=true; //dont print if timer printed or it is at begining
Font font;
Graphics g;
public long time;
int poundHit=0;
String justPressed;
String prevPressed=null;
char prevChar;
//Sms class
Form smsfrm;
TextField smsField ;
//Char Selection speed
public boolean first;
int selection_speed=1500;
//font color (blue)
public int red=0,green=0,blue=255;
//Background color (white)
public int back_red=250,back_green=250,back_blue=250;
Form menu;
public MyCanvas(textEntryMain main){
super(false);
first=true;
this.main=main;
sms=new StringBuffer();
g=getGraphics();
font=Font.getFont(Font.FACE_PROPORTIONAL,Font.STYLE_BOLD,Font.SIZE_LARGE);
keyTimer = new Timer ();
keyTimer.schedule (new task (this), selection_speed, selection_speed);
drawIndicator(currentIndicator);
public void drawIndicator(String indicator){
Font f = Font.getFont(Font.FACE_SYSTEM, Font.STYLE_ITALIC, Font.SIZE_SMALL);
Graphics g = getGraphics();
g.setFont(f);
int x= getWidth()-20;
g.setColor(back_red,back_green,back_blue);
g.fillRect(x,2,15,10);
g.setColor(20,20,20);
g.drawString(indicator, x, 2, g.TOP|g.LEFT);
public void callPaint(char ch){
drawIndicator(currentIndicator);
Graphics g= getGraphics();
g.setColor(back_red,back_green,back_blue);
if(first){
g.fillRect(0,0,getWidth(),getHeight());
reset();
redrawAll();
first=false;
//baseline -1 so that i can cover the pointer
g.fillRect(baseline-1,y_axis,font.charWidth(this.last)+3,font.getHeight());
g.setColor(red,green,blue);
g.setFont(font);
g.drawChar(ch,baseline,line*24,g.LEFT|g.BASELINE);
flushGraphics();
public void showPointer(){
Graphics g = getGraphics();
g.setColor(0,0,0);
g.drawLine(baseline,y_axis,baseline,2*line*12);
flushGraphics();
//pointer appear //pointer disappear-use white line so that it cover the pointer line
public void hidePointer(){
Graphics g = getGraphics();
g.setColor(back_red,back_green,back_blue);
g.drawLine(baseline,y_axis,baseline,2*line*12);
flushGraphics();
//draw the selected
public void ConfirmPaint(char ch){
Graphics g = getGraphics();
sms.append(ch);
g.setColor(red,green,blue);
g.setFont(font);
g.drawChar(ch,baseline,line*24,g.LEFT|g.BASELINE); //draw the selected
baseline+=font.charWidth(ch); // so that the nect letter won't be drawn on the same position
if(baseline>getWidth()-30){ //move to the next line
width.append((char)baseline);
baseline=10;y_axis+=24;
line+=1;
flushGraphics();
public synchronized void deleteChar(){
if(sms.charAt(sms.length()-1)==' '){
baseline-=white_space;
Graphics g= getGraphics();
g.setColor(back_red,back_green,back_blue);
g.fillRect(baseline,y_axis,font.charWidth(sms.charAt(sms.length()-1))+2,font.getHeight());
sms.deleteCharAt(sms.length()-1);
else{
baseline-=font.charWidth(sms.charAt(sms.length()-1));
Graphics g= getGraphics();
g.setColor(back_red,back_green,back_blue);
g.fillRect(baseline,y_axis,font.charWidth(sms.charAt(sms.length()-1))+2,font.getHeight());
sms.deleteCharAt(sms.length()-1);
flushGraphics();
public void redraw(char ch ){
Graphics g= getGraphics();
g.setColor(red,green,blue);
g.setFont(font);
g.drawChar(ch,baseline,line*24,g.LEFT|g.BASELINE);
baseline+=font.charWidth(ch);
if(baseline>getWidth()-30){
width.append((char)baseline);
baseline=10;y_axis+=24;
line+=1;
flushGraphics();
public void reset(){
if(width.length() >0)
width.delete(0,width.length()-1);
line=1;
baseline=10;y_axis=12;
public void redrawAll(){
Graphics g=getGraphics();
g.setColor(back_red,back_green,back_blue);
g.fillRect(0,0,getWidth(),getHeight());
reset();
for(int a=0;a<sms.length();a++)
redraw(sms.charAt(a));
/*public synchronized void keyRepeated (int keyCode) {
int one=1;
/* if(keyCode != KEY_POUND && keyCode != KEY_STAR){
ConfirmPaint((char)keyCode);
if (keyCode == 1){
ConfirmPaint((char)one);
public synchronized void keyPressed (int keyCode) {
justPressed=getKeyName(keyCode);
time=System.currentTimeMillis(); // record the time when the keypress is pressed
if(justPressed.equals("NUM0")){ //caps lock show indicator .............HERE HERE HERE HERE [1]
if(poundHit == 0){
currentIndicator="ABC";
poundHit++;
drawIndicator(currentIndicator);
//set the string buffer to another one
if(poundHit == 1){
currentIndicator="123";
poundHit++;
drawIndicator(currentIndicator);
if(poundHit == 2){
currentIndicator="abc";
poundHit=0;
drawIndicator(currentIndicator);
if(justPressed.equalsIgnoreCase("SEND")){ //send button allocated as clear button ................. HERE HERE HERE [2]
if(sms.length()>0){
hidePointer();
if(baseline<=10){
System.out.println(baseline);
line-=2;
baseline=(int)width.charAt(line);
line++;
y_axis-=24;
deleteChar();
if(justPressed.equals("STAR")){//space ........................................ HERE HERE HERE HERE HERE [3]
hidePointer();
sms.append(" ");
baseline+=white_space;
showPointer();
prevPressed=justPressed;
else{
if(justPressed.equals("NUM1")){index=0;}
if(justPressed.equals("NUM2")){index=1;}
if(justPressed.equals("NUM3")){index=2;}
if(justPressed.equals("NUM4")){index=3;}
if(justPressed.equals("NUM5")){index=4;}
if(justPressed.equals("NUM6")){index=5;}
if(justPressed.equals("NUM7")){index=6;}
if(justPressed.equals("NUM8")){index=7;}
if(justPressed.equals("NUM9")){index=8;}
if(index==0){
keypress=true;
if(justPressed.equalsIgnoreCase(prevPressed) || dontPrint){
if(dontPrint){countPress=35;}
if(countPress<34){
MyCanvas.ch=keys[index].charAt(countPress);
callPaint(MyCanvas.ch);
countPress++;
else{
countPress=0;
MyCanvas.ch=keys[index].charAt(countPress);
callPaint(MyCanvas.ch);
countPress++;
dontPrint=false;
else{ //this is executed when the key is not repeated (prev!=)
ConfirmPaint(last);
countPress=0;
MyCanvas.ch=keys[index].charAt(countPress);
callPaint(MyCanvas.ch);
countPress++;
last=MyCanvas.ch;
prevPressed=justPressed;
if(index==1 || index==2 || index == 3 || index == 4
|| index ==5 || index==7){
keypress=true;
if(justPressed.equalsIgnoreCase(prevPressed) || dontPrint){
if(dontPrint){countPress=4;}
if(countPress<3){
MyCanvas.ch=keys[index].charAt(countPress);
callPaint(MyCanvas.ch);
countPress++;
else{
countPress=0;
MyCanvas.ch=keys[index].charAt(countPress);
callPaint(MyCanvas.ch);
countPress++;
dontPrint = false;
else{ //this is executed when the key is not repeated
ConfirmPaint(last);
countPress=0;
MyCanvas.ch=keys[index].charAt(countPress);
callPaint(MyCanvas.ch);
countPress++;
last=MyCanvas.ch;
prevPressed=justPressed;
if(index==6 || index==8){
keypress=true;
if(justPressed.equalsIgnoreCase(prevPressed)|| dontPrint){
if(dontPrint){countPress=5;}
if(countPress<4){
MyCanvas.ch=keys[index].charAt(countPress);
callPaint(MyCanvas.ch);
countPress++;
else{
countPress=0;
MyCanvas.ch=keys[index].charAt(countPress);
callPaint(MyCanvas.ch);
countPress++;
dontPrint=false;
else{ //this is executed when the key is not repeated
ConfirmPaint(last);
countPress=0;
MyCanvas.ch=keys[index].charAt(countPress);
callPaint(MyCanvas.ch);
countPress++;
last=MyCanvas.ch;
prevPressed=justPressed;
/////////////task class for schedule on constructor
class task extends TimerTask {
public static boolean bool;
MyCanvas canvas;
public task (MyCanvas canvas) {
this.canvas=canvas;
public void run () {
if(canvas.keypress){
if(System.currentTimeMillis()-canvas.time>150){ //compare the time with the time out
canvas.ConfirmPaint(MyCanvas.ch);
canvas.counter=-1;
canvas.keypress=false;
canvas.dontPrint=true;
canvas.showPointer();
} -
How to use Multi Thread to make a animation
Hello
Currently i am writing a router simulator using Java SE 1.4.2. I am facing a problem that is I cannot use multithread to update my Jframe animation.
Here i give my approach.
My idea is I used a JPanel in JFrame and I used Graphics g draw all background in Jpanel and add it into Jframe. It works since there is no animation invovled. I want to do some animation based on this background which i draw. But all animation should be controled by other threads due to i want other threads can control all animation. But i hit a error which is nullpointexception. The reason looks like which i used another to do animation, it cannot find the reference which is point to the Jpanel and Jframe. May u teach me a correct way to do multi threads animation in Jframe? thanks.
all the best and regards!A simple annimation moving a circle round a screen. This uses a model that defines the dynamics of the annimation, a view to display a visual representation of the model and an event system (observer/observable) to notify the view that the model has changed.
I hope this helps.
import java.awt.*;
import javax.swing.*;
import java.util.*;
public class Test20041023 extends JFrame
public Test20041023()
super("Simple Annimation Demo");
AnnimationModel annimationModel = new AnnimationModel();
AnimationView animationView = new AnimationView(annimationModel);
setContentPane(animationView);
setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
pack();
private static class AnimationView extends JPanel
private static final int PREFERRED_WIDTH = 512;
private static final int PREFERRED_HEIGHT = 256;
AnimationView(AnnimationModel annimationModel)
// Save a reference to the model for use
// when the view is updated
annimationModel_ = annimationModel;
// Listen for the events indicating that the model has changed
annimationModel_.addObserver(new Observer()
public void update(Observable o, Object arg)
// All we need to do is to get the view to repaint
AnimationView.this.repaint();
public void paintComponent(Graphics g)
super.paintComponent(g);
// Update the view based on the information in the model.
g.setColor(Color.red);
// Convert the model positions to view positions
// in this case by scaling to the actual width and height.
int xScreenPosition = scaleValue(annimationModel_.getX(), getWidth() - 20 ) + 5;
int yScreenPosition = scaleValue(annimationModel_.getY(), getHeight() - 20 ) + 5;
// Display the position of the point
g.fillOval(xScreenPosition, yScreenPosition, 10, 10);
private int scaleValue(double v, double size)
return (int)((v+1.0)*0.5 * size + 0.5);
public Dimension getPreferredSize()
return new Dimension(PREFERRED_WIDTH, PREFERRED_HEIGHT);
// The saved reference to the model
private AnnimationModel annimationModel_;
private static class AnnimationModel extends Observable
AnnimationModel()
Thread annimationThread = new Thread()
public void run()
// Loop forever updating the model
// and notifying the observers.
while(true)
// Wait 0.05 seconds until the next frame update point
try
sleep(50L);
catch (InterruptedException e)
// Nothing to do
// Update the model - in this case it is very simple
theta_ += 0.1;
// Notify the observers
setChanged();
notifyObservers();
annimationThread.start();
// Model access methods
public double getX()
return Math.cos(theta_);
public double getY()
return Math.sin(theta_);
// The angular position of the point
private double theta_;
// Simple test main
static public void main(String[] args)
new Test20041023().setVisible(true);
} -
(new?) performance problem using jDriver after a Sql Server 6.5 to 2000 conversion
Hi,
This is similar - yet different - to a few of the old postings about performance
problems with using jdbc drivers against Sql Server 7 & 2000.
Here's the situation:
I am running a standalone java application on a Solaris box using BEA's jdbc driver
to connect to a Sql Server database on another network. The application retrieves
data from the database through joins on several tables for approximately 40,000
unique ids. It then processes all of this data and produces a file. We tuned
the app so that the execution time for a single run through the application was
24 minutes running against Sql Server 6.5 with BEA's jdbc driver. After performing
a DBMS conversion to upgrade it to Sql Server 2000 I switched the jDriver to the
Sql Server 2000 version. I ran the app and got an alarming execution time of
5hrs 32 min. After some research, I found the problem with unicode and nvarchar/varchar
and set the "useVarChars" property to "true" on the driver. The execution time
for a single run through the application is now 56 minutes.
56 minutes compared to 5 1/2 hrs is an amazing improvement. However, it is still
over twice the execution time that I was seeing against the 6.5 database. Theoretically,
I should be able to switch out my jdbc driver and the DBMS conversion should be
invisible to my application. That would also mean that I should be seeing the
same execution times with both versions of the DBMS. Has anybody else seen a
simlar situation? Are there any other settings or fixes that I can put into place
to get my performance back down to what I was seeing with 6.5? I would rather
not have to go through and perform another round of performance tuning after having
already done this when the app was originally built.
thanks,
mikeMike wrote:
Joe,
This was actually my next step. I replaced the BEA driver with
the MS driver and let it run through with out making any
configuration changes, just to see what happened. I got an
execution time of about 7 1/2 hrs (which was shocking). So,
(comparing apples to apples) while leaving the default unicode
property on, BEA ran faster than MS, 5 1/2 hrs to 7 1/2 hrs.
I then set the 'SendStringParametersAsUnicode' to 'false' on the
MS driver and ran another test. This time the application
executed in just over 24 minutes. The actual runtime was 24 min
16 sec, which is still ever so slightly above the actual runtime
against SS 6.5 which was 23 min 35 sec, but is twice as fast as the
56 minutes that BEA's driver was giving me.
I think that this is very interesting. I checked to make sure that
there were no outside factors that may have been influencing the
runtimes in either case, and there were none. Just to make sure,
I ran each driver again and got the same results. It sounds like
there are no known issues regarding this?
We have people looking into things on the DBMS side and I'm still
looking into things on my end, but so far none of us have found
anything. We'd like to continue using BEA's driver for the
support and the fact that we use Weblogic Server for all of our
online applications, but this new data might mean that I have to
switch drivers for this particular application.Thanks. No, there is no known issue, and if you put a packet sniffer
between the client and DBMS, you will probably not see any appreciable
difference in the content of the SQL sent be either driver. My suspicion is
that it involves the historical backward compatibility built in to the DBMS.
It must still handle several iterations of older applications, speaking obsolete
versions of the DBMS protocol, and expecting different DBMS behavior!
Our driver presents itself as a SQL7-level application, and may well be treated
differently than a newer one. This may include different query processing.
Because our driver is deprecated, it is unlikely that it will be changed in
future. We will certainly support you using the MS driver, and if you look
in the MS JDBC newsgroup, you'll see more answers from BEA folks than
from MS people!
Joe
>
>
Mike
The next test you should do, to isolate the issue, is to try another
JDBC driver.
MS provides a type-4 driver now, for free. If it is significantly faster,
it would be
interesting. However, it would still not isolate the problem, because
we still would
need to know what query plan is created by the DBMS, and why.
Joe Weinstein at BEA
PS: I can only tell you that our driver has not changed in it's semantic
function.
It essentially send SQL to the DBMS. It doesn't alter it. -
Problems using multi-lexer in 8.1.7
Hello,
Have a UTF8 database and have created a
table to hold multi-language data.
Created an intermedia index using multi-lexer . Have problems quering data out of the table ; specifically the last 2 queries.
Any ideas?
SQL> exec ctxsys.ctx_ddl.create_preference('aenglish_lexer','basic_lexer');
PL/SQL procedure successfully completed.
SQL> exec ctxsys.ctx_ddl.set_attribute('aenglish_lexer','index_themes','YES');
PL/SQL procedure successfully completed.
SQL> exec ctxsys.ctx_ddl.set_attribute('aenglish_lexer','theme_language','english');
PL/SQL procedure successfully completed.
SQL> exec ctxsys.ctx_ddl.set_attribute('aenglish_lexer','mixed_case','YES');
PL/SQL procedure successfully completed.
SQL> exec ctxsys.ctx_ddl.create_preference('agerman_lexer','basic_lexer');
PL/SQL procedure successfully completed.
SQL> exec ctxsys.ctx_ddl.set_attribute('agerman_lexer','mixed_case','YES');
PL/SQL procedure successfully completed.
SQL> exec ctxsys.ctx_ddl.create_preference('afrench_lexer','basic_lexer');
PL/SQL procedure successfully completed.
SQL> exec ctxsys.ctx_ddl.set_attribute('afrench_lexer','mixed_case','YES');
PL/SQL procedure successfully completed.
SQL> execute ctx_ddl.create_preference('aglobal_lexer','MULTI_LEXER');
PL/SQL procedure successfully completed.
SQL>
SQL> begin
2 ctx_ddl.add_sub_lexer('aglobal_lexer', 'default','aenglish_lexer');
3 ctx_ddl.add_sub_lexer('aglobal_lexer', 'german', 'agerman_lexer','ger');
4 ctx_ddl.add_sub_lexer('aglobal_lexer', 'french', 'afrench_lexer','frn');
5 end;
6 /
PL/SQL procedure successfully completed.
SQL> create table adam (
2 doc_id number primary key,
3 lang varchar2(10),
4 text varchar2(100)
5 );
Table created.
SQL>
SQL>
SQL> insert into adam values (1, 'german', 'Ich ging Berlim. ');
1 row created.
SQL> insert into adam values (2, 'french', 'Je suis alli a Paris. ');
1 row created.
SQL> insert into adam values (3, 'english', 'I went to London. ');
1 row created.
SQL> commit;
Commit complete.
SQL> create index globalx on adam(text)
2 indextype is ctxsys.context
3 parameters ('lexer aglobal_lexer
4 language column LANG'
5 );
Index created.
SQL> col text format A50
SQL> --
SQL> -- QUERIES :
SQL> --
SQL> -- These are the following 3 rows in the table :
SQL> -- (1, 'german', 'Ich ging Berlim. ')
SQL> -- (2, 'french', 'Je suis alli a Paris. ')
SQL> -- (3, 'english', 'I went to London. ')
SQL> --
SQL> alter session set nls_language=AMERICAN;
Session altered.
SQL> alter session set nls_territory=AMERICA;
Session altered.
SQL> select doc_id, text from adam
2 where contains(text, 'London') > 0;
DOC_ID TEXT
3 I went to London.
SQL> --
SQL> -- SHOULD NOT return French data!
SQL> --
SQL> select doc_id, text from adam
2 where contains(text, 'alli') > 0;
DOC_ID TEXT
2 Je suis alli a Paris.
SQL> alter session set nls_language=GERMAN;
Session altered.
SQL> alter session set nls_territory=GERMANY;
Session altered.
SQL> --
SQL> -- SHOULD NOT return ENGLISH data! Also does not return valid GERMAN data
SQL> --
SQL> select doc_id, text from adam
2 where contains(text, 'I') > 0;
DOC_ID TEXT
3 I went to London.
nullFirst of all in your aenglish_lexer, index_themes should be 'false'.
The attribute 'alternate_spelling' for German should help. Please read the documentation for examples. -
Mapviewer performance problem using image format FORMAT_RAW_COMPRESSED
I am using the MapViewer.FORMAT_RAW_COMPRESSED map image in my (java) map application because some features must be clickable and as far as I can work out, this is the only way to achieve this in a Java client. On my local system, running the map server in an oc4j container, this works about as fast as using FORMAT_GIF_URL and loading the image from this url. There also doesn't seem to be much difference in memory and cpu usage.
When I direct the request to a map server running on a remote Application Server the rendering time grows exponentially. The same maprequest using FORMAT_GIF_URL runs as fast as it does in my local OC4J container. The problem seems to be in "packing time" in RealWorker:
Remote AS:
Thu Jun 30 13:59:34 CEST 2005 DEBUG [oracle.lbs.mapserver.core.MapperPool] freeMapper() begins...
Thu Jun 30 13:59:34 CEST 2005 DEBUG [oracle.lbs.mapserver.core.RealWorker] [RealWorker] preparation time: 99ms
Thu Jun 30 13:59:34 CEST 2005 DEBUG [oracle.lbs.mapserver.core.RealWorker] [RealWorker] querying/rendering time: 5560ms
Thu Jun 30 13:59:34 CEST 2005 DEBUG [oracle.lbs.mapserver.core.RealWorker] [RealWorker] packing time: 142605ms
Thu Jun 30 13:59:34 CEST 2005 DEBUG [oracle.lbs.mapserver.core.RealWorker] [RealWorker] --------------- total time: 148264ms
Local OC4J:
Thu Jun 30 15:34:42 CEST 2005 DEBUG [oracle.lbs.mapserver.core.MapperPool] freeMapper() begins...
Thu Jun 30 15:34:42 CEST 2005 DEBUG [oracle.lbs.mapserver.core.RealWorker] [RealWorker] preparation time: 540ms
Thu Jun 30 15:34:42 CEST 2005 DEBUG [oracle.lbs.mapserver.core.RealWorker] [RealWorker] querying/rendering time: 2490ms
Thu Jun 30 15:34:42 CEST 2005 DEBUG [oracle.lbs.mapserver.core.RealWorker] [RealWorker] packing time: 120ms
Thu Jun 30 15:34:42 CEST 2005 DEBUG [oracle.lbs.mapserver.core.RealWorker] [RealWorker] --------------- total time: 3150
The test server is smaller than my local system and more applications are running on the AS, generating the map takes all the available memory and cpu, but the difference between the time it takes generating a GIF image and generating a Java image of almost a factor 50 is puzzling.
What could cause this enormous difference? Any idea's about how we can analyze or solve this? What could RealWorker be doing in this packing time? Any hints would be greatly appreciated.
Many thanks,
IdaThanks for the replies!
1. Which AS version are you using? -> 10.1.2
2. Just as a test, if you restart AS (if possible) do you still get the same values? -> yes, we restarted the AS and the results are the same.
The server is indeed running low in memory. It is a 512MB machine, just big enough to run the AS. The production server will have some more, but not very much. Could I estimate how much extra memory it will need to keep a good performance when generating maps with live features? And maybe I'm wrong, but shouldn't the extra load for the java image only be on the client, since that's where the image is made? On the server it's just the image data, isn't it?
I tried removing the basemap, but that reduces the loading time just with a few seconds. The live themes are jdbc themes and result in only some 20 to 30 geofeatures. Removing them from the request so only an empty image with a title is retrieved still takes about 117 seconds. Reducing the device size does reduce the loading time, so it does seem to have something to do with the amount of pixels in the image space, not with the data. Could it be that in the "packing" of the image something happens that takes a lot of memory, related to the amount of pixels?
In my situation it would be handy if the live features were also returned when the image format is not set to FORMAT_RAW_COMPRESSED, it is also possible to draw shapes onto an existing image and this would bypass the memory problems.
Thanks for any further help.
Ida -
Performance problems on multi processor machine
Hi,
we are using a software written in Java (as Servlets using Tomcat 4.1.29) 1.4, which has a very poor performance. Sadly we don't have the source-codes for the application, but from the log-files we can figure out, that there is a very strong overhead, when changing the processors; that means i.e. when changing from processor 1 to processor 2 a statement which usually only needs 50ms, takes around 20 secs to finish. That could not be....
Do you have any suggestion, maybe about the parameters which are used to start java?
We use the following startup-properties:
-d64 -server -Xms1G -Xmx2G -Xmn800m -XX:+DisableExplicitGC -XX:+UseParallelGC -verbose:GC -Djava.awt.headless=true
Thanks for your help,
AntonBefore anyone answers this, check out what was already attempted at his stinkin' CROSSPOST:
http://forum.java.sun.com/thread.jsp?thread=553113&forum=54&message=2706725 -
Performance problems using BPM
Hello all,
We have Request/Reply interface using the JMS adapter towards the SAP R/3 system.
So the interface has 3 steps :
1. Request from JMS adapter - Asynchronous
2. Request/Reply using RFC adapter towards the R/3 - sync
3. Reply to JMS adapter - Asynchronous
we are using the BPM to merge all those steps, but between step 1 to 2 it waits about 4 seconds (we can monitor the message at SM58 for 2-3 seconds).
Its a problem for us because we exceed the time for the Request/reply at the MQ (which is connected to the JMS adapter).
Does someone has any idea ?
Regards,
YakiHello again Michelle, Kjetil,
We looked into this and given your details provided
regarding the query executed and the fact that this
problem shows up over thin network connections, we
believe you may be hitting one/both of Bug 2658196
and Bug 1844184.
To summarise, regardless of whether you use version
control or not, Designer must check version details
for each repository object acted on.
On a local machine or LAN, this does not present a
problem, but on a WAN, this does, due the amount of
(albeit individually small) packets of information
sent backwards and forwards between the client and
the repository.
Unfortunately, Oracle Designer was never designed to
run across a WAN. To attempt to get the performance
required would involve a re-design and re-write of a
large part of the Design Editor. I'm afraid this is
not really a practical option.
Other customers have also run into this problem. They
have found that using a third party product, such as,
Tarantella solves the problem. Products like Tarantella
enable clients to use central installations of Designer
with better results than using a locally installed copy.
Please see Metalink (http://meatlink.oracle.com) for
full details on the bugs themselves.
Hope this helps.
Regards,
Dominic
Designer Product Management
Oracle Cor -
Performance problems using WLS6.1 with the thin driver for Ora9i from OTN
Hello everyone,
Has anyone been experimenting with the thin driver for Oracle 9i under WLS6.1. I got it running, but
I get extremely bad performance when having multiple concurrent accesses. It works more or less in
single user mode. Also it seems not to support XA transactions?
When could we expect the driver from BEA to be out?
Thanks in advance!
Samuel Kounev
TU-Darmstadt, GermanyI had done this from the very beginning, but I was still getting very bad performance under
concurrent accesses. I even followed Sree's instructions and removed the old thin driver from
weblogic.jar, but this didn't help. I am now trying to get the OCI driver for 9i running and hope
this will solve the problem.
Samuel
Tamilselvan Ramasamy wrote:
You have to use Oracle's Oracle 9i thin driver .
put this driver infront of the classpath i.e before weblogic_sp.jar and
weblogic.jar
/selvan
"Sree Bodapati" <[email protected]> wrote in message
news:[email protected]..
The BEA driver is available in WLS6.1SP2 which is GA.
hth
sree
"Samuel Kounev" <[email protected]> wrote in message
news:[email protected]..
Hello everyone,
Has anyone been experimenting with the thin driver for Oracle 9i under
WLS6.1. I got it running, but
I get extremely bad performance when having multiple concurrent accesses.
It
works more or less in
single user mode. Also it seems not to support XA transactions?
When could we expect the driver from BEA to be out?
Thanks in advance!
Samuel Kounev
TU-Darmstadt, Germany -
Strange Corba performance problem using java 1.6
I have a java server talking to java and C++ clients using CORBA and moved from java 1.4.2 to 1.6.
Using java 1.4.2 for a large block of data, the client consistently refreshes in about 28-32 seconds.
Using Java 1.6 the times vary between 19 and 135 seconds.
After restarting the server all clients consistently take a simlar amount of time (usually between 32-35 seconds). But sometimes when the server is started the clients see a time between 19-25 seconds, sometimes between 50-55 seconds, and very occassionally over we see times of over 100 seconds.
Once started, the server seems to pick up some setting or behaviour that causes it to run at a fairly fixed rate.
We have tried adjusting the GIOP fragment and block size, which can change the performance, but no mater what size we use, we still see this strange behaviour where the server sometime runs in "fast" mode and sometimes in "slow" mode.
The server side cpu usage is higher when it is in "fast" mode. Client side cpu is higher in slow mode. Amount of data transfered does not appear to change.
Server runing on Linux RedHat Ent 4u5 - client Linux RedHat 9, RedHat Ent 4u5.
I see a similar behaviour even when I run the client and server on the same machine.
Any thoughts on where I should look next anyone?
Write a simple corba server/client that shows the problem.
Investigate Other Corba networking settings
measure the client server packet size and performance.
Thanks3 forums is not enough to post this in, I mean, it is such a HUGE problem,
you should post it in at least another 20 forums.
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