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Posted to commits@harmony.apache.org by "Tim Ellison (JIRA)" <ji...@apache.org> on 2006/03/15 19:35:01 UTC
[jira] Closed: (HARMONY-51) java.io.Writer : write(String) should
write String as atomic operation.
[ http://issues.apache.org/jira/browse/HARMONY-51?page=all ]
Tim Ellison closed HARMONY-51:
------------------------------
Closing resolved issue -- no response from reporter, so assuming ok.
> java.io.Writer : write(String) should write String as atomic operation.
> -----------------------------------------------------------------------
>
> Key: HARMONY-51
> URL: http://issues.apache.org/jira/browse/HARMONY-51
> Project: Harmony
> Type: Bug
> Components: Classlib
> Reporter: Vladimir Ivanov
> Assignee: Tim Ellison
>
> java.io.Writer : write(String) should write String as atomic operation.
> Code to reproduce (Note, the increment of fields due to call of write(String ...) methods is occurred only after the assertion is checked):
> import java.io.*;
>
> public class test29 {
> public static void main(String args[]) {
> Object lock = new Object();
> final MockWriter w = new MockWriter(lock);
>
> class Thr extends Thread {
> int seed;
>
> Thr(int seed) {
> this.seed = seed;
> }
>
> public void run() {
> try {
> switch (seed) {
> case 0:
> w.write(new char[] { 'a' });
> break;
> case 1:
> w.write("abcd".toCharArray(), 1, 1);
> break;
> case 2:
> w.write("c");
> break;
> case 3:
> w.write("abcd", 3, 1);
> break;
> default:
> break;
> }
> } catch (Throwable e) {
> e.printStackTrace();
> }
> }
> }
>
> try {
> Thr[] thrs = new Thr[4];
> synchronized (lock) {
> for (int i = 0; i < 4; ++i) {
> thrs[i] = new Thr(i);
> thrs[i].start();
> Thread.yield();
> }
>
> Thread.sleep(3000);
>
> System.out.println("" + w.written['a'] + w.written['b'] + w.written['c'] + w.written['d']) ;
> System.out.println(("" + w.written['a'] + w.written['b'] + w.written['c'] + w.written['d']).equals("1100") ? "PASSED" : "FAILED") ;
>
> }
>
> for (int i = 0; i < thrs.length; ++i) {
> thrs[i].join();
> }
> w.close();
> } catch (Exception e) {
> System.out.println("unex: " + e);
> }
> }
> }
>
> class MockWriter extends Writer {
> public int[] written = new int['z'];
>
> MockWriter(Object lock) {
> super(lock);
> }
>
>
> public synchronized void close() throws IOException {
> }
>
> public synchronized void flush() throws IOException {
> }
>
> public void write(char[] arg0, int arg1, int arg2) throws IOException {
> if (arg1 < 0 || arg2 < 0) {
> throw new ArrayIndexOutOfBoundsException();
> }
> for (int i = arg1; i < arg1 + arg2; ++i) {
> ++written[arg0[i]];
> System.out.println("written.length=" + written.length + ", increment field: " + arg0[i]);
> }
> }
> }
> Steps to Reproduce:
> 1. Build Harmony (check-out on 2006-01-25) j2se subset as described in README.txt.
> 2. Compile test29.java using BEA 1.4 javac
> > javac -d . test29.java
> 3. Run java using compatible VM (J9)
> > java -showversion test29
> Output:
> C:\tmp\tmp17>C:\harmony\trunk\deploy\jre\bin\java -showversion test29
> java version 1.4.2 (subset)
> (c) Copyright 1991, 2005 The Apache Software Foundation or its licensors, as app
> licable.
> written.length=122, increment field: a
> written.length=122, increment field: b
> written.length=122, increment field: c
> 1110
> FAILED
> written.length=122, increment field: d
> C:\tmp\tmp17>C:\jrockit-j2sdk1.4.2_04\bin\java.exe -showversion test29
> java version "1.4.2_04"
> Java(TM) 2 Runtime Environment, Standard Edition (build 1.4.2_04-b05)
> BEA WebLogic JRockit(TM) 1.4.2_04 JVM (build ari-31788-20040616-1132-win-ia32, Native Threads, GC strategy: parallel)
> written.length=122, increment field: a
> written.length=122, increment field: b
> 1100
> PASSED
> written.length=122, increment field: d
> written.length=122, increment field: c
> C:\tmp\tmp17>
> Suggested fix: add one synchronized section to Writer.java: write(String) method
> -------------------------------------------
> old code:
> public void write(String str) throws IOException {
> char buf[] = new char[str.length()];
> str.getChars(0, buf.length, buf, 0);
> write(buf);
> }
> ------------------------------------------
> new code:
> public void write(String str) throws IOException {
> char buf[] = new char[str.length()];
> str.getChars(0, buf.length, buf, 0);
> synchronized (lock) {
> write(buf);
> }
> }
> -------------------------------------------
> junit test:
> ------------------------ WriterTest.java -------------------------------------------------
> import java.io.*;
> import junit.framework.*;
>
> public class WriterTest extends TestCase {
> public static void main(String[] args) {
> junit.textui.TestRunner.run(WriterTest.class);
> }
> public void testWrite_String() {
> Object lock = new Object();
> final MockWriter w = new MockWriter(lock);
>
> class Thr extends Thread {
> int seed;
>
> Thr(int seed) {
> this.seed = seed;
> }
>
> public void run() {
> try {
> switch (seed) {
> case 0:
> w.write(new char[] { 'a' });
> break;
> case 1:
> w.write("abcd".toCharArray(), 1, 1);
> break;
> case 2:
> w.write("c");
> break;
> case 3:
> w.write("abcd", 3, 1);
> break;
> default:
> break;
> }
> } catch (Throwable e) {
> e.printStackTrace();
> }
> }
> }
>
> try {
> Thr[] thrs = new Thr[4];
> synchronized (lock) {
> for (int i = 0; i < 4; ++i) {
> thrs[i] = new Thr(i);
> thrs[i].start();
> Thread.yield();
> }
>
> Thread.sleep(3000);
>
> assertTrue(("" + w.written['a'] + w.written['b'] + w.written['c'] + w.written['d']).equals("1100")) ;
>
> }
>
> for (int i = 0; i < thrs.length; ++i) {
> thrs[i].join();
> }
> w.close();
> } catch (Exception e) {
> System.out.println("unex: " + e);
> }
> }
> }
>
> class MockWriter extends Writer {
> public int[] written = new int['z'];
>
> MockWriter(Object lock) {
> super(lock);
> }
>
>
> public synchronized void close() throws IOException {
> }
>
> public synchronized void flush() throws IOException {
> }
>
> public void write(char[] arg0, int arg1, int arg2) throws IOException {
> if (arg1 < 0 || arg2 < 0) {
> throw new ArrayIndexOutOfBoundsException();
> }
> for (int i = arg1; i < arg1 + arg2; ++i) {
> ++written[arg0[i]];
> }
> }
> }
>
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