Running a process from JVM hangs JVM and Process . both.

Name: dbT83986 Date: 02/09/99


When a process (a.exe) is executed, if the process
writes more than 488 bytes of data on it's STDOUT
and we then call the waitFor( ) method of the Process
class to wait for completion of a.exe , both
the processes hangs. Strange enough , if in Java
we don't wait for process completion , (mask
call to waitFor( ) method), then the execution is
succeeded. Or if, in a.exe, we only write 488
bytes or less then the waitFor() method works without
hanging .


To reproduce the problem

Step 1:

Compile the follwing file a.c into a binary a.exe :
//////
#include<stdio.h>

main()
{
        char buf[500];

/*
        // Works
        memset(buf,'\0',500);
        memset(buf,'p',488);
        fprintf(stdout,"%s",buf);
*/
        // dosen't Works
        memset(buf,'\0',500);
        memset(buf,'p',489);
        fprintf(stdout,"%s",buf);
}

/////////////

Step 2:

Compile the following Java program (within a directory test) execute it.
///////////
package test;

import java.io.*;
import java.lang.*;

/**
 * Class for testing
 */
public class Test {
    public static void main(String[]args) {
InputStream input;
BufferedReader buf;
String str;
Process process;
Runtime runtimeContext;
try {
runtimeContext = Runtime.getRuntime();
process = runtimeContext.exec("a");
process.waitFor();
input = process.getInputStream();
buf = new BufferedReader(new InputStreamReader(input));
while((str = buf.readLine()) != null) {

System.out.println(str);
}

}
catch(IOException e) {}
catch(InterruptedException e) {};
    }
}

/////////////////////////

Step 3:

Run java test.Test to execute Java program and exec
a.exe through JVM.
(Review ID: 40393)
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