Name: elR10090 Date: 03/02/2001



When I fixed the bug:
    4419859 TEST_BUG: Some tests work with allocated memory after it was freed
in the test:
    nsk/serial/Unsafe/reallocateMemory/reallocmem001
I found that now it crashes Merlin's java_g for both Sevrer and Client VM's
at all platforms - Win, Lynx, and both 32-bits Solarises, and Sol for SPARC-V9.

While crashing, HS complains either:
"An unexpected exception has been detected in native code outside the VM."
or:
# SafepointSynchronize::begin: Timed out while attempting to reach a safepoint.

The exception in native code is detected inside "reallocateMemory(address,size)"
invocation found in the following cycle attempting to allocate huge amount of
memory:

        long size = 1;
        for (int i = 0; i < 64; i++) {
     ==> address = unsafe.reallocateMemory(address, size);
            size <<= 1;
        }

This kind of log looks like:
    >>>> java_g -showversion serial.Unsafe.reallocateMemory.reallocmem001 ; echo $status
    java version "1.4.0-beta"
    Java(TM) 2 Runtime Environment, Standard Edition (build 1.4.0-beta-b54)
    Java HotSpot(TM) Client VM (build 1.4beta-B54-debug, mixed mode)

    An unexpected exception has been detected in native code outside the VM.
    Unexpected Signal : 11 occurred at PC=0xFF271138
    Function=memcpy+0xB48
    Library=/usr/platform/SUNW,Ultra-60/lib/libc_psr.so.1

    Current Java thread:
     at sun.misc.Unsafe.reallocateMemory(Native Method)
     at serial.Unsafe.reallocateMemory.reallocmem001.run(reallocmem001.java:114)
     at serial.Unsafe.reallocateMemory.reallocmem001.main(reallocmem001.java:14)

    Dynamic libraries:
    0x10000 /export/ld50/java/dest/jdk1.4.0beta-b54/solsparc/bin/../bin/sparc/native_threads/java_g
    0xff360000 /usr/lib/libthread.so.1
    0xff3a0000 /usr/lib/libdl.so.1
    0xff280000 /usr/lib/libc.so.1
    0xff270000 /usr/platform/SUNW,Ultra-60/lib/libc_psr.so.1
    0xfd800000 /export/ld50/java/dest/jdk1.4.0beta-b54/solsparc/jre/lib/sparc/client/libjvm_g.so
    0xff210000 /usr/lib/libCrun.so.1
    0xff1f0000 /usr/lib/libsocket.so.1
    0xff100000 /usr/lib/libnsl.so.1
    0xff0d0000 /opt/SUNWspro/lib/libm.so.1
    0xff240000 /usr/lib/libw.so.1
    0xff0b0000 /usr/lib/libmp.so.2
    0xff080000 /export/ld50/java/dest/jdk1.4.0beta-b54/solsparc/jre/lib/sparc/native_threads/libhpi_g.so
    0xff050000 /export/ld50/java/dest/jdk1.4.0beta-b54/solsparc/jre/lib/sparc/libverify_g.so
    0xfe7c0000 /export/ld50/java/dest/jdk1.4.0beta-b54/solsparc/jre/lib/sparc/libjava_g.so
    0xff020000 /export/ld50/java/dest/jdk1.4.0beta-b54/solsparc/jre/lib/sparc/libzip_g.so

    Local Time = Fri Mar 2 16:02:13 2001
    Elapsed Time = 63
    #
    # The exception above was detected in native code outside the VM
    #
    # Java VM: Java HotSpot(TM) Client VM (1.4beta-B54-debug mixed mode)
    #
    # An error report file has been saved as hs_err_pid14655.log.
    # Please refer to the file for further information.
    #
    Dumping core....
    Abort
    134

Another kind of crash log is observed only for SolX86; it look like:
    >>>>java_g -showversion serial.Unsafe.reallocateMemory.reallocmem001 ; echo $status
    java version "1.4.0-beta"
    Java(TM) 2 Runtime Environment, Standard Edition (build 1.4.0-beta-b52)
    Java HotSpot(TM) Client VM (build 1.4beta-B52-debug, mixed mode)

    # SafepointSynchronize::begin: Fatal error:
    # SafepointSynchronize::begin: Timed out while attempting to reach a safepoint.
    # SafepointSynchronize::begin: Threads which did not reach the safepoint:
    # nid=0x1 runnable
    # SafepointSynchronize::begin: (End of list)
    ^C
(HS hangs while trying to crash here.)

Following is the fixed test source, which reveals this new bug:

/* @(#)reallocmem001.java 1.3 01/03/02
 * Copyright 03/02/01 Sun Microsystems, Inc.
 */

package serial.Unsafe.reallocateMemory;

import java.io.*;
import sun.misc.*;
import java.security.*;

class reallocmem001 {

    public static void main (String args[]) {
        System.exit(95 + run(args, System.out));
    }

    public static int run (String args[], PrintStream out) {
        boolean testFailed = false;
        long address;
        Unsafe unsafe = (Unsafe)
            AccessController.doPrivileged(new Unsafe.GetUnsafeAction());

        // Allocate memory
        try {
            address = unsafe.allocateMemory(1);
        } catch(Throwable t) {
            out.println("# FAILURE 1.");
            out.println(" Cannot allocate memory.");
            out.println(" Exception: " + t);
            return ( (t instanceof OutOfMemoryError) ||
                     (t instanceof IllegalArgumentException)
                   ) ? 0 : 2;
        }
        unsafe.putByte(address, Byte.MAX_VALUE);

        // Reallocate memory
        try {
            address = unsafe.reallocateMemory(address, 2);
            if (address == 0) {
                out.println("# FAILURE 2.");
                out.println(" Address of reallocated memory is 0.");
                testFailed = true;
            }
        } catch(Exception e) {
            out.println("# FAILURE 3.");
            out.println(" Cannot reallocate memory");
            return 2; // Not possibe to continue
        }
        
        // Check value put in the memory before reallocation
        byte b = unsafe.getByte(address);
        if (b != Byte.MAX_VALUE) {
            out.println("# FAILURE 4.");
            out.println(" " + Byte.MAX_VALUE + " was put in the "
                         + "memory before reallocation and " + b
                         + " was read.");
            testFailed = true;
        }

        // Try to reallocate memory with size 0
        try {
            address = unsafe.reallocateMemory(address, 0);
            if (address != 0) {
               out.println("# FAILURE 5.");
               out.println(" Memory was reallocated with size 0, "
                         + "but address is " + address + " (should be 0).");
               testFailed = true;
           }
        } catch(Exception e) {
            out.println("# FAILURE 6.");
            out.println(" Unexpected exception " + e);
            testFailed = true;
        }

        // Try to reallocate memory with address 0
        // (an allocation should be performed) and then
        // check if memory was allocated
        try {
            address = unsafe.reallocateMemory(0, 1);
            if (address == 0) {
               out.println("# FAILURE 7.");
               out.println(" Memory was reallocated with address 0 "
                         + "and size 1 (byte), but reallocated "
                         + "address is " + address + ".");
               testFailed = true;
           }
        } catch(Exception e) {
            out.println("# FAILURE 8.");
            out.println(" Unexpected exception " + e);
            testFailed = true;
        }
        
        // Check if memory allocated
        try {
           unsafe.putByte(address, Byte.MAX_VALUE);
           b = unsafe.getByte(address);
           if (b != Byte.MAX_VALUE) {
               out.println("# FAILURE 9.");
               out.println(" " + Byte.MAX_VALUE + " was put in the "
                         + "memory and " + b + " was read.");
               testFailed = true;
           }
        } catch (Exception e) {
            out.println("# FAILURE 10.");
            out.println(" Unexpected exception " + e);
            testFailed = true;
        }

        // Check if VM throws OutOfMemoryError if the
        // reallocation is refused by the system
        long size = 1;
        try {
            for (int i = 0; i < 64; i++) {
                address = unsafe.reallocateMemory(address, size);
                if (address == 0) {
                    out.println("# FAILURE 11.");
                    out.println(" Address of reallocated memory is 0 "
                              + "when size = " + size);
                    testFailed = true;
                }
                size <<= 1;
            }
            unsafe.freeMemory(address);
        } catch (Throwable t) {
            if (!((t instanceof OutOfMemoryError) ||
                  (t instanceof IllegalArgumentException)
                 )
               ) {
                out.println("# Unexpected exception: " + t);
                testFailed = true;
            }
        }

        if (testFailed)
            out.println("# TEST FAILED.");
        return (testFailed ? 2 : 0);
    }
}

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