[ 
https://issues.apache.org/jira/browse/DRILL-6004?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=16300341#comment-16300341
 ] 

ASF GitHub Bot commented on DRILL-6004:
---------------------------------------

Github user vrozov commented on a diff in the pull request:

    https://github.com/apache/drill/pull/1070#discussion_r158335955
  
    --- Diff: 
exec/memory/base/src/main/java/org/apache/drill/exec/memory/BoundsChecking.java 
---
    @@ -17,19 +17,92 @@
      */
     package org.apache.drill.exec.memory;
     
    +import java.lang.reflect.Field;
    +import java.util.Formatter;
    +
    +import com.google.common.base.Preconditions;
    +
    +import io.netty.buffer.AbstractByteBuf;
    +import io.netty.buffer.DrillBuf;
    +import io.netty.util.IllegalReferenceCountException;
    +
    +import static org.apache.drill.exec.util.SystemPropertyUtil.getBoolean;
    +
     public class BoundsChecking {
    -  static final org.slf4j.Logger logger = 
org.slf4j.LoggerFactory.getLogger(BoundsChecking.class);
    +  private static final org.slf4j.Logger logger = 
org.slf4j.LoggerFactory.getLogger(BoundsChecking.class);
     
    -  public static final boolean BOUNDS_CHECKING_ENABLED;
    +  public static final String ENABLE_UNSAFE_BOUNDS_CHECK_PROPERTY = 
"drill.exec.memory.enable_unsafe_bounds_check";
    +  // for backward compatibility check "drill.enable_unsafe_memory_access" 
property and enable bounds checking when
    +  // unsafe memory access is explicitly disabled
    +  public static final String ENABLE_UNSAFE_MEMORY_ACCESS_PROPERTY = 
"drill.enable_unsafe_memory_access";
    +  public static final boolean BOUNDS_CHECKING_ENABLED =
    +      getBoolean(ENABLE_UNSAFE_BOUNDS_CHECK_PROPERTY, 
!getBoolean(ENABLE_UNSAFE_MEMORY_ACCESS_PROPERTY, true));
    +  private static final boolean checkAccessible = 
getStaticBooleanField(AbstractByteBuf.class, "checkAccessible", false);
     
       static {
    -    boolean isAssertEnabled = false;
    -    assert isAssertEnabled = true;
    -    BOUNDS_CHECKING_ENABLED = isAssertEnabled
    -        || 
!"true".equals(System.getProperty("drill.enable_unsafe_memory_access"));
    +    if (BOUNDS_CHECKING_ENABLED) {
    +      logger.warn("Drill is running with direct memory bounds checking 
enabled. If this is a production system, disable it.");
    +    } else if (logger.isDebugEnabled()) {
    +      logger.debug("Direct memory bounds checking is disabled.");
    +    }
       }
     
       private BoundsChecking() {
       }
     
    +  private static boolean getStaticBooleanField(Class cls, String name, 
boolean def) {
    +    try {
    +      Field field = cls.getDeclaredField(name);
    +      field.setAccessible(true);
    +      return field.getBoolean(null);
    +    } catch (ReflectiveOperationException e) {
    +      return def;
    +    }
    +  }
    +
    +  private static void checkIndex(DrillBuf buf, int index, int fieldLength) 
{
    +    Preconditions.checkNotNull(buf);
    +    if (checkAccessible && buf.refCnt() == 0) {
    +      Formatter formatter = new Formatter().format("%s, refCnt: 0", buf);
    +      if (BaseAllocator.DEBUG) {
    +        formatter.format("%n%s", buf.toVerboseString());
    +      }
    +      throw new IllegalReferenceCountException(formatter.toString());
    +    }
    +    if (fieldLength < 0) {
    +      throw new IllegalArgumentException(String.format("length: %d 
(expected: >= 0)", fieldLength));
    +    }
    +    if (index < 0 || index > buf.capacity() - fieldLength) {
    +      Formatter formatter = new Formatter().format("%s, index: %d, length: 
%d (expected: range(0, %d))", buf, index, fieldLength, buf.capacity());
    +      if (BaseAllocator.DEBUG) {
    +        formatter.format("%n%s", buf.toVerboseString());
    +      }
    +      throw new IndexOutOfBoundsException(formatter.toString());
    +    }
    +  }
    +
    +  public static void lengthCheck(DrillBuf buf, int start, int length) {
    +    if (BOUNDS_CHECKING_ENABLED) {
    +      checkIndex(buf, start, length);
    +    }
    +  }
    +
    +  public static void rangeCheck(DrillBuf buf, int start, int end) {
    +    if (BOUNDS_CHECKING_ENABLED) {
    +      checkIndex(buf, start, end - start);
    +    }
    +  }
    +
    +  public static void rangeCheck(DrillBuf buf1, int start1, int end1, 
DrillBuf buf2, int start2, int end2) {
    --- End diff --
    
    It is a common case for `equal()` and `compare()`.


> Direct buffer bounds checking should be disabled by default
> -----------------------------------------------------------
>
>                 Key: DRILL-6004
>                 URL: https://issues.apache.org/jira/browse/DRILL-6004
>             Project: Apache Drill
>          Issue Type: Improvement
>            Reporter: Vlad Rozov
>            Assignee: Vlad Rozov
>            Priority: Minor
>
> Direct buffer bounds checking is enabled either when assertions are enabled 
> (see DRILL-6001) or when {{drill.enable_unsafe_memory_access}} property is 
> not set to true, so it is enabled in production as by default  
> {{drill.enable_unsafe_memory_access}} is not set.



--
This message was sent by Atlassian JIRA
(v6.4.14#64029)

Reply via email to