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# HG changeset patch
# User chegar
# Date 1362305505 0
# Node ID 98ad2f1e25d13aca196ad77b2f227f85072c9b16
# Parent 17ac71e7b72087f0f7b7ac793ae93a816ef22d96
8009063: Improve reliability of ConcurrentHashMap
Reviewed-by: alanb, ahgross
diff --git a/src/share/classes/java/util/concurrent/ConcurrentHashMap.java b/src/share/classes/java/util/concurrent/ConcurrentHashMap.java
--- jdk/src/share/classes/java/util/concurrent/ConcurrentHashMap.java
+++ jdk/src/share/classes/java/util/concurrent/ConcurrentHashMap.java
@@ -40,6 +40,7 @@ import java.io.IOException;
import java.io.IOException;
import java.io.ObjectInputStream;
import java.io.ObjectOutputStream;
+import java.io.ObjectStreamField;
/**
* A hash table supporting full concurrency of retrievals and
@@ -1535,7 +1536,23 @@ public class ConcurrentHashMap<K, V> ext
@SuppressWarnings("unchecked")
private void readObject(java.io.ObjectInputStream s)
throws IOException, ClassNotFoundException {
- s.defaultReadObject();
+ // Don't call defaultReadObject()
+ ObjectInputStream.GetField oisFields = s.readFields();
+ final Segment<K,V>[] oisSegments = (Segment<K,V>[])oisFields.get("segments", null);
+
+ final int ssize = oisSegments.length;
+ if (ssize < 1 || ssize > MAX_SEGMENTS
+ || (ssize & (ssize-1)) != 0 ) // ssize not power of two
+ throw new java.io.InvalidObjectException("Bad number of segments:"
+ + ssize);
+ int sshift = 0, ssizeTmp = ssize;
+ while (ssizeTmp > 1) {
+ ++sshift;
+ ssizeTmp >>>= 1;
+ }
+ UNSAFE.putIntVolatile(this, SEGSHIFT_OFFSET, 32 - sshift);
+ UNSAFE.putIntVolatile(this, SEGMASK_OFFSET, ssize - 1);
+ UNSAFE.putObjectVolatile(this, SEGMENTS_OFFSET, oisSegments);
// set hashMask
UNSAFE.putIntVolatile(this, HASHSEED_OFFSET, randomHashSeed(this));
@@ -1568,6 +1585,9 @@ public class ConcurrentHashMap<K, V> ext
private static final int SSHIFT;
private static final long TBASE;
private static final int TSHIFT;
+ private static final long SEGSHIFT_OFFSET;
+ private static final long SEGMASK_OFFSET;
+ private static final long SEGMENTS_OFFSET;
static {
int ss, ts;
@@ -1581,6 +1601,12 @@ public class ConcurrentHashMap<K, V> ext
SBASE = UNSAFE.arrayBaseOffset(sc);
ts = UNSAFE.arrayIndexScale(tc);
ss = UNSAFE.arrayIndexScale(sc);
+ SEGSHIFT_OFFSET = UNSAFE.objectFieldOffset(
+ ConcurrentHashMap.class.getDeclaredField("segmentShift"));
+ SEGMASK_OFFSET = UNSAFE.objectFieldOffset(
+ ConcurrentHashMap.class.getDeclaredField("segmentMask"));
+ SEGMENTS_OFFSET = UNSAFE.objectFieldOffset(
+ ConcurrentHashMap.class.getDeclaredField("segments"));
} catch (Exception e) {
throw new Error(e);
}
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