OpenJDK / jdk7u / jdk7u-dev / jdk
changeset 6007:98ad2f1e25d1
8009063: Improve reliability of ConcurrentHashMap
Reviewed-by: alanb, ahgross
author | chegar |
---|---|
date | Sun, 03 Mar 2013 10:11:45 +0000 |
parents | 17ac71e7b720 |
children | c2fff439d91a |
files | src/share/classes/java/util/concurrent/ConcurrentHashMap.java |
diffstat | 1 files changed, 27 insertions(+), 1 deletions(-) [+] |
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--- a/src/share/classes/java/util/concurrent/ConcurrentHashMap.java Tue Mar 05 16:46:10 2013 -0800 +++ b/src/share/classes/java/util/concurrent/ConcurrentHashMap.java Sun Mar 03 10:11:45 2013 +0000 @@ -40,6 +40,7 @@ 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 @@ @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 @@ private static final long TBASE; private static final int TSHIFT; private static final long HASHSEED_OFFSET; + 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 @@ ss = UNSAFE.arrayIndexScale(sc); HASHSEED_OFFSET = UNSAFE.objectFieldOffset( ConcurrentHashMap.class.getDeclaredField("hashSeed")); + 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); }