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Fixed issue: NETTY-64 Duplicate Channel IDs are generated.

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This commit is contained in:
Trustin Lee 2008-11-07 08:23:15 +00:00
parent de2ff34dc2
commit b8af182e8c
1 changed files with 21 additions and 7 deletions
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28
src/main/java/org/jboss/netty/util/TimeBasedUuidGenerator.java
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@ -29,7 +29,6 @@ import java.net.InetAddress;
import java.security.MessageDigest;
import java.security.NoSuchAlgorithmException;
import java.util.UUID;
import java.util.concurrent.atomic.AtomicInteger;
/**
* Generates a time-based {@link UUID}. Please note that this generator
@ -45,8 +44,11 @@ import java.util.concurrent.atomic.AtomicInteger;
*
*/
public class TimeBasedUuidGenerator {
private static final AtomicInteger SEQUENCE = new AtomicInteger((int) System.nanoTime());
private static final long NODE;
private static final Object counterLock = new Object();
private static long timestamp = System.currentTimeMillis();
private static int clockSeq = (int) System.nanoTime();
static {
// Generate nodeKey - we can't use MAC address to support Java 5.
@ -123,12 +125,24 @@ public class TimeBasedUuidGenerator {
* Returns a new time-based {@link UUID}.
*/
public static UUID generate() {
long time = System.currentTimeMillis();
int clockSeq = TimeBasedUuidGenerator.SEQUENCE.getAndIncrement();
final long ts;
final int cs;
synchronized (counterLock) {
cs = (clockSeq ++) & 0x3FFF; // 0~16383
if (cs == 0) {
// Not all platform has millisecond precision for
// System.currentTimeMillis() - Just focus on generating
// unique IDs instead of using correct timestamp.
ts = ++ timestamp;
} else {
ts = timestamp;
}
}
long msb = (time & 0xFFFFFFFFL) << 32 | (time >>> 32 & 0xFFFF) << 16 |
time >>> 48 & 0xFFFF;
long lsb = (long) clockSeq << 48 | NODE;
long msb = (ts & 0xFFFFFFFFL) << 32 |
(ts >>> 32 & 0xFFFF) << 16 |
ts >>> 48 & 0xFFFF;
long lsb = (long) cs << 48 | NODE;
// Set to version 1 (i.e. time-based UUID)
msb = msb & 0xFFFFFFFFFFFF0FFFL | 0x0000000000001000L;