Synopsis: Correlating LogRecord ThreadIDs with run-of-the-mill Thread ids Description: java.util.logging introduced the idea of a thread id, and the same idea was later introduced into java.lang.Thread itself. Unfortunately, these are not correlated, and the j.u.l. flavor is an int, while the other is a long.
Evaluation: We should try hard to make the j.u.l. thread id a copy of the java.lang thread id, as long as the latter is not outrageously large. Fix: (requires the fix for http://cr.openjdk.java.net/~martin/getHandlers as a prereq) # HG changeset patch # User martin # Date 1239744603 25200 # Node ID ef4dfb22df0ee19b070438d984d0c95f0bf070c8 # Parent 74c670b6ca1a400d3368a1b668fede43b2871fdc [mq]: LogRecord diff --git a/src/share/classes/java/util/logging/LogRecord.java b/src/share/classes/java/util/logging/LogRecord.java --- a/src/share/classes/java/util/logging/LogRecord.java +++ b/src/share/classes/java/util/logging/LogRecord.java @@ -25,6 +25,8 @@ package java.util.logging; import java.util.*; +import java.util.concurrent.atomic.AtomicInteger; +import java.util.concurrent.atomic.AtomicLong; import java.io.*; /** @@ -64,9 +66,24 @@ */ public class LogRecord implements java.io.Serializable { - private static long globalSequenceNumber; - private static int nextThreadId=10; - private static ThreadLocal<Integer> threadIds = new ThreadLocal<Integer>(); + private static final AtomicLong globalSequenceNumber + = new AtomicLong(0); + + /** + * The default value of threadID will be the current thread's + * thread id, for ease of correlation, unless it is greater than + * MIN_SEQUENTIAL_THREAD_ID, in which case we try harder to keep + * our promise to keep threadIDs unique by avoiding collisions due + * to 32-bit wraparound. Unfortunately, LogRecord.getThreadID() + * returns int, while Thread.getId() returns long. + */ + private static final int MIN_SEQUENTIAL_THREAD_ID = Integer.MAX_VALUE / 2; + + private static final AtomicInteger nextThreadId + = new AtomicInteger(MIN_SEQUENTIAL_THREAD_ID); + + private static final ThreadLocal<Integer> threadIds + = new ThreadLocal<Integer>(); /** * @serial Logging message level @@ -123,6 +140,23 @@ private transient ResourceBundle resourceBundle; /** + * Returns the default value for a new LogRecord's threadID. + */ + private int defaultThreadID() { + long tid = Thread.currentThread().getId(); + if (tid < MIN_SEQUENTIAL_THREAD_ID) { + return (int) tid; + } else { + Integer id = threadIds.get(); + if (id == null) { + id = nextThreadId.getAndIncrement(); + threadIds.set(id); + } + return id; + } + } + + /** * Construct a LogRecord with the given level and message values. * <p> * The sequence property will be initialized with a new unique value. @@ -144,15 +178,8 @@ this.level = level; message = msg; // Assign a thread ID and a unique sequence number. - synchronized (LogRecord.class) { - sequenceNumber = globalSequenceNumber++; - Integer id = threadIds.get(); - if (id == null) { - id = new Integer(nextThreadId++); - threadIds.set(id); - } - threadID = id.intValue(); - } + sequenceNumber = globalSequenceNumber.getAndIncrement(); + threadID = defaultThreadID(); millis = System.currentTimeMillis(); needToInferCaller = true; } diff --git a/test/java/util/logging/LoggerSubclass.java b/test/java/util/logging/LoggerSubclass.java --- a/test/java/util/logging/LoggerSubclass.java +++ b/test/java/util/logging/LoggerSubclass.java @@ -68,6 +68,8 @@ l.getSequenceNumber()); equal(lastThreadID.get(), l.getThreadID()); + equal((int) Thread.currentThread().getId(), + l.getThreadID()); } lastSequenceNumber.set(l.getSequenceNumber()); lastThreadID.set(l.getThreadID());
