Remove synchronized blocks in Thread isAlive and isDead methods

threadRef = NO_REF assignment will happen once, and similarly, the started field is also set once during initialization. A user of these methods will probably invoke them multiple times until the desired result is achieved. A delay in getting the most up-to-date value should not hinder the functionality of these methods. To sum up, removing synchronization in these methods improves perf by reducing lock contention without hindering the functionality. Related: eclipse-openj9#20414 Signed-off-by: Babneet Singh <[email protected]>
babsingh · Oct 25, 2024 · 53b61f4 · 53b61f4
1 parent 6544c13
commit 53b61f4
Showing 1 changed file with 3 additions and 7 deletions.
diff --git a/jcl/src/java.base/share/classes/java/lang/Thread.java b/jcl/src/java.base/share/classes/java/lang/Thread.java
@@ -746,10 +746,8 @@ public static boolean interrupted() {
  * @see			Thread#start
  */
 public final boolean isAlive() {
-	synchronized (lock) {
-		/*[PR CMVC 88976] the Thread is alive until cleanup() is called */
-		return threadRef != NO_REF;
-	}
+	/*[PR CMVC 88976] the Thread is alive until cleanup() is called */
+	return threadRef != NO_REF;
 }
 
 /*[PR 1FJMO7Q] A Thread can be !isAlive() and still be in its ThreadGroup */
@@ -765,9 +763,7 @@ public final boolean isAlive() {
  */
 private boolean isDead() {
 	// Has already started, is not alive anymore, and has been removed from the ThreadGroup
-	synchronized(lock) {
-		return started && threadRef == NO_REF;
-	}
+	return started && threadRef == NO_REF;
 }
 
 /**