stan/jdk-24
1
0
Fork 0
Code Issues Pull Requests Actions Packages Projects Releases Wiki Activity

7016208: 4/3 null sometimes returned by java.util.logging.Logger.getLogger(String name) in -server -Xcomp

Browse Source 
Logger can be GC'ed between LogManager.addLogger() and LogManager.getLogger()

Reviewed-by: dsamersoff, never, acorn, mchung
This commit is contained in:
Daniel D. Daugherty 2011-05-16 12:57:40 -07:00
parent 564b2b7a17
commit 792f2aa15e
1 changed files with 27 additions and 4 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

31
jdk/src/share/classes/java/util/logging/LogManager.java
View File

@ -1,5 +1,5 @@
/*
* Copyright (c) 2000, 2010, Oracle and/or its affiliates. All rights reserved.
* Copyright (c) 2000, 2011, Oracle and/or its affiliates. All rights reserved.
* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
*
* This code is free software; you can redistribute it and/or modify it
@ -342,12 +342,35 @@ public class LogManager {
// already been created with the given name it is returned.
// Otherwise a new logger instance is created and registered
// in the LogManager global namespace.
// This method will always return a non-null Logger object.
// Synchronization is not required here. All synchronization for
// adding a new Logger object is handled by addLogger().
Logger demandLogger(String name) {
Logger result = getLogger(name);
if (result == null) {
result = new Logger(name, null);
addLogger(result);
result = getLogger(name);
// only allocate the new logger once
Logger newLogger = new Logger(name, null);
do {
if (addLogger(newLogger)) {
// We successfully added the new Logger that we
// created above so return it without refetching.
return newLogger;
}
// We didn't add the new Logger that we created above
// because another thread added a Logger with the same
// name after our null check above and before our call
// to addLogger(). We have to refetch the Logger because
// addLogger() returns a boolean instead of the Logger
// reference itself. However, if the thread that created
// the other Logger is not holding a strong reference to
// the other Logger, then it is possible for the other
// Logger to be GC'ed after we saw it in addLogger() and
// before we can refetch it. If it has been GC'ed then
// we'll just loop around and try again.
result = getLogger(name);
} while (result == null);
}
return result;
}