view ASSEMBLY_EXCEPTION @ 1716:be3f9c242c9d

6948538: CMS: BOT walkers can fall into object allocation and initialization cracks Summary: GC workers now recognize an intermediate transient state of blocks which are allocated but have not yet completed initialization. blk_start() calls do not attempt to determine the size of a block in the transient state, rather waiting for the block to become initialized so that it is safe to query its size. Audited and ensured the order of initialization of object fields (klass, free bit and size) to respect block state transition protocol. Also included some new assertion checking code enabled in debug mode. Reviewed-by: chrisphi, johnc, poonam
author ysr
date Mon, 16 Aug 2010 15:58:42 -0700
parents c18cbe5936b8
children
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OPENJDK ASSEMBLY EXCEPTION

The OpenJDK source code made available by Oracle at openjdk.java.net and
openjdk.dev.java.net ("OpenJDK Code") is distributed under the terms of the
GNU General Public License <http://www.gnu.org/copyleft/gpl.html> version 2
only ("GPL2"), with the following clarification and special exception.

    Linking this OpenJDK Code statically or dynamically with other code
    is making a combined work based on this library.  Thus, the terms
    and conditions of GPL2 cover the whole combination.

    As a special exception, Oracle gives you permission to link this
    OpenJDK Code with certain code licensed by Oracle as indicated at
    http://openjdk.java.net/legal/exception-modules-2007-05-08.html
    ("Designated Exception Modules") to produce an executable,
    regardless of the license terms of the Designated Exception Modules,
    and to copy and distribute the resulting executable under GPL2,
    provided that the Designated Exception Modules continue to be
    governed by the licenses under which they were offered by Oracle.

As such, it allows licensees and sublicensees of Oracle's GPL2 OpenJDK Code to
build an executable that includes those portions of necessary code that Oracle
could not provide under GPL2 (or that Oracle has provided under GPL2 with the
Classpath exception).  If you modify or add to the OpenJDK code, that new
GPL2 code may still be combined with Designated Exception Modules if the
new code is made subject to this exception by its copyright holder.