On 04/12/2015 19:56, Michael Rasmussen wrote:
The usage of -Xpatch is to be a replacement for -Xbootclasspath/p, to
enable to patch boot CP classes, but at the moment it only seems to
support pointing to an "exploded" directory, containing the individual
.class files.
Are there any plans to extend this to also support some kind of container
format, for instance .jar or even .jimage?
For systems which relies on patching more than just a few classes,
exploded mode becomes rather clumpsy very quickly. The JVM is perfectly
capable of reading from these container formats, so why was the -Xpatch
option limited to exploded directory?
In the current prototype then -Xpatch supports directories of exploded
classes only. I suspect that once there is more usage for testing that
we will need to look at adding support for packaging patches in JAR
files. The jimage format is very JDK-internal so it wouldn't make sense
for a jimage container to exist outside of the run-time image. One other
thing to say about -Xpatch is that it's much more powerful than
-Xbootclasspath/p because it independent on class path, you'll find it
can be used to patch modules defined to any of the built-in class loaders.
-Alan.
