Disable Crashing...

WARNING: This blog entry was imported from my old blog on blogs.sun.com (which used different blogging software), so formatting and links may not be correct.

If you're on OSX, and you've experienced NetBeans 6.0 beta crashing on you, read on...

Right before beta1, we tweaked some of the Java VM startup flags NetBeans uses. In particular, we switched to the "Concurrent Mark Sweep" (CMS) garbage collector, which has a nice performance profile for IDE usage, since collection happens mostly in parallel so you don't get noticeable pauses.

Unfortunately, it turns out that these flags cause a lot of problems on OSX. In particular, they cause frequent virtual machine crashes!

Knowing this, for beta2 we've turned off those flags when running NetBeans on OSX. But that doesn't help you if you're trying to run beta1... Luckily, it's easy to fix it yourself, since the VM parameters are specified in a text configuration file.

First, open the netbeans.conf file. On my Mac, I installed NetBeans in Applications under NetBeans, so the file is

/Applications/NetBeans/NetBeans\ 6.0\ Beta\ 1.app/Contents/Resources/NetBeans/etc/netbeans.conf

The file contains this:

# Options used by NetBeans launcher by default, can be overridden by explicit
# command line switches:
netbeans_default_options="-J-client -J-Xms32m -J-XX:PermSize=32m -J-XX:MaxPermSize=200m
-J-Dapple.laf.useScreenMenuBar=true -J-XX:+UseConcMarkSweepGC -J-XX:+CMSClassUnloadingEnabled
-J-XX:+CMSPermGenSweepingEnabled"
# (Note that a default -Xmx is selected for you automatically.)

# For JVMs which does not support Concurrent Mark & Sweep garbage collection
# algorithm remove "-J-XX:+UseConcMarkSweepGC -J-XX:+CMSClassUnloadingEnabled
# -J-XX:+CMSPermGenSweepingEnabled" part of options
# (see http://wiki.netbeans.org/wiki/view/FaqGCPauses)

Remove the bold section above; in other words, remove these 3 flags:

-J-XX:+UseConcMarkSweepGC -J-XX:+CMSClassUnloadingEnabled -J-XX:+CMSPermGenSweepingEnabled

Now when you restart the IDE should behave better.