AhtiK Ventures

Getting TPTP installed in Ubuntu - first post from Ivar

One of the Codehoopers started to blog about Eclipse and programming, welcome aboard! :)

As he doesn’t have much readers yet I guess it’s ok to point to his first post: Eclipse TPTP and Ubuntu”

It’s about getting TPTP running. Especially under Linux. Don’t underestimate the complexity of this - it’s not that easy :)

Nice post, thank you!

PS. Some old-time readers might remember that Ivar has been featured at this blog also before - Four is the Magical Number - and so is 5920.

Enabling 3D with ATI and NVIDIA - ubuntu and debian

hmm.. getting 3D enabled for ATI and NVIDIA is still very tricky. With ubuntu you can recompile a kernel package AND/OR recompile restricted modules AND/OR compile a custom kernel with ATI/NVIDIA modules. There are 4-5 different options for getting it done. Each has it’s drawbacks. And even after spending lot of time figuring it out - next time you update the kernel, you’re screwed again :)

You can scratch your head for hours wondering why everything should work but glxinfo shows Mesa as active driver. You need direct rendering! Even if you’re not playing any games. 2D rendering saves a lot of CPU and linux runs much faster.

For ATI, when you download the linux proprietary driver installer - I’ve never seen it working without any special tweaks. Plus their installation guide is quite out-dated and not in sync with the real installer.

SO - Here’s the lifesaver - Envy! It’s a small utility that takes care of these tweaks and with a very simple user-interface fetches all the important packages, installs all the properietary stuff and makes sure that conflicting drivers are disabled/uninstalled/removed.

I gave it a try and - this thingy started from scratch and - I was done in 5minutes - everything working great!

Envy main screen

Eclipse workspace fails to start after crash - quick fix

Here’s a quick HOWTO for resolving Eclipse startup workspace loading problems. If you have a better suggestion then please leave a comment!

There can be a lot of other issues but here is one of the quite common ones - eclipse resources cache or state gets out of sync/corrupted.

This can happen when your IDE crashes OR also without crashing. For non-crashing case it’s more likely a logic/bug problem and whenever possible, try to file a bug at bugs.eclipse.org!

Sometimes, just SOMETIMES, you’ll get exceptions like following when launching Eclipse IDE after crashing it:

Root exception:
org.eclipse.core.internal.resources.ResourceException(null)[567]:
java.io.UTFDataFormatException: malformed input around byte 394
at java.io.DataInputStream.readUTF(Unknown Source)
at java.io.DataInputStream.readUTF(Unknown Source)
at org.eclipse.core.internal.resources.WorkspaceTreeReader_1.
readPluginsSavedStates(WorkspaceTreeReader_1.java:111)
at org.eclipse.core.internal.resources.WorkspaceTreeReader_1.
readTree(WorkspaceTreeReader_1.java:159)
at org.eclipse.core.internal.resources.SaveManager.restoreTree(SaveManager.java:916)
at org.eclipse.core.internal.resources.SaveManager.restore(SaveManager.java:647)
at org.eclipse.core.internal.resources.SaveManager.startup(SaveManager.java:1319)
at org.eclipse.core.internal.resources.Workspace.startup(Workspace.java:1949)
at org.eclipse.core.internal.resources.Workspace.open(Workspace.java:1713)
at org.eclipse.core.resources.ResourcesPlugin.start(ResourcesPlugin.java:363)
at org.eclipse.osgi.framework.internal.core.BundleContextImpl$2.
run(BundleContextImpl.java:999)
at java.security.AccessController.doPrivileged(Native Method)

The key here is row “org.eclipse.core.internal.resources.SaveManager.restore(SaveManager.java:647)”.

This stakctrace means your root .tree file is damaged and thereby unable to restore your opened projects.

The quickest way to fix this or any other resource-related exception is to:

1. Shut down Eclipse IDE
2. Remove and backup your workspace/.metadata/.plugins/org.eclipse.core.resources directory
3. Start Eclipse IDE (with -clean to be super-safe)
4. Reimport all projects (UPDATE: Just use File->Import->Existing Project into Workspace and browse your workspace/project directory)
5. Enjoy

Maybe deleting workspace/.metadata/.plugins/org.eclipse.core.resources/.root/*tree would have been good enough for my case but it’s definitely not a workaround for other possible workspace resource state and cache related exceptions.

I’m not sure if this information without any reproducible steps is useful for bugs.eclipse.org. Not filing it this time. Or should I?

Configuring Eclipse SVN (Subclipse) to use JavaHL(JNI)

Configuring JavaHL for Eclipse is not as straightforward as it could be so posting a quick HOWTO. Following applies mostly to Linux users.

With Ubuntu the fool-proof steps are:

1. Make sure libsvn-java, subversion and libsvn1 packages are installed
2. Add following to the end of your eclipse.ini file: -Djava.library.path=/usr/lib/jni
3. Restart eclipse and make sure JavaHL is selected under Window->Preferences->Team->SVN

By using JavaHL it gets more likely that your svn repo doesn’t get screwed up when using both command-line/shell and subclipse for svn.

Configuring Eclipse to use native SVN client - JavaHL

New Memberships

Just for the record, Codehoop is now the member of “Eclipse Friends” and official OSGi Supporter.

Ahti Kitsik (Email Me)

This work is licensed under a Creative Commons Attribution 2.5 License.

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