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Showing posts from July, 2010

Build Wine rpm with 32 bit application support

Wine is a software to allow running Windows applications in Linux, MAC etc. platforms. It is available for installation from package managers like yum (RHEL, CentOS) and apt (Ubuntu). You can find more details on how it works in Wine wiki.

But the default Wine package available from package manager does not have support for 32 bit Windows applications. This was the case for me. In Redhat Enterprise Linux 7.3, the wine package did not contain support for 32 bit windows applications. So the only option was to build a separate rpm of wine which will include this support.

All the steps are executed on a RHEL 7.3 VM (x86_64).

Step 1
Download and run shell script which will make wine 64 and 32 support for RHEL: https://github.com/zma/usefulscripts/blob/master/script/install-wine-i686-centos7.sh It accepts a version no. as CLI parameter e.g. 2.0.3

The script installs wine in /usr/local/ directory by default. We can verify the files that are being copied for wine using "cd /usr/src/wine-2.0.…

Using Multi threading with Drools

Drools is a very popular rule engine. It is based on Rete algorithm. To understand what is a rule engine and how to use it check here. But here I will assume that you have some working knowledge on Drools.

What I am going to discuss in this post is 'how to use multi-threading with Drools'. Below is a snippet which creates a KnowledgeBase from a DRL file.


If this method is called from multiple threads I get below exception -



Exception in thread "Thread-60" [Error: incomplete statement: (possible use of reserved keyword as identifier: )]
[Near : {... globals != empt ....}]
^
[Line: 0, Column: 0]
at org.mvel2.MVELInterpretedRuntime.parseAndExecuteInterpreted(* MVELInterpretedRuntime.java:153*)
at org.mvel2.MVELInterpretedRuntime.parse(* MVELInterpretedRuntime.java:44*)
at org.mvel2.MVEL.eval(*MVEL.java:514*)
at org.mvel2.templates.res.IfNode.eval(*IfNode.java:61*)
at org.mvel2.templates.res.TextNode.eval(*TextNode.java:46*)
at org.mvel2.templates.res.TerminalN…