Black and white Computer

What is deadlock? Deadlock is a permanent blocking of a set of processes that either compete for system resources or communicate with each other. A set of processes is blocked awaiting an event that can only be triggered by another blocked process in the set. The Deadlock is permanent and don have any efficient solution. Example of deadlock There are 2 process P and Q compete for resources A and B. Each resource only can use by 1 process.The process P get and hold the resource B and wait the resource A available , at the same time the process Q get and hold the resource A while waiting resource B available. And this condition it cause deadlock because both process need use resource A and B at the same time, the process P not willing to let go the resource B same as the process Q. Some time we also use the Joint Progress Diagram to illustrate the two process competing the resource. In the joint progress diagram we have 6 path of process Q ...

Domain name is very important no only in Search Engine Optimization (SEO) but also important for the website itself! Let me give you an example  http://www.google.com , I sure almost everyone know what is google. Google is a search engine, Google also synonymous with the word "search". Now you imagine that google was the search engine that just launched for few day, do you think that internet user will type google.com into their address bar or search it using yahoo! or MSN ? Another example like YouTube. Think that you are newbie on using internet, you want to watch a video, would you type the word "YouTube" inside your query or you type in "video website"? If you google "video website" you will surprise that YouTube is not on the first page. Last example I want to give is Capitol Hotel. Capitol Hotel is a hotel in Kuala Lumpur, Malaysia. If Capitol Hotel is new hotel that open for few week and it want to have a website to provide informa...

Most of the SEOs perform searches dozens or hundreds of time per day, and when you do, it's important that you to turn off the personalized search results appear. What I mean by personalized result is the search result that is influenced by your own search history which will apposed to what typical searcher would see. Firefox is a good browser for SEOs for many reason, but one of its most helpful features is the ability to search right from the address field of the browser,the area at the top of the browser where you will see the URL of the web page. By having little customization, you can perform Google searches that are DE-personalized. From the bookmarks |Organize Bookmarks .... menu, select any bookmarks folder in the left pane. (Do not simply select the all Bookmarks folder,because it won't work.) Right-click the folder and select New Bookmark.... Add the following values to the text fields: Name : Google de-personalized s...

When try to connect to the local database , you found this message : Status : Failure -Test failed: Listener refused the connection with the following error: ORA-12505, TNS:listener does not currently know of SID given in connect descriptor I consider this as error ORA-1250. In my case ,to solve this problem you need to change the SID " xe " to " e161306 " then the problem solved! Then the question come when you try, you may be fail because the SID for mine may differ from yours! If you have dint change the Connection name , then you will see that there will be some word behind the dash '-', you should key in the word behind into the SID. Like mine is 'e161306'. How to know your SID? I think it was quite easy! All you need is open your msconfig if you are using Microsoft windows Operating System. Start --> run-->type in "msconfig"/ Start --> type in msconfig--> click msconfig.exe After you open the msconfig, yo...

I recently trying to add the derby plugin into the eclipse. When I try to add derby nature (PS: right-click on the java project -> "Apache Derby" -> "Add Apache Derby nature"  ),I get the pop up says : Error adding Derby jars to the project: org.eclipse.ui.internal.WorkbenchWindow cannot be cast to org.eclipse.jface.window.ApplicationWindow error pop up Does this picture look familiar? Error adding Derby jars to the project What I was Using is when facing this problem : jdk1.7.0_03 Eclipse IDE for Java EE Developers (Win32) version Juno (build from 2012/06/14)  derby-core-plugin 10.8.2 and -ui-plugin 1.1.3 (as there is no eclipse plugin for the latest version 10.9.1.0)  I also google about this problem before but i can't find any solution. After I try many time ,I finally found a way to solve it! A bad method,but take a look! Solution: The solution is d ownload another version of Eclipse IDE for Java EE Developers like Europa! Y...

Microsoft will be in mid-November launch Windows 7 edition IE10. According to Microsoft previously said the version of IE10 will bring improved fast, smooth experience, as well as Web developers have been seeking additional support standard worth the wait.Internet explorer 10 only support window 7 and window 8. Microsoft today officially open Windows 7 Edition (Windows Server 2008 R2 users can also be used) IE10 preview download page, it is learned that Windows 7 Edition IE10 SmartScreen and download additional security features as well as the Touch API innovation, while the version of IE10 default to open a "do not track" feature. Generally speaking, Windows 7 Edition IE10 really good. If you interesting to test the ie10 click the link below to visit Microsoft official website.   Download IE10 beta/preview here! After I download IE 10, the first thing I do is do a google search"do a barrel roll". The result quite disappoint me. The interface of IE10 in...

Concurrency (computer) is a concept where many process or thread run simultaneously in uniprocessor or multiprocessor or multicore. Computer users take it for granted that their systems can do more than one thing at a time.Even a single application is often expected to do more than one thing at a time. Concurrency arises in 3 different contexts: Multiple Applications: Multiprogramming was invented to allow processing time to be dynamically shared among active applications.  Structured Applications: As Extension of the principle of modular design and structured programming.  Operating system(OS) structure: OS themselves implemented as a set of processes or threads.  Here is some of the key term use in concurrency. Atomic Operation Function or action implemented as a sequence of one or more instructions that appears to be indivisible; that is, no other process can see an intermediate state or interrupt the operations. The sequence of instruct...