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What's the difference between deadlock and livelock?
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All the content and examples here are from
Operating Systems: Internals and Design Principles
William Stallings
8º Edition
Deadlock: A situation in which two or more processes are unable to proceed because each is waiting ...
return statement vs exit() in main()
Should I use exit() or just return statements in main() ? Personally I favor the return statements because I feel it's like reading any other function and the flow control when I'm reading the code is smooth (in my opinion). And even if I want to refactor the main() function, having return...
H2 in-memory database. Table not found
...e tables with UPPERCASE names then behaving case-sensitive, even though in all scripts (including in the creation ones) i used lowercase.
Solved by adding ;DATABASE_TO_UPPER=false to the connection URL.
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how to show progress bar(circle) in an activity having a listview before loading the listview with d
I have a ListView in my second activity.OnItemClick of it I called a webservice and trying to fetch data. And after that I am moving to third activity which also have a ListView having description of previous activities ListView item.
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Retrieving the last record in each group - MySQL
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MySQL 8.0 now supports windowing functions, like almost all popular SQL implementations. With this standard syntax, we can write greatest-n-per-group queries:
WITH ranked_messages AS (
SELECT m.*, ROW_NUMBER() OVER (PARTITION BY name ORDER BY id DESC) AS rn
FROM messages AS m...
Storing Data in MySQL as JSON
.... And, so, I've never done it. Then I saw that FriendFeed did this and actually made their DB scale better and decreased latency. I'm curious if I should do this. And, if so, what's the right way to do it?
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Socket.IO Authentication
I am trying to use Socket.IO in Node.js, and am trying to allow the server to give an identity to each of the Socket.IO clients. As the socket code is outside the scope of the http server code, it doesn't have easy access to the request information sent, so I'm assuming it will need to be sent up d...
How to get the number of Characters in a String?
..."), utf8.RuneCountInString("世界"))
}
Phrozen adds in the comments:
Actually you can do len() over runes by just type casting.
len([]rune("世界")) will print 2. At leats in Go 1.3.
And with CL 108985 (May 2018, for Go 1.11), len([]rune(string)) is now optimized. (Fixes issue 24923)
The compile...
How to retrieve an element from a set without removing it?
...r(s)) only exceeds list(s)[0] by three characters and is otherwise dramatically superior in both time and space complexity. So, while the claim of "least code" is trivially true, it's also trivially true that this is the worst possible approach. Even manually removing and then re-adding the removed ...
What is a stack trace, and how can I use it to debug my application errors?
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In simple terms, a stack trace is a list of the method calls that the application was in the middle of when an Exception was thrown.
Simple Example
With the example given in the question, we can determine exactly where the exception was thrown in the application. Let's have a lo...