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What is the difference between atomic / volatile / synchronized?

...return counter++; } It basically reads value from memory, increments it and puts back to memory. This works in single thread but nowadays, in the era of multi-core, multi-CPU, multi-level caches it won't work correctly. First of all it introduces race condition (several threads can read the value...
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Which cryptographic hash function should I choose?

...Indeed, MD5 is often still used in applications where the smaller key size and speed are beneficial. That said, due to its flaws, researchers recommend the use of other hash functions in new scenarios. SHA1 has a flaw that allows collisions to be found in theoretically far less than the 2^80 steps ...
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Multithreading: What is the point of more threads than cores?

...nterruption. In reality this isn't the case. Even if you have four cores and four working threads, your process and it threads will constantly be being switched out for other processes and threads. If you are running any modern OS, every process has at least one thread, and many have more. All t...
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When to use -retainCount?

I would like to know in what situation did you use -retainCount so far, and eventually the problems that can happen using it. ...
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UnboundLocalError on local variable when reassigned after first use

The following code works as expected in both Python 2.5 and 3.0: 12 Answers 12 ...
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Differences between hard real-time, soft real-time, and firm real-time?

I have read the definitions for the different notions of real-time , and the examples provided for hard and soft real-time systems make sense to me. But, there is no real explanation or example of a firm real-time system. According to the link above: ...
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How to declare global variables in Android?

I am creating an application which requires login. I created the main and the login activity. 17 Answers ...
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How to overcome root domain CNAME restrictions?

...rd with CNAMEs. Use them when renaming hosts, but plan to get rid of them (and inform your users). Some DNS hosts provide a way to get CNAME-like functionality at the zone apex (the root domain level, for the naked domain name) using a custom record type. Such records include, for example: ALIAS...
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Must JDBC Resultsets and Statements be closed separately although the Connection is closed afterward

.... But if I have the following code, is it necessary to close the Resultset and the Statement? 12 Answers ...
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How to create .pfx file from certificate and private key?

...le is just a text file with your private key in it. If you have a root CA and intermediate certs, then include them as well using multiple -in params openssl pkcs12 -export -out domain.name.pfx -inkey domain.name.key -in domain.name.crt -in intermediate.crt -in rootca.crt You can install openssl ...