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Drawing a connecting line between two elements [closed]

... jsPlumb is an option available that supports drag and drop, as seen by its numerous demos, including the Flowchart demo. It is available in a free Community edition, and a paid Toolkit edition. The Toolkit edition wraps the Community edition with a comprehensive data bi...
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Spinlock versus Semaphore

... Spinlock and semaphore differ mainly in four things: 1. What they are A spinlock is one possible implementation of a lock, namely one that is implemented by busy waiting ("spinning"). A semaphore is a generalization of a lock (or, th...
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What are the rules for calling the superclass constructor?

...bar } }; More info on the constructor's initialization list here and here. share | improve this answer | follow | ...
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How should I log while using multiprocessing in Python?

...locks so that you don't garble things up in sys.stderr (or whatever filehandle) by having multiple processes writing to it simultaneously. ...
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How to get .pem file from .key and .crt files?

...ust named with .crt or .key. If the file's content begins with -----BEGIN and you can read it in a text editor: The file uses base64, which is readable in ASCII, not binary format. The certificate is already in PEM format. Just change the extension to .pem. If the file is in binary: For the serv...
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MongoDB and “joins” [duplicate]

...ll only be evaluated when needed. A join (in a SQL database) on the other hand will resolve relationships and return them as if they were a single table (you "join two tables into one"). You can read more about DBRef here: http://docs.mongodb.org/manual/applications/database-references/ There are ...
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Difference between framework vs Library vs IDE vs API vs SDK vs Toolkits? [closed]

...for developing (such as forms designers, resource editors, etc), compiling and debugging applications. e.g Eclipse, Visual Studio. A Library is a chunk of code that you can call from your own code, to help you do things more quickly/easily. For example, a Bitmap Processing library will provide faci...
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Checking for an empty field with MySQL

... An empty field can be either an empty string or a NULL. To handle both, use: email > '' which can benefit from the range access if you have lots of empty email record (both types) in your table. share ...
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.keyCode vs. .which

... The answer below was written in 2010. Here many years later, both keyCode and which are deprecated in favor of key (for the logical key) and code (for the physical placement of the key). But note that IE doesn't support code, and its support for key is based on an older version of the spec so isn't...
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When would you call java's thread.run() instead of thread.start()?

...() in a particular unit test that is concerned strictly with functionality and not with concurrency. share | improve this answer | follow | ...