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How efficient is locking an unlocked mutex? What is the cost of a mutex?
... I forgot the context switches... Context switches are too drain on the performance. If lock acquisition fails and thread has to wait, that is too sort of half of the context switch. CS itself is fast, but since CPU might be used by some other process, the caches would be filled with alien data. Aft...
or (HTML5)
...org state that <menu> should be used for Toolbar menus and listing form control commands.
5 Answers
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Tips for debugging .htaccess rewrite rules
...'non-matched'));
}
}
?> <p>&nbsp; </p>
<form method="post" action="<?php echo $_SERVER['SCRIPT_NAME'];?>">
<label for="pl">Regexp Pattern: </label>
<input id="p" name="pattern" size="50" value="<?php echo htmlentities($a_pattern,E...
What's the difference between a continuation and a callback?
... thing it does then it's called a tail call. Some languages like Scheme perform tail call optimizations. This means that the tail call does not incur the full overhead of a function call. Instead it's implemented as a simple goto (with the stack frame of the calling function replaced by the stack fr...
Could you explain STA and MTA?
...er thread needs to interact with the object (such as pushing a button in a form) then the message is marshalled onto the STA thread. The windows forms message pumping system is an example of this.
If the COM object can handle its own synchronization then the MTA model can be used where multiple thr...
See what process is using a file in Mac OS X
...iew regularly keep hold of files although it has quit. I often open images form Evernote in Preview in order to crop them, and most times - more often than not - even after I have quit Preview, Evernote wars that the image is still open in another application.
– Vihung
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“x not in y” or “not x in y”
....
In fact, not 'ham' in 'spam and eggs' appears to be special cased to perform a single "not in" operation, rather than an "in" operation and then negating the result:
>>> import dis
>>> def notin():
'ham' not in 'spam and eggs'
>>> dis.dis(notin)
2 0 LO...
How do you detect where two line segments intersect? [closed]
...s. So... do I just divide the z component by the other z component? Is the formula for t actually |(q − p) × s| / |(r × s)|?
– LarsH
Aug 31 '12 at 3:40
7
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What is tail recursion?
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In traditional recursion, the typical model is that you perform your recursive calls first, and then you take the return value of the recursive call and calculate the result. In this manner, you don't get the result of your calculation until you have returned from every recursive cal...
`from … import` vs `import .` [duplicate]
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You are using Python3 were urllib in the package. Both forms are acceptable and no one form of import is preferred over the other. Sometimes when there are multiple package directories involved you may to use the former from x.y.z.a import s
In this particular case with urllib p...