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How efficient is locking an unlocked mutex? What is the cost of a mutex?
... access to the object happens often, then multiple locks would increase parallelism. At the cost of maintainability, since more locking means more debugging of the locking.
How efficient is it to lock a mutex? I.e. how much assembler instructions are there likely and how much time do they take (...
os.walk without digging into directories below
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Does this function actually "walk" through the whole structure and then delete the entries below a certain point? Or is something more clever going on? I'm not even sure how to check this with code. --python beginner
– mathtic...
Are the PUT, DELETE, HEAD, etc methods available in most web browsers?
...eation of a new web
page resource, the updating of the existing page, or all of the
mentioned outcomes.
The keyword dialog, mapping to the state dialog, indicating that
submitting the form is intended to close the dialog box in which the
form finds itself, if any, and otherwise not subm...
Merge two Git repositories without breaking file history
...ose instructions mostly works, except that when I commit the subtree merge all of the files from the old repositories are recorded as new added files. I can see the commit history from the old repositories when I do git log , but if I do git log <file> it shows only one commit for that fil...
Check a radio button with javascript
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Technically it's CSS selector syntax. jQuery just borrowed and extended it
– Tim Seguine
Jan 16 '14 at 16:10
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Overloading Macro on Number of Arguments
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Simple as:
#define GET_MACRO(_1,_2,_3,NAME,...) NAME
#define FOO(...) GET_MACRO(__VA_ARGS__, FOO3, FOO2)(__VA_ARGS__)
So if you have these macros:
FOO(World, !) # expands to FOO2(World, !)
FOO(foo,bar,baz) # expands to FOO3(foo,bar...
How can i tell if an object has a key value observer attached
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Put a try catch around your removeObserver call
@try{
[someObject removeObserver:someObserver forKeyPath:somePath];
}@catch(id anException){
//do nothing, obviously it wasn't attached because an exception was thrown
}
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How to filter a dictionary according to an arbitrary condition function?
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And here is a good explanation why the function call dict() is slower than the constructor/literal syntax {} doughellmann.com/2012/11/…
– dorvak
Jul 10 '13 at 9:37
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Bash empty array expansion with `set -u`
...ad. Other patterns, such as ${arr[@]-} or ${arr[@]:0}, are not safe across all major versions of Bash.
As the table below shows, the only expansion that is reliable across all modern-ish Bash versions is ${arr[@]+"${arr[@]}"} (column +"). Of note, several other expansions fail in Bash 4.2, includin...
How to Query an NTP Server using C#?
All I need is a way to query an NTP Server using C# to get the Date Time of the NTP Server returned as either a string or as a DateTime .
...