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What is a semaphore?
...ere are a dedicated number of people that are allowed in the club at once. If the club is full no one is allowed to enter, but as soon as one person leaves another person might enter.
It's simply a way to limit the number of consumers for a specific resource. For example, to limit the number of sim...
Get current date in milliseconds
...d it'll result in a negative value.
For example, if I run that code right now, it'll result in
currentTime = 1357234941
and
currentTime /seconds / minutes / hours / days = years
1357234941 / 60 / 60 / 24 / 365 = 43.037637652207
...
Const in JavaScript: when to use it and is it necessary?
...eginning of 2014 and a lot has changed since then. ecmascript-6 support is now the norm. All modern browsers now support const so it should be pretty safe to use without any problems.
Original Answer from 2014
Despite having fairly decent browser support, I'd avoid using it for now. From MDN's a...
RESTful Authentication via Spring
... AuthenticationEntryPoint, which basically just returns a 401 Unauthorized if the request wasn't authenticated in the filter chain by our AuthenticationTokenProcessingFilter.
CustomAuthenticationEntryPoint:
public class CustomAuthenticationEntryPoint implements AuthenticationEntryPoint {
@Over...
NodeJS / Express: what is “app.use”?
...t has a middleware stack that can be customized in app.configure()(this is now deprecated in version 4.x).
To setup your middleware, you can invoke app.use(<specific_middleware_layer_here>) for every middleware layer that you want to add (it can be generic to all paths, or triggered only on ...
How can I determine what font a browser is actually using to render some text?
...
Per Wilfred Hughes' answer, Firefox now supports this natively. This article has more details.
This answer original referenced the "Font Finder" plugin, but only because it was from 4 years ago. The fact that old answers linger like this and the community can...
Getting the count of unique values in a column in bash
... with several columns. I want to count the frequency of occurrence of the different values in a column for all the files in a folder and sort them in decreasing order of count (highest count first). How would I accomplish this in a Linux command line environment?
...
For loop for HTMLCollection elements
...rties of the object):
0
1
2
item
namedItem
@@iterator
length
Hopefully, now you can see why you want to use for (var i = 0; i < list.length; i++) instead so you just get 0, 1 and 2 in your iteration.
Following below is an evolution of how browsers have evolved through the time period 2015-2...
Measuring execution time of a function in C++
...5;
}
}
int main()
{
auto t1 = std::chrono::high_resolution_clock::now();
function();
auto t2 = std::chrono::high_resolution_clock::now();
auto duration = std::chrono::duration_cast<std::chrono::microseconds>( t2 - t1 ).count();
std::cout << duration;
return...
Chrome DevTools Devices does not detect device when plugged in
...e.
Definitely not as easy as I thought it would have been but at least it now works.
Update 24 February 2016
So I updated to Windows 10 and now have a Samsung Galaxy S5, devices running Chrome v48.0.2564.116 m and v48.0.2564.95 respectively. Followed the steps from the Google docs and...it didn't...