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What is the difference between mutex and critical section?
... between the two of them. On my system for 1,000,000 uncontended acquires and releases, a mutex takes over one second. A critical section takes ~50 ms for 1,000,000 acquires.
Here's the test code, I ran this and got similar results if mutex is first or second, so we aren't seeing any other effect...
Is main() really start of a C++ program?
The section $3.6.1/1 from the C++ Standard reads,
11 Answers
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How to delete a specific line in a file?
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First, open the file and get all your lines from the file. Then reopen the file in write mode and write your lines back, except for the line you want to delete:
with open("yourfile.txt", "r") as f:
lines = f.readlines()
with open("yourfile.t...
How do you UrlEncode without using System.Web?
...at explains the difference:
What's the difference between EscapeUriString and EscapeDataString?
and recommends to use Uri.EscapeDataString() in any aspect.
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How to view or edit localStorage
I created a Chrome extension and am using localStorage for storing data.
5 Answers
5
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How to iterate over a JavaScript object?
...{
console.log(key, yourobject[key]);
}
With ES6, if you need both keys and values simultaneously, do
for (let [key, value] of Object.entries(yourobject)) {
console.log(key, value);
}
To avoid logging inherited properties, check with hasOwnProperty :
for (let key in yourobject) {
if (y...
Update built-in vim on Mac OS X
...his line to your .bashrc or .profile:
alias vim='/path/to/your/own/vim'
and/or change your $PATH so that it looks into its location before the default location.
The best thing to do, in my opinion, is to simply download the latest MacVim which comes with a very complete vim executable and use it...
What is “:-!!” in C code?
... effect, a way to check whether the expression e can be evaluated to be 0, and if not, to fail the build.
The macro is somewhat misnamed; it should be something more like BUILD_BUG_OR_ZERO, rather than ...ON_ZERO. (There have been occasional discussions about whether this is a confusing name.)
You...
What is the difference between old style and new style classes in Python?
What is the difference between old style and new style classes in Python? When should I use one or the other?
8 Answers
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Filtering for empty or NULL names in a queryset
...e.objects.exclude(alias__isnull=True)
If you need to exclude null values and empty strings, the preferred way to do so is to chain together the conditions like so:
Name.objects.exclude(alias__isnull=True).exclude(alias__exact='')
Chaining these methods together basically checks each condition i...