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Mutex example / tutorial? [closed]
... The first person to catch the door-handle of the booth, is the one who is allowed to use the phone. He has to keep holding on to the handle of the door as long as he uses the phone, otherwise someone else will catch hold of the handle, throw him out and talk to his wife :) There's no queue system a...
Visual Studio can't build due to rc.exe
...exe and rcdll.dll to visual studio 2012\vc\bin or wherever you have it installed:
Part 2: FIX LINK : fatal error LNK1158: cannot run ‘rc.exe’
Add this to your PATH environment variables:
C:\Program Files (x86)\Windows Kits\8.0\bin\x86
Copy these files:
rc.exe
rcdll.dll
From
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Please explain the exec() function and its family
...
Simplistically, in UNIX, you have the concept of processes and programs. A process is an environment in which a program executes.
The simple idea behind the UNIX "execution model" is that there are two operations you can do.
The first ...
AngularJS sorting by property
...'s rows in the filter e.g. for(var objectKey in input) { input[objectKey]['_key'] = objectKey; array.push(input[objectKey]); } Like that we can use <div ng-repeat="value in object | orderObjectBy:'order'" ng-init="key = value['_key']">
– Nicolas Janel
Jul...
What does the “@” symbol mean in reference to lists in Haskell?
...hout the @, you'd have to choose between (1) or (2):(3).
This syntax actually works for any constructor; if you have data Tree a = Tree a [Tree a], then t@(Tree _ kids) gives you access to both the tree and its children.
s...
Compelling examples of custom C++ allocators?
What are some really good reasons to ditch std::allocator in favor of a custom solution? Have you run across any situations where it was absolutely necessary for correctness, performance, scalability, etc? Any really clever examples?
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PostgreSQL create table if not exists
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CREATE TABLE myschema.mytable (i integer);
END IF;
END
$func$;
Call:
SELECT create_mytable(); -- call as many times as you want.
Notes:
The columns schemaname and tablename in pg_tables are case-sensitive. If you double-quote identifiers in the CREATE TABLE statement, you need ...
Apache Spark: map vs mapPartitions?
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I'm seeing the opposite -- even with very small operations, its faster to call mapPartitions and iterate than call map. I am assuming that this is just the overhead of starting the language engine that will process the map task. (I'm in R, which may have more startup...
iOS - Dismiss keyboard when touching outside of UITextField
...TapGestureRecognizer(target: self, action: #selector(self.dismissKeyboard (_:)))
self.view.addGestureRecognizer(tapGesture)
For dismissKeyboard
@objc func dismissKeyboard (_ sender: UITapGestureRecognizer) {
aTextField.resignFirstResponder()
}
...
Install tkinter for Python
...: No module named 'tkinter' I Use(Python 3.7.5)
– sqp_125
Dec 9 '19 at 18:30
Solution: sudo apt-get install python3.7-...