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Volatile vs. Interlocked vs. lock
...t multiple threads running on multiple CPUs can and will cache data and re-order instructions.
If it is not volatile, and CPU A increments a value, then CPU B may not actually see that incremented value until some time later, which may cause problems.
If it is volatile, this just ensures the two CPU...
Real World Example of the Strategy Pattern
... of comments, etc), and in case management doesn't yet know exactly how to order, and may want to experiment with different orderings at a later date. You make an interface (IOrderAlgorithm or something) with an order method, and let an Orderer-object delegate the ordering to a concrete implementati...
C++ Lock-free Hazard Pointer（冒险指针） - C/C++ - 清泛网 - 专注C/C++及内核技术
...（在线执行）：
#include <atomic>
#include <memory>
#include <unordered_set>
template <class T>
struct HazardPointer {
public:
class Holder {
public:
explicit Holder(HazardPointer<T> *pointer) : pointer_(pointer) {}
Holder(const HazardPointer &) = delete;
~Hold...
How to get a random value from dictionary in python
...b': 5}
>>> d.popitem()
('c', 7)
Since the dict doesn't preserve order, by using popitem you get items in an arbitrary (but not strictly random) order from it.
Also keep in mind that popitem removes the key-value pair from dictionary, as stated in the docs.
popitem() is useful to dest...
When should we call System.exit in Java
...and the shutdown process in java, in addition to the answer above:
In an orderly* shutdown, the JVM first starts all registered shutdown hooks. Shutdown hooks are unstarted threads that are registered with Runtime.addShutdownHook.
JVM makes no guarantees on the order in which shutdown hooks
are st...
generate days from date range
...ECT
date
FROM
dates
WHERE
date BETWEEN '2010-01-20' AND '2010-01-24'
ORDER BY
date
Update
It is worth noting that you will only be able to generate past dates starting from the current date. If you want to generate any kind of dates range (past, future, and in between), you will have to u...
Select Row number in postgres
...
You should also specify an order in OVER clause: OVER (ORDER BY id). Otherwise the order is not guaranteed.
– AlexM
Jun 14 '16 at 4:30
...
Use variable with TOP in select statement in SQL Server without making it dynamic [duplicate]
... or statement. So you can do things like:
SELECT TOP (@foo) a FROM table ORDER BY a
SELECT TOP (SELECT COUNT(*) FROM somewhere else) a FROM table ORDER BY a
SELECT TOP (@foo + 5 * 4 / 2) a FROM table ORDER BY a
Source
...
How to deny access to a file in .htaccess
...ding ones from the parent).
So you can have:
<Files "log.txt">
Order Allow,Deny
Deny from all
</Files>
For Apache 2.4+, you'd use:
<Files "log.txt">
Require all denied
</Files>
In an htaccess file in your inscription directory. Or you can use mod_rewrite to s...
MySQL indexes - what are the best practices?
...tant to understand what's going on.
Broadly speaking, an index imposes an ordering on the rows of a table.
For simplicity's sake, imagine a table is just a big CSV file. Whenever a row is inserted, it's inserted at the end. So the "natural" ordering of the table is just the order in which rows...