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When should the volatile keyword be used in C#?
... the processors to
do whatever it is they need to do to ensure that I am reading the
latest value, even if that means halting other processors and making
them synchronize main memory with their caches".
Actually, that last bit is a lie. The true semantics of volatile reads
and writes ar...
C fopen vs open
...tion.
That leaves the buffering question. In places where you are mainly reading or writing a file sequentially, the buffering support is really helpful and a big speed improvement. But it can lead to some interesting problems in which data does not end up in the file when you expect it to be the...
I need to securely store a username and password in Python, what are my options?
...em Functions ###
def getSaltForKey(key):
return PBKDF2(key, saltSeed).read(SALT_SIZE) # Salt is generated as the hash of the key with it's own salt acting like a seed value
def encrypt(plaintext, salt):
''' Pad plaintext, then encrypt it with a new, randomly initialised cipher. Will not pr...
How can I get the version defined in setup.py (setuptools) in my package?
...
Interrogate version string of already-installed distribution
To retrieve the version from inside your package at runtime (what your question appears to actually be asking), you can use:
import pkg_resources # part of setuptools
version = pkg_resources.re...
How does one write code that best utilizes the CPU cache to improve performance?
...andwidth is also a limiting factor, particularly for multicores and multithreaded applications where many threads wants to use the memory bus. A different set of techniques help addressing the latter issue.
Improving spatial locality means that you ensure that each cache line is used in full once i...
How can I randomize the lines in a file using standard tools on Red Hat Linux?
...s ruby example which has the benefit of being shorter: ruby -e 'puts STDIN.readlines.shuffle'. It would need testing on big inputs to see if the speed is comparable. (also works on OS X)
– mivk
May 17 '15 at 21:48
...
In-Place Radix Sort
... the temporary array fits into memory.
Reason:
The sorting does a linear read on the input array, but all writes will be nearly random. From a certain N upwards this boils down to a cache miss per write. This cache miss is what slows down your algorithm. If it's in place or not will not change thi...
How to use phpexcel to read data and insert into database?
I have a php application where I want to read data from excel, Insert into database and then generate pdf reports for specific users.
I searched a lot but nothing specific given about both things.
...
Linux: is there a read or recv from socket with timeout?
How can I try to read data from socket with timeout?
I know, select, pselect, poll, has a timeout field, but using of them disables "tcp fast-path" in tcp reno stack.
...
reference assignment is atomic so why is Interlocked.Exchange(ref Object, Object) needed?
In my multithreaded asmx web service I had a class field _allData of my own type SystemData which consists of few List<T> and Dictionary<T> marked as volatile . The system data ( _allData ) is refreshed once in a while and I do it by creating another object called newData and fill...