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Understanding Python's “is” operator
... a is int which is an immutable object. So python (I guess to save memory) allocated the same object to b when it was created with the same value. So in this case, the identities of the variables matched and a is b turned out to be True.
This will apply for all immutable objects:
>>> del ...
What is the difference between a process and a thread?
...
@JeshwanthKumarNK: Creating a new thread allocates at least enough memory for a new stack. This memory is allocated by the OS in process A.
– Greg Hewgill
Sep 20 '12 at 19:20
...
Is it safe to parse a /proc/ file?
... dest, destp, sp->sk_state,
atomic_read(&sp->sk_wmem_alloc),
atomic_read(&sp->sk_rmem_alloc),
0, 0L, 0, sock_i_uid(sp), 0, sock_i_ino(sp),
atomic_read(&sp->sk_refcnt), sp, atomic_read(&sp->sk_drops));
which outputs
[wa...
Deserializing JSON Object Array with Json.net
...
First, unnecessary memory allocation for the different types of IEnumerable implementations (3 compared to a List<Tuple>). Second, your solution implies two distinct keys - 1 for each dictionary. What happens if multiple customers have the sam...
How to run a program without an operating system?
...s back output all through the simulated UART:
enter a character
got: a
new alloc of 1 bytes at address 0x0x4000a1c0
enter a character
got: b
new alloc of 2 bytes at address 0x0x4000a1c0
enter a character
See also: How to make bare metal ARM programs and run them on QEMU?
a fully automated Raspberr...
Objective-C for Windows
...h>
int main(void)
{
NSAutoreleasePool * pool = [[NSAutoreleasePool alloc] init];
NSLog(@"Hello World!.");
[pool drain];
return;
}
Go back to the command prompt and cd to where you saved the "Hello World" program and then compile it:2
gcc -o helloworld.exe <HELLOWORLD>.m -I /...
How does the “final” keyword in Java work? (I can still modify an object.)
...ed than checking whether a variable is final. Mutable objects can be stack-allocated as well. final fields may help the escape analysis, though, but that's a quite indirect route. Also note that effectively final variables have identical treatement as those marked final in the source code.
...
How does one write code that best utilizes the CPU cache to improve performance?
...mbers by decreasing size is one way)
Beware of the standard dynamic memory allocator, which may introduce holes and spread your data around in memory as it warms up.
Make sure all adjacent data is actually used in the hot loops. Otherwise, consider breaking up data structures into hot and cold compo...
foreach vs someList.ForEach(){}
...ll more likely JIT into something efficient..
In addition, foreach() will allocate a new Enumerator no matter what. The GC is your friend, but if you're doing the same foreach repeatedly, this will make more throwaway objects, as opposed to reusing the same delegate - BUT - this is really a fringe...
std::vector performance regression when enabling C++11
...han for C++98 mode and inlining the function
void std::vector<Item,std::allocator<Item>>::_M_emplace_back_aux<Item>(Item&&)
fails in C++11 mode with the default inline-limit.
This failed inline has a domino effect. Not because this function is being called
(it is not eve...