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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...
Weak and strong property setter attributes in Objective-C
...t point to it anymore"
- in other words " I'am the owner, you cannot dealloc this before aim fine with that same as retain"
- You use strong only if you need to retain the object.
- By default all instance variables and local variables are strong pointers.
- We generally use strong f...
Speed up the loop operation in R
...s, then fill them in, rather than expanding them each
time.
Even with pre-allocation, you could switch to a pass-by-reference approach rather than a pass-by-value approach, but it may not be worth the hassle.
Take a look at the R Inferno for more pitfalls to avoid.
Try for better vectorization...
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...
What's the idiomatic syntax for prepending to a short python list?
...e reasonable explanation the questioner linked to. I suspect CPython is re-allocating each element in memory in the list in the first two cases, so all three of these probably have linear complexity. I haven't actually looked at the code or tested it myself though, so sorry if those sources are wron...
Why is the .bss segment required?
...un time, b occupies 20 * sizeof(int) bytes.
In the second program, var is allocated space and the assignment in main() modifies that space. It so happens that the space for var was described in the .bss segment rather than the .data segment, but that doesn't affect the way the program behaves when...
Set the location in iPhone Simulator
...LocationFix)
- (void)locationFix {
CLLocation *location = [[CLLocation alloc] initWithLatitude:55.932 longitude:12.321];
[[self delegate] locationManager:self didUpdateToLocation:location fromLocation:nil];
id heading = [[MyHeading alloc] init];
[[self delegate] locationManager:sel...
When should I use a struct rather than a class in C#?
...:
don't need polymorphism,
want value semantics, and
want to avoid heap allocation and the associated garbage collection overhead.
The caveat, however, is that structs (arbitrarily large) are more expensive to pass around than class references (usually one machine word), so classes could end ...
What are the differences between a pointer variable and a reference variable in C++?
...ces and pointers do not have to take space on the stack. They can both be allocated on the heap.
– Derek Park
Sep 19 '08 at 4:33
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