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List of Big-O for PHP functions
... array size has nothing to do with algorithmic complexity, it is caused by CPU cache effects. The larger the array is, the more likely it is that random-access lookups will result in cache misses (and cache misses higher in the hierarchy).
– NikiC
Jan 28 '16 at...
C dynamically growing array
... processing various things. I would like to avoid using too much memory or CPU for keeping such indexes...
7 Answers
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What REALLY happens when you don't free after malloc?
...space are simply released. By contrast, a series of free() calls will burn CPU time and can result in disk paging operations, cache misses, and cache evictions.
Regarding the possiblility of future code reuse justifing the certainty of pointless ops: that's a consideration but it's arguably not th...
What does SynchronizationContext do?
...e.g. to a ThreadPool worker thread), or (at least in theory) to a specific CPU core, or even to another network host. Where your delegates end up running is dependent on the type of SynchronizationContext used.
Windows Forms will install a WindowsFormsSynchronizationContext on the thread on which th...
Best Practice for Exception Handling in a Windows Forms Application?
...oad, but everything else should be fine), or whether it indicates that the CPU is on fire and one should head for the exits as fast as possible? Something like ArgumentException could indicate either, depending upon the circumstances in which it's thrown.
– supercat
...
How is Docker different from a virtual machine?
...ualization work at a low level?
In this case the VM manager takes over the CPU ring 0 (or the "root mode" in newer CPUs) and intercepts all privileged calls made by the guest OS to create the illusion that the guest OS has its own hardware. Fun fact: Before 1998 it was thought to be impossible to ac...
Are Stored Procedures more efficient, in general, than inline statements on modern RDBMS's? [duplica
...cro level.
Still an advantage?
Not very noticeable at all on the modern CPU, but if you are sending a single SQL statement that is VERY large eleventy-billion times a second, the parsing overhead can add up.
Pre-generated query execution plan.
If you have many JOINs the permutations can grow qu...
How does libuv compare to Boost/ASIO?
... Process
Spawning: yes Process
System Queries:
CPU: yes no
Network Interface: yes no
Serial Ports: no yes
TTY: yes no
Shared Library Loading: yes Extension[2]
...
Are Exceptions in C++ really slow
... handler)
So, mostly cache misses, and thus not trivial compared to pure CPU code.
Note: for more details, read the TR18015 report, chapter 5.4 Exception Handling (pdf)
So, yes, exceptions are slow on the exceptional path, but they are otherwise quicker than explicit checks (if strategy) in gene...
How do you parse and process HTML/XML in PHP?
...k.
Again, I would not recommend this parser. It is rather slow with high CPU usage. There is also no function to clear memory of created DOM objects. These problems scale particularly with nested loops. The documentation itself is inaccurate and misspelled, with no responses to fixes since 14 Apr ...