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wojtek1942

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wojtek1942
·9 months ago·discuss
The API was released in 2020. It amazes me how many of these kinds of apps are successful simultaneously, while doing nearly the exact same thing.

https://developer.apple.com/documentation/screentime
wojtek1942
·10 months ago·discuss
Why build a new browser in C++ when safer and more modern languages are available? [1]

> Ladybird started as a component of the SerenityOS hobby project, which only allows C++. The choice of language was not so much a technical decision, but more one of personal convenience. Andreas was most comfortable with C++ when creating SerenityOS, and now we have almost half a million lines of modern C++ to maintain.

> However, now that Ladybird has forked and become its own independent project, all constraints previously imposed by SerenityOS are no longer in effect.

> We have evaluated a number of alternatives, and will begin incremental adoption of Swift as a successor language, once Swift version 6 is released.

[1] https://ladybird.org/#faq:~:text=Why%20build%20a%20new%20bro...?
wojtek1942
·10 months ago·discuss
> However, this mode switching is expensive! Just this switch alone costs 1000-1500 CPU cycles in pure overhead, before any actual work happens.

...

> On a 3GHz processor, 1000-1500 cycles is about 500 nanoseconds. This might sound negligibly fast, but modern SSDs can handle over 1 million operations per second. If each operation requires a system call, you're burning 1.5 billion cycles per second just on mode switching.

> Package installation makes thousands of these system calls. Installing React and its dependencies might trigger 50,000+ system calls: that's seconds of CPU time lost to mode switching alone! Not even reading files or installing packages, just switching between user and kernel mode.

Am I missing something or is this incorrect. They claim 500ns per syscall with 50k syscalls. 500ns * 50000 = 25 milliseconds. So that is very far from "seconds of CPU time lost to mode switching alone!" right?