Oh wow
That will answer so many questions for anyone asking why nexus is inherently atomic.
LOL
They are trying to make the Primitives for
SharedArrayBuffer
Yeah
I want it so badly.
Sooo bookmarked.
Thanks for finding that
It showed up in my feed today, and I knew you would love to read it.
Does this affect your work? It's talking about
JavaScriptCore
Yeah, thanks.
Yep, pretty much what I'm working with
I'm going to put that in my next article
I'm curious if you could use the primitives coming down from the top instead of making your own?
Yeah, but it would be cumbersome.
Linking into JSC is enough
Actually using the sources is like madness
I'd have to clone 5GB into a git submodule for that to happen. No chance of hell. yet.
- SPIT TAKE *
oops
SPIT TAKE
lol
yeah.
that's crazy.
Exactly
I had to git clone --depth 0 to grab a copy of webkit as it is
And it took forever
Have you considdered using WTF::ParkingLot lol
It's used internally by JSC
Oh.
The WTF namespace makes me lol every time.
hehe
yeah
They paid JSC to put up a WTF::ParkingLot
WTF::Exception made me lol
It was a big moment when I first saw it
I thought my computer was making fun of me
As someone who knows how to code and has technically compiled C++ in his life, can you let me ask questions about how C++ and your repo works?
Sure
I'm prepared to read the source code.
shudders
Haha
Okay
I have the repo open
I'm looking at the src/ directory.
Just don't mock my coding skills
I have no opinion on coding skills :)
hehe
What exactly are .h files? (general question)
I'm sure you will
It stands for header, I know this.
Is a header file like a C# interface?
.h are the headers. That's where you declare stuff
What do you mean by declare stuff?
Hang on. I need a keyboard to type this. Phone won't work for this
Hahaha. Thank you for your time.
No problem. Let's do this
So, imagine a machine.. You have a blueprint, and a physical model
The header files are the blueprints
The .cpp files are the parts
The executable is the assembled machine
Great. They probably function exactly like interfaces
Something like that
.h files define WHAT functions show up in classes. right?
You use headers to declare classes.. some of them are abstract (interfaces)
Yes
Oh okay.
the CPP files define the functions.
Can you show me a simple example
You can't define a function in a .cpp file without declaring it first in a .h
Can you actually define a full function in a .h file?
class_A.h:
class A {
void hello(); // declaration
}class_A.cpp:
#include <iostream>
#include "class_A.h" // import the declaration
void A::hello() {
std::cout << "hello!" << std::endl;
}
Yeah that's an interface
You could, that'd inline it.
No, that's not an interface
void A::hello() attaches the function compile time, right?
That's a regular class. an interface would have abstract methods
Yes
in that case, header files are more like a contract
not exactly the whole blueprint
Yeah, something like that
The header files have the declarations, the cpp files have the definitions.
What if you don't define A::hello() in the cpp file?
You get an undefined reference error at link time.
Great. That makes sense to me.
Are you familiar with c#
I used to be.
Do namespaces function the same way?
Yeah
There's one more thing.
You could have a .h file with a namespace that doesn't match the directory structure
A .cpp file compiles to an object file (.obj/.o depending on the compiler)
Yep.
Directory structure is irrelevant.
Anyway, the compiled object files are then linked.
Cool.
That's when you'd get the undefined reference error.
class ProtectedArguments {
public:
//exposed stuff here
}
You don't have to attach public to every property now.
You put public: before them
No
ProtectedArguments(JSContextRef ctx, size_t argumentCount, const JSValueRef arguments[]):
myContext(ctx), myArguments(arguments, arguments + argumentCount)
{
for(auto i: myArguments)
JSValueProtect(myContext, i);
}
This is the constructor, right?
Yep
I define it inline
I'm lazy sometimes :P
it's in the util.h file, why isn't the constructor declared in the
util.cpp file
Small/trivial code can go into the headers sometimes
It's basically up to the developer where the code goes.
Whereupon the compiler will inline it
Does that make it faster?
Or is it just "i like it this way"
Yes, but that's irrelevant nowadays
So it's kindof both?
Neat.
Most compilers can inline definitions as well
Nowadays I mean
It was much harder in the past
class ProtectedArguments {
public:
ProtectedArguments(JSContextRef ctx, size_t argumentCount, const JSValueRef arguments[]):
myContext(ctx), myArguments(arguments, arguments + argumentCount)
{
for(auto i: myArguments)
JSValueProtect(myContext, i);
}
ProtectedArguments(const ProtectedArguments & other): myContext(other.myContext), myArguments(other.myArguments) {
for(auto i: myArguments)
JSValueProtect(myContext, i);
}
~ProtectedArguments() {
for(auto i: myArguments)
JSValueUnprotect(myContext, i);
}
}
These are all obviously different constructors
The last is a destructor
on line 49, there is a ~
Oh!
It looks like each class comes with a native IDisposable interface
For when an object is destroyed.
That's actually really neat.
Haha
Yes
All classes manage their own memory.
I feel like such a noob. Thanks for being patient with me.
No problem. I'm actually enjoying this. It's been a while since I explained anything to anyone.
JSValueRef operator[](int index) { return myArguments[index]; }
That's the [] operator
x[1]
....would call that.
So this is an array, and you are overriding the syntax for array access
No, this is a class, and I'm giving it array semantics.
I think you and I understand what it means, and I'm using words that don't have meaning to you.
Yes, I'm giving you the correct terminology.
Don't be offended when I point out the obvious. :D
I wasn't offended
I wanted to make sure I understood the concept before I got the word for it.
Aha
You got it right
JSValueRef operator[](int index) { return myArguments[index]; }
operator JSValueRef *() { return &myArguments[0]; }
JSValueRef operator[](int index) const { return myArguments[index]; }
operator const JSValueRef *() const { return myArguments.data(); }
This is overloaded, what's the reason?
See the last two versions, they have
const next to them
That's for
const access.. when you have a constant pointer to an object
Or a constant reference
I think I don't understand what this means.
Okay
Here we go
I'm trying to figure out what I don't understand.
Here we go
Uh oh
lol
int x = 0; // define an integer with name x and value 0
int * y = &x; // define a pointer to an integer with name y and point at x
int * y points at the address of x
now how do I operate on y to modify x?
Yes
I remember this vaugely
*y = 10;
This changes x to 10
*y = 10;
x;
//10
Yep
that's neat.
Think of x here as a space in memory(the stack really) and y as the address of that space.
So now you can write a loop over a set of objects by changing a pointer
Yeah
You can use them to implement all kinds of crazy things
Linked lists
Linked lists, graphs, etc
Yep
Jinx :D
Hahaha
So you have pointers
And then you have
const pointers
SO...
operator JSValueRef *() { return &myArguments[0]; }this defines how *y = 10; would operate
Yes
I should really say:
*args[x] = ...;
This both gives you the address and lets you dereference it
Awesome, correct.
I don't understand the last sentence
Now, as for
const pointers.
gives you the address and lets you dereference it
before you move onto const
Okay
JSValueRef * x = args[0]; // taking the address
*x = ....; // dereferencing
*args[0] = ...; // also dereferencing
dereference means grab the location using the & symbol, right?
No, that's referencing
Dereferencing is accessing a pointer via *
OH I understood the concept first before the word.
Good.
You sure you don't know C++ already? :P
Yeah. I don't know the definitions and words ;-)
I also would not ever remember how to do something like this
Haha
Ready to move on?
You bet
Okay, so we talked about pointers. Now things get a bit icky.
ProtectedArguments args = ....; // normal object
const ProtectedArguments & args2(args); /// const reference to object
args[0] // accesses the regular version of the [] operator
args2[0] // accesses the const version of the [] operator
Inside the const version, the *this value is also const.
So a const method can't call into a non-const method.
Unless it's declared mutable.
Hang on.
Ok
const Type & alwaysReferences(objectToRefernce);
OH wait
Not copy, reference
A reference is another kind of variable that differs slightly.
Another kind of variable*
alwaysReferences will permanently point to objectToReference
Yep
Okay.
And if
objectToReference goes out of scope and you access alwaysReferences, you're basically out of luck. Crash.
But that situation is hard to make happen.
You gotta do lofty things to get that to occur. :)
Hang on :)
Okay
That makes sense.
That is a constant pointer
Those are useful for Immutable collections right?
You could say that.
Or static strings
That's obviously a better example, I was trying to think outside the box lol
I wasn't thinking about DOMStrings
or other stuff like that
I need to go to a meeting, but this was super helpful, will you be available in about 15 minutes?
I think so
:)
Hahaha... Guys!!! My phone is so vibrating in my pocket that I fear people might start thinking the wrong way :)
can you chat code learning in PM?
thanks!
Yeah, sorry.
No worries :)
I thought we were alone :P
You should turn off notifications. I'm actually discussing how Nexus works...
but that's okay!
lol
(moves to a private chat)
Oh! Sorry! Haven't seen before the option on mobile...
Haha
You can keep discussing here, don't mind me
:)
Nah, it's ok, we're moving to a private chat
More suited to this anyway