darwin-libplatform VS WebKit

Apple Open Source Resources

Apple does plenty of open source stuff. Safari's browser engine, Swift, libdispatch, the XNU kernel used by iOS and macOS, etc. And macOS is generally packed with open source things, like the default shell, zsh. Also, Metal actually predates Vulkan, so Vulkan was definitely not established when they started focusing on Metal. Yeah, they probably should consider supporting Vulkan now, but it's nothing to do with open source. The main beneficiaries of Apple supporting Vulkan would be people porting closed-source games.

It's still not a great thing to do. Apple used to contribute a lot more, even if some of their stuff was exclusive to their platform. https://opensource.apple.com

There's quite a bit of macOS that's open source. The author links to source code in Firefox, and that source code has links to Apple's source code:

> // For information about the following undocumented flags and functions see

> // https://github.com/apple/darwin-xnu/blob/main/bsd/sys/ulock.... and

> // https://github.com/apple/darwin-libplatform/blob/main/privat...

Yes, but it's not so uncommon for "spinlocks" to evolve into not-actually-spinlocks. In the Linux kernel, spinlock_t is actually a mutex if PREEMPT_RT is enabled [1]. And Darwin has some code to do this in userspace [2], although I'm not sure if it's actually used.

[1] https://www.kernel.org/doc/html/latest/locking/locktypes.htm...

[2] https://github.com/apple/darwin-libplatform/blob/main/src/os...

Multiple engineers are working on adding it back: https://github.com/WebKit/WebKit/pulls?q=is%3Apr+is%3Aclosed...

Since 2023 Chrome announced the View Transition API, and it looks like Safari is also going to support it soon.

One heap per type.

Here’s an allocator optimized for that use case.

https://github.com/WebKit/WebKit/blob/main/Source/bmalloc/li...

To use this in Bun, you’d have to start Bun with the environment variable “BUN_JSC_useDollarVM=1” and then $vm.createBuiltin(mySourceCodeString)

When using this intrinsic, if any of the arguments are incorrect or it cannot otherwise enable it, the entire process will probably crash. In debug builds of JSC it will have a nicer assertion failure but that is not enabled in release builds

Example code: https://github.com/WebKit/WebKit/blob/17351231b4dedb62d81721...

also happy to answer any questions about Bun

Ah, good, let me introduce you to the wonderful world of the Chrome Devtools Protocol! (fka Chrome Remote Debugging Protocol)

I love this API for almost everything browser related. I built my RBI product atop this (BrowserBox: https://dosyago.com), and I think it's a drastically underrated API.

Also, it works out of the box in Edge, Brave, Chromium, and many parts of CRDP are supported by Firefox and Safari^1

1: See for example: https://github.com/WebKit/webkit/tree/main/Source/JavaScript...

No, it's unrelated.

https://github.com/WebKit/WebKit/commit/064df1a9f395f8c6e32c...

It's being worked on now: https://github.com/WebKit/WebKit/pull/17320

It is different. The cross-site navigation flag is a couple of years old. It was enabled by default for iOS in November 2018 for example https://github.com/WebKit/WebKit/commit/e191fc8c412850cb9fd0...