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ryanpetrich

972 karma · joined August 7, 2009

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ryanpetrich··on Abuse of the nullish coalescing operator in JS/TS
Should throw expressions (https://github.com/tc39/proposal-throw-expressions) ever make it into the JavaScript standard, the example could be simplified to:

  const env_var = process.env.MY_ENV_VAR ?? throw new Error("MY_ENV_VAR is not set");
ryanpetrich··on C is not suited to SIMD (2019)
aligned_alloc is a C function. It doesn't help the compiler prove that two pointers can't alias. restrict is the keyword that does.
ryanpetrich··on Show HN: A portable hash map in C
This is to suppress a compiler warning that the k_sz argument is unused.
ryanpetrich··on Union types ('enum types') would be complicated in Go
The bigger problem is mutability. Any pointers into the bit-packed enum storage become invalid as soon as you change its type. To solve this you can either prohibit pointers into bit-packed enum storage, which is very limiting, or introduce immutability into the language. Immutability is particularly difficult to add to go, where default zero-values emerge in unexpected places (such as the spare capacity of slices and the default state of named return values)
ryanpetrich··on How to Use the Foreign Function API in Java 22 to Call C Libraries
Memory barriers don't force a flush of all CPU cache. They will enforce the ordering of memory operations issued before and after the barrier instruction, preserving the contents of the CPU's various caches.
ryanpetrich··on Apple tells EU it has five different App Stores, not just one
Yes, that's right. You need to update the entire OS for a minor security fix to iMessage.
ryanpetrich··on Exploiting the iPhone 4
Thanks for writing this. It takes a deep understanding to explain such complicated concepts in an accessible way. Reading it brought back fond memories of hacking on jailbreak projects deep into the night.
ryanpetrich··on Why Turborepo is migrating from Go to Rust
Go's internal linker is much faster than the system linker thanks to some go-specific optimizations. Go must fall back to the system linker whenever CGO is used.
ryanpetrich··on eBPF Nuances on Minikube
If best effort is good enough and your use case doesn't require robustness, reading out of host /proc certainly works. Tracking execs with hooks in the kernel's internal exec mechanism with a separate indexing step at startup is worth the extra effort for use cases that do require accurate data, such as security observability.
ryanpetrich··on eBPF Nuances on Minikube
It's not robust at all. Programs can and will exit before the userspace daemon is able to read from /proc. Malicious programs can even attribute their network activity to any program on the system they are able to exec by execing that program immediately afterwards or concurrently from another thread. One can properly track program paths/arguments by setting kprobes on the exec functions within the kernel and copying the data to a ring buffer read in userspace or by reading out of the task struct using bpf_probe_read_kernel.
ryanpetrich··on New HTTP standards for caching on the modern web
This is what ETags are for. Upon a user's first visit the server should return an ETag uniquely representing the current version of the page. The browser will cache both the page and the tag. Upon subsequent page visits the browser will send an If-None-Match header containing the tag for the version of the page it has cached. The server should compare the incoming tag with the tag for the current version and return a "304 Not Modified" response if the tags match or a full response with the newer tag in the ETag header if they don't.
ryanpetrich··on A viable solution for Python concurrency
A benefit of storing the reference count in the high bits is that overflows will never corrupt the flag bits and can be detected using the processor's flags instead of requiring a separate check. I'm not sure if this property is used here.
ryanpetrich··on Apple announces it will switch to its own processors for future Macs
Apple's recent aarch64 implementations don't support any of the 32 bit ARM instruction sets, and aarch64 is a significant departure from armv7
ryanpetrich··on Show HN: Go Micro – A distributed systems development framework
It's pluggable in that large parts of it can be replaced or disabled at compile time. Runtime reconfiguration isn't well supported.
ryanpetrich··on Git alias for printing recently-used branches
Another option:

    git log --all --author=`git config user.email` --oneline --decorate
ryanpetrich··on Yukihiro Matsumoto: “Ruby is designed for humans, not machines”
Crystal is not Ruby, nor is it anywhere near as fast as C.
ryanpetrich··on BPF Theremin, Tetris, and Typewriters
BPF programs can be attached to uprobes and thus much of the same tooling applies to userspace as well.
ryanpetrich··on ‘No One Saw a Thing’: When a Midwest Town Banded Together to Kill the Town Bully
Being further away from killers that I'm equally likely to be victims of isn't any more comforting.
ryanpetrich··on Programming Patterns I Like
It’s also dangerous in JavaScript where properties of the Object prototype can mistakenly be dereferenced instead of the default/fallthrough case.
ryanpetrich··on The C standard library function atexit is broken
There's also the matter of someone forcibly pulling a machine's power cord. In some sense exit cleanups are fundamentally unreliable.
ryanpetrich··on A Report from the AMP Advisory Committee Meeting
That's likely due to amp-font, which will wait a certain amount of time for custom fonts to load before continuing with a fallback browser font (see: https://amp.dev/documentation/components/amp-font)
ryanpetrich··on Roshi: A large-scale CRDT set implementation for timestamped events
Cassandra’s sets, lists and maps are already CRDTs
ryanpetrich··on A guide to threads in Node.js
The code to run in the worker is passed as a string or a path, so no data can be captured. Data can be sent to the worker by posting messages, but the data is never shared—only copied. A limited set of types can be transferred to a worker, after which point they will become unusable in the parent.
ryanpetrich··on Brian Acton Tells Students to Delete Their FB Profiles
He's donated $50 million to the Signal Foundation. That sounds like putting his money where his mouth is to me.
ryanpetrich··on ARM processors like A12X are nearing performance parity with desktop processors
And since Photoshop has been announced for the iPad, the porting for the architecture-dependent components of it have already been performed.
ryanpetrich··on Google reveals “high severity” flaw in MacOS kernel
This applies to copy-on-write of files on mounted disk images only.
ryanpetrich··on Pagedraw is shutting down and going open source
For those that haven't seen it: https://ourincrediblejourney.tumblr.com/

(though unlike most of the startups on that blog, Pagedraw seems to be shutting down in the most open and responsible way)

ryanpetrich··on Why has Plan 9 chosen statically linked binaries instead of dynamic ones? (2004)
Out of curiosity, what stopped you from setting the -install_name flag when you built the libraries you are bundling with your juicysfplugin plugin? That's the standard mechanism for building app-relative libraries and wasn't listed at all under "Alternatives to manually rewriting dynamic links"
ryanpetrich··on If It Ain't TypeScript It Ain't Sexy
Enabling source maps will have the source including type annotations show up in the web inspector, but the information isn't usable by the JavaScript VM to validate types at runtime. This is also necessary to preserve line and column information when debugging.
ryanpetrich··on Misadventures in process containment
Odd that apt-get was mentioned as a tool that could use incremental downloads: it has supported them since 2006.
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