Go 1.24 is scheduled for release in February, so it’s a good time to explore what’s new. The official release notes are pretty dry, so I prepared an interactive version with lots of examples showing what has changed and what the new behavior is.

source: L

I was pleasantly surprised by the results in Chromium browsers at medium and large container widths. Hyphenation seems conservative and readable, yet there are no unsightly gaps or “rivers” between words. Safari and Firefox hyphenate a bit more frequently, but not distractingly so.

source: L

Recently I diagnosed and fixed two frame pointer unwinding crashes in Go. The root causes were two flavors of the same problem: buggy assembly code clobbered a frame pointer. By “clobbered” I mean wrote over the value without saving & restoring it. One bug clobbered the frame pointer register. The other bug clobbered a frame pointer saved on the stack. This post explains the bugs, talks a bit about ABIs and calling conventions, and makes some recommendations for how to avoid the bugs.

source: L

It seems like SHLX performs differently depending on how the shift count register is initialized. If you use a 64-bit instruction with an immediate, performance is slow. This is also true for instructions like INC (which is similar to ADD with a 1 immediate). On the other hand, 32-bit instructions, and 64-bit instructions without immediates (even no-op ones), make it fast. All of these ways to initialize RCX lead to 1-cycle latency:

source: L

Through some digging, I found that when a desktop enters S3 sleep, the system cuts power to PCIe GPUs, causing their VRAM chips to lose data. To preserve this data, GPU drivers copy VRAM in use to system RAM before the system sleeps, then restore it after the system wakes. However the Linux amdgpu driver has a bug where, if there is not enough free RAM to store all VRAM in use, the system will run out of memory and crash, instead of moving RAM to disk-based swap.

source: L

This post isn’t a scientific evaluation or an A/B study. It’s my personal opinion after trying to make Rust gamedev work for us, a small indie developer (2 people), trying to make enough money to fund our development with it.

source: L

For practical purposes, old source files are not text files. They are binary files, and must be preserved without modification. It is not OK to take an old source file and convert it to UTF-8. For one thing, UTF-8 didn’t even exist in the times of MASM 5.10 and Microsoft C 5.1, of course old tools can’t deal with it!

source: L

What happens if you take motion blur past its logical extreme? Here are some fun observations and ideas I encountered while trying to answer this question, with an attempt to apply the results in a procedural animation.

source: L

If you’ve spent much time developing with Mingw-w64 you’ve likely seen the symbol ___chkstk_ms, perhaps in an error message. It’s a little piece of runtime provided by GCC via libgcc which ensures enough of the stack is committed for the caller’s stack frame. The “function” uses a custom ABI and is implemented in assembly. So is the subject of this article, a slightly improved implementation soon to be included in w64devkit as libchkstk (-lchkstk).

source: L

I wrote a software rasterizer for occlusion culling and hit many small speed bumps along the way. Here I reveal what I’ve learned in the hope of you writing your own with more ease than I did.

source: L

I love to use soft gradients as backdrops when doing graphics programming, a love started by a Corona Renderer product shot sample scene shared by user romullus and its use of radial gradients to highlight the product. But they are quite horrible from a design standpoint, since they produce awful color banding, also referred to as posterization. Depending on things like screen type, gradient colors, viewing environment, etc., the effect can be sometimes not present at all, yet sometimes painfully obvious.

source: L

In this post we’re going to visually explore different methods of retrying requests, demonstrating why some common approaches are dangerous and ultimately ending up at what the best practice is. At the end of this post you will have a solid understanding of what makes safe retry behaviour, and a vivid understanding of what doesn’t.

source: L

There is a kind of magic to those systems that is worth experiencing. But it’s also worth examining why we prefer to build puppets.

Because I’ve had days where I’ve had to debug my surly emacs boy, and I’ve quickly discovered that his behaviour has very little to do with the code that I’m reading. Methods overridden at runtime, traces that end with a call to a closure that no longer exists, event handlers whose execution order depends on side-effects during module loading, stack-traces which contain multiple different versions of the same function. On the worst days I find myself debugging code that doesn’t even exist on disk but was evaluated in the repl weeks before.

source: L

In October 1983, 40 years ago this week, Ken Thompson chose supply chain security as the topic for his Turing award lecture, although the specific term wasn’t used back then. (The field of computer science was still young and small enough that the ACM conference where Ken spoke was the “Annual Conference on Computers.”) Ken’s lecture was later published in Communications of the ACM under the title “Reflections on Trusting Trust.” It is a classic paper, and a short one (3 pages); if you haven’t read it yet, you should. This post will still be here when you get back.

In the lecture, Ken explains in three steps how to modify a C compiler binary to insert a backdoor when compiling the “login” program, leaving no trace in the source code. In this post, we will run the backdoored compiler using Ken’s actual code. But first, a brief summary of the important parts of the lecture.

source: L

Many versions of Unix provide a /dev/fd directory to work with open file handles as if they were regular files. As usual, the devil is in the details.

source: L

Polonius refers to a few things. It is a new formulation of the borrow checker. It is also a specific project that implemented that analysis, based on datalog. Our current plan does not make use of that datalog-based implementation, but uses what we learned implementing it to focus on reimplementing Polonius within rustc.

source: L

Over the past year I’ve refined my approach to arena allocation. With practice, it’s effective, simple, and fast; typically as easy to use as garbage collection but without the costs. Depending on need, an allocator can weigh just 7–25 lines of code — perfect when lacking a runtime. With the core details of my own technique settled, now is a good time to document and share lessons learned. This is certainly not the only way to approach arena allocation, but these are practices I’ve worked out to simplify programs and reduce mistakes.

See also: https://nullprogram.com/blog/2023/09/30/

An easy-to-implement, arena-friendly hash map

source: L

Real pain for my sham friends, real tricks for my meh friends, and finding more like this with NLP

source: L

Avoiding bad dependencies can be hard without appropriate information on what the dependency’s code actually does, and reviewing every line of that code is an immense task. Every dependency also brings its own dependencies, compounding the need for review across an expanding web of transitive dependencies. But what if there was an easy way to know the capabilities–the privileged operations accessed by the code–of your dependencies?

source: L

Experiences porting FreeBSD 14 to run on the Firecracker VMM

source: L