Two changes that share the same intent of reducing per-T duplication
in code that doesn't actually depend on T:
1. Hoist the non-generic portion of newSubscriberFunc[T] into a
newSubscriberFuncCore() helper. The hoisted work is the time
timer setup, the subscriberFuncCore allocation, and the
unregister closure (which captures only the non-generic
reflect.Type and *subscribeState). The generic body now does
only the two T-bound things it has to: compute reflect.TypeFor[T]
and create the dispatch closure.
Effect on the per-shape-stencil body of newSubscriberFunc[T]:
before: 523 B per shape (in synthetic test)
after: 293 B per shape (-230 B per shape; -56% on this body)
2. Cache reflect.Type.String() once at construction (in core.typeName)
instead of recomputing it every time the dispatch closure runs.
The dispatch closure also now takes the *subscriberFuncCore directly
rather than building an intermediate dispatchFuncState struct on
every call.
Effect on the dispatch closure body (newSubscriberFunc[T].func1):
before: 581 B per shape
after: 480 B per shape (-101 B per shape; -17%)
Combined effect on tailscaled (linux/amd64):
named-symbol savings via symcost: ~7 KB
stripped binary delta: -8 KB (page-quantized)
arm64 binary delta: 0 (page-quantized)
cumulative reduction from baseline (5167ff412):
linux/amd64: -110,592 bytes (-0.391%)
linux/arm64: -131,072 bytes (-0.499%)
Throughput is also improved by the typeName cache: BenchmarkBasic
goes from 2018 ns/op to 1864 ns/op (-7.6%) because the dispatch hot
path no longer allocates a string on every event.
Updates #12614
Change-Id: Ib3a3d6796785e16506330ec034e1144580d467a3
Signed-off-by: James Tucker <james@tailscale.com>
Tailscale
Private WireGuard® networks made easy
Overview
This repository contains the majority of Tailscale's open source code.
Notably, it includes the tailscaled daemon and
the tailscale CLI tool. The tailscaled daemon runs on Linux, Windows,
macOS, and to varying degrees
on FreeBSD and OpenBSD. The Tailscale iOS and Android apps use this repo's
code, but this repo doesn't contain the mobile GUI code.
Other Tailscale repos of note:
- the Android app is at https://github.com/tailscale/tailscale-android
- the Synology package is at https://github.com/tailscale/tailscale-synology
- the QNAP package is at https://github.com/tailscale/tailscale-qpkg
- the Chocolatey packaging is at https://github.com/tailscale/tailscale-chocolatey
For background on which parts of Tailscale are open source and why, see https://tailscale.com/opensource/.
Using
We serve packages for a variety of distros and platforms at https://pkgs.tailscale.com.
Other clients
The macOS, iOS, and Windows clients use the code in this repository but additionally include small GUI wrappers. The GUI wrappers on non-open source platforms are themselves not open source.
Building
We always require the latest Go release, currently Go 1.26. (While we build releases with our Go fork, its use is not required.)
go install tailscale.com/cmd/tailscale{,d}
If you're packaging Tailscale for distribution, use build_dist.sh
instead, to burn commit IDs and version info into the binaries:
./build_dist.sh tailscale.com/cmd/tailscale
./build_dist.sh tailscale.com/cmd/tailscaled
If your distro has conventions that preclude the use of
build_dist.sh, please do the equivalent of what it does in your
distro's way, so that bug reports contain useful version information.
Bugs
Please file any issues about this code or the hosted service on the issue tracker.
Contributing
PRs welcome! But please file bugs. Commit messages should reference bugs.
We require Developer Certificate of
Origin
Signed-off-by lines in commits.
See commit-messages.md (or skim git log) for our commit message style.
About Us
Tailscale is primarily developed by the people at https://github.com/orgs/tailscale/people. For other contributors, see:
- https://github.com/tailscale/tailscale/graphs/contributors
- https://github.com/tailscale/tailscale-android/graphs/contributors
Legal
WireGuard is a registered trademark of Jason A. Donenfeld.