4bb2c6980d
testing.AllocsPerRun measures the total allocations performed by the entire program while repeatedly executing a function f. If some unrelated part of the rest of the program happens to allocate a lot during that period, you end up with a test failure. Ideally, the rest of the program would be silent while testing.AllocsPerRun executes. Realistically, that is often unachievable. AllocsPerRun attempts to mitigate this by setting GOMAXPROCS to 1, but that doesn't prevent other code from running; it only makes it less likely. You can also mitigate this by passing a large iteration count to AllocsPerRun, but that is unreliable and needlessly expensive. Unlike most of package testing, AllocsPerRun doesn't use any toolchain magic, so we can just write a replacement. One wild idea is to change how we count mallocs. Instead of using runtime.MemStats, turn on memory profiling with a memprofilerate of 1. Discard all samples from the profile whose stack does not contain testing.AllocsPerRun. Count the remaining samples to determine the number of mallocs. That's fun, but overkill. Instead, this change adds a simple API that attempts to get f to run at least once with a target number of allocations. This is useful when you know that f should allocate consistently. We can then assume that any iterations with too many allocations are probably due to one-time costs or background noise. This suits most uses of AllocsPerRun. Ratcheting tests tend to be significantly less flaky, because they are biased towards success. They can also be faster, because they can exit early, once success has been reached. Signed-off-by: Josh Bleecher Snyder <josh@tailscale.com>
Tailscale
Private WireGuard® networks made easy
Overview
This repository contains all the open source Tailscale client code and
the tailscaled daemon and tailscale CLI tool. The tailscaled
daemon runs primarily on Linux; it also works to varying degrees on
FreeBSD, OpenBSD, Darwin, and Windows.
The Android app is at https://github.com/tailscale/tailscale-android
Using
We serve packages for a variety of distros 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 that are not open source.
Building
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.
We only guarantee to support the latest Go release and any Go beta or release candidate builds (currently Go 1.17) in module mode. It might work in earlier Go versions or in GOPATH mode, but we're making no effort to keep those working.
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.
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.