03c2e56f68
The Read and Write methods of *tls.Conn call Handshake
unconditionally, every time they are called, expecting it to only
perform a new handshake if required.
However in go 1.17 handshakeContext was extended to set up a
cancelable Context, and importantly did so prior to checking if a
handshake is required. This thus causes it to allocate on every call,
even in those that are no-ops when called in a Read or Write on an
established connection, sometimes leading to very large numbers of
allocations during reads.
This change adds an early return, prior to setting up the context or
proceeding into the handshakeMutex and checking the handshake error, if
the handshake status atomic indicates handshake is already complete.
name old allocs/op new allocs/op delta
Throughput/MaxPacket/1MB/TLSv12-10 1.07k ± 0% 0.62k ± 0% -42.16% (p=0.000 n=4+5)
Throughput/MaxPacket/1MB/TLSv13-10 1.70k ± 0% 1.25k ± 0% ~ (p=0.079 n=4+5)
Throughput/MaxPacket/2MB/TLSv12-10 1.62k ± 0% 0.73k ± 0% -55.18% (p=0.008 n=5+5)
Throughput/MaxPacket/2MB/TLSv13-10 2.26k ± 0% 1.36k ± 0% -39.64% (p=0.008 n=5+5)
Throughput/MaxPacket/4MB/TLSv12-10 2.74k ± 0% 0.95k ± 0% -65.35% (p=0.008 n=5+5)
Throughput/MaxPacket/4MB/TLSv13-10 3.37k ± 0% 1.58k ± 0% -53.15% (p=0.008 n=5+5)
Throughput/MaxPacket/8MB/TLSv12-10 4.96k ± 0% 1.39k ± 0% -72.06% (p=0.016 n=4+5)
Throughput/MaxPacket/8MB/TLSv13-10 5.60k ± 0% 2.01k ± 0% -64.05% (p=0.008 n=5+5)
Throughput/MaxPacket/16MB/TLSv12-10 9.42k ± 0% 2.27k ± 1% -75.92% (p=0.016 n=4+5)
Throughput/MaxPacket/16MB/TLSv13-10 10.0k ± 0% 2.9k ± 0% -71.39% (p=0.008 n=5+5)
Throughput/MaxPacket/32MB/TLSv12-10 18.3k ± 0% 4.0k ± 0% -77.97% (p=0.008 n=5+5)
Throughput/MaxPacket/32MB/TLSv13-10 18.9k ± 0% 4.6k ± 0% -75.62% (p=0.008 n=5+5)
Throughput/MaxPacket/64MB/TLSv12-10 36.2k ± 0% 7.5k ± 0% -79.15% (p=0.008 n=5+5)
Throughput/MaxPacket/64MB/TLSv13-10 36.7k ± 0% 8.1k ± 0% -78.06% (p=0.008 n=5+5)
Throughput/DynamicPacket/1MB/TLSv12-10 1.12k ± 0% 0.63k ± 0% -44.20% (p=0.008 n=5+5)
Throughput/DynamicPacket/1MB/TLSv13-10 1.76k ± 0% 1.26k ± 0% -28.22% (p=0.016 n=5+4)
Throughput/DynamicPacket/2MB/TLSv12-10 1.68k ± 0% 0.74k ± 0% -56.11% (p=0.008 n=5+5)
Throughput/DynamicPacket/2MB/TLSv13-10 2.32k ± 0% 1.37k ± 0% -40.80% (p=0.008 n=5+5)
Throughput/DynamicPacket/4MB/TLSv12-10 2.80k ± 0% 0.96k ± 0% -65.81% (p=0.008 n=5+5)
Throughput/DynamicPacket/4MB/TLSv13-10 3.43k ± 0% 1.59k ± 0% -53.57% (p=0.008 n=5+5)
Throughput/DynamicPacket/8MB/TLSv12-10 5.03k ± 0% 1.39k ± 0% -72.27% (p=0.008 n=5+5)
Throughput/DynamicPacket/8MB/TLSv13-10 5.66k ± 0% 2.02k ± 0% -64.27% (p=0.008 n=5+5)
Throughput/DynamicPacket/16MB/TLSv12-10 9.48k ± 0% 2.28k ± 1% -75.98% (p=0.008 n=5+5)
Throughput/DynamicPacket/16MB/TLSv13-10 10.1k ± 0% 2.9k ± 0% -71.34% (p=0.008 n=5+5)
Throughput/DynamicPacket/32MB/TLSv12-10 18.4k ± 0% 4.0k ± 0% -78.13% (p=0.008 n=5+5)
Throughput/DynamicPacket/32MB/TLSv13-10 19.0k ± 0% 4.6k ± 0% -75.54% (p=0.008 n=5+5)
Throughput/DynamicPacket/64MB/TLSv12-10 36.2k ± 0% 7.6k ± 1% -79.02% (p=0.008 n=5+5)
Throughput/DynamicPacket/64MB/TLSv13-10 36.8k ± 0% 8.2k ± 1% -77.76% (p=0.008 n=5+5)
Fixes #52790
Change-Id: Iacb1f9bf7802022960d9dbce141b8c0587a614d4
Reviewed-on: https://go-review.googlesource.com/c/go/+/379034
Reviewed-by: David Chase <drchase@google.com>
TryBot-Result: Gopher Robot <gobot@golang.org>
Reviewed-by: Filippo Valsorda <valsorda@google.com>
Auto-Submit: Filippo Valsorda <filippo@golang.org>
Run-TryBot: Filippo Valsorda <filippo@golang.org>
(cherry picked from commit
|
||
---|---|---|
.github | ||
api | ||
doc | ||
lib/time | ||
misc | ||
src | ||
test | ||
.gitattributes | ||
.gitignore | ||
AUTHORS | ||
codereview.cfg | ||
CONTRIBUTING.md | ||
CONTRIBUTORS | ||
LICENSE | ||
PATENTS | ||
README.md | ||
SECURITY.md | ||
VERSION |
The Go Programming Language
Go is an open source programming language that makes it easy to build simple, reliable, and efficient software.
Gopher image by Renee French, licensed under Creative Commons 3.0 Attributions license.
Our canonical Git repository is located at https://go.googlesource.com/go. There is a mirror of the repository at https://github.com/golang/go.
Unless otherwise noted, the Go source files are distributed under the BSD-style license found in the LICENSE file.
Download and Install
Binary Distributions
Official binary distributions are available at https://golang.org/dl/.
After downloading a binary release, visit https://golang.org/doc/install for installation instructions.
Install From Source
If a binary distribution is not available for your combination of operating system and architecture, visit https://golang.org/doc/install/source for source installation instructions.
Contributing
Go is the work of thousands of contributors. We appreciate your help!
To contribute, please read the contribution guidelines at https://golang.org/doc/contribute.html.
Note that the Go project uses the issue tracker for bug reports and proposals only. See https://golang.org/wiki/Questions for a list of places to ask questions about the Go language.