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| author | Cuong Manh Le <cuong.manhle.vn@gmail.com> | 2020-09-04 17:47:44 +0700 |
|---|---|---|
| committer | Emmanuel Odeke <emm.odeke@gmail.com> | 2020-09-07 02:46:24 +0000 |
| commit | 1a119edd8b4364a8c8342194648166ca5851f061 (patch) | |
| tree | 0de7f8b1ae975387ae91bde27c8088f66ee9446d | |
| parent | 5cc030aa1996762e48ce446001078ce6447f105e (diff) | |
| download | go-1a119edd8b4364a8c8342194648166ca5851f061.tar.gz go-1a119edd8b4364a8c8342194648166ca5851f061.zip | |
runtime: rotate map key seed on clearing up maps
Same thing as CL 253020 did for map clear idiom.
name old time/op new time/op delta
MapDelete/Int32/100-12 30.0ns ± 1% 30.7ns ± 3% ~ (p=0.400 n=3+3)
MapDelete/Int32/1000-12 26.6ns ± 2% 28.1ns ± 3% ~ (p=0.100 n=3+3)
MapDelete/Int32/10000-12 28.6ns ± 1% 31.9ns ± 1% ~ (p=0.100 n=3+3)
MapDelete/Int64/100-12 30.2ns ± 0% 32.1ns ± 3% ~ (p=0.100 n=3+3)
MapDelete/Int64/1000-12 26.5ns ± 1% 27.5ns ± 3% ~ (p=0.100 n=3+3)
MapDelete/Int64/10000-12 29.6ns ± 1% 29.3ns ± 1% ~ (p=0.300 n=3+3)
MapDelete/Str/100-12 19.5ns ± 3% 19.6ns ± 2% ~ (p=0.800 n=3+3)
MapDelete/Str/1000-12 31.6ns ± 1% 31.4ns ± 1% ~ (p=0.500 n=3+3)
MapDelete/Str/10000-12 37.8ns ± 1% 37.1ns ± 1% ~ (p=0.100 n=3+3)
MapDelete/Pointer/100-12 15.9ns ± 1% 16.8ns ± 9% ~ (p=0.200 n=3+3)
MapDelete/Pointer/1000-12 26.9ns ± 1% 26.2ns ± 2% ~ (p=0.200 n=3+3)
MapDelete/Pointer/10000-12 30.6ns ± 1% 30.7ns ± 4% ~ (p=0.700 n=3+3)
Fixes #25237
Change-Id: I353cf44a2f6158549f0ef563d867f0844fec7095
Reviewed-on: https://go-review.googlesource.com/c/go/+/252940
Run-TryBot: Cuong Manh Le <cuong.manhle.vn@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Emmanuel Odeke <emm.odeke@gmail.com>
Reviewed-by: Keith Randall <khr@golang.org>
| -rw-r--r-- | src/runtime/map.go | 5 | ||||
| -rw-r--r-- | src/runtime/map_fast32.go | 5 | ||||
| -rw-r--r-- | src/runtime/map_fast64.go | 5 | ||||
| -rw-r--r-- | src/runtime/map_faststr.go | 5 |
4 files changed, 20 insertions, 0 deletions
diff --git a/src/runtime/map.go b/src/runtime/map.go index 22a0241f56..8be1d3991d 100644 --- a/src/runtime/map.go +++ b/src/runtime/map.go @@ -780,6 +780,11 @@ search: } notLast: h.count-- + // Reset the hash seed to make it more difficult for attackers to + // repeatedly trigger hash collisions. See issue 25237. + if h.count == 0 { + h.hash0 = fastrand() + } break search } } diff --git a/src/runtime/map_fast32.go b/src/runtime/map_fast32.go index d035ed0386..d80f5eac78 100644 --- a/src/runtime/map_fast32.go +++ b/src/runtime/map_fast32.go @@ -344,6 +344,11 @@ search: } notLast: h.count-- + // Reset the hash seed to make it more difficult for attackers to + // repeatedly trigger hash collisions. See issue 25237. + if h.count == 0 { + h.hash0 = fastrand() + } break search } } diff --git a/src/runtime/map_fast64.go b/src/runtime/map_fast64.go index f1f3927598..3bc84bbdd3 100644 --- a/src/runtime/map_fast64.go +++ b/src/runtime/map_fast64.go @@ -346,6 +346,11 @@ search: } notLast: h.count-- + // Reset the hash seed to make it more difficult for attackers to + // repeatedly trigger hash collisions. See issue 25237. + if h.count == 0 { + h.hash0 = fastrand() + } break search } } diff --git a/src/runtime/map_faststr.go b/src/runtime/map_faststr.go index 069cda6554..108c502394 100644 --- a/src/runtime/map_faststr.go +++ b/src/runtime/map_faststr.go @@ -369,6 +369,11 @@ search: } notLast: h.count-- + // Reset the hash seed to make it more difficult for attackers to + // repeatedly trigger hash collisions. See issue 25237. + if h.count == 0 { + h.hash0 = fastrand() + } break search } } |