encoding/gob: speedup encoding
Replace typeLock with copy-on-write map using atomic.Value.
benchmark old ns/op new ns/op delta
BenchmarkEndToEndPipe 7722 7709 -0.17%
BenchmarkEndToEndPipe-2 5114 4344 -15.06%
BenchmarkEndToEndPipe-4 3192 2429 -23.90%
BenchmarkEndToEndPipe-8 1833 1438 -21.55%
BenchmarkEndToEndPipe-16 1332 983 -26.20%
BenchmarkEndToEndPipe-32 1444 675 -53.25%
BenchmarkEndToEndByteBuffer 6474 6019 -7.03%
BenchmarkEndToEndByteBuffer-2 4280 2810 -34.35%
BenchmarkEndToEndByteBuffer-4 2264 1774 -21.64%
BenchmarkEndToEndByteBuffer-8 1275 979 -23.22%
BenchmarkEndToEndByteBuffer-16 1257 753 -40.10%
BenchmarkEndToEndByteBuffer-32 1342 644 -52.01%
BenchmarkEndToEndArrayByteBuffer 727725 671349 -7.75%
BenchmarkEndToEndArrayByteBuffer-2 394079 320473 -18.68%
BenchmarkEndToEndArrayByteBuffer-4 211785 178175 -15.87%
BenchmarkEndToEndArrayByteBuffer-8 141003 118857 -15.71%
BenchmarkEndToEndArrayByteBuffer-16 139249 86367 -37.98%
BenchmarkEndToEndArrayByteBuffer-32 144128 73454 -49.04%
LGTM=r
R=golang-codereviews, r
CC=golang-codereviews
https://golang.org/cl/
147720043