chore(performance): Change *sync.RWMutex to sync.RWMutex

[appleboy]

fix #2350

See the report: #2350

Change *sync.RWMutex to sync.RWMutex. See the commet

step and result

Testing in my Macbook Pro

$ go get github.com/gin-gonic/gin@d5a42fc8ac93cebe42cde9c9b91a138358e4f99a
go: github.com/gin-gonic/gin d5a42fc8ac93cebe42cde9c9b91a138358e4f99a => v1.6.3-0.20200503042414-d5a42fc8ac93
go: downloading github.com/gin-gonic/gin v1.6.3-0.20200503042414-d5a42fc8ac93
$ go get github.com/julienschmidt/httprouter@master
go: github.com/julienschmidt/httprouter master => v1.3.1-0.20200114094804-8c9f31f047a3
go: downloading github.com/julienschmidt/httprouter v1.3.1-0.20200114094804-8c9f31f047a3

Benchmark Result:

BenchmarkEcho_Param              	12894638	        88.9 ns/op	       0 B/op	       0 allocs/op
BenchmarkGin_Param               	16120810	        75.8 ns/op	       0 B/op	       0 allocs/op
BenchmarkHttpRouter_Param        	20860491	        59.0 ns/op	       0 B/op	       0 allocs/op
BenchmarkEcho_Param5             	 5107472	       236 ns/op	       0 B/op	       0 allocs/op
BenchmarkGin_Param5              	 8665498	       139 ns/op	       0 B/op	       0 allocs/op
BenchmarkHttpRouter_Param5       	10716376	       111 ns/op	       0 B/op	       0 allocs/op
BenchmarkEcho_Param20            	 1649486	       736 ns/op	       0 B/op	       0 allocs/op
BenchmarkGin_Param20             	 3693909	       317 ns/op	       0 B/op	       0 allocs/op
BenchmarkHttpRouter_Param20      	 4302121	       291 ns/op	       0 B/op	       0 allocs/op
BenchmarkEcho_ParamWrite         	 6067071	       206 ns/op	       8 B/op	       1 allocs/op
BenchmarkGin_ParamWrite          	 7927640	       153 ns/op	       0 B/op	       0 allocs/op
BenchmarkHttpRouter_ParamWrite   	12336866	        97.2 ns/op	       0 B/op	       0 allocs/op
BenchmarkEcho_GithubStatic       	 9660526	       123 ns/op	       0 B/op	       0 allocs/op
BenchmarkGin_GithubStatic        	12108596	        99.3 ns/op	       0 B/op	       0 allocs/op
BenchmarkHttpRouter_GithubStatic 	22733364	        53.9 ns/op	       0 B/op	       0 allocs/op
BenchmarkEcho_GithubParam        	 4760176	       241 ns/op	       0 B/op	       0 allocs/op
BenchmarkGin_GithubParam         	 6903195	       175 ns/op	       0 B/op	       0 allocs/op
BenchmarkHttpRouter_GithubParam  	 8757140	       139 ns/op	       0 B/op	       0 allocs/op
BenchmarkEcho_GithubAll          	   25303	     47044 ns/op	       0 B/op	       0 allocs/op
BenchmarkGin_GithubAll           	   35906	     32017 ns/op	       0 B/op	       0 allocs/op
BenchmarkHttpRouter_GithubAll    	   48505	     24723 ns/op	       0 B/op	       0 allocs/op
BenchmarkEcho_GPlusStatic        	13986368	        88.1 ns/op	       0 B/op	       0 allocs/op
BenchmarkGin_GPlusStatic         	15715994	        76.2 ns/op	       0 B/op	       0 allocs/op
BenchmarkHttpRouter_GPlusStatic  	40313703	        30.6 ns/op	       0 B/op	       0 allocs/op
BenchmarkEcho_GPlusParam         	 8838810	       132 ns/op	       0 B/op	       0 allocs/op
BenchmarkGin_GPlusParam          	11063152	       110 ns/op	       0 B/op	       0 allocs/op
BenchmarkHttpRouter_GPlusParam   	14874406	        83.3 ns/op	       0 B/op	       0 allocs/op
BenchmarkEcho_GPlus2Params       	 5957268	       197 ns/op	       0 B/op	       0 allocs/op
BenchmarkGin_GPlus2Params        	 8538530	       138 ns/op	       0 B/op	       0 allocs/op
BenchmarkHttpRouter_GPlus2Params 	11009853	       109 ns/op	       0 B/op	       0 allocs/op
BenchmarkEcho_GPlusAll           	  610393	      2072 ns/op	       0 B/op	       0 allocs/op
BenchmarkGin_GPlusAll            	  845540	      1452 ns/op	       0 B/op	       0 allocs/op
BenchmarkHttpRouter_GPlusAll     	 1000000	      1022 ns/op	       0 B/op	       0 allocs/op
BenchmarkEcho_ParseStatic        	13372183	        89.4 ns/op	       0 B/op	       0 allocs/op
BenchmarkGin_ParseStatic         	15553862	        76.2 ns/op	       0 B/op	       0 allocs/op
BenchmarkHttpRouter_ParseStatic  	36294546	        32.0 ns/op	       0 B/op	       0 allocs/op
BenchmarkEcho_ParseParam         	10718779	       108 ns/op	       0 B/op	       0 allocs/op
BenchmarkGin_ParseParam          	14966005	        82.9 ns/op	       0 B/op	       0 allocs/op
BenchmarkHttpRouter_ParseParam   	18341719	        65.6 ns/op	       0 B/op	       0 allocs/op
BenchmarkEcho_Parse2Params       	 8146166	       149 ns/op	       0 B/op	       0 allocs/op
BenchmarkGin_Parse2Params        	11563095	       105 ns/op	       0 B/op	       0 allocs/op
BenchmarkHttpRouter_Parse2Params 	14198692	        83.3 ns/op	       0 B/op	       0 allocs/op
BenchmarkEcho_ParseAll           	  343478	      3427 ns/op	       0 B/op	       0 allocs/op
BenchmarkGin_ParseAll            	  467335	      2817 ns/op	       0 B/op	       0 allocs/op
BenchmarkHttpRouter_ParseAll     	  739195	      1768 ns/op	       0 B/op	       0 allocs/op
BenchmarkEcho_StaticAll          	   39229	     29002 ns/op	       0 B/op	       0 allocs/op
BenchmarkGin_StaticAll           	   50160	     25493 ns/op	       0 B/op	       0 allocs/op
BenchmarkHttpRouter_StaticAll    	   90253	     12674 ns/op	       0 B/op	       0 allocs/op
PASS
ok  	github.com/julienschmidt/go-http-routing-benchmark	67.399s

Or you can see the benchmark result from Travis: https://travis-ci.org/github/gin-gonic/go-http-routing-benchmark/jobs/682559844

[codecov]

Codecov Report

Merging #2351 into master will increase coverage by 0.08%.
The diff coverage is 100.00%.

@@            Coverage Diff             @@
##           master    #2351      +/-   ##
==========================================
+ Coverage   98.39%   98.48%   +0.08%     
==========================================
  Files          41       41              
  Lines        2304     2303       -1     
==========================================
+ Hits         2267     2268       +1     
+ Misses         21       20       -1     
+ Partials       16       15       -1     

Impacted Files	Coverage Δ
context.go	98.08% <100.00%> (+0.42%)	⬆️
gin.go	99.13% <100.00%> (ø)

---

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[appleboy]

@thinkerou Please review again. I will bump to v1.6.3 after merge this PR.

[appleboy]

See the report from Travis: https://travis-ci.org/github/gin-gonic/go-http-routing-benchmark/jobs/682559844

$ go test -bench="Gin|Echo|HttpRouter"
#GithubAPI Routes: 203
   Echo: 100088 Bytes
   Gin: 58512 Bytes
   HttpRouter: 37144 Bytes
#GPlusAPI Routes: 13
   Echo: 9688 Bytes
   Gin: 4384 Bytes
   HttpRouter: 2808 Bytes
#ParseAPI Routes: 26
   Echo: 11872 Bytes
   Gin: 7776 Bytes
   HttpRouter: 5072 Bytes
#Static Routes: 157
   Echo: 80328 Bytes
   Gin: 34936 Bytes
   HttpRouter: 21712 Bytes
goos: linux
goarch: amd64
pkg: github.com/julienschmidt/go-http-routing-benchmark
BenchmarkEcho_Param              	16403503	        73.0 ns/op	       0 B/op	       0 allocs/op
BenchmarkGin_Param               	19200168	        63.0 ns/op	       0 B/op	       0 allocs/op
BenchmarkHttpRouter_Param        	24812588	        48.4 ns/op	       0 B/op	       0 allocs/op
BenchmarkEcho_Param5             	 6419178	       195 ns/op	       0 B/op	       0 allocs/op
BenchmarkGin_Param5              	11282056	       107 ns/op	       0 B/op	       0 allocs/op
BenchmarkHttpRouter_Param5       	12574981	        95.3 ns/op	       0 B/op	       0 allocs/op
BenchmarkEcho_Param20            	 2083293	       576 ns/op	       0 B/op	       0 allocs/op
BenchmarkGin_Param20             	 4224432	       269 ns/op	       0 B/op	       0 allocs/op
BenchmarkHttpRouter_Param20      	 4793692	       250 ns/op	       0 B/op	       0 allocs/op
BenchmarkEcho_ParamWrite         	 7633502	       171 ns/op	       8 B/op	       1 allocs/op
BenchmarkGin_ParamWrite          	 9792526	       124 ns/op	       0 B/op	       0 allocs/op
BenchmarkHttpRouter_ParamWrite   	14408402	        79.7 ns/op	       0 B/op	       0 allocs/op
BenchmarkEcho_GithubStatic       	11518838	       104 ns/op	       0 B/op	       0 allocs/op
BenchmarkGin_GithubStatic        	15070081	        80.0 ns/op	       0 B/op	       0 allocs/op
BenchmarkHttpRouter_GithubStatic 	27487160	        43.7 ns/op	       0 B/op	       0 allocs/op
BenchmarkEcho_GithubParam        	 5907873	       198 ns/op	       0 B/op	       0 allocs/op
BenchmarkGin_GithubParam         	 9415957	       128 ns/op	       0 B/op	       0 allocs/op
BenchmarkHttpRouter_GithubParam  	10633294	       115 ns/op	       0 B/op	       0 allocs/op
BenchmarkEcho_GithubAll          	   29670	     40039 ns/op	       0 B/op	       0 allocs/op
BenchmarkGin_GithubAll           	   44275	     27052 ns/op	       0 B/op	       0 allocs/op
BenchmarkHttpRouter_GithubAll    	   60016	     20138 ns/op	       0 B/op	       0 allocs/op
BenchmarkEcho_GPlusStatic        	17001352	        71.2 ns/op	       0 B/op	       0 allocs/op
BenchmarkGin_GPlusStatic         	18895076	        63.5 ns/op	       0 B/op	       0 allocs/op
BenchmarkHttpRouter_GPlusStatic  	48431677	        24.6 ns/op	       0 B/op	       0 allocs/op
BenchmarkEcho_GPlusParam         	11254729	       106 ns/op	       0 B/op	       0 allocs/op
BenchmarkGin_GPlusParam          	14198464	        84.6 ns/op	       0 B/op	       0 allocs/op
BenchmarkHttpRouter_GPlusParam   	15721663	        76.5 ns/op	       0 B/op	       0 allocs/op
BenchmarkEcho_GPlus2Params       	 7311615	       164 ns/op	       0 B/op	       0 allocs/op
BenchmarkGin_GPlus2Params        	11699445	       101 ns/op	       0 B/op	       0 allocs/op
BenchmarkHttpRouter_GPlus2Params 	11946534	       100 ns/op	       0 B/op	       0 allocs/op
BenchmarkEcho_GPlusAll           	  663595	      1740 ns/op	       0 B/op	       0 allocs/op
BenchmarkGin_GPlusAll            	 1000000	      1133 ns/op	       0 B/op	       0 allocs/op
BenchmarkHttpRouter_GPlusAll     	 1400403	       857 ns/op	       0 B/op	       0 allocs/op
BenchmarkEcho_ParseStatic        	16616858	        72.7 ns/op	       0 B/op	       0 allocs/op
BenchmarkGin_ParseStatic         	19508838	        61.6 ns/op	       0 B/op	       0 allocs/op
BenchmarkHttpRouter_ParseStatic  	46832966	        25.9 ns/op	       0 B/op	       0 allocs/op
BenchmarkEcho_ParseParam         	13397647	        89.1 ns/op	       0 B/op	       0 allocs/op
BenchmarkGin_ParseParam          	18163994	        66.1 ns/op	       0 B/op	       0 allocs/op
BenchmarkHttpRouter_ParseParam   	23268356	        51.1 ns/op	       0 B/op	       0 allocs/op
BenchmarkEcho_Parse2Params       	10108040	       119 ns/op	       0 B/op	       0 allocs/op
BenchmarkGin_Parse2Params        	15217050	        78.9 ns/op	       0 B/op	       0 allocs/op
BenchmarkHttpRouter_Parse2Params 	18317415	        66.1 ns/op	       0 B/op	       0 allocs/op
BenchmarkEcho_ParseAll           	  407364	      2879 ns/op	       0 B/op	       0 allocs/op
BenchmarkGin_ParseAll            	  602881	      1963 ns/op	       0 B/op	       0 allocs/op
BenchmarkHttpRouter_ParseAll     	  900546	      1322 ns/op	       0 B/op	       0 allocs/op
BenchmarkEcho_StaticAll          	   46124	     25657 ns/op	       0 B/op	       0 allocs/op
BenchmarkGin_StaticAll           	   60685	     19796 ns/op	       0 B/op	       0 allocs/op
BenchmarkHttpRouter_StaticAll    	  108180	     10973 ns/op	       0 B/op	       0 allocs/op
PASS
ok  	github.com/julienschmidt/go-http-routing-benchmark	65.607s

[thinkerou]

lgtm

[thinkerou]

@appleboy also update readme.me? thanks!

[appleboy]

@thinkerou What content in the readme I need to update?

[thinkerou]

@thinkerou What content in the readme I need to update?

@appleboy here https://github.com/gin-gonic/gin#benchmarks

[appleboy]

@thinkerou Yes. I know. I will take it after release v1.6.3 version. Thanks for your remind.

[yongliu1992]

@appleboy

Would you like to tell me Why *sync.RWMutex to sync.RWMutex can improvement performance ，I've read the code change, but I still don't know what the change solves to improve performance

[imxyb]

@appleboy i also want to know why improvement performance~

[sambsy]

@appleboy

Would you like to tell me Why *sync.RWMutex to sync.RWMutex can improvement performance ，I've read the code change, but I still don't know what the change solves to improve performance

needn't share a lock for multiple contexts. *sync.RWMutex will share a lock after Context.Copy