BUGFIX: data race on master.pos

[taylorchu]

================== WARNING: DATA RACE Write at 0x00c420240558 by goroutine 23: github.com/uservoice/indexer/vendor/github.com/siddontang/go-mysql/canal.(*masterInfo).Update() /home/ubuntu/go/src/github.com/uservoice/indexer/vendor/github.com/siddontang/go-mysql/canal/master.go:22 +0x112 github.com/uservoice/indexer/vendor/github.com/siddontang/go-mysql/canal.(*Canal).tryDump() /home/ubuntu/go/src/github.com/uservoice/indexer/vendor/github.com/siddontang/go-mysql/canal/dump.go:130 +0x777 github.com/uservoice/indexer/vendor/github.com/siddontang/go-mysql/canal.(*Canal).run() /home/ubuntu/go/src/github.com/uservoice/indexer/vendor/github.com/siddontang/go-mysql/canal/canal.go:157 +0x7b Previous read at 0x00c420240558 by goroutine 29: github.com/uservoice/indexer/vendor/github.com/siddontang/go-mysql/canal.(*Canal).Close() /home/ubuntu/go/src/github.com/uservoice/indexer/vendor/github.com/siddontang/go-mysql/canal/canal.go:186 +0x1a6 github.com/uservoice/indexer/binlog.(*Stream).Stop() github.com/uservoice/indexer/binlog/_test/_obj_test/stream.go:553 +0x68 github.com/uservoice/indexer/binlog.(*StreamManager).StopAll() github.com/uservoice/indexer/binlog/_test/_obj_test/stream_manager.go:145 +0x2cc github.com/uservoice/indexer/binlog.TestStreamManagerRemoveStream() /home/ubuntu/go/src/github.com/uservoice/indexer/binlog/stream_manager_test.go:82 +0x52f testing.tRunner() /usr/local/go/src/testing/testing.go:746 +0x16c Goroutine 23 (running) created at: github.com/uservoice/indexer/vendor/github.com/siddontang/go-mysql/canal.(*Canal).Start() /home/ubuntu/go/src/github.com/uservoice/indexer/vendor/github.com/siddontang/go-mysql/canal/canal.go:131 +0x69 github.com/uservoice/indexer/binlog.(*Stream).Start() github.com/uservoice/indexer/binlog/_test/_obj_test/stream.go:540 +0x4fa github.com/uservoice/indexer/binlog.(*StreamManager).addRotation() github.com/uservoice/indexer/binlog/_test/_obj_test/stream_manager.go:49 +0x1a9 github.com/uservoice/indexer/binlog.(*StreamManager).Add() github.com/uservoice/indexer/binlog/_test/_obj_test/stream_manager.go:92 +0x8d github.com/uservoice/indexer/binlog.(*StreamManager).StartAll() github.com/uservoice/indexer/binlog/_test/_obj_test/stream_manager.go:204 +0x8b3 github.com/uservoice/indexer/binlog.TestStreamManagerRemoveStream() /home/ubuntu/go/src/github.com/uservoice/indexer/binlog/stream_manager_test.go:62 +0x111 testing.tRunner() /usr/local/go/src/testing/testing.go:746 +0x16c Goroutine 29 (running) created at: testing.(*T).Run() /usr/local/go/src/testing/testing.go:789 +0x568 testing.runTests.func1() /usr/local/go/src/testing/testing.go:1004 +0xa7 testing.tRunner() /usr/local/go/src/testing/testing.go:746 +0x16c testing.runTests() /usr/local/go/src/testing/testing.go:1002 +0x521 testing.(*M).Run() /usr/local/go/src/testing/testing.go:921 +0x206 main.main() github.com/uservoice/indexer/binlog/_test/_testmain.go:132 +0x2f0 ==================``` 

[taylorchu]

@siddontang thanks!

[siddontang]

LGTM

Thanks @taylorchu