lysu

package main

import (
	"context"
	"testing"
)

type Iface interface {
	F(ctx context.Context) error
}

lysu

==================
WARNING: DATA RACE
Read at 0x0000028eb742 by goroutine 35:
  github.com/pingcap/tidb/plan.tryFastPlan()
      /home/jenkins/workspace/tidb_ghpr_unit_test/go/src/github.com/pingcap/tidb/plan/point_get_plan.go:117 +0x3e
  github.com/pingcap/tidb/plan.Optimize()
      /home/jenkins/workspace/tidb_ghpr_unit_test/go/src/github.com/pingcap/tidb/plan/optimizer.go:62 +0x77
  github.com/pingcap/tidb/executor.(*Compiler).Compile()
      /home/jenkins/workspace/tidb_ghpr_unit_test/go/src/github.com/pingcap/tidb/executor/compiler.go:48 +0x221
  github.com/pingcap/tidb/session.(*session).execute()

lysu

find . -name "*.go" | xargs sed -i 's/github.com\/juju\/errors/github.com\/pkg\/errors/g'
find . -name "*.go" | xargs sed -i 's/errors.Trace(/errors.WithStack(/g'
find . -name "*.go" | xargs sed -i 's/errors.ErrorStack(\(.*\))/fmt.Sprintf("%+v", \1)/g'
find . -name "*.go" | xargs sed -i 's/errors.Wrap(\(.*\), \(.*\))/errors.Wrapf(\2, "%+v", \1)/g'
find . -name "*.go" | xargs sed -i 's/errors.Annotate(\(.*\))/errors.Wrap(\1)/g'
find . -name "*.go" | xargs sed -i 's/errors.NotFoundf(\(.*\))/errors.Errorf(\1)/g'
find . -name "*.go" | xargs sed -i 's/errors.BadRequestf(/errors.Errorf(/g'
find . -name "*.go" | xargs sed -i 's/errors.NotSupportedf(/errors.Errorf(/g'
find . -name "*.go" | xargs sed -i 's/errors.Annotatef(/errors.Wrapf(/g'

lysu

.

lysu

func getLocalAddr(machines []string) (string, error) {

 for _, m := range machines {
  conn, err := net.Dial("udp", m)
  if err != nil {
   continue
  }
  defer conn.Close()

  return strings.Split(conn.LocalAddr().String(), ":")[0], nil

lysu

package main_test

import (
	"testing"
	"fmt"
)

var longStr = "121212123123231231231231311111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111123123"
var shortStr = "1212121231232312312311"

lysu

package main

import (
	"database/sql"
	"fmt"

	_ "github.com/go-sql-driver/mysql"
)

func main() {

lysu

#!/bin/bash

interface=lo
ip=10.0.0.1
delay=100ms

tc qdisc add dev $interface root handle 1: prio
tc filter add dev $interface parent 1:0 protocol ip prio 1 u32 match ip dst $ip flowid 2:1
tc qdisc add dev $interface parent 1:1 handle 2: netem delay $delay

lysu

package test;

import java.io.IOException;
import java.util.Objects;

import com.fasterxml.jackson.core.JsonFactory;
import com.fasterxml.jackson.core.JsonParser;
import com.fasterxml.jackson.core.JsonToken;
import com.fasterxml.jackson.databind.DeserializationContext;
import com.fasterxml.jackson.databind.JsonDeserializer;

lysu

Latency numbers every programmer should know

L1 cache reference ......................... 0.5 ns
Branch mispredict ............................ 5 ns
L2 cache reference ........................... 7 ns
Mutex lock/unlock ........................... 25 ns
Main memory reference ...................... 100 ns             
Compress 1K bytes with Zippy ............. 3,000 ns  =   3 µs
Send 2K bytes over 1 Gbps network ....... 20,000 ns  =  20 µs
SSD random read ........................ 150,000 ns  = 150 µs

Read 1 MB sequentially from memory ..... 250,000 ns = 250 µs