var dictionary = map[string]string{}
    // OR
    var dictionary = make(map[string]string)
  

Our team created a proof of concept (POC) that achieved near parity in performance with the C engine, 
but only if we used the right programming patterns:

- Buffer all IO to reduce the overhead on Go system calls. 
  On a system call, current Goroutines yield to that call. 
- When possible in tight loops, use structs instead of interfaces 
  to minimize the interface methods indirection overhead. 
- Use pre-allocated buffers within tight loops (similarly to how io.Reader works)
  to minimize garbage collection pressure.
- Process data rows in batches as a workaround to poor compiler inlining,
  as to move the actual computation closer to the data and minimize 
  the overhead on each function call. 

 $ go tool compile unsafe.go  (object file 생성)
 $ go tool compile -pack unsafe.go (archive file 생성)
 $ go tool compile -race unsafe.go (race condition 감지)
 $ go tool compile -S unsafe.go (assembly)
 $ go tool compile -W hello.go (node tree 생성)

 $ go build -o add.a  
 $ go tool objdump add.a

package main

import (
	"os"
	"runtime/trace"
)

func main() {
	trace.Start(os.Stderr)
	defer trace.Stop()

	ch := make(chan int)

	go func() {
		ch <-42
	}()
	
	<-ch
}

 $ go run runtime_trace.go 2>trace.out
 $ go tool trace trace.out

func main() {

    defer profile.Start(profile.CPUProfile, profile.ProfilePath(".")).Stop()  // Add this line to programe 
   
    f, err := os.Open(os.Args[1])
    if err != nil {
     ...
    }

}

:Goimports 

<< after execution >>

$ go tool pprof cpu.pprof

$ go tool pprof -http=:8080 cpu.pprof

 

func main() {

    defer profile.Start(profile.MemProfile, profile.MemProfileRate(1),profile.ProfilePath(".")).Stop()  // Add this line to programe 
   
    f, err := os.Open(os.Args[1])
    if err != nil {
     ...
    }

}

:Goimports 

<< after execution >>

$ go tool pprof mem.pprof

$ go tool pprof -http=:8080 mem.pprof
 

– Creating substrings and subslices.
– Wrong use of the defer statement.
– Unclosed HTTP response bodies (or unclosed resources in general).
– Orphaned hanging go routines.
– Global variables.

 $GODEBUG=gctrace=1 go run gColl.go