From 5e72de4ba23d85a05e03ce7e026b45ae26add049 Mon Sep 17 00:00:00 2001
From: Andrey Nering <andrey.nering@gmail.com>
Date: Thu, 7 Sep 2017 10:40:21 -0300
Subject: [PATCH] Revert "execext: use sync.Pool to instantiate parser and
 runner"

This reverts commit 451b965fb0e0c21981eda28994dab2a4fc8e56f0.
---
 execext/exec.go      | 38 ++++++------------------
 execext/exec_test.go | 69 --------------------------------------------
 2 files changed, 9 insertions(+), 98 deletions(-)
 delete mode 100644 execext/exec_test.go

diff --git a/execext/exec.go b/execext/exec.go
index b551d2ac..6d1304cc 100644
--- a/execext/exec.go
+++ b/execext/exec.go
@@ -5,26 +5,11 @@ import (
 	"errors"
 	"io"
 	"strings"
-	"sync"
 
 	"mvdan.cc/sh/interp"
 	"mvdan.cc/sh/syntax"
 )
 
-var (
-	parserPool = sync.Pool{
-		New: func() interface{} {
-			return syntax.NewParser()
-		},
-	}
-
-	runnerPool = sync.Pool{
-		New: func() interface{} {
-			return &interp.Runner{}
-		},
-	}
-)
-
 // RunCommandOptions is the options for the RunCommand func
 type RunCommandOptions struct {
 	Context context.Context
@@ -47,24 +32,19 @@ func RunCommand(opts *RunCommandOptions) error {
 		return ErrNilOptions
 	}
 
-	parser := parserPool.Get().(*syntax.Parser)
-	defer parserPool.Put(parser)
-
-	p, err := parser.Parse(strings.NewReader(opts.Command), "")
+	p, err := syntax.NewParser().Parse(strings.NewReader(opts.Command), "")
 	if err != nil {
 		return err
 	}
 
-	r := runnerPool.Get().(*interp.Runner)
-	defer runnerPool.Put(r)
-
-	r.Context = opts.Context
-	r.Dir = opts.Dir
-	r.Env = opts.Env
-	r.Stdin = opts.Stdin
-	r.Stdout = opts.Stdout
-	r.Stderr = opts.Stderr
-
+	r := interp.Runner{
+		Context: opts.Context,
+		Dir:     opts.Dir,
+		Env:     opts.Env,
+		Stdin:   opts.Stdin,
+		Stdout:  opts.Stdout,
+		Stderr:  opts.Stderr,
+	}
 	if err = r.Reset(); err != nil {
 		return err
 	}
diff --git a/execext/exec_test.go b/execext/exec_test.go
deleted file mode 100644
index a02cdcb2..00000000
--- a/execext/exec_test.go
+++ /dev/null
@@ -1,69 +0,0 @@
-// execext_test.go
-package execext
-
-import (
-	"context"
-	"io/ioutil"
-	"strings"
-	"sync"
-	"testing"
-
-	"mvdan.cc/sh/interp"
-	"mvdan.cc/sh/syntax"
-)
-
-func BenchmarkNoPool(b *testing.B) {
-	for i := 0; i < b.N; i++ {
-		f, err := syntax.NewParser().Parse(strings.NewReader(`echo "Hello, World!"`), "")
-		if err != nil {
-			panic(err)
-		}
-		r := interp.Runner{
-			Context: context.TODO(),
-			Stdout:  ioutil.Discard,
-			Stderr:  ioutil.Discard,
-		}
-		if err = r.Reset(); err != nil {
-			panic(err)
-		}
-		if err = r.Run(f); err != nil {
-			panic(err)
-		}
-	}
-}
-
-func BenchmarkPool(b *testing.B) {
-	parserPool := sync.Pool{
-		New: func() interface{} {
-			return syntax.NewParser()
-		},
-	}
-	runnerPool := sync.Pool{
-		New: func() interface{} {
-			return &interp.Runner{}
-		},
-	}
-
-	for i := 0; i < b.N; i++ {
-		parser := parserPool.Get().(*syntax.Parser)
-		defer parserPool.Put(parser)
-
-		f, err := parser.Parse(strings.NewReader(`echo "Hello, World!"`), "")
-		if err != nil {
-			panic(err)
-		}
-
-		r := runnerPool.Get().(*interp.Runner)
-		defer runnerPool.Put(r)
-
-		r.Stdout = ioutil.Discard
-		r.Stderr = ioutil.Discard
-
-		if err = r.Reset(); err != nil {
-			panic(err)
-		}
-		if err = r.Run(f); err != nil {
-			panic(err)
-		}
-	}
-}