github.com/guyezi/gofrontend@v0.0.0-20200228202240-7a62a49e62c0/libgo/go/runtime/testdata/testprog/memprof.go (about)

     1  // Copyright 2016 The Go Authors. All rights reserved.
     2  // Use of this source code is governed by a BSD-style
     3  // license that can be found in the LICENSE file.
     4  
     5  package main
     6  
     7  import (
     8  	"bytes"
     9  	"fmt"
    10  	"io/ioutil"
    11  	"os"
    12  	"runtime"
    13  	"runtime/pprof"
    14  )
    15  
    16  func init() {
    17  	register("MemProf", MemProf)
    18  }
    19  
    20  var memProfBuf bytes.Buffer
    21  var memProfStr string
    22  
    23  func MemProf() {
    24  	// Force heap sampling for determinism.
    25  	runtime.MemProfileRate = 1
    26  
    27  	for i := 0; i < 10; i++ {
    28  		fmt.Fprintf(&memProfBuf, "%*d\n", i, i)
    29  	}
    30  	memProfStr = memProfBuf.String()
    31  
    32  	runtime.GC()
    33  
    34  	f, err := ioutil.TempFile("", "memprof")
    35  	if err != nil {
    36  		fmt.Fprintln(os.Stderr, err)
    37  		os.Exit(2)
    38  	}
    39  
    40  	if err := pprof.WriteHeapProfile(f); err != nil {
    41  		fmt.Fprintln(os.Stderr, err)
    42  		os.Exit(2)
    43  	}
    44  
    45  	name := f.Name()
    46  	if err := f.Close(); err != nil {
    47  		fmt.Fprintln(os.Stderr, err)
    48  		os.Exit(2)
    49  	}
    50  
    51  	fmt.Println(name)
    52  }