go/test/mallocrep.go

// $G $D/$F.go && $L $F.$A && ./$A.out

// Copyright 2009 The Go Authors. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.

// Repeated malloc test.

package main

import (
	"flag";
	"malloc"
)

var chatty = flag.Bool("v", false, "chatty");

var oldsys uint64;
func bigger() {
	if st := malloc.GetStats(); oldsys < st.Sys {
		oldsys = st.Sys;
		if *chatty {
			println(st.Sys, " system bytes for ", st.Alloc, " Go bytes");
		}
		if st.Sys > 1e9 {
			panicln("too big");
		}
	}
}

func main() {
	flag.Parse();
	malloc.GetStats().Alloc = 0;	// ignore stacks
	for i := 0; i < 1<<8; i++ {
		for j := 1; j <= 1<<22; j<<=1 {
			if i == 0 && *chatty {
				println("First alloc:", j);
			}
			if a := malloc.GetStats().Alloc; a != 0 {
				panicln("no allocations but stats report", a, "bytes allocated");
			}
			b := malloc.Alloc(uintptr(j));
			during := malloc.GetStats().Alloc;
			malloc.Free(b);
			if a := malloc.GetStats().Alloc; a != 0 {
				panic("allocated ", j, ": wrong stats: during=", during, " after=", a, " (want 0)");
			}
			bigger();
		}
		if i%(1<<10) == 0 && *chatty {
			println(i);
		}
		if i == 0 {
			if *chatty {
				println("Primed", i);
			}
		//	malloc.frozen = true;
		}
	}
}