From: nobu.nokada@...
Date: 2003-09-18T09:16:55+09:00
Subject: Re: Testing for memory leaks

Hi,

At Thu, 18 Sep 2003 06:38:24 +0900,
Berger, Daniel wrote:
> Being as I write a lot of extensions, I've discovered that it's best to
> check for memory leaks.  The way I'm doing this now is something like this:

This is the script "memusage.rb" I'm using on Linux.  Requires
procfs mounted at /proc.

#! /usr/bin/ruby
module Memory
  keys = []
  vals = []
  IO.foreach("/proc/self/status") do |l|
    /^Vm(\w+):\s+(\d+)/ =~ l or next
    keys << $1.downcase.intern
    vals << $2.to_i
  end
  Status = Struct.new(*keys)
  Status.module_eval do
    const_set(:Header, "      "+keys.collect {|k| k.to_s.upcase.rjust(6)}.join)
    const_set(:Format, "%6d")
  end
  init = Status.new(*vals)
  class Status
    @@count = 0
    def initialize
      @count = @@count += 1
      IO.foreach("/proc/self/status") do |l|
        /^Vm(\w+):\s+(\d+)/ =~ l or next
        self.__send__($1.downcase+"=", $2.to_i)
      end
    end
    def to_s
      "%4d: "%@count + collect {|n| Format % n}.join
    end
  end
  puts Status::Header, init
end
if __FILE__ == $0
  10.times do
    puts Memory::Status.new
    GC.start
  end
end


> Is there a better and/or more streamlined way to do this?  Any chance of
> adding assert_no_memory_leak to TestUnit, for example?

I don't guess that assertion is easy.  Generally, it's
difficult to determin the memory is really leaked or not.

-- 
Nobu Nakada