>実は [ruby-talk:140537] はスレッドに対応してなくて、
>スレッドに対応したものが [ruby-talk:140548] になります。

なんか送信ミスがあったようで、違うコードが送信されてました。
正しいコードは [ruby-talk:140595] です。

以下にコードを添付しておきます。

# 前田さんのプロファイラが取り込まれると、このコードが
# 無駄になるであろうことは承知の上です。1.8.3 で
# 取り込まれるなら、ruby-prof にも同じ問題があるようなので
# 修正の必要があると思います。

//////////////////////////////////////////////////
// スレッド未対応

module Profiler__
  # internal values
  @@start = @@stack = @@map = nil
  PROFILE_PROC = proc{|event, file, line, id, binding, klass|
    case event
    when "call", "c-call"
      now = Process.times[0]
      @@stack.push [now, 0.0]
    when "return", "c-return"
      now = Process.times[0]
      key = [klass, id]
      if tick = @@stack.pop
        data = (@@map[key] ||= [0, 0.0, 0.0, key])
        data[0] += 1
        cost = now - tick[0]
        data[1] += cost
        data[2] += cost - tick[1]
        @@stack[-1][1] += cost if @@stack[-1]
      end
    end
  }
module_function
  def start_profile
    @@start = Process.times[0]
    @@stack = []
    @@map = {}
    set_trace_func PROFILE_PROC
  end
  def stop_profile
    set_trace_func nil
  end
  def print_profile(f)
    stop_profile
    total = Process.times[0] - @@start
    if total == 0 then total = 0.01 end
    data = @@map.values
    data.sort!{|a,b| b[2] <=> a[2]}
    sum = 0
    f.printf "  %%   cumulative   self              self     total\n"
    f.printf " time   seconds   seconds    calls  ms/call  ms/call  name\n"
    for d in data
      sum += d[2]
      f.printf "%6.2f %8.2f  %8.2f %8d ", d[2]/total*100, sum, d[2], d[0]
      f.printf "%8.2f %8.2f  %s\n", d[2]*1000/d[0], d[1]*1000/d[0], get_name(*d[3])
    end
    f.printf "%6.2f %8.2f  %8.2f %8d ", 0.0, total, 0.0, 1
    f.printf "%8.2f %8.2f  %s\n", 0.0, total*1000, "#toplevel"
  end
  def get_name(klass, id)
    name = klass.to_s || ""
    if klass.kind_of? Class
      name += "#"
    else
      name += "."
    end
    name + id.id2name
  end
  private :get_name
end

//////////////////////////////////////////////////
// スレッド対応

module Profiler__
  # internal values
  @@start = @@map = nil
  PROFILE_PROC = proc{|event, file, line, id, binding, klass|
    critical = Thread.critical
    Thread.critical = true
    case event
    when "call", "c-call"
      stack = (Thread.current[:__profiler_stack__] ||= [])
      now = Process.times[0]
      stack.push [now, 0.0]
    when "return", "c-return"
      now = Process.times[0]
      stack = Thread.current[:__profiler_stack__]
      key = [klass, id]
      if stack && (tick = stack.pop)
        data = (@@map[key] ||= [0, 0.0, 0.0, key])
        data[0] += 1
        cost = now - tick[0]
        data[1] += cost
        data[2] += cost - tick[1]
        stack[-1][1] += cost if stack[-1]
      end
    end
    Thread.critical = critical
  }
module_function
  def start_profile
    @@start = Process.times[0]
    @@map = {}
    set_trace_func PROFILE_PROC
  end
  def stop_profile
    set_trace_func nil
  end
  def print_profile(f)
    stop_profile
    total = Process.times[0] - @@start
    if total == 0 then total = 0.01 end
    data = @@map.values
    data.sort!{|a,b| b[2] <=> a[2]}
    sum = 0
    f.printf "  %%   cumulative   self              self     total\n"
    f.printf " time   seconds   seconds    calls  ms/call  ms/call  name\n"
    for d in data
      sum += d[2]
      f.printf "%6.2f %8.2f  %8.2f %8d ", d[2]/total*100, sum, d[2], d[0]
      f.printf "%8.2f %8.2f  %s\n", d[2]*1000/d[0], d[1]*1000/d[0], get_name(*d[3])
    end
    f.printf "%6.2f %8.2f  %8.2f %8d ", 0.0, total, 0.0, 1
    f.printf "%8.2f %8.2f  %s\n", 0.0, total*1000, "#toplevel"
  end
  def get_name(klass, id)
    name = klass.to_s || ""
    if klass.kind_of? Class
      name += "#"
    else
      name += "."
    end
    name + id.id2name
  end
  private :get_name
end