Stress Test V8 to exhibit memory usage. Uncomment line 5 to demonstrate that SetFlagsFromString has actual impact on the V8 runtime.

v8_memory_stress.rb

require 'rubygems'
require 'handlebars'
require 'v8'

# V8::C::V8.SetFlagsFromString("--max-old-space-size=200")

@heap_stats_methods = [:total_heap_size, :total_heap_size_executable, :used_heap_size, :heap_size_limit]
@st = V8::C::HeapStatistics.new

def dump_stats
    V8::C::V8.GetHeapStatistics(@st)
    @heap_stats_methods.each do |m|
      v = @st.send(m)/1_000_000
      puts "#{m} : #{"%05.2f" % v}MB"
    end
end
puts "starting up"

c = Handlebars::Context.new

1.upto(100) do |i|
  t = "pouet#{i} {{gna}} "+"this is a dummy text."*1_000
  d = {gna: "chlu"}
  c.compile(t*1_000).call(d)
  if i % 10 == 0 
    print "."
    $stdout.flush
  end
  if i % 10 == 1
    puts "At #{i}"
    dump_stats
    GC.start()
  end
end