lib/memory_profiler.rb
# This is a memory profiler for Ruby. Once started, it runs in a thread in the
# background, periodically inspecting Ruby's ObjectSpace to look for new
# objects and printing a count of objects added and removed since the previous
# cycle.
#
# To use the profiler, do something like this:
#
# require 'memory_profiler'
#
# MemoryProfiler.start
#
# The profiler will write logs to ./log/memory_profiler.log.
#
# If you start MemoryProfiler with the ':string_debug => true' option, then it
# will dump a list of all strings in the app into the log/ directory after
# each cycle. You can then use 'diff' to spot which strings were added
# between runs.
class MemoryProfiler
DEFAULTS = {delay: 10, string_debug: false}
def self.start(opt={})
opt = DEFAULTS.dup.merge(opt)
Thread.new do
prev = Hash.new(0)
curr = Hash.new(0)
curr_strings = []
delta = Hash.new(0)
file = File.open("log/memory_profiler.#{Time.now.to_i}.log",'w')
loop do
begin
GC.start
curr.clear
curr_strings = [] if opt[:string_debug]
ObjectSpace.each_object do |o|
curr[o.class] += 1 #Marshal.dump(o).size rescue 1
if opt[:string_debug] and o.class == String
curr_strings.push o
end
end
if opt[:string_debug]
File.open("log/memory_profiler_strings.log.#{Time.now.to_i}",'w') do |f|
curr_strings.sort.each do |s|
f.puts s
end
end
curr_strings.clear
end
delta.clear
(curr.keys + delta.keys).uniq.each do |k,v|
delta[k] = curr[k]-prev[k]
end
file.puts "Top 20: #{Time.now}"
delta.sort_by { |k,v| -v.abs }[0..19].sort_by { |k,v| -v}.each do |k,v|
file.printf "%+5d: %s (%d)\n", v, k.name, curr[k] unless v == 0
end
file.flush
delta.clear
prev.clear
prev.update curr
GC.start
rescue Exception => err
STDERR.puts "** memory_profiler error: #{err}"
end
sleep opt[:delay]
end
end
end
end