path: root/spec/mspec/lib/mspec/runner/actions/leakchecker.rb

# Adapted from ruby's test/lib/leakchecker.rb.
# Ruby's 2-clause BSDL follows.

# Copyright (C) 1993-2013 Yukihiro Matsumoto. All rights reserved.

# Redistribution and use in source and binary forms, with or without
# modification, are permitted provided that the following conditions
# are met:
# 1. Redistributions of source code must retain the above copyright
# notice, this list of conditions and the following disclaimer.
# 2. Redistributions in binary form must reproduce the above copyright
# notice, this list of conditions and the following disclaimer in the
# documentation and/or other materials provided with the distribution.

# THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
# ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
# IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
# ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
# FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
# DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
# OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
# HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
# LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
# OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
# SUCH DAMAGE.

class LeakChecker
  def initialize
    @fd_info = find_fds
    @tempfile_info = find_tempfiles
    @thread_info = find_threads
    @env_info = find_env
    @argv_info = find_argv
    @encoding_info = find_encodings
  end

  def check(test_name)
    @no_leaks = true
    leaks = [
      check_fd_leak(test_name),
      check_tempfile_leak(test_name),
      check_thread_leak(test_name),
      check_process_leak(test_name),
      check_env(test_name),
      check_argv(test_name),
      check_encodings(test_name)
    ]
    GC.start if leaks.any?
    return leaks.none?
  end

  private
  def find_fds
    fd_dir = "/proc/self/fd"
    if File.directory?(fd_dir)
      fds = Dir.open(fd_dir) {|d|
        a = d.grep(/\A\d+\z/, &:to_i)
        if d.respond_to? :fileno
          a -= [d.fileno]
        end
        a
      }
      fds.sort
    else
      []
    end
  end

  def check_fd_leak(test_name)
    leaked = false
    live1 = @fd_info
    if IO.respond_to?(:console) and (m = IO.method(:console)).arity.nonzero?
      m[:close]
    end
    live2 = find_fds
    fd_closed = live1 - live2
    if !fd_closed.empty?
      fd_closed.each {|fd|
        puts "Closed file descriptor: #{test_name}: #{fd}"
      }
    end
    fd_leaked = live2 - live1
    if !fd_leaked.empty?
      leaked = true
      h = {}
      ObjectSpace.each_object(IO) {|io|
        inspect = io.inspect
        begin
          autoclose = io.autoclose?
          fd = io.fileno
        rescue IOError # closed IO object
          next
        end
        (h[fd] ||= []) << [io, autoclose, inspect]
      }
      fd_leaked.each {|fd|
        str = ''
        if h[fd]
          str << ' :'
          h[fd].map {|io, autoclose, inspect|
            s = ' ' + inspect
            s << "(not-autoclose)" if !autoclose
            s
          }.sort.each {|s|
            str << s
          }
        end
        puts "Leaked file descriptor: #{test_name}: #{fd}#{str}"
      }
      #system("lsof -p #$$") if !fd_leaked.empty?
      h.each {|fd, list|
        next if list.length <= 1
        if 1 < list.count {|io, autoclose, inspect| autoclose }
          str = list.map {|io, autoclose, inspect| " #{inspect}" + (autoclose ? "(autoclose)" : "") }.sort.join
          puts "Multiple autoclose IO object for a file descriptor:#{str}"
        end
      }
    end
    @fd_info = live2
    return leaked
  end

  def extend_tempfile_counter
    return if defined? LeakChecker::TempfileCounter
    m = Module.new {
      @count = 0
      class << self
        attr_accessor :count
      end

      def new(data)
        LeakChecker::TempfileCounter.count += 1
        super(data)
      end
    }
    LeakChecker.const_set(:TempfileCounter, m)

    class << Tempfile::Remover
      prepend LeakChecker::TempfileCounter
    end
  end

  def find_tempfiles(prev_count=-1)
    return [prev_count, []] unless defined? Tempfile
    extend_tempfile_counter
    count = TempfileCounter.count
    if prev_count == count
      [prev_count, []]
    else
      tempfiles = ObjectSpace.each_object(Tempfile).find_all {|t| t.path }
      [count, tempfiles]
    end
  end

  def check_tempfile_leak(test_name)
    return false unless defined? Tempfile
    count1, initial_tempfiles = @tempfile_info
    count2, current_tempfiles = find_tempfiles(count1)
    leaked = false
    tempfiles_leaked = current_tempfiles - initial_tempfiles
    if !tempfiles_leaked.empty?
      leaked = true
      list = tempfiles_leaked.map {|t| t.inspect }.sort
      list.each {|str|
        puts "Leaked tempfile: #{test_name}: #{str}"
      }
      tempfiles_leaked.each {|t| t.close! }
    end
    @tempfile_info = [count2, initial_tempfiles]
    return leaked
  end

  def find_threads
    Thread.list.find_all {|t|
      t != Thread.current && t.alive?
    }
  end

  def check_thread_leak(test_name)
    live1 = @thread_info
    live2 = find_threads
    thread_finished = live1 - live2
    leaked = false
    if !thread_finished.empty?
      list = thread_finished.map {|t| t.inspect }.sort
      list.each {|str|
        puts "Finished thread: #{test_name}: #{str}"
      }
    end
    thread_leaked = live2 - live1
    if !thread_leaked.empty?
      leaked = true
      list = thread_leaked.map {|t| t.inspect }.sort
      list.each {|str|
        puts "Leaked thread: #{test_name}: #{str}"
      }
    end
    @thread_info = live2
    return leaked
  end

  def check_process_leak(test_name)
    subprocesses_leaked = Process.waitall
    subprocesses_leaked.each { |pid, status|
      puts "Leaked subprocess: #{pid}: #{status}"
    }
    return !subprocesses_leaked.empty?
  end

  def find_env
    ENV.to_h
  end

  def check_env(test_name)
    old_env = @env_info
    new_env = find_env
    return false if old_env == new_env
    (old_env.keys | new_env.keys).sort.each {|k|
      if old_env.has_key?(k)
        if new_env.has_key?(k)
          if old_env[k] != new_env[k]
            puts "Environment variable changed: #{test_name} : #{k.inspect} changed : #{old_env[k].inspect} -> #{new_env[k].inspect}"
          end
        else
          puts "Environment variable changed: #{test_name} : #{k.inspect} deleted"
        end
      else
        if new_env.has_key?(k)
          puts "Environment variable changed: #{test_name} : #{k.inspect} added"
        else
          flunk "unreachable"
        end
      end
    }
    @env_info = new_env
    return true
  end

  def find_argv
    ARGV.map { |e| e.dup }
  end

  def check_argv(test_name)
    old_argv = @argv_info
    new_argv = find_argv
    leaked = false
    if new_argv != old_argv
      puts "ARGV changed: #{test_name} : #{old_argv.inspect} to #{new_argv.inspect}"
      @argv_info = new_argv
      leaked = true
    end
    return leaked
  end

  def find_encodings
    [Encoding.default_internal, Encoding.default_external]
  end

  def check_encodings(test_name)
    old_internal, old_external = @encoding_info
    new_internal, new_external = find_encodings
    leaked = false
    if new_internal != old_internal
      leaked = true
      puts "Encoding.default_internal changed: #{test_name} : #{old_internal.inspect} to #{new_internal.inspect}"
    end
    if new_external != old_external
      leaked = true
      puts "Encoding.default_external changed: #{test_name} : #{old_external.inspect} to #{new_external.inspect}"
    end
    @encoding_info = [new_internal, new_external]
    return leaked
  end

  def puts(*args)
    if @no_leaks
      @no_leaks = false
      print "\n"
    end
    super(*args)
  end
end

class LeakCheckerAction
  def register
    MSpec.register :start, self
    MSpec.register :after, self
  end

  def start
    @checker = LeakChecker.new
  end

  def after(state)
    unless @checker.check(state.description)
      if state.example
        puts state.example.source_location.join(':')
      end
    end
  end
end