class GetProcessMem

Cribbed from Unicorn Worker Killer, thanks!

Constants

CONVERSION
GB_TO_BYTE
KB_TO_BYTE
MB_TO_BYTE
ROUND_UP
RUNS_ON_WINDOWS
VERSION

Attributes

pid[R]

Public Class Methods

new(pid = Process.pid) click to toggle source

# File lib/get_process_mem.rb, line 26
def initialize(pid = Process.pid)
  @status_file  = Pathname.new "/proc/#{pid}/status"
  @process_file = Pathname.new "/proc/#{pid}/smaps"
  @pid          = pid
  @linux        = @status_file.exist?
end

Public Instance Methods

bytes() click to toggle source

# File lib/get_process_mem.rb, line 37
def bytes
  memory =   linux_status_memory if linux?
  memory ||= ps_memory
end

gb(b = bytes) click to toggle source

# File lib/get_process_mem.rb, line 50
def gb(b = bytes)
  (b/BigDecimal.new(GB_TO_BYTE)).to_f
end

inspect() click to toggle source

# File lib/get_process_mem.rb, line 54
def inspect
  b = bytes
  "#<#{self.class}:0x%08x @mb=#{ mb b } @gb=#{ gb b } @kb=#{ kb b } @bytes=#{b}>" % (object_id * 2)
end

kb(b = bytes) click to toggle source

# File lib/get_process_mem.rb, line 42
def kb(b = bytes)
  (b/BigDecimal.new(KB_TO_BYTE)).to_f
end

linux?() click to toggle source

# File lib/get_process_mem.rb, line 33
def linux?
  @linux
end

linux_memory(file = @process_file) click to toggle source

linux stores detailed memory info in a file “/proc/#{pid}/smaps”

# File lib/get_process_mem.rb, line 71
def linux_memory(file = @process_file)
  lines = file.each_line.select {|line| line.match(/^Rss/) }
  return if lines.empty?
  lines.reduce(0) do |sum, line|
    line.match(/(?<value>(\d*\.{0,1}\d+))\s+(?<unit>\w\w)/) do |m|
      value = BigDecimal.new(m[:value]) + ROUND_UP
      unit  = m[:unit].downcase
      sum  += CONVERSION[unit] * value
    end
    sum
  end
rescue Errno::EACCES
  0
end

linux_status_memory(file = @status_file) click to toggle source

linux stores memory info in a file “/proc/#{pid}/status” If it's available it uses less resources than shelling out to ps

# File lib/get_process_mem.rb, line 61
def linux_status_memory(file = @status_file)
  line = file.each_line.detect {|line| line.start_with? 'VmRSS'.freeze }
  return unless line
  return unless (_name, value, unit = line.split(nil)).length == 3
  CONVERSION[unit.downcase!] * value.to_i
rescue Errno::EACCES, Errno::ENOENT
  0
end

mb(b = bytes) click to toggle source

# File lib/get_process_mem.rb, line 46
def mb(b = bytes)
  (b/BigDecimal.new(MB_TO_BYTE)).to_f
end

ps_memory() click to toggle source

Pull memory from `ps` command, takes more resources and can freeze in low memory situations

# File lib/get_process_mem.rb, line 88
def ps_memory
  if RUNS_ON_WINDOWS
    size = ProcTable.ps(pid).working_set_size
    BigDecimal.new(size)
  else
    KB_TO_BYTE * BigDecimal.new(`ps -o rss= -p #{pid}`)
  end
end