Module: Ziltoid::System

Defined in:
lib/ziltoid/system.rb

Constant Summary collapse

PS_FIELDS =

The position of each field in ps output

[:pid, :ppid, :cpu, :ram]

Class Method Summary collapse

Class Method Details

.cpu_usage(pid, include_children = true) ⇒ Object 



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# File 'lib/ziltoid/system.rb', line 42

def cpu_usage(pid, include_children = true)
  ps = ps_aux
  return unless ps[pid]
  cpu_used = ps[pid][:cpu].to_f

  get_children(pid).each do |child_pid|
    cpu_used += ps[child_pid][:cpu].to_f if ps[child_pid]
  end if include_children

  cpu_used
end

.get_children(parent_pid) ⇒ Object 



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# File 'lib/ziltoid/system.rb', line 66

def get_children(parent_pid)
  child_pids = []
  ps_aux.each_pair do |_pid, info|
    child_pids << info[:pid].to_i if info[:ppid].to_i == parent_pid.to_i
  end
  grand_children = child_pids.map { |pid| get_children(pid) }.flatten
  child_pids.concat grand_children
end

.pid_alive?(pid) ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/ziltoid/system.rb', line 10

def pid_alive?(pid)
  return false if pid.nil?
  begin
    ::Process.kill(0, pid)
    true
  rescue Errno::EPERM # no permission, but it is definitely alive
    true
  rescue Errno::ESRCH
    false
  end
end

.ps_aux ⇒ Object 



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# File 'lib/ziltoid/system.rb', line 22

def ps_aux
  # BSD style ps invocation
  processes = `ps axo pid,ppid,pcpu,rss`.split("\n")

  processes.inject({}) do |result, process|
    info = process.split(/\s+/)
    info.delete_if { |p_info| p_info.strip.empty? }
    info.map! { |p_info| p_info.gsub(",", ".") }

    info = PS_FIELDS.each_with_index.inject({}) do |info_hash, (field, field_index)|
      info_hash[field] = info[field_index]
      info_hash
    end

    pid = info[:pid].strip.to_i
    result[pid] = info
    result
  end
end

.ram_usage(pid, include_children = true) ⇒ Object 



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# File 'lib/ziltoid/system.rb', line 54

def ram_usage(pid, include_children = true)
  ps = ps_aux
  return unless ps[pid]
  mem_used = ps[pid][:ram].to_i

  get_children(pid).each do |child_pid|
    mem_used += ps[child_pid][:ram].to_i if ps[child_pid]
  end if include_children

  mem_used
end