Module: Parallel::ProcessorCount

Included in:
Parallel
Defined in:
lib/parallel/processor_count.rb

Overview

TODO: inline this method into parallel.rb and kill physical_processor_count in next major release

Instance Method Summary collapse

Instance Method Details

#physical_processor_count ⇒ Object

Number of physical processor cores on the current system.



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# File 'lib/parallel/processor_count.rb', line 13

def physical_processor_count
  @physical_processor_count ||= begin
    ppc =
      case RbConfig::CONFIG["target_os"]
      when /darwin[12]/
        IO.popen("/usr/sbin/sysctl -n hw.physicalcpu").read.to_i
      when /linux/
        cores = {} # unique physical ID / core ID combinations
        phy = 0
        IO.read("/proc/cpuinfo").scan(/^physical id.*|^core id.*/) do |ln|
          if ln.start_with?("physical")
            phy = ln[/\d+/]
          elsif ln.start_with?("core")
            cid = "#{phy}:#{ln[/\d+/]}"
            cores[cid] = true unless cores[cid]
          end
        end
        cores.count
      when /mswin|mingw/
        require 'win32ole'
        result_set = WIN32OLE.connect("winmgmts://").ExecQuery(
          "select NumberOfCores from Win32_Processor"
        )
        result_set.to_enum.collect(&:NumberOfCores).reduce(:+)
      else
        processor_count
      end
    # fall back to logical count if physical info is invalid
    ppc > 0 ? ppc : processor_count
  end
end

#processor_count ⇒ Object

Number of processors seen by the OS, used for process scheduling



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# File 'lib/parallel/processor_count.rb', line 8

def processor_count
  @processor_count ||= Integer(ENV['PARALLEL_PROCESSOR_COUNT'] || Etc.nprocessors)
end