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 12

def physical_processor_count
  @physical_processor_count ||= begin
    ppc = case RbConfig::CONFIG["target_os"]
    when /darwin1/
      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 if not 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 7

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