Method: Parallel::ProcessorCount#processor_count

Defined in:
lib/parallel/processor_count.rb

#processor_count ⇒ Object

Number of processors seen by the OS and used for process scheduling.

  • AIX: /usr/sbin/pmcycles (AIX 5+), /usr/sbin/lsdev

  • BSD: /sbin/sysctl

  • Cygwin: /proc/cpuinfo

  • Darwin: /usr/bin/hwprefs, /usr/sbin/sysctl

  • HP-UX: /usr/sbin/ioscan

  • IRIX: /usr/sbin/sysconf

  • Linux: /proc/cpuinfo

  • Minix 3+: /proc/cpuinfo

  • Solaris: /usr/sbin/psrinfo

  • Tru64 UNIX: /usr/sbin/psrinfo

  • UnixWare: /usr/sbin/psrinfo



17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
 
# File 'lib/parallel/processor_count.rb', line 17

def processor_count
  @processor_count ||= begin
    os_name = RbConfig::CONFIG["target_os"]
    if os_name =~ /mingw|mswin/
      require 'win32ole'
      result = WIN32OLE.connect("winmgmts://").ExecQuery(
        "select NumberOfLogicalProcessors from Win32_Processor")
      result.to_enum.collect(&:NumberOfLogicalProcessors).reduce(:+)
    elsif File.readable?("/proc/cpuinfo")
      IO.read("/proc/cpuinfo").scan(/^processor/).size
    elsif File.executable?("/usr/bin/hwprefs")
      IO.popen("/usr/bin/hwprefs thread_count").read.to_i
    elsif File.executable?("/usr/sbin/psrinfo")
      IO.popen("/usr/sbin/psrinfo").read.scan(/^.*on-*line/).size
    elsif File.executable?("/usr/sbin/ioscan")
      IO.popen("/usr/sbin/ioscan -kC processor") do |out|
        out.read.scan(/^.*processor/).size
      end
    elsif File.executable?("/usr/sbin/pmcycles")
      IO.popen("/usr/sbin/pmcycles -m").read.count("\n")
    elsif File.executable?("/usr/sbin/lsdev")
      IO.popen("/usr/sbin/lsdev -Cc processor -S 1").read.count("\n")
    elsif File.executable?("/usr/sbin/sysconf") and os_name =~ /irix/i
      IO.popen("/usr/sbin/sysconf NPROC_ONLN").read.to_i
    elsif File.executable?("/usr/sbin/sysctl")
      IO.popen("/usr/sbin/sysctl -n hw.ncpu").read.to_i
    elsif File.executable?("/sbin/sysctl")
      IO.popen("/sbin/sysctl -n hw.ncpu").read.to_i
    else
      $stderr.puts "Unknown platform: " + RbConfig::CONFIG["target_os"]
      $stderr.puts "Assuming 1 processor."
      1
    end
  end
end