Method: LinuxStat::CPU.count_online

Defined in:
lib/linux_stat/cpu.rb

.count_online ⇒ Object

Returns the total number of CPU online in the sysetm.

It first reads /proc/stat, if that fails, it will read /sys/devices/system/cpu/online, if that fails it will open /proc/cpuinfo. If neither of the procedures work, it will get the LinuxStat::Sysconf.processor_online

It opens /sys/devices/system/cpu/offline and performs various job to get one Ruby array.

If the information isn’t available, it will return an empty Array.



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# File 'lib/linux_stat/cpu.rb', line 135

def count_online
  @@cpuinfo_file ||= '/proc/cpuinfo'.freeze
  @@cpuinfo_readable ||= File.readable?(@@cpuinfo_file)

  @@stat_file ||= '/proc/stat'.freeze

  # Not much slow, not blazing fast, somewhat reliable
  get_online = online

  if !get_online.empty?
    get_online.length
  elsif @@cpuinfo_readable
    # Way slower but reliable!
    IO.readlines(@@cpuinfo_file).count { |x| x.strip[/\Aprocessor.*\d*\z/] }
  else
    # Way faster but absolutely unrealiable!
    LinuxStat::Sysconf.processor_online
  end
end