Method: LinuxStat::CPU.stat

Defined in:
lib/linux_stat/cpu.rb

.stat(sleep = ticks_to_ms_t5) ⇒ Object Also known as: usages

stat(sleep = 1.0 / LinuxStat::Sysconf.sc_clk_tck * 5)

Where sleep is the delay to gather the data.

The minimum possible value at anytime is 1.0 / LinuxStat::Sysconf.sc_clk_tck

This method returns the cpu usage of all threads.

The first one is aggregated CPU usage reported by the Linux kernel.

And the consecutive ones are the real core usages.

For example, on a system with 4 threads:

LinuxStat::CPU.stat

=> {0=>84.38, 1=>100.0, 2=>50.0, 3=>87.5, 4=>87.5}

It discards any offline CPU or disabled CPU. For example, if your system CPU has 4 cores, and you disabled core 3, the output will be:

LinuxStat::CPU.stat

=> {0=>26.67, 1=>0.0, 2=>20.0, 4=>20.0}

If the information is not available, it will return an empty Hash



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# File 'lib/linux_stat/cpu.rb', line 31

def stat(sleep = ticks_to_ms_t5)
	return {} unless stat?

	data = IO.readlines('/proc/stat'.freeze).select { |x| x[/^cpu\d*/] }
	cpu_names1 = []
	data.map! { |x|
		splitted = x.split
		name = splitted.shift[/\d*$/]
		cpu_names1.push(name.empty? ? 0 : name.to_i + 1)
		splitted.map!(&:to_f)
	}

	sleep(sleep)
	data2 = IO.readlines('/proc/stat'.freeze).select { |x| x[/^cpu\d*/] }

	cpu_names2 = []
	data2.map! { |x|
		splitted = x.split
		name = splitted.shift[/\d*$/]
		cpu_names2.push(name.empty? ? 0 : name.to_i + 1)
		splitted.map!(&:to_f)
	}

	# On devices like android, the core count can change anytime (hotplugging).
	# I had crashes on Termux.
	# So better just count the min number of CPU and iterate over that
	# If data.length is smaller than data2.length, we don't have enough data to compare.
	dl, d2l = cpu_names1.length, cpu_names2.length
	if dl > d2l
		min = d2l
		cpu_cores = cpu_names2
	else
		min = dl
		cpu_cores = cpu_names1
	end

	min.times.reduce({}) do |h, x|
		cpu_core = cpu_cores[x]
		user, nice, sys, idle, iowait, irq, softirq, steal = *data[x]
		user2, nice2, sys2, idle2, iowait2, irq2, softirq2, steal2 = *data2[x]

		idle_then, idle_now  = idle + iowait, idle2 + iowait2
		totald = idle_now.+(user2 + nice2 + sys2 + irq2 + softirq2 + steal2) - idle_then.+(user + nice + sys + irq + softirq + steal)

		res = totald.-(idle_now - idle_then).fdiv(totald).abs.*(100)
		res = res.nan? ? 0.0 : res > 100 ? 100.0 : res.round(2)

		h.store(cpu_core, res)
		h
	end
end