`class Linux`

Definitions

`def self.total_size`

Signature

returns　Numeric: Total memory size in kilobytes.

Implementation

def self.total_size
	File.read("/proc/meminfo").each_line do |line|
		if /MemTotal:\s+(?<total>\d+) kB/ =~ line
			return total.to_i
		end
	end
end

`SMAP = {...}`

The fields that will be extracted from the smaps data.

Implementation

SMAP = {
	"Rss" => :resident_size,
	"Pss" => :proportional_size,
	"Shared_Clean" => :shared_clean_size,
	"Shared_Dirty" => :shared_dirty_size,
	"Private_Clean" => :private_clean_size,
	"Private_Dirty" => :private_dirty_size,
	"Referenced" => :referenced_size,
	"Anonymous" => :anonymous_size,
	"Swap" => :swap_size,
	"SwapPss" => :proportional_swap_size,
}

`def self.supported?`

Whether the memory usage can be captured on this system.

Implementation

def self.supported?
	true
end

`def self.supported?`

Whether the memory usage can be captured on this system.

Implementation

def self.supported?
	true
end

`def self.capture(pid, **options)`

Capture memory usage for the given process IDs.

Implementation

def self.capture(pid, **options)
	usage = Memory.zero
	
	begin
		File.foreach("/proc/#{pid}/smaps_rollup") do |line|
			if /(?<name>.*?):\s+(?<value>\d+) kB/ =~ line
				if key = SMAP[name]
					usage[key] += value.to_i
				end
			end
		end
		
		usage.map_count += File.readlines("/proc/#{pid}/maps").size
	rescue Errno::ENOENT => error
		# Ignore.
	end
	
	return usage
end

`def self.capture(pid, **options)`

Capture memory usage for the given process IDs.

Implementation

def self.capture(pid, **options)
	usage = Memory.zero
	
	begin
		File.foreach("/proc/#{pid}/smaps") do |line|
			# The format of this is fixed according to:
			# https://github.com/torvalds/linux/blob/351c8a09b00b5c51c8f58b016fffe51f87e2d820/fs/proc/task_mmu.c#L804-L814
			if /(?<name>.*?):\s+(?<value>\d+) kB/ =~ line
				if key = SMAP[name]
					usage[key] += value.to_i
				end
			elsif /VmFlags:\s+(?<flags>.*)/ =~ line
				# It should be possible to extract the number of fibers and each fiber's memory usage.
				# flags = flags.split(/\s+/)
				usage.map_count += 1
			end
		end
	rescue Errno::ENOENT => error
		# Ignore.
	end
	
	return usage
end