Class: EventMachine::Monitor

Inherits:

Object

• Object
• EventMachine::Monitor

Defined in:

lib/em-monitor.rb

Overview

The monitor object itself deals with maintaining lspace and timers.

Constant Summary

DEFAULT_INTERVAL =

How long (by default) between calls to monitors

60

DEFAULT_BUCKETS =

Which buckets to include in the histogram by default

[0.001, 0.01, 0.1, 1, 10]

Instance Method Summary

• #initialize(&block) {|self| ... } ⇒ Monitor constructor

  Create a new monitor.

• #monitor_spans(interval, &block) {|spans, from, to| ... } ⇒ Object

  Attach a listener to this monitor.

Constructor Details

#initialize(&block) {|self| ... } ⇒ Monitor

Create a new monitor.

The block will be called in the monitor’s LSpace, all further EM work should happen within the block to ensure that we measure everything.

Parameters:

• block (Proc) —

  The block during which to monitor events

Yield Parameters:

• self (Monitor)

# File 'lib/em-monitor.rb', line 145

def initialize(&block)
  create_lspace.enter do
    block.call self
  end
end

Instance Method Details

#monitor_spans(interval, &block) {|spans, from, to| ... } ⇒ Object

Attach a listener to this monitor.

Only one listener can be active at a time, and the interval set here will take affect after the next tick of the previous interval.

Parameters:

• interval (Number) —

  The (lower bound of) time in seconds between calls to block

• block (Proc) —

  The block to call

Yield Parameters:

• spans (Array<Float>) —

  Each number of seconds the event loop spent processing.

• from (Time) —

  The time at which the block was previously called

• to (Time) —

  The current time

See Also:

• EM.monitor_spans

# File 'lib/em-monitor.rb', line 162

def monitor_spans(interval, &block)
  @periodic_timer ||= create_timer(interval)
  @periodic_timer.interval = interval
  @monitor = block
end