From a581fda5562e6669d2a8a6f458fc924dcfa009eb Mon Sep 17 00:00:00 2001
From: pjs <pjs@alum.mit.edu>
Date: Mon, 9 Jul 2018 12:36:29 -0700
Subject: [PATCH] Updated arg passing & demos
---
demos/MyModelArgs.rb | 8 ++--
demos/sptf.rb | 89 ++++++++++++++++++++++++++++++++++++++++++++
lib/simplekit.rb | 6 +--
3 files changed, 96 insertions(+), 7 deletions(-)
create mode 100644 demos/sptf.rb
diff --git a/demos/MyModelArgs.rb b/demos/MyModelArgs.rb
index ebbd404..d75ff65 100644
--- a/demos/MyModelArgs.rb
+++ b/demos/MyModelArgs.rb
@@ -7,13 +7,13 @@ class MyModel
def init
@x = 1
- schedule(:increment, rand(2), n: 1, c: 97)
+ schedule(:increment, rand(2), n: 1, char: 'z'.ord)
end
- def increment(n:, c:)
+ def increment(n:, char:)
@x += n
- schedule(:increment, 2.0 * rand(2), n: @x, c: c + 1)
- printf "%f, %f, %c\n", model_time, @x, c
+ schedule(:increment, 2.0 * rand(2), n: @x, char: char - 1)
+ printf "%f, %f, %c\n", model_time, @x, char
schedule(:halt, 0.0) if model_time > 10
end
end
diff --git a/demos/sptf.rb b/demos/sptf.rb
new file mode 100644
index 0000000..e19ad0d
--- /dev/null
+++ b/demos/sptf.rb
@@ -0,0 +1,89 @@
+#!/usr/bin/env ruby
+
+require_relative '../lib/simplekit'
+require_relative '../lib/priority_queue'
+
+# Customer class to store arrival times and processing times.
+class Customer
+ attr_reader :arrival_time, :processing_time
+
+ def initialize(arrival, processing)
+ @arrival_time = arrival
+ @processing_time = processing
+ end
+
+ include Comparable
+ def <=>(other)
+ processing_time <=> other.processing_time
+ end
+end
+
+# Demonstration model of a shortest-processing-time-first queueing system.
+# There are k servers and both the arrival and service processes could
+# be anything.
+class SPTF
+ include SimpleKit
+
+ # Constructor - initializes the model parameters.
+ # param: arrivalRate - The rate at which customers arrive to the system.
+ # param: serviceRate - The rate at which individual servers serve.
+ # param: maxServers - The total number of servers in the system.
+ # param: closeTime - The time the server would like to shut down.
+ def initialize(arrivalRate, serviceRate, maxServers, closeTime)
+ @arrivalRate = arrivalRate
+ @serviceRate = serviceRate
+ @maxServers = maxServers
+ @closeTime = closeTime
+ end
+
+ # Initialize the model state and schedule any necessary events.
+ def init
+ @numAvailableServers = @maxServers
+ @q = PriorityQueue.new
+ schedule(:arrival, 0.0)
+ end
+
+
+ # An arrival event generates a customer and their associated service
+ # time, adds the customer to the queue, schedules the next arrival,
+ # and schedules a beginService event if a server is available.
+ def arrival
+ @q.push Customer.new(model_time, exponential(@serviceRate))
+ schedule(:arrival, exponential(@arrivalRate))
+ schedule(:beginService, 0.0) if (@numAvailableServers > 0)
+ end
+
+ # Start service for the first customer in line, removing that
+ # customer from the queue and utilizing one of the available
+ # servers. An endService will be scheduled. Report the current
+ # time and how long this customer spent in line.
+ def beginService
+ current_customer = @q.pop
+ @numAvailableServers -= 1
+ schedule(:endService, current_customer.processing_time)
+ printf "%f,%f\n", model_time, model_time - current_customer.arrival_time
+ end
+
+ # Frees up an available server, and schedules a beginService if
+ # anybody is waiting in line. If the line is empty and it's after
+ # the desired closing time, halt the simulation.
+ def endService
+ @numAvailableServers += 1
+ if (@q.empty?)
+ halt if model_time >= @closeTime
+ else
+ schedule(:beginService, 0.0)
+ end
+ end
+
+ # Exponential random variate generator.
+ # param: rate - The rate (= 1 / mean) of the distribution.
+ # returns: A realization of the specified distribution.
+ def exponential(rate)
+ -Math.log(rand) / rate
+ end
+
+end
+
+# Instantiate an SPTF object with a particular parameterization and run it.
+SPTF.new(4.5, 1.0, 5, 100.0).run
diff --git a/lib/simplekit.rb b/lib/simplekit.rb
index 1f00ad3..96b5fd1 100644
--- a/lib/simplekit.rb
+++ b/lib/simplekit.rb
@@ -55,7 +55,7 @@ module SimpleKit
# at invocation time.
def schedule(event, delay, **args)
raise 'Model scheduled event with negative delay.' if delay < 0
- @event_list.push EventNotice.new(event, @model_time, delay, args)
+ @event_list.push EventNotice.new(event, @model_time, delay, **args)
end
# Start execution of a model. The simulation +model_time+ is initialized
@@ -71,7 +71,7 @@ module SimpleKit
if current_event.args.empty?
@user_model.send(current_event.event)
else
- @user_model.send(current_event.event, current_event.args)
+ @user_model.send(current_event.event, **current_event.args)
end
end
end
@@ -88,7 +88,7 @@ module SimpleKit
private class EventNotice
attr_reader :event, :time, :time_stamp, :args
- def initialize(event, time, delay, **args)
+ def initialize(event, time, delay, args)
@event = event
@time_stamp = time
@time = time + delay
--
GitLab