add file descriptors and processes limits

Change-Id: I9fe74de30ea1fc9a6de896c87e316239bcab6fb7
Signed-off-by: Pin Xie <pxie@vmware.com>

sinatra/app_quota_app/Gemfile

@@ -1,3 +1,4 @@
 source "http://rubygems.org"
 
 gem 'sinatra'
+gem 'json'

sinatra/app_quota_app/Gemfile.lock

@@ -1,6 +1,7 @@
 GEM
   remote: http://rubygems.org/
   specs:
+    json (1.7.3)
     rack (1.4.1)
     rack-protection (1.2.0)
       rack
@@ -14,4 +15,5 @@ PLATFORMS
   ruby
 
 DEPENDENCIES
+  json
   sinatra

sinatra/app_quota_app/app.rb

@@ -1,4 +1,5 @@
 require 'sinatra'
+require 'json'
 
 MILLION         = 1 * 1024 * 1024
 LARGE_INTEGER   = 2 ** 64
@@ -7,10 +8,27 @@
 MAX_WORKERS     = 10
 MAX_DIRECTORIES = 10
 
+SIXTY_SECONDES  = 60
+
 $data = {}
 
 get '/data' do
-  $data.keys.to_s
+  $data.to_json
+end
+
+delete '/data' do
+  n = params['n'].to_i
+  n = 1 if n < 1
+  n.times do
+    key = $data.keys.first
+    case $data[key]
+      when File
+        $data[key].close
+      else
+        # do nothing
+    end
+    $data.delete(key)
+  end
 end
 
 get '/eat/ram' do
@@ -50,6 +68,81 @@
   puts "generate #{n}MB files"
 end
 
+get '/fds' do
+  data = {}
+  results = `lsof -p #{Process.pid}`.split("\n")
+  data[:count] = results.length
+  data[:details] = results
+  data.each do |k, v|
+    puts k
+    if v.class == Array
+      v.each { |item| puts item}
+    else
+      puts v
+    end
+  end
+  data.to_json
+end
+
+get '/allocate/fds' do
+  n = params['n'].to_i
+  n = 1 if n < 1
+  src_file = File.join(Dir.pwd, "tempfile")
+  puts `dd if=/dev/urandom of=#{src_file} bs=1b count=1`
+
+  queue = Queue.new
+  n.times do |job|
+    queue << job
+  end
+
+  MAX_DIRECTORIES.times do |index|
+    Dir.mkdir(index.to_s) unless Dir.exist?(index.to_s)
+  end
+
+  # 10 concurrent workers to allocate file descriptor
+  threads = []
+  lock = Mutex.new
+  MAX_WORKERS.times do
+    threads << Thread.new do
+      until queue.empty?
+        job = queue.pop
+        dirname = (job % MAX_DIRECTORIES).to_s
+        filename = rand_str
+        filepath = File.join(Dir.pwd, dirname, rand_str)
+        begin
+          FileUtils.cp(src_file, filepath)
+          lock.synchronize do
+            $data[filename] = open(filepath)
+          end
+        rescue Exception => e
+          puts e.to_s
+          break
+        end
+      end
+    end
+  end
+  threads.each { |t| t.join }
+  FileUtils.rm(src_file)
+  puts "allocate #{n} file descriptors"
+end
+
+get '/allocate/process' do
+  n = params['n'].to_i
+  n = 1 if n < 1
+  $data[:theads] = Queue.new
+  n.times do
+    begin
+      $data[:theads] << Thread.new do
+        sleep(60)
+      end
+    rescue Exception => e
+      puts e.to_s
+      break
+    end
+  end
+  "allocate #{n} threads"
+end
+
 def generate_data(size)
   size = 1 if size < 1
   (1..size).to_a.each do |index|