Merge pull request #4 from divakar1800/master

Optimisation of Scilab code execution merged after discussion with mentor

1 files changed, 64 insertions, 9 deletions

diff --git a/tornado_main.py b/tornado_main.py
index 534a5a6..98ac671 100644
--- a/tornado_main.py
+++ b/tornado_main.py
@@ -2,9 +2,6 @@
 
 # Run this with
 # PYTHONPATH=. DJANGO_SETTINGS_MODULE=testsite.settings testsite/tornado_main.py
-# Serves by default at
-# http://localhost:8080/hello-tornado and
-# http://localhost:8080/hello-django
 
 from tornado.options import options, define, parse_command_line
 import django.core.handlers.wsgi
@@ -13,25 +10,82 @@ import tornado.ioloop
 import tornado.web
 import tornado.wsgi
 import os
+from django.utils import simplejson
+from website.models import TextbookCompanionExampleDependency, TextbookCompanionDependencyFiles
+
+from concurrent.futures import ThreadPoolExecutor
+from tornado import gen
+from instances import ScilabInstance
+import threading
 
 define('port', type=int, default=8080)
 
 # Custom settings
 from soc.settings import PROJECT_DIR
+from django.core.wsgi import get_wsgi_application
 os.environ.setdefault("DJANGO_SETTINGS_MODULE", "soc.settings")
 
+# request_count keeps track of the number of requests at hand, it is incremented 
+# when post method is invoked and decremented before exiting post method in 
+# class ExecutionHandler.
+DEFAULT_WORKERS = 5
+request_count = 0
+
+# ThreadPoolExecutor is an Executor subclass that uses a pool of threads to execute
+# function calls asynchronously.
+# It runs numbers of threads equal to DEFAULT_WORKERS in the background.
+executor = ThreadPoolExecutor(max_workers = DEFAULT_WORKERS)
+
+# scilab_executor is an object of class ScilabInstance used to manage(spawn, kill)
+# the Scilab instances and execute the code using those instances.
+scilab_executor = ScilabInstance()
+scilab_executor.spawn_instance()
+
+# instance_manager function is run at a fixed interval to kill the Scilab instances 
+# not in use. If the number of user requests is more than the count of active Scilab
+# instances, maximum instances defined will be in process. Instances will be killed
+# only when their number is more than the user requests.
+def instance_manager():
+  if(scilab_executor.count > request_count):
+    scilab_executor.kill_instances(scilab_executor.count-request_count-1)
+  threading.Timer(300, instance_manager).start()
+  
+instance_manager()
+
+# Whenever django server sends an ajax request,
+# the request is handled by the  ExecutionHandler
+# post method passes all the parameters received from the ajax call and
+# passes it to the submit method of ThreadPoolExecutor class through its object.
+# yield is used to gather the output asynchronously in the variable data
+class ExecutionHandler(tornado.web.RequestHandler): 
+	@gen.coroutine
+	def post(self):
+		global request_count
+		request_count += 1
+
+		token = buffer(self.request.arguments['token'][0])
+		token = str(token)
+		code =  buffer(self.request.arguments['code'][0])
+		code = str(code)
+		book_id = int(self.request.arguments['book_id'][0])
+		chapter_id = int(self.request.arguments['chapter_id'][0])
+		example_id = int(self.request.arguments['example_id'][0])
+		
+		dependency_exists = TextbookCompanionExampleDependency.objects.using('scilab')\
+			.filter(example_id=example_id).exists()
+		data  = yield executor.submit(scilab_executor.execute_code, code, token, 
+			book_id, dependency_exists)
+		self.write(data)
+		request_count -= 1
 
-class HelloHandler(tornado.web.RequestHandler):
-  def get(self):
-    self.write('Hello from tornado')
 
 def main():
   parse_command_line()
   wsgi_app = tornado.wsgi.WSGIContainer(
-    django.core.handlers.wsgi.WSGIHandler())
+    get_wsgi_application())
   tornado_app = tornado.web.Application(
     [
-      ('/hello-tornado', HelloHandler),
+      ('/execute-code', ExecutionHandler),
       ('/static/(.*)', tornado.web.StaticFileHandler, {'path': PROJECT_DIR + '/static/'}),
       ('.*', tornado.web.FallbackHandler, dict(fallback=wsgi_app)),
       ], debug=False)
@@ -39,5 +93,6 @@ def main():
   server.listen(options.port)
   tornado.ioloop.IOLoop.instance().start()
 
+
 if __name__ == '__main__':
-  main()
+  main()
\ No newline at end of file