From 46b348e46a0a00740be745a1ed9d6289163a3035 Mon Sep 17 00:00:00 2001
From: Julien Duponchelle <julien@duponchelle.info>
Date: Tue, 24 Feb 2015 21:53:38 +0100
Subject: [PATCH] VM concurrency

---
 gns3server/handlers/api/version_handler.py | 11 +++++++++++
 gns3server/web/route.py                    | 19 +++++++++++++++++--
 2 files changed, 28 insertions(+), 2 deletions(-)

diff --git a/gns3server/handlers/api/version_handler.py b/gns3server/handlers/api/version_handler.py
index 000e932a..af01fe14 100644
--- a/gns3server/handlers/api/version_handler.py
+++ b/gns3server/handlers/api/version_handler.py
@@ -20,6 +20,8 @@ from ...schemas.version import VERSION_SCHEMA
 from ...version import __version__
 from aiohttp.web import HTTPConflict
 
+import asyncio
+
 
 class VersionHandler:
 
@@ -45,3 +47,12 @@ class VersionHandler:
         if request.json["version"] != __version__:
             raise HTTPConflict(text="Client version {} differs with server version {}".format(request.json["version"], __version__))
         response.json({"version": __version__})
+
+    @staticmethod
+    @Route.get(
+        r"/sleep/{vm_id}",
+        description="Retrieve the server version number",
+        output=VERSION_SCHEMA)
+    def sleep(request, response):
+        yield from asyncio.sleep(1)
+        response.json({"version": __version__})
diff --git a/gns3server/web/route.py b/gns3server/web/route.py
index 13344bf9..4e411b5a 100644
--- a/gns3server/web/route.py
+++ b/gns3server/web/route.py
@@ -63,6 +63,8 @@ class Route(object):
     _routes = []
     _documentation = {}
 
+    _vms_lock = {}
+
     @classmethod
     def get(cls, path, *args, **kw):
         return cls._route('GET', path, *args, **kw)
@@ -150,9 +152,22 @@ class Route(object):
 
                 return response
 
-            cls._routes.append((method, cls._path, control_schema))
+            @asyncio.coroutine
+            def vm_concurrency(request):
+                """
+                To avoid strange effect we prevent concurrency
+                between the same instance of the vm
+                """
+
+                if "vm_id" in request.match_info:
+                    cls._vms_lock.setdefault(request.match_info["vm_id"], asyncio.Lock())
+                    with (yield from cls._vms_lock[request.match_info["vm_id"]]):
+                        response = yield from control_schema(request)
+                return response
+
+            cls._routes.append((method, cls._path, vm_concurrency))
 
-            return control_schema
+            return vm_concurrency
         return register
 
     @classmethod