Drop Python 3.4 and switch to async / await syntax for asyncio. Fixes #1425

gns3server/compute/dynamips/hypervisor.py

@@ -111,8 +111,7 @@ class Hypervisor(DynamipsHypervisor):
 
         self._path = path
 
-    @asyncio.coroutine
-    def start(self):
+    async def start(self):
         """
         Starts the Dynamips hypervisor process.
         """
@@ -129,7 +128,7 @@ class Hypervisor(DynamipsHypervisor):
             self._stdout_file = os.path.join(self.working_dir, "dynamips_i{}_stdout.txt".format(self._id))
             log.info("Dynamips process logging to {}".format(self._stdout_file))
             with open(self._stdout_file, "w", encoding="utf-8") as fd:
-                self._process = yield from asyncio.create_subprocess_exec(*self._command,
+                self._process = await asyncio.create_subprocess_exec(*self._command,
                                                                           stdout=fd,
                                                                           stderr=subprocess.STDOUT,
                                                                           cwd=self._working_dir,
@@ -140,20 +139,19 @@ class Hypervisor(DynamipsHypervisor):
             log.error("Could not start Dynamips: {}".format(e))
             raise DynamipsError("Could not start Dynamips: {}".format(e))
 
-    @asyncio.coroutine
-    def stop(self):
+    async def stop(self):
         """
         Stops the Dynamips hypervisor process.
         """
 
         if self.is_running():
             log.info("Stopping Dynamips process PID={}".format(self._process.pid))
-            yield from DynamipsHypervisor.stop(self)
+            await DynamipsHypervisor.stop(self)
             # give some time for the hypervisor to properly stop.
             # time to delete UNIX NIOs for instance.
-            yield from asyncio.sleep(0.01)
+            await asyncio.sleep(0.01)
             try:
-                yield from wait_for_process_termination(self._process, timeout=3)
+                await wait_for_process_termination(self._process, timeout=3)
             except asyncio.TimeoutError:
                 if self._process.returncode is None:
                     log.warning("Dynamips process {} is still running... killing it".format(self._process.pid))