PRoces handler.

src/snek/system/terminal.py

@@ -11,20 +11,40 @@ commands = {
 
 class TerminalSession:
     def __init__(self, command):
-        self.master, self.slave = pty.openpty()
+        self.master, self.slave = None,None
+        self.process = None
         self.sockets = []
         self.history = b""
         self.history_size = 1024 * 20
-        self.process = subprocess.Popen(
-            command.split(" "),
-            stdin=self.slave,
-            stdout=self.slave,
-            stderr=self.slave,
-            bufsize=0,
-            universal_newlines=True,
-        )
+        self.command = command 
+        self.start_process(self.command)
+
+    def start_process(self, command):
+        if not self.is_running():
+            if self.master:
+                os.close(self.master)
+                os.close(self.slave)
+                self.master = None 
+                self.slave = None
+
+            self.master, self.slave = pty.openpty()
+            self.process = subprocess.Popen(
+                command.split(" "),
+                stdin=self.slave,
+                stdout=self.slave,
+                stderr=self.slave,
+                bufsize=0,
+                universal_newlines=True,
+            )
+
+    def is_running(self):
+        if not self.process:
+            return False
+        loop = asyncio.get_event_loop()
+        return self.process.poll() is None
 
     async def add_websocket(self, ws):
+        self.start_process(self.command)
         asyncio.create_task(self.read_output(ws))
 
     async def read_output(self, ws):
@@ -52,21 +72,37 @@ class TerminalSession:
                 except:
                     self.sockets.remove(ws)
             except Exception:
-                print("Terminating process")
-                self.process.terminate()
-                print("Terminated process")
-                for ws in self.sockets:
-                    try:
-                        await ws.close()
-                    except Exception:
-                        pass
-                break
+                await self.close()
+                break 
+
+    async def close(self):
+        print("Terminating process")
+        if self.process:
+            self.process.terminate()
+            self.process = None
+        if self.master:
+            os.close(self.master)
+            os.close(self.slave)
+            self.master = None 
+            self.slave = None 
+
+        print("Terminated process")
+        for ws in self.sockets:
+            try:
+                await ws.close()
+            except Exception:
+                pass
+        self.sockets = []
 
     async def write_input(self, data):
         try:
             data = data.encode()
         except AttributeError:
             pass
-        await asyncio.get_event_loop().run_in_executor(
-            None, os.write, self.master, data
-        )
+        try:
+            await asyncio.get_event_loop().run_in_executor(
+                None, os.write, self.master, data
+            )
+        except Exception as ex:
+            print(ex)
+            await self.close()