Address tmux cleanup review feedback

Co-authored-by: openhands <openhands@all-hands.dev>

Author: openhands-agent

openhands-agent-server/openhands/agent_server/api.py

@@ -44,34 +44,30 @@
 from openhands.agent_server.vscode_service import get_vscode_service
 from openhands.sdk.logger import DEBUG, get_logger
 from openhands.sdk.utils.redact import sanitize_dict
+from openhands.tools.terminal.constants import TMUX_SOCKET_NAME
 
 
 logger = get_logger(__name__)
 
 
-async def cleanup_stale_tmux_sessions() -> None:
+def cleanup_stale_tmux_sessions() -> None:
     """Clean up any stale tmux sessions on server startup.
 
     Tmux sessions live in a separate process that survives agent-server restarts.
-    This function kills all existing sessions on the openhands socket to prevent
-    accumulation of orphaned sessions. Reconnecting conversations will create
-    fresh sessions as needed.
+    This function kills all existing sessions on the shared OpenHands tmux socket
+    to prevent accumulation of orphaned sessions.
     """
     try:
         import libtmux
 
-        # Connect to the dedicated OpenHands tmux server
-        server = libtmux.Server(socket_name="openhands")
-
-        # Get all sessions on this server
+        server = libtmux.Server(socket_name=TMUX_SOCKET_NAME)
         sessions = server.sessions
         if not sessions:
-            logger.debug("No tmux sessions found on openhands socket")
+            logger.debug("No tmux sessions found on %s socket", TMUX_SOCKET_NAME)
             return
 
         logger.info("Cleaning up %d stale tmux session(s) on startup", len(sessions))
 
-        # Kill all sessions - they're all stale since we're starting up
         for session in sessions:
             try:
                 logger.debug("Killing tmux session: %s", session.name)
@@ -91,7 +87,7 @@ async def cleanup_stale_tmux_sessions() -> None:
 @asynccontextmanager
 async def api_lifespan(api: FastAPI) -> AsyncIterator[None]:
     # Clean up stale tmux sessions from previous server runs
-    await cleanup_stale_tmux_sessions()
+    cleanup_stale_tmux_sessions()
 
     service = get_default_conversation_service()
     vscode_service = get_vscode_service()

openhands-tools/openhands/tools/terminal/constants.py

@@ -34,6 +34,8 @@
 POLL_INTERVAL: Final[float] = 0.5
 HISTORY_LIMIT: Final[int] = 10_000
 
+TMUX_SOCKET_NAME: Final[str] = "openhands"
+
 # Tmux session dimensions (columns x rows).
 # Large values ensure output is not wrapped or truncated by the virtual terminal.
 TMUX_SESSION_WIDTH: Final[int] = 1000

openhands-tools/openhands/tools/terminal/terminal/tmux_pane_pool.py

@@ -23,6 +23,7 @@
     HISTORY_LIMIT,
     TMUX_SESSION_HEIGHT,
     TMUX_SESSION_WIDTH,
+    TMUX_SOCKET_NAME,
 )
 from openhands.tools.terminal.terminal.tmux_terminal import TmuxTerminal
 
@@ -112,7 +113,7 @@ def initialize(self) -> None:
             return
 
         env = sanitized_env()
-        self._server = libtmux.Server(socket_name="openhands", environment=env)
+        self._server = libtmux.Server(socket_name=TMUX_SOCKET_NAME, environment=env)
         session_name = f"openhands-pool-{self.username}-{uuid.uuid4()}"
         self._session = self._server.new_session(
             session_name=session_name,

openhands-tools/openhands/tools/terminal/terminal/tmux_terminal.py

@@ -11,6 +11,7 @@
     HISTORY_LIMIT,
     TMUX_SESSION_HEIGHT,
     TMUX_SESSION_WIDTH,
+    TMUX_SOCKET_NAME,
 )
 from openhands.tools.terminal.metadata import CmdOutputMetadata
 from openhands.tools.terminal.terminal import TerminalInterface
@@ -47,7 +48,7 @@ def initialize(self) -> None:
 
         env = sanitized_env()
         # Use a dedicated socket to isolate OpenHands sessions from the user's tmux
-        self.server = libtmux.Server(socket_name="openhands", environment=env)
+        self.server = libtmux.Server(socket_name=TMUX_SOCKET_NAME, environment=env)
         _shell_command = "/bin/bash"
         if self.username in ["root", "openhands"]:
             # This starts a non-login (new) shell for the given user