Function _wait_for_process_exit

src/mcp/client/stdio.py:276–287

Returns whether the process died within the timeout, by polling returncode. Not process.wait(): on asyncio 3.11+ it also waits for pipe EOF, and a child that inherited the pipes makes an exited server look hung.

(process: ServerProcess, timeout: float)

async def _wait_for_process_exit(process: ServerProcess, timeout: float) -> bool:
    """Returns whether the process died within the timeout, by polling returncode.

    Not process.wait(): on asyncio 3.11+ it also waits for pipe EOF, and a
    child that inherited the pipes makes an exited server look hung.
    """
    deadline = anyio.current_time() + timeout
    while process.returncode is None:
        if anyio.current_time() >= deadline:
            return False
        await anyio.sleep(_EXIT_POLL_INTERVAL)
    return True


async def _terminate_process_tree(process: ServerProcess) -> None: