Method Close

agent/x/agentmcp/manager.go:872–920

Close terminates all MCP server connections and child processes, stops the config file watcher, and waits for any in-flight watcher-driven reload to complete.

()

// processes, stops the config file watcher, and waits for any
// in-flight watcher-driven reload to complete.
func (m *Manager) Close() error {
	// Mark the manager closed and signal closedCh first, then
	// hand the watcher off and release the lock. Marking closed
	// before w.Close() ensures that any in-flight
	// handleWatchedConfigChange short-circuits and any Reload
	// blocked in waitReload observes m.closedCh, instead of
	// blocking firesWG.Wait() inside w.Close() until a 30 s
	// connectAll times out.
	m.mu.Lock()
	m.closed = true
	m.closeOnce.Do(func() { close(m.closedCh) })
	w := m.watcher
	m.watcher = nil
	m.mu.Unlock()

	// Close the watcher outside the manager lock. Its goroutine
	// may call handleWatchedConfigChange, which takes m.mu, so
	// holding m.mu while waiting for the watcher to drain would
	// deadlock. Close on a nil watcher is a no-op.
	if w != nil {
		_ = w.Close()
	}

	m.mu.Lock()
	defer m.mu.Unlock()

	var errs []error
	for _, entry := range m.servers {
		if err := entry.client.Close(); err != nil {
			// Subprocess kill signals are expected during shutdown.
			// The stdio transport returns cmd.Wait() which surfaces
			// "signal: killed" as an exec.ExitError.
			var exitErr *exec.ExitError
			if !errors.As(err, &exitErr) {
				errs = append(errs, err)
			}
		}
	}
	m.servers = make(map[string]*serverEntry)
	// Prevent an in-flight RefreshTools from repopulating tools
	// after Close clears the cache.
	m.serverGen++
	m.tools = nil

	// Cancel while holding the lock so waiters that observe
	// m.ctx.Done also observe m.closed when checking closeErr.
	m.cancel()
	return errors.Join(errs...)
}

// connectServer establishes a connection to a single MCP server
// and returns the connected client. It does not modify any Manager