Method configLoop

tailnet/configmaps.go:147–203

configLoop waits for the config to be dirty, then reconfigures the engine. It is internal to configMaps

()

// configLoop waits for the config to be dirty, then reconfigures the engine.
// It is internal to configMaps
func (c *configMaps) configLoop() {
	c.L.Lock()
	defer c.L.Unlock()
	defer func() {
		c.phase = closed
		c.Broadcast()
	}()
	for {
		for !(c.closing || c.netmapDirty || c.filterDirty || c.derpMapDirty) {
			c.phase = idle
			c.Wait()
		}
		if c.closing {
			c.logger.Debug(context.Background(), "closing configMaps configLoop")
			return
		}
		// queue up the reconfiguration actions we will take while we have
		// the configMaps locked. We will execute them while unlocked to avoid
		// blocking during reconfig.
		actions := make([]func(), 0, 3)
		if c.derpMapDirty {
			derpMap := c.derpMapLocked()
			actions = append(actions, func() {
				c.logger.Debug(context.Background(), "updating engine DERP map", slog.F("derp_map", (*derpMapStringer)(derpMap)))
				c.engine.SetDERPMap(derpMap)
			})
		}
		if c.netmapDirty {
			nm := c.netMapLocked()
			hosts := c.hostsLocked()
			actions = append(actions, func() {
				c.logger.Debug(context.Background(), "updating engine network map", slog.F("network_map", nm))
				c.engine.SetNetworkMap(nm)
				c.reconfig(nm, hosts)
			})
		}
		if c.filterDirty {
			f := c.filterLocked()
			actions = append(actions, func() {
				c.logger.Debug(context.Background(), "updating engine filter", slog.F("filter", f))
				c.engine.SetFilter(f)
			})
		}

		c.netmapDirty = false
		c.filterDirty = false
		c.derpMapDirty = false
		c.phase = configuring
		c.Broadcast()

		c.L.Unlock()
		for _, a := range actions {
			a()
		}
		c.L.Lock()
	}
}