load isupport directly into the config object

eliminates Server.configurableStateMutex

irc/client.go

@@ -836,7 +836,8 @@ func (client *Client) LoggedIntoAccount() bool {
 func (client *Client) RplISupport(rb *ResponseBuffer) {
 	translatedISupport := client.t("are supported by this server")
 	nick := client.Nick()
-	for _, cachedTokenLine := range client.server.ISupport().CachedReply {
+	config := client.server.Config()
+	for _, cachedTokenLine := range config.Server.isupport.CachedReply {
 		length := len(cachedTokenLine) + 2
 		tokenline := make([]string, length)
 		tokenline[0] = nick

irc/config.go

@@ -20,6 +20,7 @@ import (
 	"code.cloudfoundry.org/bytefmt"
 	"github.com/oragono/oragono/irc/connection_limits"
 	"github.com/oragono/oragono/irc/custime"
+	"github.com/oragono/oragono/irc/isupport"
 	"github.com/oragono/oragono/irc/languages"
 	"github.com/oragono/oragono/irc/logger"
 	"github.com/oragono/oragono/irc/modes"
@@ -293,6 +294,7 @@ type Config struct {
 			forceTrailing      bool
 			SendUnprefixedSasl bool `yaml:"send-unprefixed-sasl"`
 		}
+		isupport            isupport.List
 		ConnectionLimiter   connection_limits.LimiterConfig   `yaml:"connection-limits"`
 		ConnectionThrottler connection_limits.ThrottlerConfig `yaml:"connection-throttling"`
 	}
@@ -713,6 +715,11 @@ func LoadConfig(filename string) (config *Config, err error) {
 
 	config.loadMOTD()
 
+	err = config.generateISupport()
+	if err != nil {
+		return nil, err
+	}
+
 	// in the current implementation, we disable history by creating a history buffer
 	// with zero capacity. but the `enabled` config option MUST be respected regardless
 	// of this detail

irc/getters.go

@@ -8,7 +8,6 @@ import (
 	"time"
 	"unsafe"
 
-	"github.com/oragono/oragono/irc/isupport"
 	"github.com/oragono/oragono/irc/languages"
 	"github.com/oragono/oragono/irc/modes"
 )
@@ -21,12 +20,6 @@ func (server *Server) SetConfig(config *Config) {
 	atomic.StorePointer(&server.config, unsafe.Pointer(config))
 }
 
-func (server *Server) ISupport() *isupport.List {
-	server.configurableStateMutex.RLock()
-	defer server.configurableStateMutex.RUnlock()
-	return server.isupport
-}
-
 func (server *Server) Limits() Limits {
 	return server.Config().Limits
 }

irc/isupport/list.go

@@ -22,9 +22,13 @@ type List struct {
 // NewList returns a new List
 func NewList() *List {
 	var il List
+	il.Initialize()
+	return &il
+}
+
+func (il *List) Initialize() {
 	il.Tokens = make(map[string]*string)
 	il.CachedReply = make([][]string, 0)
-	return &il
 }
 
 // Add adds an RPL_ISUPPORT token to our internal list

irc/server.go

@@ -68,7 +68,6 @@ type Server struct {
 	clients             ClientManager
 	config              unsafe.Pointer
 	configFilename      string
-	configurableStateMutex sync.RWMutex // tier 1; generic protection for server state modified by rehash()
 	connectionLimiter   *connection_limits.Limiter
 	connectionThrottler *connection_limits.Throttler
 	ctime               time.Time
@@ -141,13 +140,12 @@ func NewServer(config *Config, logger *logger.Manager) (*Server, error) {
 }
 
 // setISupport sets up our RPL_ISUPPORT reply.
-func (server *Server) setISupport() (err error) {
+func (config *Config) generateISupport() (err error) {
 	maxTargetsString := strconv.Itoa(maxTargets)
 
-	config := server.Config()
-
 	// add RPL_ISUPPORT tokens
-	isupport := isupport.NewList()
+	isupport := &config.Server.isupport
+	isupport.Initialize()
 	isupport.Add("AWAYLEN", strconv.Itoa(config.Limits.AwayLen))
 	isupport.Add("CASEMAPPING", "ascii")
 	isupport.Add("CHANMODES", strings.Join([]string{modes.Modes{modes.BanMask, modes.ExceptMask, modes.InviteMask}.String(), "", modes.Modes{modes.UserLimit, modes.Key}.String(), modes.Modes{modes.InviteOnly, modes.Moderated, modes.NoOutside, modes.OpOnlyTopic, modes.ChanRoleplaying, modes.Secret}.String()}, ","))
@@ -175,13 +173,6 @@ func (server *Server) setISupport() (err error) {
 	isupport.Add("UTF8MAPPING", casemappingName)
 
 	err = isupport.RegenerateCachedReply()
-	if err != nil {
-		return
-	}
-
-	server.configurableStateMutex.Lock()
-	server.isupport = isupport
-	server.configurableStateMutex.Unlock()
 	return
 }
 
@@ -786,13 +777,8 @@ func (server *Server) applyConfig(config *Config, initial bool) (err error) {
 
 	// set RPL_ISUPPORT
 	var newISupportReplies [][]string
-	oldISupportList := server.ISupport()
+	if oldConfig != nil {
-	err = server.setISupport()
+		newISupportReplies = oldConfig.Server.isupport.GetDifference(&config.Server.isupport)
-	if err != nil {
-		return err
-	}
-	if oldISupportList != nil {
-		newISupportReplies = oldISupportList.GetDifference(server.ISupport())
 	}
 
 	// we are now open for business