added some code to exit the whole process upon panic in http goroutines

client-ctl.go

@@ -99,6 +99,11 @@ func (ctl *client_ctl_client_conns) ServeHTTP(w http.ResponseWriter, req *http.R
 	var err error
 	var je *json.Encoder
 
+	defer func() {
+		var err interface{} = recover()
+		if err != nil { dump_call_frame_and_exit(ctl.c.log, req, err) }
+	}()
+
 	c = ctl.c
 	je = json.NewEncoder(w)
 
@@ -207,6 +212,11 @@ func (ctl *client_ctl_client_conns_id) ServeHTTP(w http.ResponseWriter, req *htt
 	var je *json.Encoder
 	var cts *ClientConn
 
+	defer func() {
+		var err interface{} = recover()
+		if err != nil { dump_call_frame_and_exit(ctl.c.log, req, err) }
+	}()
+
 	c = ctl.c
 	je = json.NewEncoder(w)
 
@@ -286,6 +296,11 @@ func (ctl *client_ctl_client_conns_id_routes) ServeHTTP(w http.ResponseWriter, r
 	var je *json.Encoder
 	var cts *ClientConn
 
+	defer func() {
+		var err interface{} = recover()
+		if err != nil { dump_call_frame_and_exit(ctl.c.log, req, err) }
+	}()
+
 	c = ctl.c
 	je = json.NewEncoder(w)
 
@@ -378,6 +393,11 @@ func (ctl *client_ctl_client_conns_id_routes_id) ServeHTTP(w http.ResponseWriter
 	var je *json.Encoder
 	var cts *ClientConn
 
+	defer func() {
+		var err interface{} = recover()
+		if err != nil { dump_call_frame_and_exit(ctl.c.log, req, err) }
+	}()
+
 	c = ctl.c
 	je = json.NewEncoder(w)
 
@@ -451,6 +471,11 @@ func (ctl *client_ctl_client_conns_id_routes_id_peers) ServeHTTP(w http.Response
 	var je *json.Encoder
 	var r *ClientRoute
 
+	defer func() {
+		var err interface{} = recover()
+		if err != nil { dump_call_frame_and_exit(ctl.c.log, req, err) }
+	}()
+
 	c = ctl.c
 	je = json.NewEncoder(w)
 
@@ -529,6 +554,11 @@ func (ctl *client_ctl_client_conns_id_routes_id_peers_id) ServeHTTP(w http.Respo
 	var je *json.Encoder
 	var p *ClientPeerConn
 
+	defer func() {
+		var err interface{} = recover()
+		if err != nil { dump_call_frame_and_exit(ctl.c.log, req, err) }
+	}()
+
 	c = ctl.c
 	je = json.NewEncoder(w)
 

cmd/main.go

@@ -327,8 +327,8 @@ func main() {
 	os.Exit(0)
 
 wrong_usage:
-	fmt.Fprintf(os.Stderr, "USAGE: %s server --rpc-on=addr:port --ctl-on=addr:port\n", os.Args[0])
+	fmt.Fprintf(os.Stderr, "USAGE: %s server --rpc-on=addr:port --ctl-on=addr:port [--config-file=file]\n", os.Args[0])
-	fmt.Fprintf(os.Stderr, "       %s client --rpc-server=addr:port --ctl-on=addr:port [peer-addr:peer-port ...]\n", os.Args[0])
+	fmt.Fprintf(os.Stderr, "       %s client --rpc-server=addr:port --ctl-on=addr:port [--config-file=file] [peer-addr:peer-port ...]\n", os.Args[0])
 	fmt.Fprintf(os.Stderr, "       %s version\n", os.Args[0])
 	os.Exit(1)
 

hodu.go

@@ -1,5 +1,8 @@
 package hodu
 
+import "net/http"
+import "os"
+import "runtime"
 import "sync"
 
 const HODU_RPC_VERSION uint32 = 0x010000
@@ -39,3 +42,10 @@ func tcp_addr_str_class(addr string) string {
 
 	return "tcp"
 }
+
+func dump_call_frame_and_exit(log Logger, req *http.Request, err interface{}) {
+	var buf []byte
+	buf = make([]byte, 65536); buf = buf[:min(65536, runtime.Stack(buf, false))]
+	log.Write("", LOG_ERROR, "[%s] %s %s - %v\n%s", req.RemoteAddr, req.Method, req.URL.String(), err, string(buf))
+	os.Exit(99) // fatal error. treat panic() as a fatal runtime error
+}

server-ctl.go

@@ -2,9 +2,9 @@ package hodu
 
 import "encoding/json"
 import "net/http"
+import "runtime"
 import "strconv"
 
-
 type json_out_server_conn struct {
 	Id uint32 `json:"id"`
 	ServerAddr string `json:"server-addr"`
@@ -20,6 +20,11 @@ type json_out_server_route struct {
 	ServerPeerProto ROUTE_PROTO `json:"server-peer-proto"`
 }
 
+type json_out_stats struct {
+	NumCPUs int `json:"num-cpus"`
+	NumGoroutines int `json:"num-goroutines"`
+}
+
 // ------------------------------------
 
 type server_ctl_server_conns struct {
@@ -38,6 +43,10 @@ type server_ctl_server_conns_id_routes_id struct {
 	s *Server
 }
 
+type server_ctl_server_stats struct {
+	s *Server
+}
+
 // ------------------------------------
 
 func (ctl *server_ctl_server_conns) ServeHTTP(w http.ResponseWriter, req *http.Request) {
@@ -46,6 +55,16 @@ func (ctl *server_ctl_server_conns) ServeHTTP(w http.ResponseWriter, req *http.R
 	var err error
 	var je *json.Encoder
 
+	// this deferred function is to overcome the recovering implemenation
+	// from panic done in go's http server. in that implemenation, panic
+	// is isolated to a single gorountine. however, i want this program
+	// to exit immediately once a panic condition is caught. (e.g. nil
+	// pointer dererence)
+	defer func() {
+		var err interface{} = recover()
+		if err != nil { dump_call_frame_and_exit(ctl.s.log, req, err) }
+	}()
+
 	s = ctl.s
 	je = json.NewEncoder(w)
 
@@ -112,6 +131,11 @@ func (ctl *server_ctl_server_conns_id) ServeHTTP(w http.ResponseWriter, req *htt
 	var conn_nid uint64
 	var cts *ServerConn
 
+	defer func() {
+		var err interface{} = recover()
+		if err != nil { dump_call_frame_and_exit(ctl.s.log, req, err) }
+	}()
+
 	s = ctl.s
 	je = json.NewEncoder(w)
 
@@ -180,10 +204,48 @@ oops:
 // ------------------------------------
 
 func (ctl *server_ctl_server_conns_id_routes) ServeHTTP(w http.ResponseWriter, req *http.Request) {
-
+	// TODO
 }
 
 // ------------------------------------
 
 func (ctl *server_ctl_server_conns_id_routes_id) ServeHTTP(w http.ResponseWriter, req *http.Request) {
+	// TODO
+}
+
+// ------------------------------------
+
+func (ctl *server_ctl_server_stats) ServeHTTP(w http.ResponseWriter, req *http.Request) {
+	var s *Server
+	var status_code int
+	var err error
+	var je *json.Encoder
+
+	defer func() {
+		var err interface{} = recover()
+		if err != nil { dump_call_frame_and_exit(ctl.s.log, req, err) }
+	}()
+
+	s = ctl.s
+	je = json.NewEncoder(w)
+
+	switch req.Method {
+		case http.MethodGet:
+			var stats json_out_stats
+			stats.NumCPUs = runtime.NumCPU()
+			stats.NumGoroutines = runtime.NumGoroutine()
+			status_code = http.StatusOK; w.WriteHeader(status_code)
+			if err = je.Encode(stats); err != nil { goto oops }
+
+		default:
+			status_code = http.StatusBadRequest; w.WriteHeader(status_code)
+	}
+
+//done:
+	s.log.Write("", LOG_DEBUG, "[%s] %s %s %d", req.RemoteAddr, req.Method, req.URL.String(), status_code) // TODO: time taken
+	return
+
+oops:
+	s.log.Write("", LOG_ERROR, "[%s] %s %s - %s", req.RemoteAddr, req.Method, req.URL.String(), err.Error())
+	return
 }

server.go

@@ -881,6 +881,7 @@ func NewServer(ctx context.Context, ctl_addrs []string, rpc_addrs []string, logg
 	s.ctl_mux.Handle(s.ctl_prefix + "/server-conns/{conn_id}", &server_ctl_server_conns_id{s: &s})
 	s.ctl_mux.Handle(s.ctl_prefix + "/server-conns/{conn_id}/routes", &server_ctl_server_conns_id_routes{s: &s})
 	s.ctl_mux.Handle(s.ctl_prefix + "/server-conns/{conn_id}/routes/{route_id}", &server_ctl_server_conns_id_routes_id{s: &s})
+	s.ctl_mux.Handle(s.ctl_prefix + "/stats", &server_ctl_server_stats{s: &s})
 
 	s.ctl_addr = make([]string, len(ctl_addrs))
 	s.ctl = make([]*http.Server, len(ctl_addrs))