simplificed monotonic time functions by using x/sys/unix

Makefile

@@ -14,8 +14,7 @@ SRCS=\
 	server-ctl.go \
 	server-peer.go \
 	server-ws.go \
-	system-freebsd.go \
+	system.go
-	system-linux.go
 
 CMD_DATA=\
 	cmd/tls.crt \

cmd/config.go

@@ -65,6 +65,8 @@ type AppConfig  struct {
 type ServerConfig struct {
 	APP AppConfig                   `yaml:"app"`
 
+// TODO: add some limits
+//       max number of clients, max nubmer of peers
 	CTL struct {
 		Service CTLServiceConfig    `yaml:"service"`
 		TLS ServerTLSConfig         `yaml:"tls"`
@@ -79,6 +81,8 @@ type ServerConfig struct {
 type ClientConfig struct {
 	APP AppConfig                   `yaml:"app"`
 
+// TODO: add some limits
+//       max nubmer of peers
 	CTL struct {
 		Service CTLServiceConfig    `yaml:"service"`
 		TLS ServerTLSConfig         `yaml:"tls"`

go.mod

@@ -3,15 +3,14 @@ module hodu
 go 1.22.0
 
 require (
-	github.com/google/uuid v1.6.0
+	golang.org/x/net v0.28.0
+	golang.org/x/sys v0.24.0
 	google.golang.org/grpc v1.67.1
 	google.golang.org/protobuf v1.34.2
+	gopkg.in/yaml.v3 v3.0.1
 )
 
 require (
-	golang.org/x/net v0.28.0 // indirect
-	golang.org/x/sys v0.24.0 // indirect
 	golang.org/x/text v0.17.0 // indirect
 	google.golang.org/genproto/googleapis/rpc v0.0.0-20240814211410-ddb44dafa142 // indirect
-	gopkg.in/yaml.v3 v3.0.1 // indirect
 )

go.sum

@@ -1,7 +1,5 @@
 github.com/google/go-cmp v0.6.0 h1:ofyhxvXcZhMsU5ulbFiLKl/XBFqE1GSq7atu8tAmTRI=
 github.com/google/go-cmp v0.6.0/go.mod h1:17dUlkBOakJ0+DkrSSNjCkIjxS6bF9zb3elmeNGIjoY=
-github.com/google/uuid v1.6.0 h1:NIvaJDMOsjHA8n1jAhLSgzrAzy1Hgr+hNrb57e+94F0=
-github.com/google/uuid v1.6.0/go.mod h1:TIyPZe4MgqvfeYDBFedMoGGpEw/LqOeaOT+nhxU+yHo=
 golang.org/x/net v0.28.0 h1:a9JDOJc5GMUJ0+UDqmLT86WiEy7iWyIhz8gz8E4e5hE=
 golang.org/x/net v0.28.0/go.mod h1:yqtgsTWOOnlGLG9GFRrK3++bGOUEkNBoHZc8MEDWPNg=
 golang.org/x/sys v0.24.0 h1:Twjiwq9dn6R1fQcyiK+wQyHWfaz/BJB+YIpzU/Cv3Xg=
@@ -14,6 +12,7 @@ google.golang.org/grpc v1.67.1 h1:zWnc1Vrcno+lHZCOofnIMvycFcc0QRGIzm9dhnDX68E=
 google.golang.org/grpc v1.67.1/go.mod h1:1gLDyUQU7CTLJI90u3nXZ9ekeghjeM7pTDZlqFNg2AA=
 google.golang.org/protobuf v1.34.2 h1:6xV6lTsCfpGD21XK49h7MhtcApnLqkfYgPcdHftf6hg=
 google.golang.org/protobuf v1.34.2/go.mod h1:qYOHts0dSfpeUzUFpOMr/WGzszTmLH+DiWniOlNbLDw=
+gopkg.in/check.v1 v0.0.0-20161208181325-20d25e280405 h1:yhCVgyC4o1eVCa2tZl7eS0r+SDo693bJlVdllGtEeKM=
 gopkg.in/check.v1 v0.0.0-20161208181325-20d25e280405/go.mod h1:Co6ibVJAznAaIkqp8huTwlJQCZ016jof/cbN4VW5Yz0=
 gopkg.in/yaml.v3 v3.0.1 h1:fxVm/GzAzEWqLHuvctI91KS9hhNmmWOoWu0XTYJS7CA=
 gopkg.in/yaml.v3 v3.0.1/go.mod h1:K4uyk7z7BCEPqu6E+C64Yfv1cQ7kz7rIZviUmN+EgEM=

packet.go

@@ -1,8 +1,8 @@
 package hodu
 
 type ConnId  uint64
-type RouteId uint32
+type RouteId uint32 // keep this in sync with the type of RouteId in hodu.proto
-type PeerId uint32
+type PeerId  uint32 // keep this in sync with the type of RouteId in hodu.proto
 
 func MakeRouteStartPacket(route_id RouteId, proto ROUTE_PROTO, addr string, svcnet string) *Packet {
 	return &Packet{

server.go

@@ -345,6 +345,10 @@ func (cts *ServerConn) AddNewServerRoute(route_id RouteId, proto ROUTE_PROTO, pt
 
 	cts.route_mtx.Lock()
 	if cts.route_map[route_id] != nil {
+		// If this happens, something must be wrong between the server and the client
+		// most likely, it must be a logic error. the state must not go out of sync
+		// as the route_id and the peer_id are supposed to be the same between the client
+		// and the server.
 		cts.route_mtx.Unlock()
 		return nil, fmt.Errorf("existent route id - %d", route_id)
 	}

system-freebsd.go

@@ -1,26 +0,0 @@
-//go:build freebsd 
-package hodu
-
-import "syscall"
-import "unsafe"
-
-//#include <time.h>
-//import "C"
-
-// C.CLOCK_MONOTONIC is more accurate when compiled with CGO.
-// I want to avoid using it. so assume it is 1 on linux
-//const FREEBSD_CLOCK_MONOTONIC uintptr = C.CLOCK_MONOTONIC
-const CLOCK_MONOTONIC uintptr = 4
-
-// utilize the builtin runtime.nanotime()
-//go:noescape
-//go:linkname nanotime runtime.nanotime
-func nanotime() int64
-
-func monotonic_time() uint64 {
-	var ts syscall.Timespec
-	var errno syscall.Errno
-	_, _, errno = syscall.Syscall(syscall.SYS_CLOCK_GETTIME, CLOCK_MONOTONIC, uintptr(unsafe.Pointer(&ts)), 0)
-	if errno != 0 { return uint64(nanotime()) }
-	return uint64(ts.Nano())
-}

system-linux.go

@@ -1,26 +0,0 @@
-//go:build linux
-package hodu
-
-import "syscall"
-import "unsafe"
-
-//#include <time.h>
-//import "C"
-
-// C.CLOCK_MONOTONIC is more accurate when compiled with CGO.
-// I want to avoid using it. so assume it is 1 on linux
-//const CLOCK_MONOTONIC uintptr = C.CLOCK_MONOTONIC
-const CLOCK_MONOTONIC uintptr = 1
-
-// utilize the builtin runtime.nanotime()
-//go:noescape
-//go:linkname nanotime runtime.nanotime
-func nanotime() int64
-
-func monotonic_time() uint64 {
-	var ts syscall.Timespec
-	var errno syscall.Errno
-	_, _, errno = syscall.Syscall(syscall.SYS_CLOCK_GETTIME, CLOCK_MONOTONIC, uintptr(unsafe.Pointer(&ts)), 0)
-	if errno != 0 { return uint64(nanotime()) }
-	return uint64(ts.Nano())
-}

system.go

@@ -0,0 +1,32 @@
+package hodu
+
+import "syscall"
+import "unsafe"
+import "golang.org/x/sys/unix"
+
+
+// utilize the builtin runtime.nanotime()
+//go:noescape
+//go:linkname nanotime runtime.nanotime
+func nanotime() int64
+
+func monotonic_time() uint64 {
+	var n int64
+	var err error
+	var uts unix.Timespec
+
+	n = nanotime() // hopefully it's faster than a system call. say, vdso is utilized.
+	if (n >= 0) { return uint64(n) }
+
+	err = unix.ClockGettime(unix.CLOCK_MONOTONIC, &uts)
+	if err != nil {
+		//var errno syscall.Errno
+		var r uintptr
+		var sts syscall.Timespec
+		r, _, _/*errno*/ = syscall.Syscall(syscall.SYS_CLOCK_GETTIME, unix.CLOCK_MONOTONIC, uintptr(unsafe.Pointer(&sts)), 0)
+		if r == ^uintptr(0) { return uint64(n) } // may be negative cast to unsigned. no other fall-back
+		return uint64(sts.Nano())
+	}
+
+	return uint64(uts.Nano())
+}