added a function to get the monotonic time

Makefile

@@ -13,7 +13,9 @@ SRCS=\
 	server.go \
 	server-ctl.go \
 	server-peer.go \
-	server-ws.go
+	server-ws.go \
+	system-freebsd.go \
+	system-linux.go
 
 CMD_DATA=\
 	cmd/tls.crt \

server.go

@@ -1100,7 +1100,8 @@ func (s *Server) AddNewServerConn(remote_addr *net.Addr, local_addr *net.Addr, p
 		return nil, fmt.Errorf("too many connections - %d", s.cts_limit)
 	}
 
-	id = rand.Uint32()
+	id = uint32(monotonic_time())
+	//id = rand.Uint32()
 	for {
 		_, ok = s.cts_map[id]
 		if !ok { break }

system-freebsd.go

@@ -0,0 +1,22 @@
+//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
+
+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 0 }
+	return uint64(ts.Nano())
+}

system-linux.go

@@ -0,0 +1,22 @@
+//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
+
+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 0 }
+	return uint64(ts.Nano())
+}