From de113d150ff77f002592cee304b52592c6e32d2f Mon Sep 17 00:00:00 2001
From: hyung-hwan <hyunghwan.chung@gmail.com>
Date: Mon, 9 Dec 2024 19:04:22 +0900
Subject: [PATCH] added a function to get the monotonic time

---
 Makefile          |  4 +++-
 server.go         |  3 ++-
 system-freebsd.go | 22 ++++++++++++++++++++++
 system-linux.go   | 22 ++++++++++++++++++++++
 4 files changed, 49 insertions(+), 2 deletions(-)
 create mode 100644 system-freebsd.go
 create mode 100644 system-linux.go

diff --git a/Makefile b/Makefile
index f36c4fa..24b7d71 100644
--- a/Makefile
+++ b/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 \
diff --git a/server.go b/server.go
index 6cd39d4..0ac47e8 100644
--- a/server.go
+++ b/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 }
diff --git a/system-freebsd.go b/system-freebsd.go
new file mode 100644
index 0000000..796dd65
--- /dev/null
+++ b/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())
+}
diff --git a/system-linux.go b/system-linux.go
new file mode 100644
index 0000000..efb7866
--- /dev/null
+++ b/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())
+}