From 6d982c1ddf0735d19887d608ed68b63df7ef25bc Mon Sep 17 00:00:00 2001
From: Sola <dev@sola.love>
Date: Thu, 12 Dec 2024 20:54:03 +0800
Subject: [PATCH] impl `Sync` for `SerialPort` trait

---
 src/lib.rs         |  2 +-
 src/windows/com.rs | 10 ++++++++++
 2 files changed, 11 insertions(+), 1 deletion(-)

diff --git a/src/lib.rs b/src/lib.rs
index fbc7ab8..fc40627 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -447,7 +447,7 @@ impl SerialPortBuilder {
 ///
 /// This trait is all that's necessary to implement a new serial port driver
 /// for a new platform.
-pub trait SerialPort: Send + io::Read + io::Write {
+pub trait SerialPort: Send + Sync + io::Read + io::Write {
     // Port settings getters
 
     /// Returns the name of this port if it exists.
diff --git a/src/windows/com.rs b/src/windows/com.rs
index 1bf368f..7457271 100644
--- a/src/windows/com.rs
+++ b/src/windows/com.rs
@@ -32,7 +32,17 @@ pub struct COMPort {
     port_name: Option<String>,
 }
 
+// The Windows [`HANDLE`] type is considered safe according to the standard library.
+// See explanation on [`OwnedHandle`] in stdlib for more information.
+//
+// [`HANDLE`]: std::os::windows::raw::HANDLE
+// [`OwnedHandle`]: std::os::windows::io::OwnedHandle
+//
+// In the future we might want to consider using `OwnedHandle` instead of `HANDLE` directly.
+// At the time of writing, such work is blocked by this crate's MSRV (1.59.0) policy as
+// `OwnedHandle` was stabilized in 1.63.0.
 unsafe impl Send for COMPort {}
+unsafe impl Sync for COMPort {}
 
 impl COMPort {
     /// Opens a COM port as a serial device.