--- nono/host/hostnet.cpp	2026/04/29 17:05:47	1.1.1.9
+++ nono/host/hostnet.cpp	2026/04/29 17:05:51	1.1.1.10
@@ -145,7 +145,7 @@ HostNetDevice::SetLogLevel(int loglevel_
 {
 	inherited::SetLogLevel(loglevel_);
 
-	std::lock_guard<std::mutex> guard(driverlock);
+	RWLockGuard_Read guard(driverlock);
 	if ((bool)driver) {
 		driver->SetLogLevel(loglevel_);
 	}
@@ -184,7 +184,7 @@ HostNetDevice::Create2()
 bool
 HostNetDevice::SelectDriver(bool startup)
 {
-	std::lock_guard<std::mutex> guard(driverlock);
+	RWLockGuard_Write guard(driverlock);
 
 	driver.reset();
 	errmsg.clear();
@@ -267,7 +267,7 @@ HostNetDevice::SelectDriver(bool startup
 		} else {
 			// UI に通知してフォールバック。
 			int n = GetId() - OBJ_HOSTNET0;
-			UIMessage::Post(UIMessage::HOSTNET_FAILED, n);
+			gMainApp.GetUIMessage()->Post(UIMessage::HOSTNET_FAILED, n);
 
 			CreateNone();
 		}
@@ -487,7 +487,7 @@ HostNetDevice::Read()
 	int queued = 0;
 	int left = 0;
 
-	std::lock_guard<std::mutex> guard(driverlock);
+	RWLockGuard_Read guard(driverlock);
 	assert((bool)driver);
 
 	do {
@@ -585,7 +585,7 @@ HostNetDevice::Write()
 {
 	const NetPacket *p;
 
-	std::lock_guard<std::mutex> guard(driverlock);
+	RWLockGuard_Read guard(driverlock);
 	assert((bool)driver);
 
 	// 送信キューから取り出す
@@ -625,7 +625,7 @@ HostNetDevice::Write()
 const std::string
 HostNetDevice::GetDriverName()
 {
-	std::lock_guard<std::mutex> guard(driverlock);
+	RWLockGuard_Read guard(driverlock);
 	assert((bool)driver);
 	return driver->GetDriverName();
 }
@@ -648,7 +648,7 @@ HostNetDevice::MonitorUpdate(Monitor *,
 
 	screen.Print(0, 0, "Device(Port)  : %s", GetPortName().c_str());
 	{
-		std::lock_guard<std::mutex> guard(driverlock);
+		RWLockGuard_Read guard(driverlock);
 		screen.Print(0, 1, "HostNet Driver: %s", driver->GetDriverName());
 		// 次の2行はドライバ依存情報
 		driver->MonitorUpdateMD(screen, 2);