NamedEvent is no longer an Event-type object.

Platforms other than Windows do not really have a named event-like
primitive or ones that are close are fallible if a process
hard-terminates. Separating from Event more clearly conveys the use of
NamedEvent objects; to synchronise two processes.

3 files changed, 69 insertions, 7 deletions

diff --git a/zencore/include/zencore/thread.h b/zencore/include/zencore/thread.h
index 3feb12936..2fe7cc63e 100644
--- a/zencore/include/zencore/thread.h
+++ b/zencore/include/zencore/thread.h
@@ -102,11 +102,36 @@ protected:
 
 /** Basic abstraction of an IPC mechanism (aka 'binary semaphore')
  */
-class NamedEvent : public Event
+class NamedEvent
 {
 public:
-	ZENCORE_API explicit NamedEvent(std::string_view EventName);
-	ZENCORE_API explicit NamedEvent(std::u8string_view EventName);
+							NamedEvent() = default;
+	ZENCORE_API explicit	NamedEvent(std::string_view EventName);
+	ZENCORE_API explicit	NamedEvent(std::u8string_view EventName);
+	ZENCORE_API				~NamedEvent();
+	ZENCORE_API void		Close();
+	ZENCORE_API void		Set();
+	ZENCORE_API bool		Wait(int TimeoutMs=-1);
+
+	NamedEvent(NamedEvent&& Rhs) noexcept
+	: m_EventHandle(Rhs.m_EventHandle)
+	{
+		Rhs.m_EventHandle = nullptr;
+	}
+
+	inline NamedEvent& operator = (NamedEvent&& Rhs) noexcept
+	{
+		std::swap(m_EventHandle, Rhs.m_EventHandle);
+		return *this;
+	}
+
+
+protected:
+	void*		m_EventHandle = nullptr;
+
+private:
+				NamedEvent(const NamedEvent& Rhs) = delete;
+	NamedEvent&	operator = (const NamedEvent& Rhs) = delete;
 };
 
 /** Basic abstraction of a named (system wide) mutex primitive
diff --git a/zencore/thread.cpp b/zencore/thread.cpp
index 3e40b6336..6c5419494 100644
--- a/zencore/thread.cpp
+++ b/zencore/thread.cpp
@@ -228,7 +228,7 @@ Event::Wait(int TimeoutMs)
 
 #if ZEN_PLATFORM_WINDOWS
 
-NamedEvent::NamedEvent(std::u8string_view EventName) : Event(nullptr)
+NamedEvent::NamedEvent(std::u8string_view EventName)
 {
 	using namespace std::literals;
 
@@ -239,7 +239,7 @@ NamedEvent::NamedEvent(std::u8string_view EventName) : Event(nullptr)
 	m_EventHandle = CreateEventA(nullptr, true, false, Name.c_str());
 }
 
-NamedEvent::NamedEvent(std::string_view EventName) : Event(nullptr)
+NamedEvent::NamedEvent(std::string_view EventName)
 {
 	using namespace std::literals;
 
@@ -250,6 +250,43 @@ NamedEvent::NamedEvent(std::string_view EventName) : Event(nullptr)
 	m_EventHandle = CreateEventA(nullptr, true, false, Name.c_str());
 }
 
+NamedEvent::~NamedEvent()
+{
+	Close();
+}
+
+void NamedEvent::Close()
+{
+	if (m_EventHandle == nullptr)
+	{
+		return;
+	}
+
+	CloseHandle(m_EventHandle);
+
+	m_EventHandle = nullptr;
+}
+
+void NamedEvent::Set()
+{
+	SetEvent(m_EventHandle);
+}
+
+bool NamedEvent::Wait(int TimeoutMs)
+{
+	const DWORD Timeout = (TimeoutMs < 0) ? INFINITE : TimeoutMs;
+
+	DWORD Result = WaitForSingleObject(m_EventHandle, Timeout);
+
+	if (Result == WAIT_FAILED)
+	{
+		using namespace std::literals;
+		zen::ThrowLastError("Event wait failed"sv);
+	}
+
+	return (Result == WAIT_OBJECT_0);
+}
+
 #endif // ZEN_PLATFORM_WINDOWS
 
 //////////////////////////////////////////////////////////////////////////
diff --git a/zenutil/include/zenutil/zenserverprocess.h b/zenutil/include/zenutil/zenserverprocess.h
index 8a4f9604d..55b9a50cd 100644
--- a/zenutil/include/zenutil/zenserverprocess.h
+++ b/zenutil/include/zenutil/zenserverprocess.h
@@ -67,8 +67,8 @@ struct ZenServerInstance
 private:
 	ZenServerEnvironment& m_Env;
 	ProcessHandle		  m_Process;
-	Event				  m_ReadyEvent;
-	Event				  m_ShutdownEvent;
+	NamedEvent			  m_ReadyEvent;
+	NamedEvent			  m_ShutdownEvent;
 	bool				  m_Terminate = false;
 	std::filesystem::path m_TestDir;
 	bool				  m_MeshEnabled = false;