Merged main.

1 files changed, 764 insertions, 39 deletions

diff --git a/zencore/thread.cpp b/zencore/thread.cpp
index da711fe89..6d17e6968 100644
--- a/zencore/thread.cpp
+++ b/zencore/thread.cpp
@@ -3,14 +3,32 @@
 #include <zencore/thread.h>
 
 #include <zencore/except.h>
+#include <zencore/filesystem.h>
+#include <zencore/scopeguard.h>
 #include <zencore/string.h>
+#include <zencore/testing.h>
 
 #if ZEN_PLATFORM_WINDOWS
+#	include <shellapi.h>
+#	include <Shlobj.h>
 #	include <zencore/windows.h>
 #elif ZEN_PLATFORM_LINUX
+#	include <chrono>
+#	include <condition_variable>
+#	include <mutex>
+
+#	include <fcntl.h>
+#	include <mqueue.h>
+#	include <pthread.h>
+#	include <signal.h>
+#	include <sys/file.h>
+#	include <sys/wait.h>
+#	include <time.h>
 #	include <unistd.h>
 #endif
 
+#include <thread>
+
 ZEN_THIRD_PARTY_INCLUDES_START
 #include <fmt/format.h>
 ZEN_THIRD_PARTY_INCLUDES_END
@@ -69,6 +87,8 @@ SetCurrentThreadName([[maybe_unused]] std::string_view ThreadName)
 	std::string ThreadNameZ{ThreadName};
 	SetNameInternal(GetCurrentThreadId(), ThreadNameZ.c_str());
 #else
+	std::string ThreadNameZ{ThreadName};
+	pthread_setname_np(pthread_self(), ThreadNameZ.c_str());
 #endif
 }  // namespace zen
 
@@ -98,40 +118,80 @@ RwLock::ReleaseExclusive()
 
 //////////////////////////////////////////////////////////////////////////
 
-#if ZEN_PLATFORM_WINDOWS
+#if !ZEN_PLATFORM_WINDOWS
+struct EventInner
+{
+	std::mutex				Mutex;
+	std::condition_variable CondVar;
+	bool volatile bSet = false;
+};
+#endif	// !ZEN_PLATFORM_WINDOWS
 
 Event::Event()
 {
-	m_EventHandle = CreateEvent(nullptr, true, false, nullptr);
+	bool bManualReset  = true;
+	bool bInitialState = false;
+
+#if ZEN_PLATFORM_WINDOWS
+	m_EventHandle = CreateEvent(nullptr, bManualReset, bInitialState, nullptr);
+#else
+	ZEN_UNUSED(bManualReset);
+	auto* Inner	  = new EventInner();
+	Inner->bSet	  = bInitialState;
+	m_EventHandle = Inner;
+#endif
 }
 
 Event::~Event()
 {
-	CloseHandle(m_EventHandle);
+	Close();
 }
 
 void
 Event::Set()
 {
+#if ZEN_PLATFORM_WINDOWS
 	SetEvent(m_EventHandle);
+#else
+	auto* Inner	  = (EventInner*)m_EventHandle;
+	{
+		std::unique_lock Lock(Inner->Mutex);
+		Inner->bSet = true;
+	}
+	Inner->CondVar.notify_all();
+#endif
 }
 
 void
 Event::Reset()
 {
+#if ZEN_PLATFORM_WINDOWS
 	ResetEvent(m_EventHandle);
+#else
+	auto* Inner = (EventInner*)m_EventHandle;
+	{
+		std::unique_lock Lock(Inner->Mutex);
+		Inner->bSet = false;
+	}
+#endif
 }
 
 void
 Event::Close()
 {
+#if ZEN_PLATFORM_WINDOWS
 	CloseHandle(m_EventHandle);
+#else
+	auto* Inner = (EventInner*)m_EventHandle;
+	delete Inner;
+#endif
 	m_EventHandle = nullptr;
 }
 
 bool
 Event::Wait(int TimeoutMs)
 {
+#if ZEN_PLATFORM_WINDOWS
 	using namespace std::literals;
 
 	const DWORD Timeout = (TimeoutMs < 0) ? INFINITE : TimeoutMs;
@@ -144,12 +204,48 @@ Event::Wait(int TimeoutMs)
 	}
 
 	return (Result == WAIT_OBJECT_0);
+#else
+	auto* Inner = (EventInner*)m_EventHandle;
+
+	if (TimeoutMs >= 0)
+	{
+		std::unique_lock Lock(Inner->Mutex);
+
+		if (Inner->bSet)
+		{
+			return true;
+		}
+
+		return Inner->CondVar.wait_for(Lock, std::chrono::milliseconds(TimeoutMs), [&] { return Inner->bSet; });
+	}
+
+	std::unique_lock Lock(Inner->Mutex);
+
+	if (!Inner->bSet)
+	{
+		Inner->CondVar.wait(Lock, [&] { return Inner->bSet; });
+	}
+
+	return true;
+#endif
 }
 
 //////////////////////////////////////////////////////////////////////////
 
-NamedEvent::NamedEvent(std::u8string_view EventName) : Event(nullptr)
+#if ZEN_PLATFORM_LINUX
+static bool
+IsMessageQueueEmpty(int Fd)
 {
+	// Check if there is already a message in the queue.
+	mq_attr Attributes = {O_NONBLOCK, 1, 1, 0};
+	mq_getattr(Fd, &Attributes);
+	return (Attributes.mq_curmsgs == 0);
+}
+#endif	// ZEN_PLATFORM_LINUX
+
+NamedEvent::NamedEvent(std::string_view EventName)
+{
+#if ZEN_PLATFORM_WINDOWS
 	using namespace std::literals;
 
 	ExtendableStringBuilder<64> Name;
@@ -157,30 +253,151 @@ NamedEvent::NamedEvent(std::u8string_view EventName) : Event(nullptr)
 	Name << EventName;
 
 	m_EventHandle = CreateEventA(nullptr, true, false, Name.c_str());
+#elif ZEN_PLATFORM_LINUX
+	ExtendableStringBuilder<64> Name;
+	Name << "/";
+	Name << EventName;
+
+	mq_attr Attributes = {
+		0,	// flags
+		1,	// max message count
+		1,	// max message size
+		0,	// current messages
+	};
+
+	int Inner = mq_open(Name.c_str(), O_RDWR | O_CREAT | O_CLOEXEC, 0644, &Attributes);
+	if (Inner < 0)
+	{
+		ThrowLastError("Failed to get message queue from mq_open()");
+	}
+
+	int LockResult = flock(Inner, LOCK_EX | LOCK_NB);
+	if (LockResult == 0)
+	{
+		// This is really thread safe as the message queue could be set between
+		// getting the exclusive lock and checking the queue. But for the our
+		// simple synchronising of process, this should be okay.
+		while (!IsMessageQueueEmpty(Inner))
+		{
+			char Sink;
+			mq_receive(Inner, &Sink, sizeof(Sink), nullptr);
+		}
+	}
+
+	m_EventHandle = (void*)intptr_t(Inner);
+#else
+#	error Implement NamedEvent for this platform
+#endif
 }
 
-NamedEvent::NamedEvent(std::string_view EventName) : Event(nullptr)
+NamedEvent::~NamedEvent()
 {
-	using namespace std::literals;
+	Close();
+}
 
-	ExtendableStringBuilder<64> Name;
-	Name << "Local\\"sv;
-	Name << EventName;
+void
+NamedEvent::Close()
+{
+	if (m_EventHandle == nullptr)
+	{
+		return;
+	}
 
-	m_EventHandle = CreateEventA(nullptr, true, false, Name.c_str());
+#if ZEN_PLATFORM_WINDOWS
+	CloseHandle(m_EventHandle);
+#elif ZEN_PLATFORM_LINUX
+	int Inner	  = int(intptr_t(m_EventHandle));
+
+	if (flock(Inner, LOCK_EX | LOCK_NB) == 0)
+	{
+		flock(Inner, LOCK_UN | LOCK_NB);
+		std::filesystem::path Name = PathFromHandle((void*)(intptr_t(Inner)));
+		mq_unlink(Name.c_str());
+	}
+
+	close(Inner);
+#endif
+
+	m_EventHandle = nullptr;
+}
+
+void
+NamedEvent::Set()
+{
+#if ZEN_PLATFORM_WINDOWS
+	SetEvent(m_EventHandle);
+#elif ZEN_PLATFORM_LINUX
+	int Inner = int(intptr_t(m_EventHandle));
+
+	if (!IsMessageQueueEmpty(Inner))
+	{
+		return;
+	}
+
+	char Message = 0x49;
+	if (mq_send(Inner, &Message, sizeof(Message), 0) != 0)
+	{
+		ThrowLastError("Unable to send set message to queue");
+	}
+#endif
 }
 
+bool
+NamedEvent::Wait(int TimeoutMs)
+{
+#if ZEN_PLATFORM_WINDOWS
+	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);
+#elif ZEN_PLATFORM_LINUX
+	int Inner = int(intptr_t(m_EventHandle));
+
+	if (!IsMessageQueueEmpty(Inner))
+	{
+		return true;
+	}
+
+	struct timeval TimeoutValue = {
+		.tv_sec	 = 0,
+		.tv_usec = TimeoutMs << 10,
+	};
+	struct timeval* TimeoutPtr = (TimeoutMs < 0) ? nullptr : &TimeoutValue;
+
+	fd_set FdSet;
+	FD_ZERO(&FdSet);
+	FD_SET(Inner, &FdSet);
+	return select(Inner + 1, &FdSet, nullptr, nullptr, TimeoutPtr) > 0;
+#endif
+}
+
+//////////////////////////////////////////////////////////////////////////
+
 NamedMutex::~NamedMutex()
 {
+#if ZEN_PLATFORM_WINDOWS
 	if (m_MutexHandle)
 	{
 		CloseHandle(m_MutexHandle);
 	}
+#else
+	int Inner = int(intptr_t(m_MutexHandle));
+	flock(Inner, LOCK_UN);
+	close(Inner);
+#endif
 }
 
 bool
 NamedMutex::Create(std::string_view MutexName)
 {
+#if ZEN_PLATFORM_WINDOWS
 	ZEN_ASSERT(m_MutexHandle == nullptr);
 
 	using namespace std::literals;
@@ -192,11 +409,32 @@ NamedMutex::Create(std::string_view MutexName)
 	m_MutexHandle = CreateMutexA(nullptr, /* InitialOwner */ TRUE, Name.c_str());
 
 	return !!m_MutexHandle;
+#else
+	ExtendableStringBuilder<64> Name;
+	Name << "/tmp/" << MutexName;
+
+	int Inner = open(Name.c_str(), O_RDWR | O_CREAT | O_CLOEXEC, 0644);
+	if (Inner < 0)
+	{
+		return false;
+	}
+
+	if (flock(Inner, LOCK_EX) != 0)
+	{
+		close(Inner);
+		Inner = 0;
+		return false;
+	}
+
+	m_MutexHandle = (void*)(intptr_t(Inner));
+	return true;
+#endif	// ZEN_PLATFORM_WINDOWS
 }
 
 bool
 NamedMutex::Exists(std::string_view MutexName)
 {
+#if ZEN_PLATFORM_WINDOWS
 	using namespace std::literals;
 
 	ExtendableStringBuilder<64> Name;
@@ -213,24 +451,49 @@ NamedMutex::Exists(std::string_view MutexName)
 	CloseHandle(MutexHandle);
 
 	return true;
-}
+#else
+	ExtendableStringBuilder<64> Name;
+	Name << "/tmp/" << MutexName;
 
-#endif	// ZEN_PLATFORM_WINDOWS
+	bool bExists = false;
+	int	 Fd		 = open(Name.c_str(), O_RDWR, 0644);
+	if (Fd >= 0)
+	{
+		if (flock(Fd, LOCK_EX | LOCK_NB) == 0)
+		{
+			flock(Fd, LOCK_UN | LOCK_NB);
+		}
+		else
+		{
+			bExists = true;
+		}
+		close(Fd);
+	}
 
-#if ZEN_PLATFORM_WINDOWS
+	return bExists;
+#endif	// ZEN_PLATFORM_WINDOWS
+}
 
 //////////////////////////////////////////////////////////////////////////
 
 ProcessHandle::ProcessHandle() = default;
 
+#if ZEN_PLATFORM_WINDOWS
 void
 ProcessHandle::Initialize(void* ProcessHandle)
 {
 	ZEN_ASSERT(m_ProcessHandle == nullptr);
+
+	if (ProcessHandle == INVALID_HANDLE_VALUE)
+	{
+		ProcessHandle = nullptr;
+	}
+
 	// TODO: perform some debug verification here to verify it's a valid handle?
 	m_ProcessHandle = ProcessHandle;
 	m_Pid			= GetProcessId(m_ProcessHandle);
 }
+#endif	// ZEN_PLATFORM_WINDOWS
 
 ProcessHandle::~ProcessHandle()
 {
@@ -241,12 +504,21 @@ void
 ProcessHandle::Initialize(int Pid)
 {
 	ZEN_ASSERT(m_ProcessHandle == nullptr);
-	m_ProcessHandle = OpenProcess(PROCESS_QUERY_INFORMATION | SYNCHRONIZE, FALSE, Pid);
 
-	using namespace fmt::literals;
+#if ZEN_PLATFORM_WINDOWS
+	m_ProcessHandle = OpenProcess(PROCESS_QUERY_INFORMATION | SYNCHRONIZE, FALSE, Pid);
+#elif ZEN_PLATFORM_LINUX
+	if (Pid > 0)
+	{
+		m_ProcessHandle = (void*)(intptr_t(Pid));
+	}
+#else
+#	error Check process control on this platform
+#endif
 
 	if (!m_ProcessHandle)
 	{
+		using namespace fmt::literals;
 		ThrowLastError("ProcessHandle::Initialize(pid: {}) failed"_format(Pid));
 	}
 
@@ -256,29 +528,51 @@ ProcessHandle::Initialize(int Pid)
 bool
 ProcessHandle::IsRunning() const
 {
+	bool bActive = false;
+
+#if ZEN_PLATFORM_WINDOWS
 	DWORD ExitCode = 0;
 	GetExitCodeProcess(m_ProcessHandle, &ExitCode);
+	bActive = (ExitCode == STILL_ACTIVE);
+#elif ZEN_PLATFORM_LINUX
+	StringBuilder<64> ProcPath;
+	ProcPath << "/proc/" << m_Pid;
+	bActive = (access(ProcPath.c_str(), F_OK) != 0);
+#else
+#	error Check process control on this platform
+#endif
 
-	return ExitCode == STILL_ACTIVE;
+	return bActive;
 }
 
 bool
 ProcessHandle::IsValid() const
 {
-	return (m_ProcessHandle != nullptr) && (m_ProcessHandle != INVALID_HANDLE_VALUE);
+	return (m_ProcessHandle != nullptr);
 }
 
 void
 ProcessHandle::Terminate(int ExitCode)
 {
-	if (IsRunning())
+	if (!IsRunning())
 	{
-		TerminateProcess(m_ProcessHandle, ExitCode);
+		return;
 	}
 
+	bool bSuccess = false;
+
+#if ZEN_PLATFORM_WINDOWS
+	TerminateProcess(m_ProcessHandle, ExitCode);
 	DWORD WaitResult = WaitForSingleObject(m_ProcessHandle, INFINITE);
+	bSuccess		 = (WaitResult != WAIT_OBJECT_0);
+#elif ZEN_PLATFORM_LINUX
+	ZEN_UNUSED(ExitCode);
+	bSuccess			= (kill(m_Pid, SIGKILL) == 0);
+#else
+#	error Check kill() on this platform
+#endif
 
-	if (WaitResult != WAIT_OBJECT_0)
+	if (!bSuccess)
 	{
 		// What might go wrong here, and what is meaningful to act on?
 	}
@@ -289,14 +583,20 @@ ProcessHandle::Reset()
 {
 	if (IsValid())
 	{
+#if ZEN_PLATFORM_WINDOWS
 		CloseHandle(m_ProcessHandle);
+#endif
 		m_ProcessHandle = nullptr;
+		m_Pid			= 0;
 	}
 }
 
 bool
 ProcessHandle::Wait(int TimeoutMs)
 {
+	using namespace std::literals;
+
+#if ZEN_PLATFORM_WINDOWS
 	const DWORD Timeout = (TimeoutMs < 0) ? INFINITE : TimeoutMs;
 
 	const DWORD WaitResult = WaitForSingleObject(m_ProcessHandle, Timeout);
@@ -310,19 +610,301 @@ ProcessHandle::Wait(int TimeoutMs)
 			return false;
 
 		case WAIT_FAILED:
-			// What might go wrong here, and what is meaningful to act on?
-			using namespace std::literals;
-			ThrowLastError("Process::Wait failed"sv);
+			break;
 	}
+#elif ZEN_PLATFORM_LINUX
+	const int SleepMs	= 20;
+	timespec  SleepTime = {0, SleepMs * 1000 * 1000};
+	for (int i = 0;; i += SleepMs)
+	{
+		int WaitState = 0;
+		waitpid(m_Pid, &WaitState, WNOHANG | WCONTINUED | WUNTRACED);
 
-	return false;
-}
+		if (kill(m_Pid, 0) < 0)
+		{
+			if (zen::GetLastError() == ESRCH)
+			{
+				return true;
+			}
+			break;
+		}
 
-#endif	// ZEN_PLATFORM_WINDOWS
+		if (TimeoutMs >= 0 && i >= TimeoutMs)
+		{
+			return false;
+		}
+
+		nanosleep(&SleepTime, nullptr);
+	}
+#else
+#	error Check kill() on this platform
+#endif
+
+	// What might go wrong here, and what is meaningful to act on?
+	ThrowLastError("Process::Wait failed"sv);
+}
 
 //////////////////////////////////////////////////////////////////////////
 
+#if !ZEN_PLATFORM_WINDOWS || ZEN_WITH_TESTS
+static void
+BuildArgV(std::vector<char*>& Out, char* CommandLine)
+{
+	char* Cursor = CommandLine;
+	while (true)
+	{
+		// Skip leading whitespace
+		for (; *Cursor == ' '; ++Cursor)
+			;
+
+		// Check for nullp terminator
+		if (*Cursor == '\0')
+		{
+			break;
+		}
+
+		Out.push_back(Cursor);
+
+		// Extract word
+		int QuoteCount = 0;
+		do
+		{
+			QuoteCount += (*Cursor == '\"');
+			if (*Cursor == ' ' && !(QuoteCount & 1))
+			{
+				break;
+			}
+			++Cursor;
+		} while (*Cursor != '\0');
+
+		if (*Cursor == '\0')
+		{
+			break;
+		}
+
+		*Cursor = '\0';
+		++Cursor;
+	}
+}
+#endif	// !WINDOWS || TESTS
+
+#if ZEN_PLATFORM_WINDOWS
+static CreateProcResult
+CreateProcNormal(const std::filesystem::path& Executable, std::string_view CommandLine, const CreateProcOptions& Options)
+{
+	PROCESS_INFORMATION ProcessInfo{};
+	STARTUPINFO			StartupInfo{.cb = sizeof(STARTUPINFO)};
+
+	const bool			  InheritHandles	= false;
+	void*				  Environment		= nullptr;
+	LPSECURITY_ATTRIBUTES ProcessAttributes = nullptr;
+	LPSECURITY_ATTRIBUTES ThreadAttributes	= nullptr;
+
+	DWORD CreationFlags = 0;
+	if (Options.Flags & CreateProcOptions::Flag_NewConsole)
+	{
+		CreationFlags |= CREATE_NEW_CONSOLE;
+	}
+
+	const wchar_t* WorkingDir = nullptr;
+	if (Options.WorkingDirectory != nullptr)
+	{
+		WorkingDir = Options.WorkingDirectory->c_str();
+	}
+
+	ExtendableWideStringBuilder<256> CommandLineZ;
+	CommandLineZ << CommandLine;
+
+	BOOL Success = CreateProcessW(Executable.c_str(),
+								  CommandLineZ.Data(),
+								  ProcessAttributes,
+								  ThreadAttributes,
+								  InheritHandles,
+								  CreationFlags,
+								  Environment,
+								  WorkingDir,
+								  &StartupInfo,
+								  &ProcessInfo);
+
+	if (!Success)
+	{
+		return nullptr;
+	}
+
+	CloseHandle(ProcessInfo.hThread);
+	return ProcessInfo.hProcess;
+}
+
+static CreateProcResult
+CreateProcUnelevated(const std::filesystem::path& Executable, std::string_view CommandLine, const CreateProcOptions& Options)
+{
+	/* Launches a binary with the shell as its parent. The shell (such as
+	   Explorer) should be an unelevated process. */
+
+	// No sense in using this route if we are not elevated in the first place
+	if (IsUserAnAdmin() == FALSE)
+	{
+		return CreateProcNormal(Executable, CommandLine, Options);
+	}
+
+	// Get the users' shell process and open it for process creation
+	HWND ShellWnd = GetShellWindow();
+	if (ShellWnd == nullptr)
+	{
+		return nullptr;
+	}
+
+	DWORD ShellPid;
+	GetWindowThreadProcessId(ShellWnd, &ShellPid);
+
+	HANDLE Process = OpenProcess(PROCESS_CREATE_PROCESS, FALSE, ShellPid);
+	if (Process == nullptr)
+	{
+		return nullptr;
+	}
+	auto $0 = MakeGuard([&] { CloseHandle(Process); });
+
+	// Creating a process as a child of another process is done by setting a
+	// thread-attribute list on the startup info passed to CreateProcess()
+	SIZE_T AttrListSize;
+	InitializeProcThreadAttributeList(nullptr, 1, 0, &AttrListSize);
+
+	auto AttrList = (PPROC_THREAD_ATTRIBUTE_LIST)malloc(AttrListSize);
+	auto $1		  = MakeGuard([&] { free(AttrList); });
+
+	if (!InitializeProcThreadAttributeList(AttrList, 1, 0, &AttrListSize))
+	{
+		return nullptr;
+	}
+
+	BOOL bOk =
+		UpdateProcThreadAttribute(AttrList, 0, PROC_THREAD_ATTRIBUTE_PARENT_PROCESS, (HANDLE*)&Process, sizeof(Process), nullptr, nullptr);
+	if (!bOk)
+	{
+		return nullptr;
+	}
+
+	// By this point we know we are an elevated process. It is not allowed to
+	// create a process as a child of another unelevated process that share our
+	// elevated console window if we have one. So we'll need to create a new one.
+	uint32_t CreateProcFlags = EXTENDED_STARTUPINFO_PRESENT;
+	if (GetConsoleWindow() != nullptr)
+	{
+		CreateProcFlags |= CREATE_NEW_CONSOLE;
+	}
+	else
+	{
+		CreateProcFlags |= DETACHED_PROCESS;
+	}
+
+	// Everything is set up now so we can proceed and launch the process
+	STARTUPINFOEXW StartupInfo = {
+		.StartupInfo	 = {.cb = sizeof(STARTUPINFOEXW)},
+		.lpAttributeList = AttrList,
+	};
+	PROCESS_INFORMATION ProcessInfo = {};
+
+	if (Options.Flags & CreateProcOptions::Flag_NewConsole)
+	{
+		CreateProcFlags |= CREATE_NEW_CONSOLE;
+	}
+
+	ExtendableWideStringBuilder<256> CommandLineZ;
+	CommandLineZ << CommandLine;
+
+	bOk = CreateProcessW(Executable.c_str(),
+						 CommandLineZ.Data(),
+						 nullptr,
+						 nullptr,
+						 FALSE,
+						 CreateProcFlags,
+						 nullptr,
+						 nullptr,
+						 &StartupInfo.StartupInfo,
+						 &ProcessInfo);
+	if (bOk == FALSE)
+	{
+		return nullptr;
+	}
+
+	CloseHandle(ProcessInfo.hThread);
+	return ProcessInfo.hProcess;
+}
+
+static CreateProcResult
+CreateProcElevated(const std::filesystem::path& Executable, std::string_view CommandLine, const CreateProcOptions& Options)
+{
+	ExtendableWideStringBuilder<256> CommandLineZ;
+	CommandLineZ << CommandLine;
+
+	SHELLEXECUTEINFO ShellExecuteInfo;
+	ZeroMemory(&ShellExecuteInfo, sizeof(ShellExecuteInfo));
+	ShellExecuteInfo.cbSize		  = sizeof(ShellExecuteInfo);
+	ShellExecuteInfo.fMask		  = SEE_MASK_UNICODE | SEE_MASK_NOCLOSEPROCESS;
+	ShellExecuteInfo.lpFile		  = Executable.c_str();
+	ShellExecuteInfo.lpVerb		  = TEXT("runas");
+	ShellExecuteInfo.nShow		  = SW_SHOW;
+	ShellExecuteInfo.lpParameters = CommandLineZ.c_str();
+
+	if (Options.WorkingDirectory != nullptr)
+	{
+		ShellExecuteInfo.lpDirectory = Options.WorkingDirectory->c_str();
+	}
+
+	if (::ShellExecuteEx(&ShellExecuteInfo))
+	{
+		return ShellExecuteInfo.hProcess;
+	}
+
+	return nullptr;
+}
+#endif	// ZEN_PLATFORM_WINDOWS
+
+CreateProcResult
+CreateProc(const std::filesystem::path& Executable, std::string_view CommandLine, const CreateProcOptions& Options)
+{
 #if ZEN_PLATFORM_WINDOWS
+	if (Options.Flags & CreateProcOptions::Flag_Unelevated)
+	{
+		return CreateProcUnelevated(Executable, CommandLine, Options);
+	}
+
+	if (Options.Flags & CreateProcOptions::Flag_Elevated)
+	{
+		return CreateProcElevated(Executable, CommandLine, Options);
+	}
+
+	return CreateProcNormal(Executable, CommandLine, Options);
+#else
+	std::vector<char*> ArgV;
+	std::string		   CommandLineZ(CommandLine);
+	BuildArgV(ArgV, CommandLineZ.data());
+	ArgV.push_back(nullptr);
+
+	int ChildPid = fork();
+	if (ChildPid < 0)
+	{
+		ThrowLastError("Failed to fork a new child process");
+	}
+	else if (ChildPid == 0)
+	{
+		if (Options.WorkingDirectory != nullptr)
+		{
+			int Result = chdir(Options.WorkingDirectory->c_str());
+			ZEN_UNUSED(Result);
+		}
+
+		if (execv(Executable.c_str(), ArgV.data()) < 0)
+		{
+			ThrowLastError("Failed to exec() a new process image");
+		}
+	}
+
+	return ChildPid;
+#endif
+}
+
+//////////////////////////////////////////////////////////////////////////
 
 ProcessMonitor::ProcessMonitor()
 {
@@ -332,9 +914,11 @@ ProcessMonitor::~ProcessMonitor()
 {
 	RwLock::ExclusiveLockScope _(m_Lock);
 
-	for (HANDLE& Proc : m_ProcessHandles)
+	for (HandleType& Proc : m_ProcessHandles)
 	{
+#if ZEN_PLATFORM_WINDOWS
 		CloseHandle(Proc);
+#endif
 		Proc = 0;
 	}
 }
@@ -346,24 +930,34 @@ ProcessMonitor::IsRunning()
 
 	bool FoundOne = false;
 
-	for (HANDLE& Proc : m_ProcessHandles)
+	for (HandleType& Proc : m_ProcessHandles)
 	{
+		bool ProcIsActive;
+
+#if ZEN_PLATFORM_WINDOWS
 		DWORD ExitCode = 0;
 		GetExitCodeProcess(Proc, &ExitCode);
 
-		if (ExitCode != STILL_ACTIVE)
+		ProcIsActive = (ExitCode == STILL_ACTIVE);
+		if (!ProcIsActive)
 		{
 			CloseHandle(Proc);
-			Proc = 0;
 		}
-		else
+#else
+		int Pid		 = int(intptr_t(Proc));
+		ProcIsActive = IsProcessRunning(Pid);
+#endif
+
+		if (!ProcIsActive)
 		{
-			// Still alive
-			FoundOne = true;
+			Proc = 0;
 		}
+
+		// Still alive
+		FoundOne |= ProcIsActive;
 	}
 
-	std::erase_if(m_ProcessHandles, [](HANDLE Handle) { return Handle == 0; });
+	std::erase_if(m_ProcessHandles, [](HandleType Handle) { return Handle == 0; });
 
 	return FoundOne;
 }
@@ -371,7 +965,13 @@ ProcessMonitor::IsRunning()
 void
 ProcessMonitor::AddPid(int Pid)
 {
-	HANDLE ProcessHandle = OpenProcess(PROCESS_QUERY_INFORMATION | SYNCHRONIZE, FALSE, Pid);
+	HandleType ProcessHandle;
+
+#if ZEN_PLATFORM_WINDOWS
+	ProcessHandle = OpenProcess(PROCESS_QUERY_INFORMATION | SYNCHRONIZE, FALSE, Pid);
+#else
+	ProcessHandle = HandleType(intptr_t(Pid));
+#endif
 
 	if (ProcessHandle)
 	{
@@ -387,8 +987,6 @@ ProcessMonitor::IsActive() const
 	return m_ProcessHandles.empty() == false;
 }
 
-#endif	// ZEN_PLATFORM_WINDOWS
-
 //////////////////////////////////////////////////////////////////////////
 
 bool
@@ -418,7 +1016,9 @@ IsProcessRunning(int pid)
 
 	return true;
 #else
-	ZEN_NOT_IMPLEMENTED();
+	char Buffer[64];
+	sprintf(Buffer, "/proc/%d", pid);
+	return access(Buffer, F_OK) == 0;
 #endif
 }
 
@@ -428,7 +1028,17 @@ GetCurrentProcessId()
 #if ZEN_PLATFORM_WINDOWS
 	return ::GetCurrentProcessId();
 #else
-	return getpid();
+	return int(getpid());
+#endif
+}
+
+int
+GetCurrentThreadId()
+{
+#if ZEN_PLATFORM_WINDOWS
+	return ::GetCurrentThreadId();
+#else
+	return int(gettid());
 #endif
 }
 
@@ -447,9 +1057,124 @@ Sleep(int ms)
 // Testing related code follows...
 //
 
+#if ZEN_WITH_TESTS
+
 void
 thread_forcelink()
 {
 }
 
+TEST_CASE("Thread")
+{
+	int Pid = GetCurrentProcessId();
+	CHECK(Pid > 0);
+	CHECK(IsProcessRunning(Pid));
+}
+
+TEST_CASE("BuildArgV")
+{
+	const char* Words[] = {"one", "two", "three", "four", "five"};
+	struct
+	{
+		int			WordCount;
+		const char* Input;
+	} Cases[] = {
+		{0, ""},
+		{0, "  "},
+		{1, "one"},
+		{1, " one"},
+		{1, "one  "},
+		{2, "one two"},
+		{2, " one two"},
+		{2, "one two "},
+		{2, " one two"},
+		{2, "one two "},
+		{2, "one two "},
+		{3, "one two three"},
+		{3, "\"one\" two \"three\""},
+		{5, "one two three four five"},
+	};
+
+	for (const auto& Case : Cases)
+	{
+		std::vector<char*> OutArgs;
+		StringBuilder<64>  Mutable;
+		Mutable << Case.Input;
+		BuildArgV(OutArgs, Mutable.Data());
+
+		CHECK_EQ(OutArgs.size(), Case.WordCount);
+
+		for (int i = 0, n = int(OutArgs.size()); i < n; ++i)
+		{
+			const char* Truth	 = Words[i];
+			size_t		TruthLen = strlen(Truth);
+
+			const char* Candidate = OutArgs[i];
+			bool		bQuoted	  = (Candidate[0] == '\"');
+			Candidate += bQuoted;
+
+			CHECK(strncmp(Truth, Candidate, TruthLen) == 0);
+
+			if (bQuoted)
+			{
+				CHECK_EQ(Candidate[TruthLen], '\"');
+			}
+		}
+	}
+}
+
+TEST_CASE("NamedEvent")
+{
+	std::string Name = "zencore_test_event";
+	NamedEvent	TestEvent(Name);
+
+	// Timeout test
+	for (uint32_t i = 0; i < 8; ++i)
+	{
+		bool bEventSet = TestEvent.Wait(100);
+		CHECK(!bEventSet);
+	}
+
+	// Thread check
+	std::thread Waiter = std::thread([Name]() {
+		NamedEvent ReadyEvent(Name + "_ready");
+		ReadyEvent.Set();
+
+		NamedEvent TestEvent(Name);
+		TestEvent.Wait(1000);
+	});
+
+	NamedEvent ReadyEvent(Name + "_ready");
+	ReadyEvent.Wait();
+
+	zen::Sleep(500);
+	TestEvent.Set();
+
+	Waiter.join();
+
+	// Manual reset property
+	for (uint32_t i = 0; i < 8; ++i)
+	{
+		bool bEventSet = TestEvent.Wait(100);
+		CHECK(bEventSet);
+	}
+}
+
+TEST_CASE("NamedMutex")
+{
+	static const char* Name = "zen_test_mutex";
+
+	CHECK(!NamedMutex::Exists(Name));
+
+	{
+		NamedMutex TestMutex;
+		CHECK(TestMutex.Create(Name));
+		CHECK(NamedMutex::Exists(Name));
+	}
+
+	CHECK(!NamedMutex::Exists(Name));
+}
+
+#endif	// ZEN_WITH_TESTS
+
 }  // namespace zen