// Copyright (C) 2003 Dolphin Project.

// This program is free software: you can redistribute it and/or modify
// it under the terms of the GNU General Public License as published by
// the Free Software Foundation, version 2.0.

// This program is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
// GNU General Public License 2.0 for more details.

// A copy of the GPL 2.0 should have been included with the program.
// If not, see http://www.gnu.org/licenses/

// Official SVN repository and contact information can be found at
// http://code.google.com/p/dolphin-emu/

#include "Setup.h"
#include "Thread.h"
#include "Common.h"

#ifdef USE_BEGINTHREADEX
#include <process.h>
#endif

namespace Common
{
	
	int Thread::CurrentId()
	{
#ifdef _WIN32
		return GetCurrentThreadId();
#else
		return 0;
#endif
	}
	
#ifdef _WIN32
	
	void InitThreading()
	{
		// Nothing to do in Win32 build.
	}
	
	CriticalSection::CriticalSection(int spincount)
	{
		if (spincount)
		{
			if (!InitializeCriticalSectionAndSpinCount(&section, spincount))
				ERROR_LOG(COMMON, "CriticalSection could not be initialized!\n%s", GetLastErrorMsg());
		}
		else
		{
			InitializeCriticalSection(&section);
		}
	}
	
	CriticalSection::~CriticalSection()
	{
		DeleteCriticalSection(&section);
	}
	
	void CriticalSection::Enter()
	{
		EnterCriticalSection(&section);
	}
	
	bool CriticalSection::TryEnter()
	{
		return TryEnterCriticalSection(&section) ? true : false;
	}
	
	void CriticalSection::Leave()
	{
		LeaveCriticalSection(&section);
	}
	
	Thread::Thread(ThreadFunc function, void* arg)
	: m_hThread(NULL), m_threadId(0)
	{
#ifdef USE_BEGINTHREADEX
		m_hThread = (HANDLE)_beginthreadex(NULL, 0, function, arg, 0, &m_threadId);
#else
		m_hThread = CreateThread(NULL, 0, function, arg, 0, &m_threadId);
#endif
	}
	
	Thread::~Thread()
	{
		WaitForDeath();
	}
	
	DWORD Thread::WaitForDeath(const int iWait)
	{
		if (m_hThread)
		{
			DWORD Wait = WaitForSingleObject(m_hThread, iWait);
			CloseHandle(m_hThread);
			m_hThread = NULL;
			return Wait;
		}
		return NULL;
	}
	
	void Thread::SetAffinity(int mask)
	{
		SetThreadAffinityMask(m_hThread, mask);
	}
	
	void Thread::SetPriority(int priority)
	{
		SetThreadPriority(m_hThread, priority);
	}
	
	void Thread::SetCurrentThreadAffinity(int mask)
	{
		SetThreadAffinityMask(GetCurrentThread(), mask);
	}
	
	bool Thread::IsCurrentThread()
	{
		return GetCurrentThreadId() == m_threadId;
	}
	
	
	EventEx::EventEx()
	{
		InterlockedExchange(&m_Lock, 1);
	}
	
	void EventEx::Init()
	{
		InterlockedExchange(&m_Lock, 1);
	}
	
	void EventEx::Shutdown()
	{
		InterlockedExchange(&m_Lock, 0);
	}
	
	void EventEx::Set()
	{
		InterlockedExchange(&m_Lock, 0);
	}
	
	void EventEx::Spin()
	{
		while (InterlockedCompareExchange(&m_Lock, 1, 0))
			// This only yields when there is a runnable thread on this core
			// If not, spin
			SwitchToThread();
	}
	
	void EventEx::Wait()
	{
		while (InterlockedCompareExchange(&m_Lock, 1, 0))
			// This directly enters Ring0 and enforces a sleep about 15ms
			SleepCurrentThread(1);
	}
	
	bool EventEx::MsgWait()
	{
		while (InterlockedCompareExchange(&m_Lock, 1, 0))
		{
			MSG msg;
			while (PeekMessage(&msg, 0, 0, 0, PM_REMOVE))
			{
				if (msg.message == WM_QUIT) return false;
				TranslateMessage(&msg);
				DispatchMessage(&msg);
			}
			// This directly enters Ring0 and enforces a sleep about 15ms
			SleepCurrentThread(1);
		}
		return true;
	}
	
	
	// Regular same thread loop based waiting
	Event::Event()
	{
		m_hEvent = 0;
	}
	
	void Event::Init()
	{
		m_hEvent = CreateEvent(NULL, FALSE, FALSE, NULL);
	}
	
	void Event::Shutdown()
	{
		CloseHandle(m_hEvent);
		m_hEvent = 0;
	}
	
	void Event::Set()
	{
		SetEvent(m_hEvent);
	}
	
	bool Event::Wait(const u32 timeout)
	{
		return WaitForSingleObject(m_hEvent, timeout) != WAIT_OBJECT_0;
	}
	
	inline HRESULT MsgWaitForSingleObject(HANDLE handle, DWORD timeout)
	{
		return MsgWaitForMultipleObjects(1, &handle, FALSE, timeout, 0);
	}
	
	void Event::MsgWait()
	{
		// Adapted from MSDN example http://msdn.microsoft.com/en-us/library/ms687060.aspx
		while (true)
		{
			DWORD result; 
			MSG msg; 
			// Read all of the messages in this next loop, 
			// removing each message as we read it.
			while (PeekMessage(&msg, NULL, 0, 0, PM_REMOVE)) 
			{ 
				// If it is a quit message, exit.
				if (msg.message == WM_QUIT)  
					return; 
				// Otherwise, dispatch the message.
				TranslateMessage(&msg);
				DispatchMessage(&msg); 
			}
			
			// Wait for any message sent or posted to this queue 
			// or for one of the passed handles be set to signaled.
			result = MsgWaitForSingleObject(m_hEvent, THREAD_WAIT_TIMEOUT); 
			
			// The result tells us the type of event we have.
			if (result == (WAIT_OBJECT_0 + 1))
			{
				// New messages have arrived. 
				// Continue to the top of the always while loop to 
				// dispatch them and resume waiting.
				continue;
			} 
			else
			{
				// result == WAIT_OBJECT_0
				// Our event got signaled
				return;
			}
		}
	}
	
	// Supporting functions
	void SleepCurrentThread(int ms)
	{
		Sleep(ms);
	}
	
	typedef struct tagTHREADNAME_INFO
	{
		DWORD dwType; // must be 0x1000
		LPCSTR szName; // pointer to name (in user addr space)
		DWORD dwThreadID; // thread ID (-1=caller thread)
		DWORD dwFlags; // reserved for future use, must be zero
	} THREADNAME_INFO;
	// Usage: SetThreadName (-1, "MainThread");
	//
	// Sets the debugger-visible name of the current thread.
	// Uses undocumented (actually, it is now documented) trick.
	// http://msdn.microsoft.com/library/default.asp?url=/library/en-us/vsdebug/html/vxtsksettingthreadname.asp
	
	// This is implemented much nicer in upcoming msvc++, see:
	// http://msdn.microsoft.com/en-us/library/xcb2z8hs(VS.100).aspx
	void SetCurrentThreadName(const TCHAR* szThreadName)
	{
		THREADNAME_INFO info;
		info.dwType = 0x1000;
#ifdef UNICODE
		//TODO: Find the proper way to do this.
		char tname[256];
		unsigned int i;
		
		for (i = 0; i < _tcslen(szThreadName); i++)
		{
			tname[i] = (char)szThreadName[i]; //poor man's unicode->ansi, TODO: fix
		}
		
		tname[i] = 0;
		info.szName = tname;
#else
		info.szName = szThreadName;
#endif
		
		info.dwThreadID = -1; //dwThreadID;
		info.dwFlags = 0;
		__try
		{
			RaiseException(0x406D1388, 0, sizeof(info) / sizeof(DWORD), (ULONG_PTR*)&info);
		}
		__except(EXCEPTION_CONTINUE_EXECUTION)
		{}
	}
	
#else // !WIN32, so must be POSIX threads
	
	pthread_key_t threadname_key;
	
	CriticalSection::CriticalSection(int spincount_unused)
	{
		pthread_mutex_init(&mutex, NULL);
	}
	
	
	CriticalSection::~CriticalSection()
	{
		pthread_mutex_destroy(&mutex);
	}
	
	
	void CriticalSection::Enter()
	{
		int ret = pthread_mutex_lock(&mutex);
		if (ret) ERROR_LOG(COMMON, "%s: pthread_mutex_lock(%p) failed: %s\n", 
						   __FUNCTION__, &mutex, strerror(ret));
	}
	
	
	bool CriticalSection::TryEnter()
	{
		return(!pthread_mutex_trylock(&mutex));
	}
	
	
	void CriticalSection::Leave()
	{
		int ret = pthread_mutex_unlock(&mutex);
		if (ret) ERROR_LOG(COMMON, "%s: pthread_mutex_unlock(%p) failed: %s\n", 
						   __FUNCTION__, &mutex, strerror(ret));
	}
	
	
	Thread::Thread(ThreadFunc function, void* arg)
	: thread_id(0)
	{
		pthread_attr_t attr;
		pthread_attr_init(&attr);
		pthread_attr_setstacksize(&attr, 1024 * 1024);
		int ret = pthread_create(&thread_id, &attr, function, arg);
		if (ret) ERROR_LOG(COMMON, "%s: pthread_create(%p, %p, %p, %p) failed: %s\n", 
						   __FUNCTION__, &thread_id, &attr, function, arg, strerror(ret));
		
		INFO_LOG(COMMON, "created new thread %lu (func=%p, arg=%p)\n", thread_id, function, arg);
	}
	
	
	Thread::~Thread()
	{
		WaitForDeath();
	}
	
	
	void Thread::WaitForDeath()
	{
		if (thread_id)
		{
			void* exit_status;
			int ret = pthread_join(thread_id, &exit_status);
			if (ret) ERROR_LOG(COMMON, "error joining thread %lu: %s\n", thread_id, strerror(ret));
			if (exit_status)
				ERROR_LOG(COMMON, "thread %lu exited with status %d\n", thread_id, *(int *)exit_status);
			thread_id = 0;
		}
	}
	
	
	void Thread::SetAffinity(int mask)
	{
		// This is non-standard
#ifdef __linux__
		cpu_set_t cpu_set;
		CPU_ZERO(&cpu_set);
		
		for (unsigned int i = 0; i < sizeof(mask) * 8; i++)
		{
			if ((mask >> i) & 1){CPU_SET(i, &cpu_set);}
		}
		
		pthread_setaffinity_np(thread_id, sizeof(cpu_set), &cpu_set);
#endif
	}
	
	void Thread::SetCurrentThreadAffinity(int mask)
	{
#ifdef __linux__
		cpu_set_t cpu_set;
		CPU_ZERO(&cpu_set);
		
		for (size_t i = 0; i < sizeof(mask) * 8; i++)
		{
			if ((mask >> i) & 1){CPU_SET(i, &cpu_set);}
		}
		
		pthread_setaffinity_np(pthread_self(), sizeof(cpu_set), &cpu_set);
#endif
	}
	
	bool Thread::IsCurrentThread()
	{
		return pthread_equal(pthread_self(), thread_id) != 0;
	}
	
	void InitThreading() {
		static int thread_init_done = 0;
		if (thread_init_done)
			return;
		
		if (pthread_key_create(&threadname_key, NULL/*free*/) != 0)
			perror("Unable to create thread name key: ");
		
		thread_init_done++;
	}
	
	void SleepCurrentThread(int ms)
	{
		usleep(1000 * ms);
	}
	
	
	void SetCurrentThreadName(const TCHAR* szThreadName)
	{
		char *name = strdup(szThreadName);
		// pthread_setspecific returns 0 on success
		// free the string from strdup if fails
		// creates a memory leak if it actually doesn't fail
		// since we don't delete it once we delete the thread
		// we are using a single threadname_key anyway for all threads
		if(!pthread_setspecific(threadname_key, name))
			free(name);
		INFO_LOG(COMMON, "%s(%s)\n", __FUNCTION__, szThreadName);
	}
	
	
	Event::Event()
	{
		is_set_ = false;
	}
	
	
	void Event::Init()
	{
		pthread_cond_init(&event_, 0);
		pthread_mutex_init(&mutex_, 0);
	}
	
	
	void Event::Shutdown()
	{
		pthread_mutex_destroy(&mutex_);
		pthread_cond_destroy(&event_);
	}
	
	
	void Event::Set()
	{
		pthread_mutex_lock(&mutex_);
		
		if (!is_set_)
		{
			is_set_ = true;
			pthread_cond_signal(&event_);
		}
		
		pthread_mutex_unlock(&mutex_);
	}
	
	
	bool Event::Wait(const u32 timeout)
	{
		bool timedout = false;
		struct timespec wait;
		pthread_mutex_lock(&mutex_);
		
		if (timeout != INFINITE) 
		{
			struct timeval now;
			gettimeofday(&now, NULL);
			
			memset(&wait, 0, sizeof(wait));
			//TODO: timespec also has nanoseconds, but do we need them?
			//as consequence, waiting is limited to seconds for now.
			//the following just looks ridiculous, and probably fails for
			//values 429 < ms <= 999 since it overflows the long.
			//wait.tv_nsec = (now.tv_usec + (timeout % 1000) * 1000) * 1000);
			wait.tv_sec = now.tv_sec + (timeout / 1000);
		}
		
		while (!is_set_ && !timedout)
		{
			if (timeout == INFINITE) 
			{
				pthread_cond_wait(&event_, &mutex_);
			}
			else 
			{
				timedout = pthread_cond_timedwait(&event_, &mutex_, &wait) == ETIMEDOUT;
			}
		}
		
		is_set_ = false;
		pthread_mutex_unlock(&mutex_);
		
		return timedout;
	}
	
#endif
	
} // namespace Common
