/* 

flext - C++ layer for Max/MSP and pd (pure data) externals

Copyright (c) 2001,2002 Thomas Grill (xovo@gmx.net)
For information on usage and redistribution, and for a DISCLAIMER OF ALL
WARRANTIES, see the file, "license.txt," in this distribution.  

*/

/*! \file flthr.cpp
    \brief Implementation of the flext thread functionality.
*/
 
#include "flext.h"
#include "flinternal.h"

#ifdef FLEXT_THREADS

#if FLEXT_OS == FLEXT_OS_WIN
#include <windows.h>
#endif

#include <errno.h>

//! Thread id of system thread
pthread_t flext_base::thrid;

//! Thread id of helper thread
pthread_t flext_base::thrhelpid;

flext_base::thr_entry *flext_base::thrhead = NULL,*flext_base::thrtail = NULL;
flext::ThrMutex flext_base::tlmutex;

//! Helper thread should terminate
bool thrhelpexit = false;

flext::ThrCond *thrhelpcond = NULL;

//! Start helper thread
bool flext_base::StartHelper()
{
	pthread_attr_t attr;
	pthread_attr_init(&attr);
	pthread_attr_setdetachstate(&attr,PTHREAD_CREATE_DETACHED);

	thrhelpexit = false;
	int ret = pthread_create (&thrhelpid,&attr,(void *(*)(void *))ThrHelper,NULL);
	if(ret) { 
		error((char *)("flext - Could not launch helper thread!")); 
		return false;
	}
	else
		return true;
}

#if 0
/*! \brief Stop helper thread
	\note not called!
*/
bool flext_base::StopHelper()
{
	thrhelpexit = true;
	if(thrhelpcond) thrhelpcond->Signal();
}
#endif

//! Static helper thread function
void flext_base::ThrHelper(void *)
{
	// set prototype thread attributes
	pthread_attr_t attr;
	pthread_attr_init(&attr);
	pthread_attr_setdetachstate(&attr,PTHREAD_CREATE_DETACHED);

	// set thread priority one point below normal
	// so thread construction won't disturb real-time audio
	sched_param parm;
	int policy;
	pthread_getschedparam(thrhelpid,&policy,&parm);
	int prio = parm.sched_priority;
	int schmin = sched_get_priority_min(policy);
	if(prio > schmin) {
		parm.sched_priority = prio-1;
		pthread_setschedparam(thrhelpid,policy,&parm);
	}

	thrhelpcond = new ThrCond;

	// helper loop
	for(;;) {
		thrhelpcond->Wait();
		if(thrhelpexit) break;

		tlmutex.Lock();

		// start all inactive threads in queue
		thr_entry *prv = NULL,*ti;
		for(ti = thrhead; ti; prv = ti,ti = ti->nxt) {
			if(!ti->active) {
				int ret = pthread_create (&ti->thrid,&attr,(void *(*)(void *))ti->meth,ti->params);
				if(ret) { 
					error((char *)("flext - Could not launch thread!")); 
					
					// delete from queue
					if(prv) 
						prv->nxt = ti->nxt;
					else 
						thrhead = ti->nxt;
					if(thrtail == ti) thrtail = prv;

					ti->nxt = NULL;
					delete ti;
				}
				else {
					// set active flag
					ti->active = true;
				}
			}
		}

		tlmutex.Unlock();
	}

	delete thrhelpcond;
	thrhelpcond = NULL;
}


bool flext_base::StartThread(void *(*meth)(thr_params *p),thr_params *p,char *methname)
{
#ifdef FLEXT_DEBUG
	if(!p || !thrhelpcond) {
		ERRINTERNAL(); 
		return false;
	}
#endif

	tlmutex.Lock();

	// make an entry into thread list
	thr_entry *nt = new thr_entry(this,meth,p);
	if(thrtail) thrtail->nxt = nt; 
	else thrhead = nt;
	thrtail = nt;

	// signal thread helper
	thrhelpcond->Signal();

	tlmutex.Unlock();
	return true;
}

/*
bool flext_base::StartThread(void *(*meth)(thr_params *p),thr_params *p,char *methname)
{
#ifdef FLEXT_DEBUG
	if(!p) {
		ERRINTERNAL(); 
		return false;
	}
#endif

	static bool init = false;
	static pthread_attr_t attr;
	if(!init) {
		pthread_attr_init(&attr);
		pthread_attr_setdetachstate(&attr,PTHREAD_CREATE_DETACHED);
		init = true;
	}

	// set thread priority one point below normal
	// so thread construction won't disturb real-time audio
	pthread_t id = pthread_self();
	sched_param parm;
	int policy;
	pthread_getschedparam(id,&policy,&parm);
	int prio = parm.sched_priority;
	int schmin = sched_get_priority_min(policy);
	if(prio > schmin) {
		parm.sched_priority = prio-1;
		pthread_setschedparam(id,policy,&parm);
	}
	
	pthread_t thrid; 
	int ret = pthread_create (&thrid,&attr,(void *(*)(void *))meth,p);

	// set thread priority back to normal
	parm.sched_priority = prio;
	pthread_setschedparam(id,policy,&parm);

	if(ret) { 
#ifdef FLEXT_DEBUG	
		error((char *)(ret == EAGAIN?"%s - Unsufficient resources to launch thread!":"%s - Could not launch method!"),methname); 
#else
		error((char *)("%s - Could not launch method!"),methname); 
#endif		

		delete p; 
		return false;
	}
	else
		return true;
}
*/

bool flext_base::PushThread()
{
	tlmutex.Lock();

//	post("Push thread");

/*
	// make an entry into thread list
	thr_entry *nt = new thr_entry;
	if(thrtail) thrtail->nxt = nt; 
	else thrhead = nt;
	thrtail = nt;
*/
	{
#if FLEXT_OS == FLEXT_OS_WIN
	// set detached thread to lower priority class
	DWORD err;
	HANDLE thr = GetCurrentThread();
	DWORD cl = GetThreadPriority(thr);
	if(!cl && (err = GetLastError()))
		post("flext - error getting thread priority");
	else {
		BOOL ret = SetThreadPriority(thr,cl-2);
		if(!ret) {
			err = GetLastError();
			if(!err) post("flext - error setting thread priority");
		}
	}
#else
	// set initial detached thread priority two points below normal
	sched_param parm;
	int policy;
	if(pthread_getschedparam(nt->thrid,&policy,&parm))
		post("flext - can't get thread parameters");
	int prio = parm.sched_priority;
	int schmin = sched_get_priority_min(policy);
	if(prio > schmin) {
		parm.sched_priority = prio-2;
		if(pthread_setschedparam(nt->thrid,policy,&parm))
			post("flext - can't set thread parameters");
	}
#endif
	}

	tlmutex.Unlock();
	
	return true;
}

void flext_base::PopThread()
{
	tlmutex.Lock();

//	post("Pop thread");

	pthread_t id = pthread_self();

	thr_entry *prv = NULL,*ti;
	for(ti = thrhead; ti; prv = ti,ti = ti->nxt)
		if(ti->Is()) break;

	if(ti) {
		if(prv) 
			prv->nxt = ti->nxt;
		else 
			thrhead = ti->nxt;
		if(thrtail == ti) thrtail = prv;

		ti->nxt = NULL;
		delete ti;
	}
	else {
#ifdef FLEXT_DEBUG
		post("%s - INTERNAL ERROR: Thread not found!",thisName());
#endif
	}
	
	tlmutex.Unlock();
}

void flext_base::TermThreads()
{
	// wait for thread termination
	shouldexit = true;
	for(int wi = 0; thrhead && wi < 100; ++wi) Sleep(0.01f);

	qmutex.Lock(); // Lock message queue
	tlmutex.Lock();

	// timeout -> hard termination
	for(thr_entry *t = thrhead; t; )
		if(t->th == this) {
			if(pthread_cancel(t->thrid)) post("%s - Thread could not be terminated!",thisName());
			thr_entry *tn = t->nxt;
			t->nxt = NULL; delete t;
			t = tn;
		}
		else t = t->nxt;

	tlmutex.Unlock();
	qmutex.Unlock();
}

flext_base::thrid_t flext_base::GetThreadId() 
{ 
	return pthread_self(); 
}

bool flext_base::ChangePriority(int dp,thrid_t id)
{
	sched_param parm;
	int policy;
	if(pthread_getschedparam(id,&policy,&parm) < 0) {
#ifdef FLEXT_DEBUG
		post("flext - failed to get parms");
#endif
		return false;
	}
	else {
		parm.sched_priority += dp;
		if(pthread_setschedparam(id,policy,&parm) < 0) {
#ifdef FLEXT_DEBUG		
			post("flext - failed to change priority");
#endif
			return false;
		}
	}
	return true;
}


int flext_base::GetPriority(thrid_t id)
{
	sched_param parm;
	int policy;
	if(pthread_getschedparam(id,&policy,&parm) < 0) {
#ifdef FLEXT_DEBUG
		post("flext - failed to get parms");
#endif
		return -1;
	}
	return parm.sched_priority;
}


bool flext_base::SetPriority(int p,thrid_t id)
{
	sched_param parm;
	int policy;
	if(pthread_getschedparam(id,&policy,&parm) < 0) {
#ifdef FLEXT_DEBUG
		post("flext - failed to get parms");
#endif
		return false;
	}
	else {
		parm.sched_priority = p;
		if(pthread_setschedparam(id,policy,&parm) < 0) {
#ifdef FLEXT_DEBUG		
			post("flext - failed to change priority");
#endif
			return false;
		}
	}
	return true;
}

flext_base::thr_params::thr_params(flext_base *c,int n): cl(c),var(new _data[n]) {}
flext_base::thr_params::~thr_params() { if(var) delete[] var; }

void flext_base::thr_params::set_any(const t_symbol *s,int argc,const t_atom *argv) { var[0]._any.args = new AtomAnything(s,argc,argv); }
void flext_base::thr_params::set_list(int argc,const t_atom *argv) { var[0]._list.args = new AtomList(argc,argv); }

#endif // FLEXT_THREADS