#include "threads.h"

/*
 *	Starts executing the thread. Needs to clean up memory a tad better.
 */

#ifdef WIN32
THREAD_RET_TYPE Perl_thread_run(LPVOID arg) {
#else
void* Perl_thread_run(void * arg) {
#endif
	ithread* thread = (ithread*) arg;
	SV* thread_tid_ptr;
	SV* thread_ptr;
	dTHXa(thread->interp);
	PERL_SET_CONTEXT(thread->interp);

#ifdef WIN32
	thread->thr = GetCurrentThreadId();
#else
	thread->thr = pthread_self();
#endif

	SHAREDSvLOCK(threads);
	SHAREDSvEDIT(threads);
	PERL_THREAD_ALLOC_SPECIFIC(self_key);
	PERL_THREAD_SETSPECIFIC(self_key,INT2PTR(void*,thread->tid));
	thread_tid_ptr = Perl_newSVuv(PL_sharedsv_space, thread->tid);	
	thread_ptr = Perl_newSVuv(PL_sharedsv_space, PTR2UV(thread));
	hv_store_ent((HV*)SHAREDSvGET(threads), thread_tid_ptr, thread_ptr,0);
   	SvREFCNT_dec(thread_tid_ptr);
	SHAREDSvRELEASE(threads);
	SHAREDSvUNLOCK(threads);
	PL_perl_destruct_level = 2;

	{

		AV* params;
		I32 len;
		int i;
		dSP;
		params = (AV*) SvRV(thread->params);
		len = av_len(params);
		ENTER;
		SAVETMPS;
		PUSHMARK(SP);
		if(len > -1) {
			for(i = 0; i < len + 1; i++) {
				XPUSHs(av_shift(params));
			}	
		}
		PUTBACK;
	 	call_sv(thread->init_function, G_DISCARD);
		FREETMPS;
		LEAVE;


	}

	MUTEX_LOCK(&thread->mutex);
	PerlIO_flush((PerlIO*)NULL);
 	perl_destruct(thread->interp);	
	perl_free(thread->interp);
	if(thread->detached == 1) {
		MUTEX_UNLOCK(&thread->mutex);
		Perl_thread_destruct(thread);
	} else {
	  	MUTEX_UNLOCK(&thread->mutex);
   	}
#ifdef WIN32
	return (DWORD)0;
#else
	return 0;
#endif

}

/*
 * iThread->create();
 */

SV* Perl_thread_create(char* class, SV* init_function, SV* params) {
	ithread* thread = malloc(sizeof(ithread));
  	SV*      obj_ref;
  	SV*      obj;
	SV*		temp_store;
	PerlInterpreter *current_perl;

	MUTEX_LOCK(&create_mutex);  
	obj_ref = newSViv(0);
	obj = newSVrv(obj_ref, class);
	sv_setiv(obj, (IV)thread);
	SvREADONLY_on(obj);

	current_perl = PERL_GET_CONTEXT;	

	/*
	 * here we put the values of params and function to call onto
	 * namespace, this is so perl will properly clone them when we
	 * call perl_clone.
	 */

	temp_store = Perl_get_sv(current_perl, "threads::paramtempstore",
				 TRUE | GV_ADDMULTI);
	Perl_sv_setsv(current_perl, temp_store,params);
	params = NULL;
	temp_store = NULL;

	temp_store = Perl_get_sv(current_perl, "threads::calltempstore",
				 TRUE | GV_ADDMULTI);
	Perl_sv_setsv(current_perl,temp_store, init_function);
	init_function = NULL;
	temp_store = NULL;

#ifdef WIN32
	thread->interp = perl_clone(current_perl, 4);
#else
	thread->interp = perl_clone(current_perl, 0);
#endif

	thread->init_function = newSVsv(Perl_get_sv(thread->interp,
						    "threads::calltempstore",FALSE));
	thread->params = newSVsv(Perl_get_sv(thread->interp,
					     "threads::paramtempstore",FALSE));

	/*
	 * And here we make sure we clean up the data we put in the
	 * namespace of iThread, both in the new and the calling
	 * inteprreter */

	temp_store = Perl_get_sv(thread->interp, "threads::paramtempstore",FALSE);
	Perl_sv_setsv(thread->interp,temp_store, &PL_sv_undef);

	temp_store = Perl_get_sv(thread->interp,"threads::calltempstore",FALSE);
	Perl_sv_setsv(thread->interp,temp_store, &PL_sv_undef);

	PERL_SET_CONTEXT(current_perl);

	temp_store = Perl_get_sv(current_perl,"threads::paramtempstore",FALSE);
	Perl_sv_setsv(current_perl, temp_store, &PL_sv_undef);

	temp_store = Perl_get_sv(current_perl,"threads::calltempstore",FALSE);
	Perl_sv_setsv(current_perl, temp_store, &PL_sv_undef);

	/* let's init the thread */

	MUTEX_INIT(&thread->mutex);
	thread->tid = tid_counter++;
	thread->detached = 0;
	thread->count = 1;

#ifdef WIN32

	thread->handle = CreateThread(NULL, 0, Perl_thread_run,
			(LPVOID)thread, 0, &thread->thr);


#else
	{
	  static pthread_attr_t attr;
	  static int attr_inited = 0;
	  sigset_t fullmask, oldmask;
	  static int attr_joinable = PTHREAD_CREATE_JOINABLE;
	  if (!attr_inited) {
	    attr_inited = 1;
	    pthread_attr_init(&attr);
	  }
#  ifdef PTHREAD_ATTR_SETDETACHSTATE
            PTHREAD_ATTR_SETDETACHSTATE(&attr, attr_joinable);
#  endif
#  ifdef THREAD_CREATE_NEEDS_STACK
	    if(pthread_attr_setstacksize(&attr, THREAD_CREATE_NEEDS_STACK))
	      croak("panic: pthread_attr_setstacksize failed");
#  endif

#ifdef OLD_PTHREADS_API
	  pthread_create( &thread->thr, attr, Perl_thread_run, (void *)thread);
#else
	  pthread_create( &thread->thr, &attr, Perl_thread_run, (void *)thread);
#endif
	}
#endif
	MUTEX_UNLOCK(&create_mutex);	

	return obj_ref;
}

/*
 * returns the id of the thread
 */
I32 Perl_thread_tid (SV* obj) {
	ithread* thread;
	if(!SvROK(obj)) {
		obj = Perl_thread_self(SvPV_nolen(obj));
		thread = (ithread*)SvIV(SvRV(obj));	
		SvREFCNT_dec(obj);
	} else {
		thread = (ithread*)SvIV(SvRV(obj));	
	}
	return thread->tid;
}

SV* Perl_thread_self (char* class) {
	dTHX;
	SV*      obj_ref;
	SV*      obj;
	SV*	thread_tid_ptr;
	SV*	thread_ptr;
	HE*	thread_entry;
	void*   id;
	PERL_THREAD_GETSPECIFIC(self_key,id);
	SHAREDSvLOCK(threads);
	SHAREDSvEDIT(threads);
	
	thread_tid_ptr = Perl_newSVuv(PL_sharedsv_space, PTR2UV(id));	

	thread_entry = Perl_hv_fetch_ent(PL_sharedsv_space,
					 (HV*) SHAREDSvGET(threads),
					 thread_tid_ptr, 0,0);
	thread_ptr = HeVAL(thread_entry);
	SvREFCNT_dec(thread_tid_ptr);	
	SHAREDSvRELEASE(threads);
	SHAREDSvUNLOCK(threads);

	obj_ref = newSViv(0);
	obj = newSVrv(obj_ref, class);
   	sv_setsv(obj, thread_ptr);
   	SvREADONLY_on(obj);
	return obj_ref;
}

/*
 * joins the thread this code needs to take the returnvalue from the
 * call_sv and send it back */

void Perl_thread_join(SV* obj) {
	ithread* thread = (ithread*)SvIV(SvRV(obj));
#ifdef WIN32
	DWORD waitcode;
	waitcode = WaitForSingleObject(thread->handle, INFINITE);
#else
	void *retval;
	pthread_join(thread->thr,&retval);
#endif
}

/* detaches a thread
 * needs to better clean up memory */

void Perl_thread_detach(SV* obj) {
	ithread* thread = (ithread*)SvIV(SvRV(obj));
	MUTEX_LOCK(&thread->mutex);
	thread->detached = 1;
	PERL_THREAD_DETACH(thread->thr);
	MUTEX_UNLOCK(&thread->mutex);
}

void Perl_thread_DESTROY (SV* obj) {
	ithread* thread = (ithread*)SvIV(SvRV(obj));
	
	MUTEX_LOCK(&thread->mutex);
	thread->count--;
	MUTEX_UNLOCK(&thread->mutex);
	Perl_thread_destruct(thread);
}

void Perl_thread_destruct (ithread* thread) {
	return;
	MUTEX_LOCK(&thread->mutex);
	if(thread->count != 0) {
		MUTEX_UNLOCK(&thread->mutex);
		return;	
	}
	MUTEX_UNLOCK(&thread->mutex);
	/* it is safe noone is holding a ref to this */
	/*printf("proper destruction!\n");*/
}

MODULE = threads		PACKAGE = threads		
BOOT:
	Perl_sharedsv_init(aTHX);
	PL_perl_destruct_level = 2;
	threads = Perl_sharedsv_new(aTHX);
	SHAREDSvEDIT(threads);
	SHAREDSvGET(threads) = (SV *)newHV();
	SHAREDSvRELEASE(threads);
	{
	    
	
	    SV* temp = get_sv("threads::sharedsv_space", TRUE | GV_ADDMULTI);
	    SV* temp2 = newSViv((IV)PL_sharedsv_space );
	    sv_setsv( temp , temp2 );
	}
	{
		ithread* thread = malloc(sizeof(ithread));
		SV* thread_tid_ptr;
		SV* thread_ptr;
		MUTEX_INIT(&thread->mutex);
		thread->tid = 0;
#ifdef WIN32
		thread->thr = GetCurrentThreadId();
#else
		thread->thr = pthread_self();
#endif
		SHAREDSvEDIT(threads);
		PERL_THREAD_ALLOC_SPECIFIC(self_key);
		PERL_THREAD_SETSPECIFIC(self_key,0);
		thread_tid_ptr = Perl_newSVuv(PL_sharedsv_space, 0);
		thread_ptr = Perl_newSVuv(PL_sharedsv_space, PTR2UV(thread));
		hv_store_ent((HV*) SHAREDSvGET(threads), thread_tid_ptr, thread_ptr,0);
	   	SvREFCNT_dec(thread_tid_ptr);
		SHAREDSvRELEASE(threads);
	}
	MUTEX_INIT(&create_mutex);

PROTOTYPES: DISABLE

SV *
create (class, function_to_call, ...)
        char *  class
        SV *    function_to_call
		CODE:
			AV* params = newAV();
			if(items > 2) {
				int i;
				for(i = 2; i < items ; i++) {
					av_push(params, ST(i));
				}
			}
			RETVAL = Perl_thread_create(class, function_to_call, newRV_noinc((SV*) params));
			OUTPUT:
			RETVAL

SV *
self (class)
		char* class
	CODE:
		RETVAL = Perl_thread_self(class);
	OUTPUT:
		RETVAL

int
tid (obj)	
		SV *	obj;
	CODE:
		RETVAL = Perl_thread_tid(obj);
	OUTPUT:
	RETVAL

void
join (obj)
        SV *    obj
        PREINIT:
        I32* temp;
        PPCODE:
        temp = PL_markstack_ptr++;
        Perl_thread_join(obj);
        if (PL_markstack_ptr != temp) {
          /* truly void, because dXSARGS not invoked */
          PL_markstack_ptr = temp;
          XSRETURN_EMPTY; /* return empty stack */
        }
        /* must have used dXSARGS; list context implied */
        return; /* assume stack size is correct */

void
detach (obj)
        SV *    obj
        PREINIT:
        I32* temp;
        PPCODE:
        temp = PL_markstack_ptr++;
        Perl_thread_detach(obj);
        if (PL_markstack_ptr != temp) {
          /* truly void, because dXSARGS not invoked */
          PL_markstack_ptr = temp;
          XSRETURN_EMPTY; /* return empty stack */
        }
        /* must have used dXSARGS; list context implied */
        return; /* assume stack size is correct */

void
DESTROY (obj)
        SV *    obj
        PREINIT:
        I32* temp;
        PPCODE:
        temp = PL_markstack_ptr++;
        Perl_thread_DESTROY(obj);
        if (PL_markstack_ptr != temp) {
          /* truly void, because dXSARGS not invoked */
          PL_markstack_ptr = temp;
          XSRETURN_EMPTY; /* return empty stack */
        }
        /* must have used dXSARGS; list context implied */
        return; /* assume stack size is correct */