/*--------------------------------------------------------
 Projet: InsoL@b
 File  : pt.h                                     08/28/20 
 Authors: initial work of Adam Dunkels,      user@W500; 
  little dressing & minor changes to limit compile warnings     
----------------------------------------------------------*/
#ifndef __PT_H__
#define __PT_H__
typedef struct  pt { unsigned short lc; } pt_t ;

#define PT_WAITING 0
#define PT_YIELDED 1
#define PT_EXITED  2
#define PT_ENDED   3
#define PT_INIT(pt)  (pt)->lc =  0;              // INIT
#define PT_THREAD(name_args) char name_args      // THREAD
#define PT_BEGIN(pt) {                                      \
        /*char PT_YIELD_FLAG = 1 ; not used here */         \
        switch((pt)->lc)                                    \
        { case 0:                                // BEGIN
#define PT_END(pt) ((pt)->lc = 0 ); };                      \
        /*PT_YIELD_FLAG = 0; not used here */		            \
        PT_INIT(pt); return PT_ENDED; }          // END
#define PT_WAIT_UNTIL(pt, condition)	                      \
        do {					                                    	\
          (pt)->lc = __LINE__;                              \
          case __LINE__: 		                                \
          if(!(condition)) {		                            \
            return PT_WAITING;			                        \
          }					                                        \
        } while(0)                               // WAIT_UNTIL
#define PT_WAIT_WHILE(pt, cond)                             \
        PT_WAIT_UNTIL((pt), !(cond))             // WAIT_WHILE
#define PT_WAIT_THREAD(pt, thread)                          \
        PT_WAIT_WHILE((pt), PT_SCHEDULE(thread)) // WAIT_THREAD
#define PT_SPAWN(pt, child, thread)		                      \
        do {					                                    	\
          PT_INIT((child));		                            	\
          PT_WAIT_THREAD((pt), (thread));		                \
        } while(0)                               // SPAWN
#define PT_RESTART(pt)			                               	\
        do {					                                    	\
          PT_INIT(pt);				                              \
          return PT_WAITING;		                            \
        } while(0)                               // RESTART
#define PT_EXIT(pt)				                                  \
        do {						                                    \
          PT_INIT(pt);			                               	\
          return PT_EXITED;		                              \
        } while(0) // EXIT
#define PT_SCHEDULE(f) ((f) < PT_EXITED)         // SCHEDULE
#define PT_YIELD(pt)			                                 	\
        do {					                                    	\
          PT_YIELD_FLAG = 0;		                          	\
          (pt)->lc = __LINE__;                              \
          case __LINE__:			                              \
          if(PT_YIELD_FLAG == 0) {		                      \
            return PT_YIELDED;		                        	\
          }					                                        \
        } while(0)                               // YIELD
#define PT_YIELD_UNTIL(pt, cond)	                        	\
        do {					                                    	\
          PT_YIELD_FLAG = 0;		                          	\
          (pt)->lc = __LINE__;                              \
          case __LINE__:			                              \
          if((PT_YIELD_FLAG == 0) || !(cond)) {	            \
            return PT_YIELDED;			                        \
          }					                                        \
        } while(0)                               // YIELD_UNTIL
#define PT_DELAY(pt, ms)                                    \
        do {			                                          \
          static unsigned long _PTTTL_ ;                    \
          _PTTTL_ = millis() + (unsigned int)(ms);          \
          PT_WAIT_UNTIL((pt), (millis() > _PTTTL_));        \
        } while(0)                               // DELAY
#define PT_SYNC(pt, mark, ms)                               \
        do {                                                \
          PT_WAIT_UNTIL((pt), (millis() - (mark) > (ms) )); \
        } while(0)                               // SYNC
#endif /* __PT_H__ */