laurent@366: /*
laurent@366:  * Python Asynchronous execution code
laurent@366:  *
laurent@366:  * PLC put python commands in a fifo, respecting execution order
laurent@366:  * with the help of C pragmas inserted in python_eval FB code
laurent@366:  *
laurent@366:  * Buffer content is read asynchronously, (from non real time part),
laurent@366:  * commands are executed and result stored for later use by PLC.
laurent@366:  *
laurent@366:  * In this implementation, fifo is a list of pointer to python_eval
laurent@366:  * function blocks structures. Some local variables have been added in
laurent@366:  * python_eval interface. We use those local variables as buffer and state
laurent@366:  * flags.
laurent@366:  *
laurent@366:  * */
laurent@366: 
laurent@366: #include "iec_types_all.h"
laurent@366: #include "POUS.h"
laurent@366: #include <string.h>
laurent@366: 
laurent@366: /* The fifo (fixed size, as number of FB is fixed) */
laurent@366: static PYTHON_EVAL* EvalFBs[%(python_eval_fb_count)d];
laurent@366: /* Producer and consumer cursors */
laurent@366: static int Current_PLC_EvalFB;
laurent@366: static int Current_Python_EvalFB;
laurent@366: 
laurent@366: /* A global IEC-Python gateway state, for use inside python_eval FBs*/
laurent@366: static int PythonState;
laurent@366: #define PYTHON_LOCKED_BY_PYTHON 0
laurent@366: #define PYTHON_LOCKED_BY_PLC 1
laurent@366: #define PYTHON_MUSTWAKEUP 2
laurent@366: #define PYTHON_FINISHED 4
laurent@366: 
laurent@366: /* Each python_eval FunctionBlock have it own state */
laurent@366: #define PYTHON_FB_FREE 0
laurent@366: #define PYTHON_FB_REQUESTED 1
laurent@366: #define PYTHON_FB_PROCESSING 2
laurent@366: #define PYTHON_FB_ANSWERED 3
laurent@366: 
laurent@366: int WaitPythonCommands(void);
laurent@366: void UnBlockPythonCommands(void);
laurent@366: int TryLockPython(void);
laurent@366: void UnLockPython(void);
laurent@366: void LockPython(void);
laurent@366: 
Edouard@728: int __init_py_ext()
laurent@366: {
laurent@366: 	int i;
laurent@366: 	/* Initialize cursors */
laurent@366: 	Current_Python_EvalFB = 0;
laurent@366: 	Current_PLC_EvalFB = 0;
laurent@366: 	PythonState = PYTHON_LOCKED_BY_PYTHON;
laurent@366: 	for(i = 0; i < %(python_eval_fb_count)d; i++)
laurent@366: 		EvalFBs[i] = NULL;
laurent@366:   return 0;
laurent@366: }
laurent@366: 
Edouard@728: void __cleanup_py_ext()
laurent@366: {
laurent@366: 	PythonState = PYTHON_FINISHED;
laurent@366: 	UnBlockPythonCommands();
laurent@366: }
laurent@366: 
Edouard@728: void __retrieve_py_ext()
laurent@366: {
laurent@366: 	/* Check Python thread is not being
laurent@366: 	 * modifying internal python_eval data */
laurent@366: 	PythonState = TryLockPython() ?
laurent@366: 	                PYTHON_LOCKED_BY_PLC :
laurent@366: 	                PYTHON_LOCKED_BY_PYTHON;
laurent@366: 	/* If python thread _is_ in, then PythonState remains PYTHON_LOCKED_BY_PYTHON
laurent@366: 	 * and python_eval will no do anything */
laurent@366: }
laurent@366: 
Edouard@728: void __publish_py_ext()
laurent@366: {
laurent@366: 	if(PythonState & PYTHON_LOCKED_BY_PLC){
laurent@366: 		/* If runnig PLC did push something in the fifo*/
laurent@366: 		if(PythonState & PYTHON_MUSTWAKEUP){
laurent@366: 			/* WakeUp python thread */
laurent@366: 			UnBlockPythonCommands();
laurent@366: 		}
laurent@366: 		UnLockPython();
laurent@366: 	}
laurent@366: }
laurent@366: /**
laurent@366:  * Called by the PLC, each time a python_eval
laurent@366:  * FB instance is executed
laurent@366:  */
laurent@366: void __PythonEvalFB(int poll, PYTHON_EVAL* data__)
laurent@366: {
laurent@366: 	/* detect rising edge on TRIG to trigger evaluation */
ed@454: 	if(((__GET_VAR(data__->TRIG) && !__GET_VAR(data__->TRIGM1)) ||
laurent@366: 	   /* polling is equivalent to trig on value rather than on rising edge*/
ed@454: 	    (poll && __GET_VAR(data__->TRIG) )) &&
laurent@366: 	    /* trig only if not already trigged */
ed@454: 	    __GET_VAR(data__->TRIGGED) == 0){
laurent@366: 		/* mark as trigged */
laurent@638: 	    __SET_VAR(data__->, TRIGGED, 1);
laurent@366: 		/* make a safe copy of the code */
laurent@638: 		__SET_VAR(data__->, PREBUFFER, __GET_VAR(data__->CODE));
laurent@366: 	}
laurent@366: 	/* retain value for next rising edge detection */
laurent@638: 	__SET_VAR(data__->, TRIGM1, __GET_VAR(data__->TRIG));
laurent@366: 
laurent@366: 	/* python thread is not in ? */
laurent@366: 	if( PythonState & PYTHON_LOCKED_BY_PLC){
laurent@366: 		/* if some answer are waiting, publish*/
ed@454: 		if(__GET_VAR(data__->STATE) == PYTHON_FB_ANSWERED){
laurent@366: 			/* Copy buffer content into result*/
laurent@638: 			__SET_VAR(data__->, RESULT, __GET_VAR(data__->BUFFER));
laurent@366: 			/* signal result presece to PLC*/
laurent@638: 			__SET_VAR(data__->, ACK, 1);
laurent@366: 			/* Mark as free */
laurent@638: 			__SET_VAR(data__->, STATE, PYTHON_FB_FREE);
laurent@366: 			/* mark as not trigged */
laurent@366: 			if(!poll)
laurent@638: 			    __SET_VAR(data__->, TRIGGED, 0);
laurent@366: 			/*printf("__PythonEvalFB pop %%d - %%*s\n",Current_PLC_EvalFB, data__->BUFFER.len, data__->BUFFER.body);*/
laurent@366: 		}else if(poll){
laurent@366: 			/* when in polling, no answer == ack down */
laurent@638: 		    __SET_VAR(data__->, ACK, 0);
laurent@366: 		}
laurent@366: 		/* got the order to act ?*/
ed@454: 		if(__GET_VAR(data__->TRIGGED) == 1 &&
laurent@366: 		   /* and not already being processed */
ed@454: 		   __GET_VAR(data__->STATE) == PYTHON_FB_FREE)
laurent@366: 		{
laurent@366: 			/* Enter the block in the fifo
Edouard@613: 			 * Don't have to check if fifo cell is free
laurent@366: 			 * as fifo size == FB count, and a FB cannot
laurent@366: 			 * be requested twice */
laurent@366: 			EvalFBs[Current_PLC_EvalFB] = data__;
laurent@366: 			/* copy into BUFFER local*/
laurent@638: 			__SET_VAR(data__->, BUFFER, __GET_VAR(data__->PREBUFFER));
laurent@366: 			/* Set ACK pin to low so that we can set a rising edge on result */
laurent@366: 			if(!poll){
laurent@366: 				/* when not polling, a new answer imply reseting ack*/
laurent@638: 			    __SET_VAR(data__->, ACK, 0);
laurent@366: 			}else{
laurent@366: 				/* when in polling, acting reset trigger */
laurent@638: 			    __SET_VAR(data__->, TRIGGED, 0);
laurent@366: 			}
laurent@366: 			/* Mark FB busy */
laurent@638: 			__SET_VAR(data__->, STATE, PYTHON_FB_REQUESTED);
laurent@366: 			/* Have to wakeup python thread in case he was asleep */
laurent@366: 			PythonState |= PYTHON_MUSTWAKEUP;
laurent@366: 			/*printf("__PythonEvalFB push %%d - %%*s\n",Current_PLC_EvalFB, data__->BUFFER.len, data__->BUFFER.body);*/
laurent@366: 			/* Get a new line */
laurent@366: 			Current_PLC_EvalFB = (Current_PLC_EvalFB + 1) %% %(python_eval_fb_count)d;
laurent@366: 		}
laurent@366: 	}
laurent@366: }
laurent@366: 
laurent@366: char* PythonIterator(char* result)
laurent@366: {
laurent@366: 	char* next_command;
laurent@366: 	PYTHON_EVAL* data__;
laurent@366: 	//printf("PythonIterator result %%s\n", result);
edouard@483:     /*emergency exit*/
edouard@483:     if(PythonState & PYTHON_FINISHED) return NULL;
laurent@366: 	/* take python mutex to prevent changing PLC data while PLC running */
laurent@366: 	LockPython();
laurent@366: 	/* Get current FB */
laurent@366: 	data__ = EvalFBs[Current_Python_EvalFB];
laurent@366: 	if(data__ && /* may be null at first run */
ed@454: 	    __GET_VAR(data__->STATE) == PYTHON_FB_PROCESSING){ /* some answer awaited*/
laurent@366: 	   	/* If result not None */
laurent@366: 	   	if(result){
laurent@366: 			/* Get results len */
laurent@638: 	   	    __SET_VAR(data__->, BUFFER, strlen(result), .len);
laurent@366: 			/* prevent results overrun */
ed@454: 			if(__GET_VAR(data__->BUFFER, .len) > STR_MAX_LEN)
laurent@366: 			{
laurent@638: 			    __SET_VAR(data__->, BUFFER, STR_MAX_LEN, .len );
laurent@366: 				/* TODO : signal error */
laurent@366: 			}
laurent@366: 			/* Copy results to buffer */
Edouard@613: 			strncpy((char*)__GET_VAR(data__->BUFFER, .body), result, __GET_VAR(data__->BUFFER,.len));
laurent@366: 	   	}else{
laurent@638: 	   	    __SET_VAR(data__->, BUFFER, 0, .len);
laurent@366: 	   	}
laurent@366: 		/* remove block from fifo*/
laurent@366: 		EvalFBs[Current_Python_EvalFB] = NULL;
laurent@366: 		/* Mark block as answered */
laurent@638: 		__SET_VAR(data__->, STATE, PYTHON_FB_ANSWERED);
laurent@366: 		/* Get a new line */
laurent@366: 		Current_Python_EvalFB = (Current_Python_EvalFB + 1) %% %(python_eval_fb_count)d;
laurent@366: 		//printf("PythonIterator ++ Current_Python_EvalFB %%d\n", Current_Python_EvalFB);
laurent@366: 	}
laurent@366: 	/* while next slot is empty */
laurent@366: 	while(((data__ = EvalFBs[Current_Python_EvalFB]) == NULL) ||
laurent@366: 	 	  /* or doesn't contain command */
ed@454: 	      __GET_VAR(data__->STATE) != PYTHON_FB_REQUESTED)
laurent@366: 	{
laurent@366: 		UnLockPython();
laurent@366: 		/* wait next FB to eval */
laurent@366: 		//printf("PythonIterator wait\n");
laurent@366: 		if(WaitPythonCommands()) return NULL;
laurent@366: 		/*emergency exit*/
laurent@366: 		if(PythonState & PYTHON_FINISHED) return NULL;
laurent@366: 		LockPython();
laurent@366: 	}
laurent@366: 	/* Mark block as processing */
laurent@638: 	__SET_VAR(data__->, STATE, PYTHON_FB_PROCESSING);
laurent@366: 	//printf("PythonIterator\n");
laurent@366: 	/* make BUFFER a null terminated string */
laurent@638: 	__SET_VAR(data__->, BUFFER, 0, .body[__GET_VAR(data__->BUFFER, .len)]);
laurent@366: 	/* next command is BUFFER */
Edouard@613: 	next_command = (char*)__GET_VAR(data__->BUFFER, .body);
laurent@366: 	/* free python mutex */
laurent@366: 	UnLockPython();
laurent@366: 	/* return the next command to eval */
laurent@366: 	return next_command;
laurent@366: }
laurent@366: