I don't know your specific code, but is there a reason something like this:
typedef enum {
STATE1, STATE2, STATE3
} myState_e;
void myFsm(void)
{
myState_e State = STATE1;
while(1)
{
switch(State)
{
case STATE1:
State = STATE2;
break;
case STATE2:
State = STATE3;
break;
case STATE3:
State = STATE1;
break;
}
}
}
wouldn't work for you? It doesn't use goto, and is relatively easy to follow.
Edit: All those State = fragments violate DRY, so I might instead do something like:
typedef int (*myStateFn_t)(int OldState);
int myStateFn_Reset(int OldState, void *ObjP);
int myStateFn_Start(int OldState, void *ObjP);
int myStateFn_Process(int OldState, void *ObjP);
myStateFn_t myStateFns[] = {
#define MY_STATE_RESET 0
myStateFn_Reset,
#define MY_STATE_START 1
myStateFn_Start,
#define MY_STATE_PROCESS 2
myStateFn_Process
}
int myStateFn_Reset(int OldState, void *ObjP)
{
return shouldStart(ObjP) ? MY_STATE_START : MY_STATE_RESET;
}
int myStateFn_Start(int OldState, void *ObjP)
{
resetState(ObjP);
return MY_STATE_PROCESS;
}
int myStateFn_Process(int OldState, void *ObjP)
{
return (process(ObjP) == DONE) ? MY_STATE_RESET : MY_STATE_PROCESS;
}
int stateValid(int StateFnSize, int State)
{
return (State >= 0 && State < StateFnSize);
}
int stateFnRunOne(myStateFn_t StateFns, int StateFnSize, int State, void *ObjP)
{
return StateFns[OldState])(State, ObjP);
}
void stateFnRun(myStateFn_t StateFns, int StateFnSize, int CurState, void *ObjP)
{
int NextState;
while(stateValid(CurState))
{
NextState = stateFnRunOne(StateFns, StateFnSize, CurState, ObjP);
if(! stateValid(NextState))
LOG_THIS(CurState, NextState);
CurState = NextState;
}
}
which is, of course, much longer than the first attempt (funny thing about DRY). But it's also more robust - failure to return the state from one of the state functions will result in a compiler warning, rather than silently ignore a missing State = in the earlier code.
