Fix init -- solution to initial state startup

Fsm.cpp

@@ -26,7 +26,8 @@ State::State(void (*on_enter)(), void (*on_exit)())
 Fsm::Fsm(State* initial_state)
 : m_current_state(initial_state),
   m_transitions(NULL),
-  m_num_transitions(0)
+  m_num_transitions(0),
+  m_initialized(false)
 {
 }
 
@@ -96,6 +97,14 @@ void Fsm::trigger(int event)
     if (m_transitions[i].state_from == m_current_state &&
         m_transitions[i].event == event)
     {
+      if (! m_initialized)
+      {
+        m_initialized = true;
+        if (m_transitions[i].state_from->on_enter != NULL)
+        {
+          m_transitions[i].state_from->on_enter();
+        }
+      }
       m_current_state = m_transitions[i].make_transition();
       return;
     }
@@ -112,12 +121,20 @@ void Fsm::check_timer()
     {
       if (transition->start == 0)
       {
+        if (! m_initialized)
+        {
+          m_initialized = true;
+          if (transition->transition.state_from->on_enter != NULL)
+          {
+            transition->transition.state_from->on_enter();
+          }
+        }
         transition->start = millis();
       }
       else
       {
         unsigned long now = millis();
-        Serial.println(now);
+        //Serial.println(now); //jfm
         if (now - transition->start >= transition->interval)
         {
           m_current_state = transition->transition.make_transition();

Fsm.h

@@ -72,6 +72,7 @@ class Fsm
   State* m_current_state;
   Transition* m_transitions;
   int m_num_transitions;
+  boolean m_initialized;
 
   TimedTransition* m_timed_transitions;
   int m_num_timed_transitions;

examples/initBugTest/initBugTest.ino

@@ -0,0 +1,74 @@
+/*
+ initBugTest -- sketch to demonstrate startup behaviour of a classic event
+                driven FSM and also a timed-transition FSM.
+
+                Issue with first invokation of the trigger() function.
+                Issue with first invokation of the check_timer() function.
+
+                Expect to see the "on_enterX" function called followed by
+                the "on_exitX" function.
+
+                Only one state machine is needed to demonstrate the problem.
+                However the change I made to fix the problem requires a fresh
+                copy of the FSM to excercise the two code paths affected.
+
+ John Mauzey 20160212
+*/
+#include <Fsm.h>
+
+#define BAUD 115200 //for console log of status messages
+
+//define a standard FSM that prints a text message on both enter and exit
+#define TRANS_TEST 1  //for testing classic transitions (not timed)
+void on_enter1(void)
+{
+  Serial.print(millis());
+  Serial.println(" fsm1: on_enter called");
+}
+
+void on_exit1(void)
+{
+  Serial.print(millis());
+  Serial.println(" fsm1: on_exit  called ");
+}
+
+State state_enter_exit1(&on_enter1,&on_exit1);
+Fsm fsm1(&state_enter_exit1);
+
+//define a periodic FSM that prints a text message on both enter and exit
+void on_enter2(void)
+{
+  Serial.print(millis());
+  Serial.println(" fsm2: on_enter called");
+}
+
+void on_exit2(void)
+{
+  Serial.print(millis());
+  Serial.println(" fsm2: on_exit  called ");
+}
+
+State state_enter_exit2(&on_enter2,&on_exit2);
+
+Fsm fsm2(&state_enter_exit2);
+
+void setup()
+{
+  Serial.begin(BAUD);
+  fsm1.add_transition(&state_enter_exit1, &state_enter_exit1, TRANS_TEST, NULL);
+  fsm2.add_timed_transition(&state_enter_exit2, &state_enter_exit2, 3000, NULL);
+
+  Serial.println("Testing classic state machine -- Sending first trigger");
+  fsm1.trigger(TRANS_TEST);
+
+  Serial.println("Testing classic state machine -- Sending second trigger");
+  fsm1.trigger(TRANS_TEST);
+  Serial.println("");
+  Serial.println("Testing timed state machine -- 3 second periodic timer");
+}
+
+void loop(void)
+{
+  fsm2.check_timer();
+}
+