From ebdcc7be0ba0d4d2f0a08f8af28766e3429ada2b Mon Sep 17 00:00:00 2001
From: Douglas Clowes <dcl@ansto.gov.au>
Date: Tue, 15 Jan 2008 12:27:25 +1100
Subject: [PATCH] Extracted abstract Finite State Machine (from DMC2280 motor
 driver)

r2272 | dcl | 2008-01-15 12:27:25 +1100 (Tue, 15 Jan 2008) | 2 lines
---
 site_ansto/fsm.c | 93 ++++++++++++++++++++++++++++++++++++++++++++++++
 site_ansto/fsm.h | 62 ++++++++++++++++++++++++++++++++
 2 files changed, 155 insertions(+)
 create mode 100644 site_ansto/fsm.c
 create mode 100644 site_ansto/fsm.h

diff --git a/site_ansto/fsm.c b/site_ansto/fsm.c
new file mode 100644
index 00000000..1a85760c
--- /dev/null
+++ b/site_ansto/fsm.c
@@ -0,0 +1,93 @@
+#include "fsm.h"
+
+static void report_event(pStateMachine self, pEvtEvent event) {
+  char line[132];
+  char text[132];
+  snprintf(line, sizeof(line), "StateMachine=%s, State=%s(%d), event=%s",
+      self->name ? self->name : "<unknown>",
+      self->state_name ? self->state_name(self->myState) : "<unknown>",
+      self->mySubState,
+      self->event_name ? self->event_name(event, text, sizeof(text)) : "<unknown>");
+  SICSLogWrite(line, eStatus);
+}
+
+static void handle_event(pStateMachine self, pEvtEvent event) {
+  if (self->debug)
+    report_event(self, event);
+  if (self->myState)
+    self->myState(self, event);
+}
+
+int fsm_msg_callback(pAsyncTxn pCmd)
+{
+  pStateMachine self = (pStateMachine) pCmd->cntx;
+  EvtEvent event;
+
+  if (pCmd->txn_status == ATX_TIMEOUT) {
+    if (self->debug) {
+      SICSLogWrite(pCmd->out_buf, eStatus);
+      SICSLogWrite("<TIMEOUT>", eStatus);
+    }
+    event.event_type = eTimeoutEvent;
+    event.event.msg.cmd = pCmd;
+  }
+  else {
+    if (self->debug) {
+      SICSLogWrite(pCmd->out_buf, eStatus);
+      SICSLogWrite(pCmd->inp_buf, eStatus);
+    }
+    event.event_type = eMessageEvent;
+    event.event.msg.cmd = pCmd;
+  }
+  handle_event(self, &event);
+  return 0;
+}
+
+int fsm_tmr_callback(void* ctx, int mode)
+{
+  pStateMachine self = (pStateMachine) ctx;
+  EvtEvent event;
+  event.event_type = eTimerEvent;
+  handle_event(self, &event);
+  return 0;
+}
+
+int fsm_cmd_execute(pStateMachine self, const void* cmd) {
+  EvtEvent event;
+  event.event_type = eCommandEvent;
+  event.event.cmd.cmd_text = cmd;
+  handle_event(self, &event);
+  return 0;
+}
+
+void fsm_change_state(pStateMachine self, StateFunc func) {
+  if (self->debug) {
+    char line[132];
+    snprintf(line, sizeof(line), "StateMachine=%s, OldState=%s(%d), NewState=%s",
+        self->name ? self->name : "<unknown>",
+        self->state_name ? self->state_name(self->myState) : "<unknown>",
+        self->mySubState,
+        self->state_name ? self->state_name(func) : "<unknown>");
+    if (self->debug)
+      SICSLogWrite(line, eStatus);
+  }
+  self->myPrevState = self->myState;
+  self->myState = func;
+  self->mySubState = 0;
+  EvtEvent evt;
+  evt.event_type = eStateEvent;
+  if (self->myState)
+    self->myState(self, &evt);
+}
+
+void fsm_unhandled_event(pStateMachine self, pEvtEvent event) {
+    char line[132];
+    char text[132];
+    snprintf(line, sizeof(line), "StateMachine=%s, State=%s(%d), unhandled event=%s",
+        self->name ? self->name : "<unknown>",
+        self->state_name ? self->state_name(self->myState) : "<unknown>",
+        self->mySubState,
+        self->event_name ? self->event_name(event, text, sizeof(text)) : "<unknown>");
+    SICSLogWrite(line, eError);
+}
+
diff --git a/site_ansto/fsm.h b/site_ansto/fsm.h
new file mode 100644
index 00000000..e4f9c070
--- /dev/null
+++ b/site_ansto/fsm.h
@@ -0,0 +1,62 @@
+#ifndef FINITESTATEMACHINE
+#define FINITESTATEMACHINE
+
+#include <stdlib.h>
+#include <stdbool.h>
+#include <sics.h>
+#include <asyncqueue.h>
+
+typedef struct statemachine_s  StateMachine, *pStateMachine;
+typedef struct EvtEvent_s EvtEvent, *pEvtEvent;
+typedef void (*StateFunc)(pStateMachine self, pEvtEvent event);
+
+enum eventtype {
+  eStateEvent,
+  eTimerEvent,
+  eMessageEvent,
+  eCommandEvent,
+  eTimeoutEvent
+};
+
+typedef struct EvtState_s { } EvtState;
+typedef struct EvtTimer_s { } EvtTimer;
+
+typedef struct EvtMessage_s {
+  pAsyncTxn cmd;
+} EvtMessage;
+
+typedef struct EvtCommand_s {
+  const void* cmd_text;
+} EvtCommand;
+
+typedef struct EvtTimeout_s { } EvtTimeout;
+
+struct EvtEvent_s {
+  enum eventtype event_type;
+  union {
+    EvtState sta;
+    EvtTimer tmr;
+    EvtMessage msg;
+    EvtCommand cmd;
+    EvtTimeout tmo;
+  } event;
+};
+
+struct statemachine_s {
+  void* context;
+  char* name;
+  bool debug;
+  StateFunc myState;
+  int mySubState;
+  StateFunc myPrevState;
+  const char* (*state_name)(StateFunc func);
+  const char* (*event_name)(pEvtEvent event, char* text, int length);
+};
+
+int fsm_msg_callback(pAsyncTxn pCmd);
+int fsm_tmr_callback(void* ctx, int mode);
+int fsm_cmd_execute(pStateMachine self, const void* cmd);
+
+void fsm_change_state(pStateMachine self, StateFunc func);
+void fsm_unhandled_event(pStateMachine self, pEvtEvent event);
+#endif /* FINITESTATEMACHINE */