From ec3ef4474edb863902c0543202d716d9847ed8ea Mon Sep 17 00:00:00 2001
From: Francisco Paisana <paisanaf@tcd.ie>
Date: Thu, 2 Apr 2020 20:30:33 +0100
Subject: [PATCH] created a simple procedure fsm

---
 lib/include/srslte/common/fsm.h | 78 ++++++++++++++++++++++++++++++++-
 lib/test/common/fsm_test.cc     | 65 ++++++++++++++++++++++++++-
 2 files changed, 140 insertions(+), 3 deletions(-)

diff --git a/lib/include/srslte/common/fsm.h b/lib/include/srslte/common/fsm.h
index 0100b87e7..ed1329870 100644
--- a/lib/include/srslte/common/fsm.h
+++ b/lib/include/srslte/common/fsm.h
@@ -23,6 +23,7 @@
 #define SRSLTE_FSM_H
 
 #include "choice_type.h"
+#include "srslte/common/logmap.h"
 #include <cassert>
 #include <cstdio>
 #include <cstring>
@@ -101,7 +102,7 @@ struct fsm_helper {
   {
     static_assert(not std::is_same<State, PrevState>::value, "State cannot transition to itself.\n");
     if (p != nullptr) {
-      srslte::get<PrevState>(f->states).exit();
+      srslte::get<PrevState>(f->states).do_exit();
     }
     f->states.transit(std::move(*s));
     srslte::get<State>(f->states).do_enter();
@@ -112,7 +113,7 @@ struct fsm_helper {
   {
     static_assert(FSM::is_nested, "State is not present in the FSM list of valid states");
     if (p != nullptr) {
-      srslte::get<PrevState>(f->states).exit();
+      srslte::get<PrevState>(f->states).do_exit();
     }
     handle_state_change(f->parent_fsm()->derived(), s, static_cast<typename FSM::derived_t*>(f));
   }
@@ -282,6 +283,79 @@ protected:
   ParentFSM* fsm_ptr = nullptr;
 };
 
+template <typename Proc>
+struct proc_complete_ev {
+  proc_complete_ev(bool success_) : success(success_) {}
+  bool success;
+};
+
+// event
+template <typename... Args>
+struct proc_launch_ev {
+  std::tuple<Args...> args;
+  explicit proc_launch_ev(Args&&... args_) : args(std::forward<Args>(args_)...) {}
+};
+
+template <typename Derived, typename Result = srslte::same_state>
+class proc_fsm_t : public fsm_t<Derived>
+{
+  using fsm_type = Derived;
+  using fsm_t<Derived>::derived;
+
+public:
+  using base_t = proc_fsm_t<Derived, Result>;
+  using fsm_t<Derived>::trigger;
+
+  // states
+  struct idle_st : public state_t {
+    const char* name() const final { return "idle"; }
+    idle_st(Derived* f_) : fsm(f_) {}
+    void exit()
+    {
+      fsm->launch_counter++;
+      fsm->log_h->info("Proc %s: Starting run no. %d\n", fsm->derived()->name(), fsm->launch_counter);
+    }
+    Derived* fsm;
+  };
+  struct complete_st : public srslte::state_t {
+    complete_st(Derived* fsm_, bool success_) : fsm(fsm_), success(success_) {}
+    const char* name() const final { return "complete"; }
+    void        enter() { fsm->trigger(srslte::proc_complete_ev<bool>{success}); }
+    Derived*    fsm;
+    bool        success;
+  };
+
+  explicit proc_fsm_t(srslte::log_ref log_) : log_h(log_) {}
+
+  bool is_running() const { return base_t::template is_in_state<idle_st>(); }
+
+  srslte::log_ref log_h;
+
+  template <typename... Args>
+  void launch(Args&&... args)
+  {
+    trigger(proc_launch_ev<Args...>(std::forward<Args>(args)...));
+  }
+
+  //  template <typename... Args>
+  //  void trigger(proc_launch_ev<Args...> e)
+  //  {
+  //    if (not base_t::template is_in_state<idle_st>()) {
+  //      log_h->error("Proc %s: Ignoring launch because procedure is already running\n", base_t::derived()->name());
+  //      return;
+  //    }
+  //    base_t::trigger(std::move(e));
+  //  }
+  //  template <typename T>
+  //  void trigger(T&& t)
+  //  {
+  //    base_t::trigger(std::forward<T>(t));
+  //  }
+
+private:
+  int launch_counter = 0;
+};
+
 } // namespace srslte
 
 #endif // SRSLTE_FSM_H
diff --git a/lib/test/common/fsm_test.cc b/lib/test/common/fsm_test.cc
index f2f7f9735..47156c975 100644
--- a/lib/test/common/fsm_test.cc
+++ b/lib/test/common/fsm_test.cc
@@ -188,9 +188,72 @@ int test_hsm()
   return SRSLTE_SUCCESS;
 }
 
+///////////////////////////
+
+struct procevent1 {
+};
+struct procevent2 {
+};
+
+struct proc1 : public srslte::proc_fsm_t<proc1, int> {
+public:
+  struct procstate1 : public srslte::state_t {
+    const char* name() const final { return "procstate1"; }
+  };
+
+  proc1(srslte::log_ref log_) : base_t(log_) {}
+
+  const char* name() const final { return "proc1"; }
+
+protected:
+  // Transitions
+  auto react(idle_st& s, srslte::proc_launch_ev<int*> ev) -> procstate1;
+  auto react(procstate1& s, procevent1 ev) -> complete_st;
+  auto react(procstate1& s, procevent2 ev) -> complete_st;
+  auto react(complete_st& s, srslte::proc_complete_ev<bool> ev) -> idle_st;
+
+  state_list<idle_st, procstate1, complete_st> states{this};
+};
+
+auto proc1::react(idle_st& s, srslte::proc_launch_ev<int*> ev) -> procstate1
+{
+  log_h->info("started!\n");
+  return {};
+}
+auto proc1::react(procstate1& s, procevent1 ev) -> complete_st
+{
+  log_h->info("success!\n");
+  return {this, true};
+}
+auto proc1::react(procstate1& s, procevent2 ev) -> complete_st
+{
+  log_h->info("failure!\n");
+  return {this, false};
+}
+auto proc1::react(complete_st& s, srslte::proc_complete_ev<bool> ev) -> idle_st
+{
+  log_h->info("propagate results %s\n", s.success ? "success" : "failure");
+  return {this};
+}
+
+int test_fsm_proc()
+{
+  proc1 proc{srslte::logmap::get("TEST")};
+  int   v = 2;
+  proc.launch(&v);
+  proc.launch(&v);
+  proc.trigger(procevent1{});
+  proc.launch(&v);
+  proc.trigger(procevent2{});
+
+  return SRSLTE_SUCCESS;
+}
+
 int main()
 {
-  TESTASSERT(test_hsm() == SRSLTE_SUCCESS);
+  srslte::logmap::get("TEST")->set_level(srslte::LOG_LEVEL_INFO);
+  //  TESTASSERT(test_hsm() == SRSLTE_SUCCESS);
+  TESTASSERT(test_fsm_proc() == SRSLTE_SUCCESS);
 
   return SRSLTE_SUCCESS;
 }