From 8049c64a5b00c2f35118fa975015756ddf1c4df5 Mon Sep 17 00:00:00 2001
From: Michael du Breuil <wicked.shell.scripts@gmail.com>
Date: Thu, 27 Sep 2018 16:04:37 -0700
Subject: [PATCH] AP_Scripting: Create a thread and spin

---
 libraries/AP_Scripting/AP_Scripting.cpp | 65 +++++++++++++++++++++----
 libraries/AP_Scripting/AP_Scripting.h   | 24 ++++++---
 2 files changed, 74 insertions(+), 15 deletions(-)

diff --git a/libraries/AP_Scripting/AP_Scripting.cpp b/libraries/AP_Scripting/AP_Scripting.cpp
index b19c098d9a..9d878c244c 100644
--- a/libraries/AP_Scripting/AP_Scripting.cpp
+++ b/libraries/AP_Scripting/AP_Scripting.cpp
@@ -13,12 +13,43 @@
    along with this program.  If not, see <http://www.gnu.org/licenses/>.
  */
 
-#if ENABLE_SCRIPTING
-
 #include <AP_Scripting/AP_Scripting.h>
 #include <AP_HAL/AP_HAL.h>
+#include <GCS_MAVLink/GCS.h>
+
+// ensure that we have a set of stack sizes, and enforce constraints around it
+// except for the minimum size, these are allowed to be defined by the build system
+#undef SCRIPTING_STACK_MIN_SIZE
+#define SCRIPTING_STACK_MIN_SIZE 2048
+
+#if !defined(SCRIPTING_STACK_SIZE)
+  #define SCRIPTING_STACK_SIZE 2048
+#endif // !defined(SCRIPTING_STACK_SIZE)
+
+#if !defined(SCRIPTING_STACK_MAX_SIZE)
+  #define SCRIPTING_STACK_MAX_SIZE 16384
+#endif // !defined(SCRIPTING_STACK_MAX_SIZE)
+
+static_assert(SCRIPTING_STACK_SIZE >= SCRIPTING_STACK_MIN_SIZE, "Scripting requires a larger minimum stack size");
+static_assert(SCRIPTING_STACK_SIZE <= SCRIPTING_STACK_MAX_SIZE, "Scripting requires a smaller stack size");
+
+extern const AP_HAL::HAL& hal;
+
+const AP_Param::GroupInfo AP_Scripting::var_info[] = {
+    // @Param: ENABLE
+    // @DisplayName: Enable Scripting
+    // @Description: Controls if scripting is enabled
+    // @Values: 0:None,1:Lua Scripts
+    // @RebootRequired: True
+    // @User: Advanced
+    AP_GROUPINFO_FLAGS("ENABLE", 1, AP_Scripting, _enable, 1, AP_PARAM_FLAG_ENABLE),
+
+    AP_GROUPEND
+};
 
 AP_Scripting::AP_Scripting() {       
+    AP_Param::setup_object_defaults(this, var_info);
+
 #if CONFIG_HAL_BOARD == HAL_BOARD_SITL
     if (_singleton != nullptr) {
         AP_HAL::panic("Scripting must be a singleton");
@@ -27,16 +58,32 @@ AP_Scripting::AP_Scripting() {
     _singleton = this;
 }
 
+bool AP_Scripting::init(void) {
+    if (!_enable) {
+        return true;
+    }
 
+    if (!hal.scheduler->thread_create(FUNCTOR_BIND_MEMBER(&AP_Scripting::thread, void),
+                                      "Scripting", SCRIPTING_STACK_SIZE, AP_HAL::Scheduler::PRIORITY_SCRIPTING, 0)) {
+        return false;
+    }
+
+    _running = true;
+    return true;
+}
+
+void AP_Scripting::thread(void) {
+    unsigned int loop = 0;
+    while (true) {
+        hal.scheduler->delay(1000);
+        gcs().send_text(MAV_SEVERITY_INFO, "Scripting Loop: %u", loop++);
+    }
+}
 
 AP_Scripting *AP_Scripting::_singleton = nullptr;
 
 namespace AP {
-
-AP_Scripting *scripting() {
-    return AP_Scripting::get_singleton();
+    AP_Scripting *scripting() {
+        return AP_Scripting::get_singleton();
+    }
 }
-
-};
-
-#endif // ENABLE_SCRIPTING
diff --git a/libraries/AP_Scripting/AP_Scripting.h b/libraries/AP_Scripting/AP_Scripting.h
index 95ea22c0be..aeb61be6cc 100644
--- a/libraries/AP_Scripting/AP_Scripting.h
+++ b/libraries/AP_Scripting/AP_Scripting.h
@@ -14,9 +14,10 @@
  */
 #pragma once
 
-#include <AP_Common/AP_Common.h>
+#ifdef ENABLE_SCRIPTING
 
-#if ENABLE_SCRIPTING
+#include <AP_Common/AP_Common.h>
+#include <AP_Param/AP_Param.h>
 
 class AP_Scripting
 {
@@ -27,16 +28,27 @@ public:
     AP_Scripting(const AP_Scripting &other) = delete;
     AP_Scripting &operator=(const AP_Scripting&) = delete;
 
-    static AP_Scripting * get_singleton() {
-        return _singleton;
-    }
+    bool init(void);
+
+    bool is_running(void) const { return _running; }
+
+    static AP_Scripting * get_singleton(void) { return _singleton; }
+
+    static const struct AP_Param::GroupInfo var_info[];
 
 private:
+    void thread(void); // main script execution thread
+
+    bool _running;
+
+    AP_Int8 _enable;
+
     static AP_Scripting *_singleton;
+
 };
 
 namespace AP {
-    AP_Scripting * scripting();
+    AP_Scripting * scripting(void);
 };
 
 #endif // ENABLE_SCRIPTING