[code] Get rid of malloc: keep a buffer in Code::App to be used as python heap

apps/code/app.cpp

@@ -77,18 +77,24 @@ void App::Snapshot::setOpt(const char * name, char * value) {
 
 App::App(Container * container, Snapshot * snapshot) :
   ::App(container, snapshot, &m_codeStackViewController, I18n::Message::Warning),
-  m_consoleController(nullptr, snapshot->scriptStore()
+  m_pythonHeap{},
+  m_pythonUser(nullptr),
+  m_consoleController(nullptr, this, snapshot->scriptStore()
 #if EPSILON_GETOPT
       , snapshot->lockOnConsole()
 #endif
       ),
   m_listFooter(&m_codeStackViewController, &m_menuController, &m_menuController, ButtonRowController::Position::Bottom, ButtonRowController::Style::EmbossedGrey, ButtonRowController::Size::Large),
-  m_menuController(&m_listFooter, snapshot->scriptStore(), &m_listFooter),
+  m_menuController(&m_listFooter, this, snapshot->scriptStore(), &m_listFooter),
   m_codeStackViewController(&m_modalViewController, &m_listFooter),
   m_variableBoxController(&m_menuController, snapshot->scriptStore())
 {
 }
 
+App::~App() {
+  deinitPython();
+}
+
 bool App::handleEvent(Ion::Events::Event event) {
   if (event == Ion::Events::Home && m_consoleController.inputRunLoopActive()) {
     // We need to return true here because we want to actually exit from the
@@ -117,4 +123,17 @@ bool App::textInputDidReceiveEvent(TextInput * textInput, Ion::Events::Event eve
   return false;
 }
 
+void App::initPythonWithUser(const void * pythonUser) {
+  assert(m_pythonUser == nullptr);
+  m_pythonUser = pythonUser;
+  MicroPython::init(m_pythonHeap, m_pythonHeap + k_pythonHeapSize);
+}
+
+void App::deinitPython() {
+  if (m_pythonUser) {
+    MicroPython::deinit();
+    m_pythonUser = nullptr;
+  }
+}
+
 }

apps/code/app.h

@@ -36,12 +36,26 @@ public:
 #endif
     ScriptStore m_scriptStore;
   };
+  ~App();
   StackViewController * stackViewController() { return &m_codeStackViewController; }
   ConsoleController * consoleController() { return &m_consoleController; }
   PythonToolbox * pythonToolbox() { return &m_toolbox; }
   bool handleEvent(Ion::Events::Event event) override;
   bool textInputDidReceiveEvent(TextInput * textInput, Ion::Events::Event event);
+  // Python delegate
+  bool isPythonUser(const void * pythonUser) { return m_pythonUser == pythonUser; }
+  void initPythonWithUser(const void * pythonUser);
+  void deinitPython();
 private:
+  /* Python delegate:
+   * MicroPython requires a heap. To avoid dynamic allocation, we keep a working
+   * buffer here and we give to controllers that load Python environment. We
+   * also memoize the last Python user to avoid re-initiating MicroPython when
+   * unneeded. */
+  static constexpr int k_pythonHeapSize = 16384;
+  char m_pythonHeap[k_pythonHeapSize];
+  const void * m_pythonUser;
+
   App(Container * container, Snapshot * snapshot);
   ConsoleController m_consoleController;
   ButtonRowController m_listFooter;

apps/code/console_controller.cpp

@@ -15,7 +15,7 @@ namespace Code {
 
 static const char * sStandardPromptText = ">>> ";
 
-ConsoleController::ConsoleController(Responder * parentResponder, ScriptStore * scriptStore
+ConsoleController::ConsoleController(Responder * parentResponder, App * pythonDelegate, ScriptStore * scriptStore
 #if EPSILON_GETOPT
       , bool lockOnConsole
 #endif
@@ -24,11 +24,11 @@ ConsoleController::ConsoleController(Responder * parentResponder, ScriptStore *
   SelectableTableViewDataSource(),
   TextFieldDelegate(),
   MicroPython::ExecutionEnvironment(),
+  m_pythonDelegate(pythonDelegate),
   m_rowHeight(KDText::charSize(k_fontSize).height()),
   m_importScriptsWhenViewAppears(false),
   m_selectableTableView(this, this, this, this),
   m_editCell(this, this),
-  m_pythonHeap(nullptr),
   m_scriptStore(scriptStore),
   m_sandboxController(this),
   m_inputRunLoopActive(false)
@@ -44,22 +44,12 @@ ConsoleController::ConsoleController(Responder * parentResponder, ScriptStore *
   }
 }
 
-ConsoleController::~ConsoleController() {
-  unloadPythonEnvironment();
-}
-
 bool ConsoleController::loadPythonEnvironment(bool autoImportScripts) {
   if(pythonEnvironmentIsLoaded()) {
     return true;
   }
   emptyOutputAccumulationBuffer();
-  m_pythonHeap = (char *)malloc(k_pythonHeapSize);
-  if (m_pythonHeap == nullptr) {
-    // In DEBUG mode, the assert at the end of malloc would have already failed
-    // and the program crashed.
-    return false;
-  }
-  MicroPython::init(m_pythonHeap, m_pythonHeap + k_pythonHeapSize);
+  m_pythonDelegate->initPythonWithUser(this);
   MicroPython::registerScriptProvider(m_scriptStore);
   m_importScriptsWhenViewAppears = autoImportScripts;
   return true;
@@ -68,14 +58,12 @@ bool ConsoleController::loadPythonEnvironment(bool autoImportScripts) {
 void ConsoleController::unloadPythonEnvironment() {
   if (pythonEnvironmentIsLoaded()) {
     m_consoleStore.startNewSession();
-    MicroPython::deinit();
-    free(m_pythonHeap);
-    m_pythonHeap = nullptr;
+    m_pythonDelegate->deinitPython();
   }
 }
 
 bool ConsoleController::pythonEnvironmentIsLoaded() {
-  return (m_pythonHeap != nullptr);
+  return m_pythonDelegate->isPythonUser(this);
 }
 
 void ConsoleController::autoImport() {

apps/code/console_controller.h

@@ -12,20 +12,17 @@
 
 namespace Code {
 
+class App;
+
 class ConsoleController : public ViewController, public ListViewDataSource, public SelectableTableViewDataSource, public SelectableTableViewDelegate, public TextFieldDelegate, public MicroPython::ExecutionEnvironment {
 public:
   static constexpr KDText::FontSize k_fontSize = KDText::FontSize::Large;
 
-  ConsoleController(Responder * parentResponder, ScriptStore * scriptStore
+  ConsoleController(Responder * parentResponder, App * pythonDelegate, ScriptStore * scriptStore
 #if EPSILON_GETOPT
       , bool m_lockOnConsole
 #endif
       );
-  ~ConsoleController();
-  ConsoleController(const ConsoleController& other) = delete;
-  ConsoleController(ConsoleController&& other) = delete;
-  ConsoleController operator=(const ConsoleController& other) = delete;
-  ConsoleController& operator=(ConsoleController&& other) = delete;
 
   bool loadPythonEnvironment(bool autoImportScripts = true);
   void unloadPythonEnvironment();
@@ -81,20 +78,19 @@ private:
   static constexpr int LineCellType = 0;
   static constexpr int EditCellType = 1;
   static constexpr int k_numberOfLineCells = 15; // May change depending on the screen height
-  static constexpr int k_pythonHeapSize = 16384;
   static constexpr int k_outputAccumulationBufferSize = 100;
   void flushOutputAccumulationBufferToStore();
   void appendTextToOutputAccumulationBuffer(const char * text, size_t length);
   void emptyOutputAccumulationBuffer();
   size_t firstNewLineCharIndex(const char * text, size_t length);
   StackViewController * stackViewController();
+  App * m_pythonDelegate;
   int m_rowHeight;
   bool m_importScriptsWhenViewAppears;
   ConsoleStore m_consoleStore;
   SelectableTableView m_selectableTableView;
   ConsoleLineCell m_cells[k_numberOfLineCells];
   ConsoleEditCell m_editCell;
-  char * m_pythonHeap;
   char m_outputAccumulationBuffer[k_outputAccumulationBufferSize];
   /* The Python machine might call printText several times to print a single
    * string. We thus use m_outputAccumulationBuffer to store and concatenate the

apps/code/editor_controller.cpp

@@ -8,9 +8,9 @@
 
 namespace Code {
 
-EditorController::EditorController(MenuController * menuController) :
+EditorController::EditorController(MenuController * menuController, App * pythonDelegate) :
   ViewController(nullptr),
-  m_editorView(this),
+  m_editorView(this, pythonDelegate),
   m_script(Ion::Storage::Record()),
   m_menuController(menuController)
 {

apps/code/editor_controller.h

@@ -12,7 +12,7 @@ class ScriptParameterController;
 
 class EditorController : public ViewController, public TextAreaDelegate {
 public:
-  EditorController(MenuController * menuController);
+  EditorController(MenuController * menuController, App * pythonDelegate);
   void setScript(Script script);
 
   /* ViewController */

apps/code/editor_view.cpp

@@ -8,10 +8,10 @@ namespace Code {
 
 constexpr KDText::FontSize editorFontSize = KDText::FontSize::Large;
 
-EditorView::EditorView(Responder * parentResponder) :
+EditorView::EditorView(Responder * parentResponder, App * pythonDelegate) :
   Responder(parentResponder),
   View(),
-  m_textArea(parentResponder, editorFontSize),
+  m_textArea(parentResponder, pythonDelegate, editorFontSize),
   m_gutterView(editorFontSize)
 {
   m_textArea.setScrollViewDelegate(this);

apps/code/editor_view.h

@@ -8,7 +8,7 @@ namespace Code {
 
 class EditorView : public Responder, public View, public ScrollViewDelegate {
 public:
-  EditorView(Responder * parentResponder);
+  EditorView(Responder * parentResponder, App * pythonDelegate);
   void setTextAreaDelegate(TextAreaDelegate * delegate) {
     m_textArea.setDelegate(delegate);
   }

apps/code/menu_controller.cpp

@@ -8,7 +8,7 @@
 
 namespace Code {
 
-MenuController::MenuController(Responder * parentResponder, ScriptStore * scriptStore, ButtonRowController * footer) :
+MenuController::MenuController(Responder * parentResponder, App * pythonDelegate, ScriptStore * scriptStore, ButtonRowController * footer) :
   ViewController(parentResponder),
   ButtonRowDelegate(nullptr, footer),
   m_scriptStore(scriptStore),
@@ -23,7 +23,7 @@ MenuController::MenuController(Responder * parentResponder, ScriptStore * script
   }, this), KDText::FontSize::Large),
   m_selectableTableView(this, this, this, this),
   m_scriptParameterController(nullptr, I18n::Message::ScriptOptions, this),
-  m_editorController(this),
+  m_editorController(this, pythonDelegate),
   m_reloadConsoleWhenBecomingFirstResponder(false),
   m_shouldDisplayAddScriptRow(true)
 {

apps/code/menu_controller.h

@@ -13,7 +13,7 @@ class ScriptParameterController;
 
 class MenuController : public ViewController, public TableViewDataSource, public SelectableTableViewDataSource, public SelectableTableViewDelegate, public TextFieldDelegate, public ButtonRowDelegate {
 public:
-  MenuController(Responder * parentResponder, ScriptStore * scriptStore, ButtonRowController * footer);
+  MenuController(Responder * parentResponder, App * pythonDelegate, ScriptStore * scriptStore, ButtonRowController * footer);
   ConsoleController * consoleController();
   StackViewController * stackViewController();
   void willExitResponderChain(Responder * nextFirstResponder) override;

apps/code/python_text_area.cpp

@@ -1,4 +1,5 @@
 #include "python_text_area.h"
+#include "app.h"
 
 extern "C" {
 #include "py/nlr.h"
@@ -75,19 +76,11 @@ static inline size_t TokenLength(mp_lexer_t * lex) {
 }
 
 void PythonTextArea::ContentView::loadSyntaxHighlighter() {
-  assert(m_pythonHeap == nullptr);
-  m_pythonHeap = static_cast<char *>(malloc(k_pythonHeapSize));
-  if (m_pythonHeap != nullptr) {
-    MicroPython::init(m_pythonHeap, m_pythonHeap + k_pythonHeapSize);
-  }
+  m_pythonDelegate->initPythonWithUser(this);
 }
 
 void PythonTextArea::ContentView::unloadSyntaxHighlighter() {
-  if (m_pythonHeap != nullptr) {
-    MicroPython::deinit();
-    free(m_pythonHeap);
-    m_pythonHeap = nullptr;
-  }
+  m_pythonDelegate->deinitPython();
 }
 
 void PythonTextArea::ContentView::clearRect(KDContext * ctx, KDRect rect) const {
@@ -105,7 +98,7 @@ void PythonTextArea::ContentView::clearRect(KDContext * ctx, KDRect rect) const
 void PythonTextArea::ContentView::drawLine(KDContext * ctx, int line, const char * text, size_t length, int fromColumn, int toColumn) const {
   LOG_DRAW("Drawing \"%.*s\"\n", length, text);
 
-  if (m_pythonHeap == nullptr) {
+  if (!m_pythonDelegate->isPythonUser(this)) {
     drawStringAt(
       ctx,
       line,

apps/code/python_text_area.h

@@ -5,11 +5,13 @@
 
 namespace Code {
 
+class App;
+
 class PythonTextArea : public TextArea {
 public:
-  PythonTextArea(Responder * parentResponder, KDText::FontSize fontSize) :
+  PythonTextArea(Responder * parentResponder, App * pythonDelegate, KDText::FontSize fontSize) :
     TextArea(parentResponder, &m_contentView, fontSize),
-    m_contentView(fontSize)
+    m_contentView(pythonDelegate, fontSize)
   {
   }
   void loadSyntaxHighlighter() { m_contentView.loadSyntaxHighlighter(); }
@@ -17,9 +19,9 @@ public:
 protected:
   class ContentView : public TextArea::ContentView {
   public:
-    ContentView(KDText::FontSize fontSize) :
+    ContentView(App * pythonDelegate, KDText::FontSize fontSize) :
       TextArea::ContentView(fontSize),
-      m_pythonHeap(nullptr)
+      m_pythonDelegate(pythonDelegate)
     {
     }
     void loadSyntaxHighlighter();
@@ -28,8 +30,7 @@ protected:
     void drawLine(KDContext * ctx, int line, const char * text, size_t length, int fromColumn, int toColumn) const override;
     KDRect dirtyRectFromCursorPosition(size_t index, bool lineBreak) const override;
   private:
-    static constexpr size_t k_pythonHeapSize = 4096;
-    char * m_pythonHeap;
+    App * m_pythonDelegate;
   };
 private:
   const ContentView * nonEditableContentView() const override { return &m_contentView; }