Line data    Source code

       1             : /* ✔ */
       2             : 
       3             : #pragma once
       4             : 
       5             : #include <AH/Settings/Warnings.hpp>
       6             : 
       7             : AH_DIAGNOSTIC_WERROR() // Enable errors on warnings
       8             : 
       9             : #include <AH/Containers/CRTP.hpp>
      10             : #include <AH/Containers/LinkedList.hpp>
      11             : #include <AH/Containers/Mutex.hpp>
      12             : #include <AH/Error/Error.hpp>
      13             : #include <AH/STL/type_traits>
      14             : #include <AH/STL/utility> // std::forward
      15             : #include <AH/Settings/SettingsWrapper.hpp>
      16             : #include <stddef.h>
      17             : 
      18             : BEGIN_AH_NAMESPACE
      19             : 
      20             : /**
      21             :  * @brief   A super class for object that have to be updated regularly.
      22             :  * 
      23             :  * All instances of this class are kept in a linked list, so it's easy to 
      24             :  * iterate over all of them to update them.  
      25             :  * 
      26             :  * This version uses static polymorphism using the Curiously Recurring Template
      27             :  * Pattern. This requires less virtual function calls.  
      28             :  * (Only the destructor is virtual.)
      29             :  * 
      30             :  * @nosubgrouping
      31             :  */
      32             : template <class Derived, bool ThreadSafe = false>
      33             : class UpdatableCRTP : public DoublyLinkable<Derived> {
      34             : 
      35             :   public:
      36             :     using Mutex =
      37             :         typename std::conditional<ThreadSafe, DefaultMutEx, EmptyMutex>::type;
      38             :     using LockGuard =
      39             :         typename std::conditional<ThreadSafe, DefaultLockGuard<Mutex>,
      40             :                                   EmptyLockGuard<Mutex>>::type;
      41             : 
      42             : #if defined(__GNUC__) && !defined(__clang__)
      43             : #pragma GCC diagnostic push
      44             : #pragma GCC diagnostic ignored "-Wattributes"
      45             : #endif
      46             : 
      47             :     // When a Derived instance is constructed, the base class constructor
      48             :     // UpdatableCRTP is called first. Because the Derived constructor hasn't
      49             :     // been run yet, the dynamic type is just Updatable, not yet Derived.
      50             :     // The undefined behavior sanitizer checks this dynamic type when the this
      51             :     // pointer is casted to Derived using the CRTP macro, and thus causes an
      52             :     // error.
      53             :     // The constructor only casts and stores the pointer, it doesn't dereference
      54             :     // it to call any of Derived methods, so I don't think that it's undefined
      55             :     // behavior (and I don't know of a better way to do this).
      56             :     // Also see https://stackoverflow.com/q/61061051/6356744
      57             : 
      58             :   protected:
      59             :     /// Constructor: create an Updatable and add it to the linked list of
      60             :     /// instances.
      61         255 :     UpdatableCRTP() __attribute__((no_sanitize("undefined"))) {
      62         255 :         LockGuard lock(mutex);
      63         255 :         updatables.append(CRTP(Derived));
      64         255 :     }
      65             : 
      66             :   public:
      67             :     /// Destructor: remove the updatable from the linked list of instances.
      68         255 :     virtual ~UpdatableCRTP() __attribute__((no_sanitize("undefined"))) {
      69         255 :         LockGuard lock(mutex);
      70         255 :         if (updatables.couldContain(CRTP(Derived)))
      71         255 :             updatables.remove(CRTP(Derived));
      72         255 :     }
      73             : 
      74             : #if defined(__GNUC__) && !defined(__clang__)
      75             : #pragma GCC diagnostic pop
      76             : #endif
      77             : 
      78             :   public:
      79             :     static Mutex &getMutex() { return mutex; }
      80             : 
      81             :     /// @name Main initialization and updating methods
      82             :     /// @{
      83             : 
      84             :     template <class... Args>
      85          44 :     static void applyToAll(const LockGuard &,
      86             :                            void (Derived::*method)(Args &&...),
      87             :                            Args &&... args) {
      88          90 :         for (auto &el : updatables)
      89          46 :             (el.*method)(std::forward<Args>(args)...);
      90          44 :     }
      91             : 
      92             :     template <class... Args>
      93          44 :     static void applyToAll(void (Derived::*method)(Args &&...),
      94             :                            Args &&... args) {
      95          44 :         applyToAll(LockGuard(mutex), method, std::forward<Args>(args)...);
      96          44 :     }
      97             : 
      98             :     /// @}
      99             : 
     100             :   public:
     101             :     /// @name Enabling and disabling updatables
     102             :     /// @{
     103             : 
     104             :     /// Enable this updatable: insert it into the linked list of instances,
     105             :     /// so it gets updated automatically
     106          16 :     void enable(const LockGuard &lock) {
     107          16 :         if (isEnabled(lock)) {
     108           0 :             ERROR(F("Error: This element is already enabled."), 0x1212);
     109           0 :             return;
     110             :         }
     111          16 :         updatables.append(CRTP(Derived));
     112          16 :     }
     113             : 
     114             :     /// @copydoc enable
     115          16 :     void enable() { enable(LockGuard(mutex)); }
     116             : 
     117             :     /// Disable this updatable: remove it from the linked list of instances,
     118             :     /// so it no longer gets updated automatically
     119          16 :     void disable(const LockGuard &lock) {
     120          16 :         if (!isEnabled(lock)) {
     121           0 :             ERROR(F("Error: This element is already disabled."), 0x1213);
     122           0 :             return;
     123             :         }
     124          16 :         updatables.remove(CRTP(Derived));
     125          16 :     }
     126             : 
     127             :     /// @copydoc disable
     128          16 :     void disable() { disable(LockGuard(mutex)); }
     129             : 
     130             :     /**
     131             :      * @brief   Check if this updatable is enabled.
     132             :      * 
     133             :      * @note    Assumes that the updatable is not added to a different linked 
     134             :      *          list by the user.
     135             :      */
     136          32 :     bool isEnabled(const LockGuard &) const {
     137          32 :         return updatables.couldContain(CRTP(const Derived));
     138             :     }
     139             : 
     140             :     /// @copydoc isEnabled
     141             :     bool isEnabled() { return isEnabled(LockGuard(mutex)); }
     142             : 
     143             :     /// @copydoc enable
     144             :     static void enable(UpdatableCRTP *element) { element->enable(); }
     145             :     /// @copydoc enable
     146          16 :     static void enable(UpdatableCRTP &element) { element.enable(); }
     147             :     /// @copydoc enable
     148             :     template <class U, size_t N>
     149           1 :     static void enable(U (&array)[N]) {
     150          17 :         for (U &el : array)
     151          16 :             enable(el);
     152           1 :     }
     153             : 
     154             :     /// @copydoc disable
     155             :     static void disable(UpdatableCRTP *element) { element->disable(); }
     156             :     /// @copydoc disable
     157          16 :     static void disable(UpdatableCRTP &element) { element.disable(); }
     158             :     /// @copydoc disable
     159             :     template <class U, size_t N>
     160           1 :     static void disable(U (&array)[N]) {
     161          17 :         for (U &el : array)
     162          16 :             disable(el);
     163           1 :     }
     164             : 
     165             :     /// Move down this element in the list.
     166     1048576 :     void moveDown(const LockGuard &) { updatables.moveDown(CRTP(Derived)); }
     167             :     /// Move down this element in the list.
     168     1030153 :     void moveDown() { moveDown(LockGuard(mutex)); }
     169             : 
     170             :     /// @}
     171             : 
     172             :   protected:
     173             :     static DoublyLinkedList<Derived> updatables;
     174             :     static Mutex mutex;
     175             : };
     176             : 
     177             : template <class Derived, bool ThreadSafe>
     178             : DoublyLinkedList<Derived> UpdatableCRTP<Derived, ThreadSafe>::updatables;
     179             : 
     180             : template <class Derived, bool ThreadSafe>
     181             : typename UpdatableCRTP<Derived, ThreadSafe>::Mutex
     182             :     UpdatableCRTP<Derived, ThreadSafe>::mutex;
     183             : 
     184             : struct NormalUpdatable {};
     185             : 
     186             : /**
     187             :  * @brief   A super class for object that have to be updated regularly.
     188             :  * 
     189             :  * All instances of this class are kept in a linked list, so it's easy to 
     190             :  * iterate over all of them to update them.
     191             :  * 
     192             :  * @nosubgrouping
     193             :  */
     194             : template <class T = NormalUpdatable, bool ThreadSafe = false>
     195         440 : class Updatable : public UpdatableCRTP<Updatable<T, ThreadSafe>, ThreadSafe> {
     196             :   public:
     197             :     /// @name Main initialization and updating methods
     198             :     /// @{
     199             : 
     200             :     /// Initialize this updatable.
     201             :     virtual void begin() = 0;
     202             : 
     203             :     /// Update this updatable.
     204             :     virtual void update() = 0;
     205             : 
     206             :     /// Begin all enabled instances of this class
     207             :     /// @see    begin()
     208           7 :     static void beginAll() { Updatable::applyToAll(&Updatable::begin); }
     209             : 
     210             :     /// Update all enabled instances of this class
     211             :     /// @see    update()
     212          26 :     static void updateAll() { Updatable::applyToAll(&Updatable::update); }
     213             : 
     214             :     /// @}
     215             : };
     216             : 
     217             : END_AH_NAMESPACE
     218             : 
     219             : AH_DIAGNOSTIC_POP()