Diff: api/FunctionPointer.h

Revision:

525:c320967f86b9

Parent:

212:34d62c0b2af6

--- a/api/FunctionPointer.h	Mon Apr 27 09:45:08 2015 +0100
+++ b/api/FunctionPointer.h	Tue Apr 28 11:45:12 2015 +0100
@@ -1,5 +1,5 @@
 /* mbed Microcontroller Library
- * Copyright (c) 2006-2013 ARM Limited
+ * Copyright (c) 2006-2015 ARM Limited
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -17,21 +17,109 @@
 #define MBED_FUNCTIONPOINTER_H
 
 #include <string.h>
+#include <stdint.h>
 
 namespace mbed {
 
-typedef void (*pvoidf_t)(void);
+/* If we had variaditic templates, this wouldn't be a problem, but until C++11 is enabled, we are stuck with multiple classes... */
 
-/** A class for storing and calling a pointer to a static or member void function
+/** A class for storing and calling a pointer to a static or member function
  */
-class FunctionPointer {
+template <typename R, typename A1>
+class FunctionPointerArg1{
 public:
-
     /** Create a FunctionPointer, attaching a static function
      *
-     *  @param function The void static function to attach (default is none)
+     *  @param function The static function to attach (default is none)
+     */
+    FunctionPointerArg1(R (*function)(A1) = 0) {
+        attach(function);
+    }
+
+    /** Create a FunctionPointer, attaching a member function
+     *
+     *  @param object The object pointer to invoke the member function on (i.e. the this pointer)
+     *  @param function The address of the member function to attach
+     */
+    template<typename T>
+    FunctionPointerArg1(T *object, R (T::*member)(A1)) {
+        attach(object, member);
+    }
+
+    /** Attach a static function
+     *
+     *  @param function The static function to attach (default is none)
+     */
+    void attach(R (*function)(A1)) {
+        _p.function = function;
+        _membercaller = 0;
+    }
+
+    /** Attach a member function
+     *
+     *  @param object The object pointer to invoke the member function on (i.e. the this pointer)
+     *  @param function The address of the member function to attach
+     */
+    template<typename T>
+    void attach(T *object, R (T::*member)(A1)) {
+        _p.object = static_cast<void*>(object);
+        *reinterpret_cast<R (T::**)(A1)>(_member) = member;
+        _membercaller = &FunctionPointerArg1::membercaller<T>;
+    }
+
+    /** Call the attached static or member function
      */
-    FunctionPointer(void (*function)(void) = 0);
+    R call(A1 a) {
+        if (_membercaller == 0 && _p.function) {
+           return _p.function(a);
+        } else if (_membercaller && _p.object) {
+           return _membercaller(_p.object, _member, a);
+        }
+        return (R)0;
+    }
+
+    /** Get registered static function
+     */
+    R(*get_function(A1))() {
+        return _membercaller ? (R(*)(A1))0 : (R(*)(A1))_p.function;
+    }
+
+#ifdef MBED_OPERATORS
+    R operator ()(A1 a) {
+        return call(a);
+    }
+    operator bool(void) const {
+        return (_membercaller != NULL ? _p.object : (void*)_p.function) != NULL;
+    }
+#endif
+private:
+    template<typename T>
+    static R membercaller(void *object, uintptr_t *member, A1 a) {
+        T* o = static_cast<T*>(object);
+        R (T::**m)(A1) = reinterpret_cast<R (T::**)(A1)>(member);
+        return (o->**m)(a);
+    }
+
+    union {
+        R (*function)(A1); // static function pointer
+        void *object;      // object this pointer
+    } _p;
+    uintptr_t _member[4]; // aligned raw member function pointer storage - converted back by registered _membercaller
+    R (*_membercaller)(void*, uintptr_t*, A1); // registered membercaller function to convert back and call _m.member on _object
+};
+
+/** A class for storing and calling a pointer to a static or member function (R ()(void))
+ */
+template <typename R>
+class FunctionPointerArg1<R, void>{
+public:
+    /** Create a FunctionPointer, attaching a static function
+     *
+     *  @param function The static function to attach (default is none)
+     */
+    FunctionPointerArg1(R (*function)(void) = 0) {
+        attach(function);
+    }
 
     /** Create a FunctionPointer, attaching a member function
      *
@@ -39,7 +127,7 @@
      *  @param function The address of the void member function to attach
      */
     template<typename T>
-    FunctionPointer(T *object, void (T::*member)(void)) {
+    FunctionPointerArg1(T *object, R (T::*member)(void)) {
         attach(object, member);
     }
 
@@ -47,7 +135,10 @@
      *
      *  @param function The void static function to attach (default is none)
      */
-    void attach(void (*function)(void) = 0);
+    void attach(R (*function)(void)) {
+        _p.function = function;
+        _membercaller = 0;
+    }
 
     /** Attach a member function
      *
@@ -55,40 +146,57 @@
      *  @param function The address of the void member function to attach
      */
     template<typename T>
-    void attach(T *object, void (T::*member)(void)) {
-        _object = static_cast<void*>(object);
-        memcpy(_member, (char*)&member, sizeof(member));
-        _membercaller = &FunctionPointer::membercaller<T>;
-        _function = 0;
+    void attach(T *object, R (T::*member)(void)) {
+        _p.object = static_cast<void*>(object);
+        *reinterpret_cast<R (T::**)(void)>(_member) = member;
+        _membercaller = &FunctionPointerArg1::membercaller<T>;
     }
 
     /** Call the attached static or member function
      */
-    void call();
+    R call(){
+        if (_membercaller == 0 && _p.function) {
+            return _p.function();
+        } else if (_membercaller && _p.object) {
+            return _membercaller(_p.object, _member);
+        }
+        return (R)0;
+    }
 
-    pvoidf_t get_function() const {
-        return (pvoidf_t)_function;
+    /** Get registered static function
+     */
+    R(*get_function())() {
+        return _membercaller ? (R(*)())0 : (R(*)())_p.function;
     }
 
 #ifdef MBED_OPERATORS
-    void operator ()(void);
+    R operator ()(void) {
+        return call();
+    }
+    operator bool(void) const {
+        return (_membercaller != NULL ? _p.object : (void*)_p.function) != NULL;
+    }
 #endif
 
 private:
     template<typename T>
-    static void membercaller(void *object, char *member) {
+    static R membercaller(void *object, uintptr_t *member) {
         T* o = static_cast<T*>(object);
-        void (T::*m)(void);
-        memcpy((char*)&m, member, sizeof(m));
-        (o->*m)();
+        R (T::**m)(void) = reinterpret_cast<R (T::**)(void)>(member);
+        return (o->**m)();
     }
 
-    void (*_function)(void);             // static function pointer - 0 if none attached
-    void *_object;                       // object this pointer - 0 if none attached
-    char _member[16];                    // raw member function pointer storage - converted back by registered _membercaller
-    void (*_membercaller)(void*, char*); // registered membercaller function to convert back and call _member on _object
+    union {
+        R (*function)(void); // static function pointer
+        void *object;        // object this pointer
+    } _p;
+    uintptr_t _member[4]; // aligned raw member function pointer storage - converted back by registered _membercaller
+    R (*_membercaller)(void*, uintptr_t*); // registered membercaller function to convert back and call _m.member on _object
 };
 
+typedef FunctionPointerArg1<void, void> FunctionPointer;
+typedef FunctionPointerArg1<void, int> event_callback_t;
+
 } // namespace mbed
 
 #endif