Varun Bahl / BahlDecrypModified

Updated

Fork of BLE_API by Bluetooth Low Energy

ble/FunctionPointerWithContext.h@957:15f5e9046dde, 2015-11-26 (annotated)

Committer:
rgrover1
Date:
Thu Nov 26 12:52:33 2015 +0000
Revision:
957:15f5e9046dde
Parent:
953:f6eb43f524b2
Child:
965:212c16f6247f
Synchronized with git rev 57e69cb0

Author: Vincent Coubard

Add safe bool conversion to ninic function pointer semantic

Who changed what in which revision?

UserRevisionLine numberNew contents of line
rgrover1 710:b2e1a2660ec2 1 /* mbed Microcontroller Library
rgrover1 710:b2e1a2660ec2 2 * Copyright (c) 2006-2013 ARM Limited
rgrover1 710:b2e1a2660ec2 3 *
rgrover1 710:b2e1a2660ec2 4 * Licensed under the Apache License, Version 2.0 (the "License");
rgrover1 710:b2e1a2660ec2 5 * you may not use this file except in compliance with the License.
rgrover1 710:b2e1a2660ec2 6 * You may obtain a copy of the License at
rgrover1 710:b2e1a2660ec2 7 *
rgrover1 710:b2e1a2660ec2 8 * http://www.apache.org/licenses/LICENSE-2.0
rgrover1 710:b2e1a2660ec2 9 *
rgrover1 710:b2e1a2660ec2 10 * Unless required by applicable law or agreed to in writing, software
rgrover1 710:b2e1a2660ec2 11 * distributed under the License is distributed on an "AS IS" BASIS,
rgrover1 710:b2e1a2660ec2 12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
rgrover1 710:b2e1a2660ec2 13 * See the License for the specific language governing permissions and
rgrover1 710:b2e1a2660ec2 14 * limitations under the License.
rgrover1 710:b2e1a2660ec2 15 */
rgrover1 710:b2e1a2660ec2 16
rgrover1 710:b2e1a2660ec2 17 #ifndef MBED_FUNCTIONPOINTER_WITH_CONTEXT_H
rgrover1 710:b2e1a2660ec2 18 #define MBED_FUNCTIONPOINTER_WITH_CONTEXT_H
rgrover1 710:b2e1a2660ec2 19
rgrover1 710:b2e1a2660ec2 20 #include <string.h>
rgrover1 710:b2e1a2660ec2 21
rgrover1 710:b2e1a2660ec2 22 /** A class for storing and calling a pointer to a static or member void function
rgrover1 937:4932e700daf2 23 * that takes a context.
rgrover1 710:b2e1a2660ec2 24 */
rgrover1 710:b2e1a2660ec2 25 template <typename ContextType>
rgrover1 949:1902cbd0dd83 26 class FunctionPointerWithContext {
rgrover1 710:b2e1a2660ec2 27 public:
rgrover1 710:b2e1a2660ec2 28 typedef FunctionPointerWithContext<ContextType> *pFunctionPointerWithContext_t;
rgrover1 952:8a6c287de1be 29 typedef const FunctionPointerWithContext<ContextType> *cpFunctionPointerWithContext_t;
rgrover1 710:b2e1a2660ec2 30 typedef void (*pvoidfcontext_t)(ContextType context);
rgrover1 710:b2e1a2660ec2 31
rgrover1 937:4932e700daf2 32 /** Create a FunctionPointerWithContext, attaching a static function.
rgrover1 710:b2e1a2660ec2 33 *
rgrover1 937:4932e700daf2 34 * @param function The void static function to attach (default is none).
rgrover1 710:b2e1a2660ec2 35 */
rgrover1 710:b2e1a2660ec2 36 FunctionPointerWithContext(void (*function)(ContextType context) = NULL) :
rgrover1 952:8a6c287de1be 37 _memberFunctionAndPointer(), _caller(NULL), _next(NULL) {
rgrover1 710:b2e1a2660ec2 38 attach(function);
rgrover1 710:b2e1a2660ec2 39 }
rgrover1 710:b2e1a2660ec2 40
rgrover1 937:4932e700daf2 41 /** Create a FunctionPointerWithContext, attaching a member function.
rgrover1 710:b2e1a2660ec2 42 *
rgrover1 937:4932e700daf2 43 * @param object The object pointer to invoke the member function on (the "this" pointer).
rgrover1 937:4932e700daf2 44 * @param function The address of the void member function to attach.
rgrover1 710:b2e1a2660ec2 45 */
rgrover1 710:b2e1a2660ec2 46 template<typename T>
rgrover1 710:b2e1a2660ec2 47 FunctionPointerWithContext(T *object, void (T::*member)(ContextType context)) :
rgrover1 897:838e1375dbaa 48 _memberFunctionAndPointer(), _caller(NULL), _next(NULL) {
rgrover1 710:b2e1a2660ec2 49 attach(object, member);
rgrover1 710:b2e1a2660ec2 50 }
rgrover1 710:b2e1a2660ec2 51
rgrover1 952:8a6c287de1be 52 FunctionPointerWithContext(const FunctionPointerWithContext& that) :
rgrover1 952:8a6c287de1be 53 _memberFunctionAndPointer(that._memberFunctionAndPointer), _caller(that._caller), _next(NULL) {
rgrover1 952:8a6c287de1be 54 }
rgrover1 952:8a6c287de1be 55
rgrover1 952:8a6c287de1be 56 FunctionPointerWithContext& operator=(const FunctionPointerWithContext& that) {
rgrover1 952:8a6c287de1be 57 _memberFunctionAndPointer = that._memberFunctionAndPointer;
rgrover1 952:8a6c287de1be 58 _caller = that._caller;
rgrover1 952:8a6c287de1be 59 _next = NULL;
rgrover1 952:8a6c287de1be 60 return *this;
rgrover1 952:8a6c287de1be 61 }
rgrover1 952:8a6c287de1be 62
rgrover1 937:4932e700daf2 63 /** Attach a static function.
rgrover1 710:b2e1a2660ec2 64 *
rgrover1 937:4932e700daf2 65 * @param function The void static function to attach (default is none).
rgrover1 710:b2e1a2660ec2 66 */
rgrover1 710:b2e1a2660ec2 67 void attach(void (*function)(ContextType context) = NULL) {
rgrover1 710:b2e1a2660ec2 68 _function = function;
rgrover1 897:838e1375dbaa 69 _caller = functioncaller;
rgrover1 710:b2e1a2660ec2 70 }
rgrover1 710:b2e1a2660ec2 71
rgrover1 937:4932e700daf2 72 /** Attach a member function.
rgrover1 710:b2e1a2660ec2 73 *
rgrover1 937:4932e700daf2 74 * @param object The object pointer to invoke the member function on (the "this" pointer).
rgrover1 937:4932e700daf2 75 * @param function The address of the void member function to attach.
rgrover1 710:b2e1a2660ec2 76 */
rgrover1 710:b2e1a2660ec2 77 template<typename T>
rgrover1 710:b2e1a2660ec2 78 void attach(T *object, void (T::*member)(ContextType context)) {
rgrover1 897:838e1375dbaa 79 _memberFunctionAndPointer._object = static_cast<void *>(object);
rgrover1 897:838e1375dbaa 80 memcpy(_memberFunctionAndPointer._memberFunction, (char*) &member, sizeof(member));
rgrover1 897:838e1375dbaa 81 _caller = &FunctionPointerWithContext::membercaller<T>;
rgrover1 710:b2e1a2660ec2 82 }
rgrover1 710:b2e1a2660ec2 83
rgrover1 937:4932e700daf2 84 /** Call the attached static or member function; if there are chained
rgrover1 710:b2e1a2660ec2 85 * FunctionPointers their callbacks are invoked as well.
rgrover1 937:4932e700daf2 86 * @Note: All chained callbacks stack up, so hopefully there won't be too
rgrover1 710:b2e1a2660ec2 87 * many FunctionPointers in a chain. */
rgrover1 952:8a6c287de1be 88 void call(ContextType context) const {
rgrover1 952:8a6c287de1be 89 _caller(this, context);
rgrover1 952:8a6c287de1be 90
rgrover1 952:8a6c287de1be 91 /* Propagate the call to next in the chain. */
rgrover1 952:8a6c287de1be 92 if (_next) {
rgrover1 952:8a6c287de1be 93 _next->call(context);
rgrover1 952:8a6c287de1be 94 }
rgrover1 952:8a6c287de1be 95 }
rgrover1 952:8a6c287de1be 96
rgrover1 953:f6eb43f524b2 97 /**
rgrover1 953:f6eb43f524b2 98 * @brief Same as above
rgrover1 953:f6eb43f524b2 99 */
rgrover1 953:f6eb43f524b2 100 void operator()(ContextType context) const {
rgrover1 953:f6eb43f524b2 101 call(context);
rgrover1 953:f6eb43f524b2 102 }
rgrover1 953:f6eb43f524b2 103
rgrover1 952:8a6c287de1be 104 /** Same as above, workaround for mbed os FunctionPointer implementation. */
rgrover1 949:1902cbd0dd83 105 void call(ContextType context) {
rgrover1 921:ea542e6519bb 106 _caller(this, context);
rgrover1 921:ea542e6519bb 107
rgrover1 949:1902cbd0dd83 108 /* Propagate the call to next in the chain. */
rgrover1 949:1902cbd0dd83 109 if (_next) {
rgrover1 949:1902cbd0dd83 110 _next->call(context);
rgrover1 949:1902cbd0dd83 111 }
rgrover1 921:ea542e6519bb 112 }
rgrover1 921:ea542e6519bb 113
rgrover1 957:15f5e9046dde 114 typedef void (FunctionPointerWithContext::*bool_type)() const;
rgrover1 957:15f5e9046dde 115
rgrover1 957:15f5e9046dde 116 /**
rgrover1 957:15f5e9046dde 117 * implementation of safe bool operator
rgrover1 957:15f5e9046dde 118 */
rgrover1 957:15f5e9046dde 119 operator bool_type() const {
rgrover1 957:15f5e9046dde 120 if(_function || _memberFunctionAndPointer._object) {
rgrover1 957:15f5e9046dde 121 return &FunctionPointerWithContext::trueValue;
rgrover1 957:15f5e9046dde 122 }
rgrover1 957:15f5e9046dde 123
rgrover1 957:15f5e9046dde 124 return 0;
rgrover1 957:15f5e9046dde 125 }
rgrover1 957:15f5e9046dde 126
rgrover1 921:ea542e6519bb 127 /**
rgrover1 937:4932e700daf2 128 * Set up an external FunctionPointer as a next in the chain of related
rgrover1 710:b2e1a2660ec2 129 * callbacks. Invoking call() on the head FunctionPointer will invoke all
rgrover1 710:b2e1a2660ec2 130 * chained callbacks.
rgrover1 710:b2e1a2660ec2 131 *
rgrover1 710:b2e1a2660ec2 132 * Refer to 'CallChain' as an alternative.
rgrover1 710:b2e1a2660ec2 133 */
rgrover1 710:b2e1a2660ec2 134 void chainAsNext(pFunctionPointerWithContext_t next) {
rgrover1 710:b2e1a2660ec2 135 _next = next;
rgrover1 710:b2e1a2660ec2 136 }
rgrover1 710:b2e1a2660ec2 137
rgrover1 710:b2e1a2660ec2 138 pFunctionPointerWithContext_t getNext(void) const {
rgrover1 710:b2e1a2660ec2 139 return _next;
rgrover1 710:b2e1a2660ec2 140 }
rgrover1 710:b2e1a2660ec2 141
rgrover1 710:b2e1a2660ec2 142 pvoidfcontext_t get_function() const {
rgrover1 710:b2e1a2660ec2 143 return (pvoidfcontext_t)_function;
rgrover1 710:b2e1a2660ec2 144 }
rgrover1 710:b2e1a2660ec2 145
rgrover1 952:8a6c287de1be 146 friend bool operator==(const FunctionPointerWithContext& lhs, const FunctionPointerWithContext& rhs) {
rgrover1 952:8a6c287de1be 147 return rhs._caller == lhs._caller &&
rgrover1 952:8a6c287de1be 148 memcmp(
rgrover1 952:8a6c287de1be 149 &rhs._memberFunctionAndPointer,
rgrover1 952:8a6c287de1be 150 &lhs._memberFunctionAndPointer,
rgrover1 952:8a6c287de1be 151 sizeof(rhs._memberFunctionAndPointer)
rgrover1 952:8a6c287de1be 152 ) == 0;
rgrover1 952:8a6c287de1be 153 }
rgrover1 952:8a6c287de1be 154
rgrover1 710:b2e1a2660ec2 155 private:
rgrover1 710:b2e1a2660ec2 156 template<typename T>
rgrover1 952:8a6c287de1be 157 static void membercaller(cpFunctionPointerWithContext_t self, ContextType context) {
rgrover1 897:838e1375dbaa 158 if (self->_memberFunctionAndPointer._object) {
rgrover1 897:838e1375dbaa 159 T *o = static_cast<T *>(self->_memberFunctionAndPointer._object);
rgrover1 897:838e1375dbaa 160 void (T::*m)(ContextType);
rgrover1 897:838e1375dbaa 161 memcpy((char*) &m, self->_memberFunctionAndPointer._memberFunction, sizeof(m));
rgrover1 897:838e1375dbaa 162 (o->*m)(context);
rgrover1 897:838e1375dbaa 163 }
rgrover1 897:838e1375dbaa 164 }
rgrover1 897:838e1375dbaa 165
rgrover1 952:8a6c287de1be 166 static void functioncaller(cpFunctionPointerWithContext_t self, ContextType context) {
rgrover1 897:838e1375dbaa 167 if (self->_function) {
rgrover1 897:838e1375dbaa 168 self->_function(context);
rgrover1 897:838e1375dbaa 169 }
rgrover1 710:b2e1a2660ec2 170 }
rgrover1 710:b2e1a2660ec2 171
rgrover1 957:15f5e9046dde 172 /**
rgrover1 957:15f5e9046dde 173 * @brief True value used in conversion to bool, this function is useless
rgrover1 957:15f5e9046dde 174 * beside this usage
rgrover1 957:15f5e9046dde 175 */
rgrover1 957:15f5e9046dde 176 void trueValue() const {}
rgrover1 957:15f5e9046dde 177
rgrover1 897:838e1375dbaa 178 struct MemberFunctionAndPtr {
rgrover1 897:838e1375dbaa 179 /*
rgrover1 937:4932e700daf2 180 * Forward declaration of a class and a member function to this class.
rgrover1 897:838e1375dbaa 181 * Because the compiler doesn't know anything about the forwarded member
rgrover1 897:838e1375dbaa 182 * function, it will always use the biggest size and the biggest alignment
rgrover1 897:838e1375dbaa 183 * that a member function can take for objects of type UndefinedMemberFunction.
rgrover1 897:838e1375dbaa 184 */
rgrover1 897:838e1375dbaa 185 class UndefinedClass;
rgrover1 897:838e1375dbaa 186 typedef void (UndefinedClass::*UndefinedMemberFunction)(ContextType);
rgrover1 897:838e1375dbaa 187
rgrover1 897:838e1375dbaa 188 void* _object;
rgrover1 897:838e1375dbaa 189 union {
rgrover1 897:838e1375dbaa 190 char _memberFunction[sizeof(UndefinedMemberFunction)];
rgrover1 897:838e1375dbaa 191 UndefinedMemberFunction _alignment;
rgrover1 897:838e1375dbaa 192 };
rgrover1 897:838e1375dbaa 193 };
rgrover1 897:838e1375dbaa 194
rgrover1 897:838e1375dbaa 195 union {
rgrover1 937:4932e700daf2 196 pvoidfcontext_t _function; /**< Static function pointer - NULL if none attached */
rgrover1 897:838e1375dbaa 197 /**
rgrover1 897:838e1375dbaa 198 * object this pointer and pointer to member -
rgrover1 897:838e1375dbaa 199 * _memberFunctionAndPointer._object will be NULL if none attached
rgrover1 897:838e1375dbaa 200 */
rgrover1 952:8a6c287de1be 201 mutable MemberFunctionAndPtr _memberFunctionAndPointer;
rgrover1 897:838e1375dbaa 202 };
rgrover1 897:838e1375dbaa 203
rgrover1 952:8a6c287de1be 204 void (*_caller)(const FunctionPointerWithContext*, ContextType);
rgrover1 897:838e1375dbaa 205
rgrover1 937:4932e700daf2 206 pFunctionPointerWithContext_t _next; /**< Optional link to make a chain out of functionPointers. This
rgrover1 710:b2e1a2660ec2 207 * allows chaining function pointers without requiring
rgrover1 937:4932e700daf2 208 * external memory to manage the chain. Refer to
rgrover1 710:b2e1a2660ec2 209 * 'CallChain' as an alternative. */
rgrover1 710:b2e1a2660ec2 210 };
rgrover1 710:b2e1a2660ec2 211
rgrover1 952:8a6c287de1be 212 /**
rgrover1 952:8a6c287de1be 213 * @brief Create a new FunctionPointerWithContext which bind an instance and a
rgrover1 952:8a6c287de1be 214 * a member function together.
rgrover1 952:8a6c287de1be 215 * @details This little helper is a just here to eliminate the need to write the
rgrover1 952:8a6c287de1be 216 * FunctionPointerWithContext type each time you want to create one by kicking
rgrover1 952:8a6c287de1be 217 * automatic type deduction of function templates. With this function, it is easy
rgrover1 952:8a6c287de1be 218 * to write only one entry point for functions which expect a FunctionPointer
rgrover1 952:8a6c287de1be 219 * in parameters.
rgrover1 952:8a6c287de1be 220 *
rgrover1 952:8a6c287de1be 221 * @param object to bound with member function
rgrover1 952:8a6c287de1be 222 * @param member The member function called
rgrover1 952:8a6c287de1be 223 * @return a new FunctionPointerWithContext
rgrover1 952:8a6c287de1be 224 */
rgrover1 952:8a6c287de1be 225 template<typename T, typename ContextType>
rgrover1 952:8a6c287de1be 226 FunctionPointerWithContext<ContextType> makeFunctionPointer(T *object, void (T::*member)(ContextType context))
rgrover1 952:8a6c287de1be 227 {
rgrover1 952:8a6c287de1be 228 return FunctionPointerWithContext<ContextType>(object, member);
rgrover1 952:8a6c287de1be 229 }
rgrover1 952:8a6c287de1be 230
rgrover1 710:b2e1a2660ec2 231 #endif // ifndef MBED_FUNCTIONPOINTER_WITH_CONTEXT_H