CThunkBase.h

00001 /* mbed Microcontroller Library
00002  * Copyright (c) 2018-2018 ARM Limited
00003  * SPDX-License-Identifier: Apache-2.0
00004  *
00005  * Licensed under the Apache License, Version 2.0 (the "License");
00006  * you may not use this file except in compliance with the License.
00007  * You may obtain a copy of the License at
00008  *
00009  *     http://www.apache.org/licenses/LICENSE-2.0
00010  *
00011  * Unless required by applicable law or agreed to in writing, software
00012  * distributed under the License is distributed on an "AS IS" BASIS,
00013  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
00014  * See the License for the specific language governing permissions and
00015  * limitations under the License.
00016  */
00017 
00018 #ifndef __CTHUNK_BASE_H__
00019 #define __CTHUNK_BASE_H__
00020 
00021 /** \defgroup platform-internal-api Platform
00022  * \ingroup mbed-os-internal
00023  */
00024 
00025 /* IRQ/Exception compatible thunk entry function */
00026 typedef void (*CThunkEntry)(void);
00027 
00028 /**
00029  * \defgroup platform_CThunkBase CThunkBase class
00030  * \ingroup platform-internal-api
00031  * @{
00032  */
00033 class CThunkBase {
00034 protected:
00035     typedef void (*Trampoline)(CThunkBase *);
00036 
00037     Trampoline _trampoline;
00038 
00039     /*
00040      * Allocate a CThunkEntry which can be called without arguments
00041      *
00042      * Calling the CThunkEntry invokes the _trampoline of the
00043      * given cthunk. This function traps if there are no more
00044      * free thunks.
00045      */
00046     static CThunkEntry cthunk_alloc(CThunkBase *cthunk);
00047 
00048     /*
00049      * Free a cthunk_entry so it can be reused
00050      */
00051     static void cthunk_free(CThunkEntry cthunk_entry);
00052 
00053 private:
00054     typedef void (*CthunkFree)(CThunkEntry cthunk_entry);
00055 
00056     /*
00057      * Table of thunk functions
00058      */
00059     static const CThunkEntry _thunk_table[MBED_CONF_PLATFORM_CTHUNK_COUNT_MAX];
00060 
00061     /*
00062      * Table of active CThunk classes
00063      */
00064     static CThunkBase *_thunk_storage[MBED_CONF_PLATFORM_CTHUNK_COUNT_MAX];
00065 
00066     /*
00067      * Lazily initialized free function pointer
00068      */
00069     static CthunkFree _cthunk_free_real;
00070 
00071     /*
00072      * Actual free function
00073      */
00074     static void cthunk_free_real(CThunkEntry cthunk_entry);
00075 
00076     /*
00077      * Template function which stored in the _thunk_table
00078      */
00079     template<int N>
00080     static void thunk_entry()
00081     {
00082         _thunk_storage[N]->_trampoline(_thunk_storage[N]);
00083     }
00084 };
00085 
00086 /**@}*/
00087 
00088 #endif/*__CTHUNK_BASE_H__*/