Wendy Warne / microbit-dal

updates

Dependencies:   BLE_API mbed-dev-bin nRF51822

Fork of microbit-dal-eddystone by Martin Woolley

inc/core/MicroBitHeapAllocator.h@36:6837feb07da4, 2016-07-13 (annotated)

Committer:
LancasterUniversity
Date:
Wed Jul 13 12:18:15 2016 +0100
Revision:
36:6837feb07da4
Parent:
1:8aa5cdb4ab67 
Synchronized with git rev 4e71d613

Author: James Devine

microbit-dal: Added setPull to MicroBitPin



This new member function allows the configuration of the pull currently

applied to the MicroBitPin instance. This member function only has

affect when the MicroBitPin instance is in a digital input mode.

Who changed what in which revision?

UserRevisionLine numberNew contents of line
Jonathan Austin 1:8aa5cdb4ab67 1 /*
Jonathan Austin 1:8aa5cdb4ab67 2 The MIT License (MIT)
Jonathan Austin 1:8aa5cdb4ab67 3
Jonathan Austin 1:8aa5cdb4ab67 4 Copyright (c) 2016 British Broadcasting Corporation.
Jonathan Austin 1:8aa5cdb4ab67 5 This software is provided by Lancaster University by arrangement with the BBC.
Jonathan Austin 1:8aa5cdb4ab67 6
Jonathan Austin 1:8aa5cdb4ab67 7 Permission is hereby granted, free of charge, to any person obtaining a
Jonathan Austin 1:8aa5cdb4ab67 8 copy of this software and associated documentation files (the "Software"),
Jonathan Austin 1:8aa5cdb4ab67 9 to deal in the Software without restriction, including without limitation
Jonathan Austin 1:8aa5cdb4ab67 10 the rights to use, copy, modify, merge, publish, distribute, sublicense,
Jonathan Austin 1:8aa5cdb4ab67 11 and/or sell copies of the Software, and to permit persons to whom the
Jonathan Austin 1:8aa5cdb4ab67 12 Software is furnished to do so, subject to the following conditions:
Jonathan Austin 1:8aa5cdb4ab67 13
Jonathan Austin 1:8aa5cdb4ab67 14 The above copyright notice and this permission notice shall be included in
Jonathan Austin 1:8aa5cdb4ab67 15 all copies or substantial portions of the Software.
Jonathan Austin 1:8aa5cdb4ab67 16
Jonathan Austin 1:8aa5cdb4ab67 17 THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
Jonathan Austin 1:8aa5cdb4ab67 18 IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
Jonathan Austin 1:8aa5cdb4ab67 19 FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
Jonathan Austin 1:8aa5cdb4ab67 20 THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
Jonathan Austin 1:8aa5cdb4ab67 21 LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
Jonathan Austin 1:8aa5cdb4ab67 22 FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
Jonathan Austin 1:8aa5cdb4ab67 23 DEALINGS IN THE SOFTWARE.
Jonathan Austin 1:8aa5cdb4ab67 24 */
Jonathan Austin 1:8aa5cdb4ab67 25
Jonathan Austin 1:8aa5cdb4ab67 26 /**
Jonathan Austin 1:8aa5cdb4ab67 27 * A simple 32 bit block based memory allocator. This allows one or more memory segments to
Jonathan Austin 1:8aa5cdb4ab67 28 * be designated as heap storage, and is designed to run in a static memory area or inside the standard C
Jonathan Austin 1:8aa5cdb4ab67 29 * heap for use by the micro:bit runtime. This is required for several reasons:
Jonathan Austin 1:8aa5cdb4ab67 30 *
Jonathan Austin 1:8aa5cdb4ab67 31 * 1) It reduces memory fragmentation due to the high churn sometime placed on the heap
Jonathan Austin 1:8aa5cdb4ab67 32 * by ManagedTypes, fibers and user code. Underlying heap implentations are often have very simplistic
Jonathan Austin 1:8aa5cdb4ab67 33 * allocation pilicies and suffer from fragmentation in prolonged use - which can cause programs to
Jonathan Austin 1:8aa5cdb4ab67 34 * stop working after a period of time. The algorithm implemented here is simple, but highly tolerant to
Jonathan Austin 1:8aa5cdb4ab67 35 * large amounts of churn.
Jonathan Austin 1:8aa5cdb4ab67 36 *
Jonathan Austin 1:8aa5cdb4ab67 37 * 2) It allows us to reuse the 8K of SRAM set aside for SoftDevice as additional heap storage
Jonathan Austin 1:8aa5cdb4ab67 38 * when BLE is not in use.
Jonathan Austin 1:8aa5cdb4ab67 39 *
Jonathan Austin 1:8aa5cdb4ab67 40 * 3) It gives a simple example of how memory allocation works! :-)
Jonathan Austin 1:8aa5cdb4ab67 41 *
Jonathan Austin 1:8aa5cdb4ab67 42 * P.S. This is a very simple allocator, therefore not without its weaknesses. Why don't you consider
Jonathan Austin 1:8aa5cdb4ab67 43 * what these are, and consider the tradeoffs against simplicity...
Jonathan Austin 1:8aa5cdb4ab67 44 *
Jonathan Austin 1:8aa5cdb4ab67 45 * @note The need for this should be reviewed in the future, if a different memory allocator is
Jonathan Austin 1:8aa5cdb4ab67 46 * made availiable in the mbed platform.
Jonathan Austin 1:8aa5cdb4ab67 47 *
Jonathan Austin 1:8aa5cdb4ab67 48 * TODO: Consider caching recently freed blocks to improve allocation time.
Jonathan Austin 1:8aa5cdb4ab67 49 */
Jonathan Austin 1:8aa5cdb4ab67 50
Jonathan Austin 1:8aa5cdb4ab67 51 #ifndef MICROBIT_HEAP_ALLOCTOR_H
Jonathan Austin 1:8aa5cdb4ab67 52 #define MICROBIT_HEAP_ALLOCTOR_H
Jonathan Austin 1:8aa5cdb4ab67 53
Jonathan Austin 1:8aa5cdb4ab67 54 #include "mbed.h"
Jonathan Austin 1:8aa5cdb4ab67 55 #include "MicroBitConfig.h"
Jonathan Austin 1:8aa5cdb4ab67 56 #include <new>
Jonathan Austin 1:8aa5cdb4ab67 57
Jonathan Austin 1:8aa5cdb4ab67 58 // The maximum number of heap segments that can be created.
Jonathan Austin 1:8aa5cdb4ab67 59 #define MICROBIT_MAXIMUM_HEAPS 2
Jonathan Austin 1:8aa5cdb4ab67 60
Jonathan Austin 1:8aa5cdb4ab67 61 // Flag to indicate that a given block is FREE/USED
Jonathan Austin 1:8aa5cdb4ab67 62 #define MICROBIT_HEAP_BLOCK_FREE 0x80000000
Jonathan Austin 1:8aa5cdb4ab67 63
Jonathan Austin 1:8aa5cdb4ab67 64 /**
Jonathan Austin 1:8aa5cdb4ab67 65 * Create and initialise a given memory region as for heap storage.
Jonathan Austin 1:8aa5cdb4ab67 66 * After this is called, any future calls to malloc, new, free or delete may use the new heap.
Jonathan Austin 1:8aa5cdb4ab67 67 * The heap allocator will attempt to allocate memory from heaps in the order that they are created.
Jonathan Austin 1:8aa5cdb4ab67 68 * i.e. memory will be allocated from first heap created until it is full, then the second heap, and so on.
Jonathan Austin 1:8aa5cdb4ab67 69 *
Jonathan Austin 1:8aa5cdb4ab67 70 * @param start The start address of memory to use as a heap region.
Jonathan Austin 1:8aa5cdb4ab67 71 *
Jonathan Austin 1:8aa5cdb4ab67 72 * @param end The end address of memory to use as a heap region.
Jonathan Austin 1:8aa5cdb4ab67 73 *
Jonathan Austin 1:8aa5cdb4ab67 74 * @return MICROBIT_OK on success, or MICROBIT_NO_RESOURCES if the heap could not be allocated.
Jonathan Austin 1:8aa5cdb4ab67 75 *
Jonathan Austin 1:8aa5cdb4ab67 76 * @note Only code that #includes MicroBitHeapAllocator.h will use this heap. This includes all micro:bit runtime
Jonathan Austin 1:8aa5cdb4ab67 77 * code, and user code targetting the runtime. External code can choose to include this file, or
Jonathan Austin 1:8aa5cdb4ab67 78 * simply use the standard heap.
Jonathan Austin 1:8aa5cdb4ab67 79 */
Jonathan Austin 1:8aa5cdb4ab67 80 int microbit_create_heap(uint32_t start, uint32_t end);
Jonathan Austin 1:8aa5cdb4ab67 81
Jonathan Austin 1:8aa5cdb4ab67 82 /**
Jonathan Austin 1:8aa5cdb4ab67 83 * Create and initialise a heap region within the current the heap region specified
Jonathan Austin 1:8aa5cdb4ab67 84 * by the linker script.
Jonathan Austin 1:8aa5cdb4ab67 85 *
Jonathan Austin 1:8aa5cdb4ab67 86 * If the requested amount is not available, then the amount requested will be reduced
Jonathan Austin 1:8aa5cdb4ab67 87 * automatically to fit the space available.
Jonathan Austin 1:8aa5cdb4ab67 88 *
Jonathan Austin 1:8aa5cdb4ab67 89 * @param ratio The proportion of the underlying heap to allocate.
Jonathan Austin 1:8aa5cdb4ab67 90 *
Jonathan Austin 1:8aa5cdb4ab67 91 * @return MICROBIT_OK on success, or MICROBIT_NO_RESOURCES if the heap could not be allocated.
Jonathan Austin 1:8aa5cdb4ab67 92 */
Jonathan Austin 1:8aa5cdb4ab67 93 int microbit_create_nested_heap(float ratio);
Jonathan Austin 1:8aa5cdb4ab67 94
Jonathan Austin 1:8aa5cdb4ab67 95 /**
Jonathan Austin 1:8aa5cdb4ab67 96 * Attempt to allocate a given amount of memory from any of our configured heap areas.
Jonathan Austin 1:8aa5cdb4ab67 97 *
Jonathan Austin 1:8aa5cdb4ab67 98 * @param size The amount of memory, in bytes, to allocate.
Jonathan Austin 1:8aa5cdb4ab67 99 *
Jonathan Austin 1:8aa5cdb4ab67 100 * @return A pointer to the allocated memory, or NULL if insufficient memory is available.
Jonathan Austin 1:8aa5cdb4ab67 101 */
Jonathan Austin 1:8aa5cdb4ab67 102 void *microbit_malloc(size_t size);
Jonathan Austin 1:8aa5cdb4ab67 103
Jonathan Austin 1:8aa5cdb4ab67 104
Jonathan Austin 1:8aa5cdb4ab67 105 /**
Jonathan Austin 1:8aa5cdb4ab67 106 * Release a given area of memory from the heap.
Jonathan Austin 1:8aa5cdb4ab67 107 *
Jonathan Austin 1:8aa5cdb4ab67 108 * @param mem The memory area to release.
Jonathan Austin 1:8aa5cdb4ab67 109 */
Jonathan Austin 1:8aa5cdb4ab67 110 void microbit_free(void *mem);
Jonathan Austin 1:8aa5cdb4ab67 111
Jonathan Austin 1:8aa5cdb4ab67 112 /*
Jonathan Austin 1:8aa5cdb4ab67 113 * Wrapper function to ensure we have an explicit handle on the heap allocator provided
Jonathan Austin 1:8aa5cdb4ab67 114 * by our underlying platform.
Jonathan Austin 1:8aa5cdb4ab67 115 *
Jonathan Austin 1:8aa5cdb4ab67 116 * @param size The amount of memory, in bytes, to allocate.
Jonathan Austin 1:8aa5cdb4ab67 117 *
Jonathan Austin 1:8aa5cdb4ab67 118 * @return A pointer to the memory allocated. NULL if no memory is available.
Jonathan Austin 1:8aa5cdb4ab67 119 */
Jonathan Austin 1:8aa5cdb4ab67 120 inline void *native_malloc(size_t size)
Jonathan Austin 1:8aa5cdb4ab67 121 {
Jonathan Austin 1:8aa5cdb4ab67 122 return malloc(size);
Jonathan Austin 1:8aa5cdb4ab67 123 }
Jonathan Austin 1:8aa5cdb4ab67 124
Jonathan Austin 1:8aa5cdb4ab67 125 /*
Jonathan Austin 1:8aa5cdb4ab67 126 * Wrapper function to ensure we have an explicit handle on the heap allocator provided
Jonathan Austin 1:8aa5cdb4ab67 127 * by our underlying platform.
Jonathan Austin 1:8aa5cdb4ab67 128 *
Jonathan Austin 1:8aa5cdb4ab67 129 * @param p Pointer to the memory to be freed.
Jonathan Austin 1:8aa5cdb4ab67 130 */
Jonathan Austin 1:8aa5cdb4ab67 131 inline void native_free(void *p)
Jonathan Austin 1:8aa5cdb4ab67 132 {
Jonathan Austin 1:8aa5cdb4ab67 133 free(p);
Jonathan Austin 1:8aa5cdb4ab67 134 }
Jonathan Austin 1:8aa5cdb4ab67 135
Jonathan Austin 1:8aa5cdb4ab67 136 /**
Jonathan Austin 1:8aa5cdb4ab67 137 * Overrides the 'new' operator globally, and redirects calls to the micro:bit heap allocator.
Jonathan Austin 1:8aa5cdb4ab67 138 */
Jonathan Austin 1:8aa5cdb4ab67 139 inline void* operator new(size_t size) throw(std::bad_alloc)
Jonathan Austin 1:8aa5cdb4ab67 140 {
Jonathan Austin 1:8aa5cdb4ab67 141 return microbit_malloc(size);
Jonathan Austin 1:8aa5cdb4ab67 142 }
Jonathan Austin 1:8aa5cdb4ab67 143
Jonathan Austin 1:8aa5cdb4ab67 144 /**
Jonathan Austin 1:8aa5cdb4ab67 145 * Overrides the 'new' operator globally, and redirects calls to the micro:bit theap allocator.
Jonathan Austin 1:8aa5cdb4ab67 146 */
Jonathan Austin 1:8aa5cdb4ab67 147 inline void* operator new[](size_t size) throw(std::bad_alloc)
Jonathan Austin 1:8aa5cdb4ab67 148 {
Jonathan Austin 1:8aa5cdb4ab67 149 return microbit_malloc(size);
Jonathan Austin 1:8aa5cdb4ab67 150 }
Jonathan Austin 1:8aa5cdb4ab67 151
Jonathan Austin 1:8aa5cdb4ab67 152 /**
Jonathan Austin 1:8aa5cdb4ab67 153 * Overrides the 'delete' operator globally, and redirects calls to the micro:bit theap allocator.
Jonathan Austin 1:8aa5cdb4ab67 154 */
Jonathan Austin 1:8aa5cdb4ab67 155 inline void operator delete(void *ptr) throw()
Jonathan Austin 1:8aa5cdb4ab67 156 {
Jonathan Austin 1:8aa5cdb4ab67 157 microbit_free(ptr);
Jonathan Austin 1:8aa5cdb4ab67 158 }
Jonathan Austin 1:8aa5cdb4ab67 159
Jonathan Austin 1:8aa5cdb4ab67 160
Jonathan Austin 1:8aa5cdb4ab67 161 // Macros to override overrides the 'malloc' and 'delete' functions globally, and redirects calls
Jonathan Austin 1:8aa5cdb4ab67 162 // to the micro:bit theap allocator.
Jonathan Austin 1:8aa5cdb4ab67 163
Jonathan Austin 1:8aa5cdb4ab67 164 #define malloc(X) microbit_malloc( X )
Jonathan Austin 1:8aa5cdb4ab67 165 #define free(X) microbit_free( X )
Jonathan Austin 1:8aa5cdb4ab67 166
Jonathan Austin 1:8aa5cdb4ab67 167 #endif