/* ChibiOS/RT - Copyright (C) 2006,2007,2008,2009,2010 Giovanni Di Sirio. This file is part of ChibiOS/RT. ChibiOS/RT is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation; either version 3 of the License, or (at your option) any later version. ChibiOS/RT is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details. You should have received a copy of the GNU General Public License along with this program. If not, see . */ /** * @file chheap.c * @brief Heaps code. * * @addtogroup heaps * @details Heap Allocator related APIs. *

Operation mode

* The heap allocator implements a first-fit strategy and its APIs * are functionally equivalent to the usual @p malloc() and @p free() * library functions. The main difference is that the OS heap APIs * are guaranteed to be thread safe.
* By enabling the @p CH_USE_MALLOC_HEAP option the heap manager * will use the runtime-provided @p malloc() and @p free() as * backend for the heap APIs instead of the system provided * allocator. * @pre In order to use the heap APIs the @p CH_USE_HEAP option must * be enabled in @p chconf.h. * @{ */ #include "ch.h" #if CH_USE_HEAP || defined(__DOXYGEN__) #if !CH_USE_MALLOC_HEAP || defined(__DOXYGEN__) /* * Defaults on the best synchronization mechanism available. */ #if CH_USE_MUTEXES || defined(__DOXYGEN__) #define H_LOCK(h) chMtxLock(&(h)->h_mtx) #define H_UNLOCK(h) chMtxUnlock() #else #define H_LOCK(h) chSemWait(&(h)->h_sem) #define H_UNLOCK(h) chSemSignal(&(h)->h_sem) #endif /** * @brief Default heap descriptor. */ static MemoryHeap default_heap; /** * @brief Initializes the default heap. * * @notapi */ void heap_init(void) { default_heap.h_provider = chCoreAlloc; default_heap.h_free.h.u.next = (union heap_header *)NULL; default_heap.h_free.h.size = 0; #if CH_USE_MUTEXES || defined(__DOXYGEN__) chMtxInit(&default_heap.h_mtx); #else chSemInit(&default_heap.h_sem, 1); #endif } /** * @brief Initializes a memory heap from a static memory area. * @pre Both the heap buffer base and the heap size must be aligned to * the @p stkalign_t type size. * * @param[out] heapp pointer to the memory heap descriptor to be initialized * @param[in] buf heap buffer base * @param[in] size heap size * * @init */ void chHeapInit(MemoryHeap *heapp, void *buf, size_t size) { union heap_header *hp; chDbgCheck(MEM_IS_ALIGNED(buf) && MEM_IS_ALIGNED(size), "chHeapInit"); heapp->h_provider = (memgetfunc_t)NULL; heapp->h_free.h.u.next = hp = buf; heapp->h_free.h.size = 0; hp->h.u.next = NULL; hp->h.size = size - sizeof(union heap_header); #if CH_USE_MUTEXES || defined(__DOXYGEN__) chMtxInit(&heapp->h_mtx); #else chSemInit(&heapp->h_sem, 1); #endif } /** * @brief Allocates a block of memory from the heap by using the first-fit * algorithm. * @details The allocated block is guaranteed to be properly aligned for a * pointer data type (@p stkalign_t). * * @param[in] heapp pointer to a heap descriptor or @p NULL in order to * access the default heap. * @param[in] size the size of the block to be allocated. Note that the * allocated block may be a bit bigger than the requested * size for alignment and fragmentation reasons. * @return A pointer to the allocated block. * @retval NULL if the block cannot be allocated. * * @api */ void *chHeapAlloc(MemoryHeap *heapp, size_t size) { union heap_header *qp, *hp, *fp; if (heapp == NULL) heapp = &default_heap; size = MEM_ALIGN_SIZE(size); qp = &heapp->h_free; H_LOCK(heapp); while (qp->h.u.next != NULL) { hp = qp->h.u.next; if (hp->h.size >= size) { if (hp->h.size < size + sizeof(union heap_header)) { /* Gets the whole block even if it is slightly bigger than the requested size because the fragment would be too small to be useful.*/ qp->h.u.next = hp->h.u.next; } else { /* Block bigger enough, must split it.*/ fp = (void *)((uint8_t *)(hp) + sizeof(union heap_header) + size); fp->h.u.next = hp->h.u.next; fp->h.size = hp->h.size - sizeof(union heap_header) - size; qp->h.u.next = fp; hp->h.size = size; } hp->h.u.heap = heapp; H_UNLOCK(heapp); return (void *)(hp + 1); } qp = hp; } H_UNLOCK(heapp); /* More memory is required, tries to get it from the associated provider else fails.*/ if (heapp->h_provider) { hp = heapp->h_provider(size + sizeof(union heap_header)); if (hp != NULL) { hp->h.u.heap = heapp; hp->h.size = size; hp++; return (void *)hp; } } return NULL; } #define LIMIT(p) (union heap_header *)((uint8_t *)(p) + \ sizeof(union heap_header) + \ (p)->h.size) /** * @brief Frees a previously allocated memory block. * * @param[in] p pointer to the memory block to be freed * * @api */ void chHeapFree(void *p) { union heap_header *qp, *hp; MemoryHeap *heapp; chDbgCheck(p != NULL, "chHeapFree"); hp = (union heap_header *)p - 1; heapp = hp->h.u.heap; qp = &heapp->h_free; H_LOCK(heapp); while (TRUE) { chDbgAssert((hp < qp) || (hp >= LIMIT(qp)), "chHeapFree(), #1", "within free block"); if (((qp == &heapp->h_free) || (hp > qp)) && ((qp->h.u.next == NULL) || (hp < qp->h.u.next))) { /* Insertion after qp.*/ hp->h.u.next = qp->h.u.next; qp->h.u.next = hp; /* Verifies if the newly inserted block should be merged.*/ if (LIMIT(hp) == hp->h.u.next) { /* Merge with the next block.*/ hp->h.size += hp->h.u.next->h.size + sizeof(union heap_header); hp->h.u.next = hp->h.u.next->h.u.next; } if ((LIMIT(qp) == hp)) { /* Merge with the previous block.*/ qp->h.size += hp->h.size + sizeof(union heap_header); qp->h.u.next = hp->h.u.next; } break; } qp = qp->h.u.next; } H_UNLOCK(heapp); return; } /** * @brief Reports the heap status. * @note This function is meant to be used in the test suite, it should * not be really useful for the application code. * @note This function is not implemented when the @p CH_USE_MALLOC_HEAP * configuration option is used (it always returns zero). * * @param[in] heapp pointer to a heap descriptor or @p NULL in order to * access the default heap. * @param[in] sizep pointer to a variable that will receive the total * fragmented free space * @return The number of fragments in the heap. * * @api */ size_t chHeapStatus(MemoryHeap *heapp, size_t *sizep) { union heap_header *qp; size_t n, sz; if (heapp == NULL) heapp = &default_heap; H_LOCK(heapp); sz = 0; for (n = 0, qp = &heapp->h_free; qp->h.u.next; n++, qp = qp->h.u.next) sz += qp->h.u.next->h.size; if (sizep) *sizep = sz; H_UNLOCK(heapp); return n; } #else /* CH_USE_MALLOC_HEAP */ #include #if CH_USE_MUTEXES #define H_LOCK() chMtxLock(&hmtx) #define H_UNLOCK() chMtxUnlock() static Mutex hmtx; #elif CH_USE_SEMAPHORES #define H_LOCK() chSemWait(&hsem) #define H_UNLOCK() chSemSignal(&hsem) static Semaphore hsem; #endif void heap_init(void) { #if CH_USE_MUTEXES chMtxInit(&hmtx); #else chSemInit(&hsem, 1); #endif } void *chHeapAlloc(MemoryHeap *heapp, size_t size) { void *p; chDbgCheck(heapp == NULL, "chHeapAlloc"); H_LOCK(); p = malloc(size); H_UNLOCK(); return p; } void chHeapFree(void *p) { chDbgCheck(p != NULL, "chHeapFree"); H_LOCK(); free(p); H_UNLOCK(); } size_t chHeapStatus(MemoryHeap *heapp, size_t *sizep) { chDbgCheck(heapp == NULL, "chHeapStatus"); if (sizep) *sizep = 0; return 0; } #endif /* CH_USE_MALLOC_HEAP */ #endif /* CH_USE_HEAP */ /** @} */ a> 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262