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- /* This Source Code Form is subject to the terms of the Mozilla Public
- * License, v. 2.0. If a copy of the MPL was not distributed with this
- * file, You can obtain one at http://mozilla.org/MPL/2.0/.
- *
- * Copyright 2018 (c) Stefan Profanter, fortiss GmbH
- */
- /**
- * This memory manager allows to manually reduce the available RAM.
- *
- * It keeps track of malloc and free calls and counts the available RAM.
- * If the requested memory allocation results in hitting the limit,
- * it will return NULL and prevent the new allocation.
- */
- #include "custom_memory_manager.h"
- #include <stdlib.h>
- #include <stdio.h>
- #include <stdint.h>
- #include <limits.h>
- #include <pthread.h>
- pthread_mutex_t mutex;
- struct UA_mm_entry {
- size_t size;
- void* address;
- struct UA_mm_entry *next;
- struct UA_mm_entry *prev;
- };
- unsigned long long totalMemorySize = 0;
- unsigned long long memoryLimit = ULONG_MAX;
- /*
- * Head and Tail of the double linked list
- */
- struct UA_mm_entry *address_map_first = NULL;
- struct UA_mm_entry *address_map_last = NULL;
- void UA_memoryManager_setLimit(unsigned long long newLimit) {
- memoryLimit = newLimit;
- //printf("MemoryManager: Setting memory limit to %lld\n", newLimit);
- }
- int UA_memoryManager_setLimitFromLast4Bytes(const uint8_t *data, size_t size) {
- if (size <4)
- return 0;
- // just cast the last 4 bytes to uint32
- const uint32_t *newLimit = (const uint32_t*)(uintptr_t)&(data[size-4]);
- UA_memoryManager_setLimit(*newLimit);
- return 1;
- }
- /**
- * Add address entry to the linked list after it was allocated.
- *
- * @param size Size of the allocated memory block
- * @param addr Address of the allocated memory block
- * @return 1 on success, 0 if it failed
- */
- static int addToMap(size_t size, void *addr) {
- struct UA_mm_entry *newEntry = (struct UA_mm_entry*)malloc(sizeof(struct UA_mm_entry));
- if (!newEntry) {
- //printf("MemoryManager: Could not allocate memory");
- return 0;
- }
- newEntry->size = size;
- newEntry->address = addr;
- newEntry->next = NULL;
- pthread_mutex_lock(&mutex);
- newEntry->prev = address_map_last;
- if (address_map_last)
- address_map_last->next = newEntry;
- address_map_last = newEntry;
- totalMemorySize += size;
- if (address_map_first == NULL) {
- address_map_first = newEntry;
- }
- pthread_mutex_unlock(&mutex);
- //printf("Total size (malloc): %lld And new address: %p Entry %p\n", totalMemorySize, addr, (void*)newEntry);
- return 1;
- }
- /**
- * Remove entry from the list before the memory block is freed.
- *
- * @param addr Address of the memory block which is freed.
- *
- * @return 1 on success, 0 if the memory block was not found in the list.
- */
- static int removeFromMap(void *addr) {
- if (addr == NULL)
- return 1;
- pthread_mutex_lock(&mutex);
- struct UA_mm_entry *e = address_map_last;
- while (e) {
- if (e->address == addr) {
- if (e == address_map_first)
- address_map_first = e->next;
- if (e == address_map_last)
- address_map_last = e->prev;
- if (e->prev) {
- e->prev->next = e->next;
- }
- if (e->next) {
- e->next->prev = e->prev;
- }
- totalMemorySize -= e->size;
- //printf("Total size (free): %lld after addr %p and deleting %p\n", totalMemorySize, addr, (void*)e);
- free(e);
- pthread_mutex_unlock(&mutex);
- return 1;
- }
- e = e->prev;
- }
- pthread_mutex_unlock(&mutex);
- printf("MemoryManager: Entry with address %p not found", addr);
- return 0;
- }
- void* UA_memoryManager_malloc(size_t size) {
- if (totalMemorySize + size > memoryLimit)
- return NULL;
- void *addr = malloc(size);
- if (!addr)
- return NULL;
- addToMap(size, addr);
- return addr;
- }
- void* UA_memoryManager_calloc(size_t num, size_t size) {
- if (totalMemorySize + (size * num) > memoryLimit)
- return NULL;
- void *addr = calloc(num, size);
- if (!addr)
- return NULL;
- addToMap(size*num, addr);
- return addr;
- }
- void* UA_memoryManager_realloc(void *ptr, size_t new_size) {
- removeFromMap(ptr);
- if (totalMemorySize + new_size > memoryLimit)
- return NULL;
- void *addr = realloc(ptr, new_size);
- if (!addr)
- return NULL;
- addToMap(new_size, addr);
- return addr;
- }
- void UA_memoryManager_free(void* ptr) {
- removeFromMap(ptr);
- free(ptr);
- }
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