//Emulation heap calloc function
unsigned int EmuHeap::calloc(unsigned int nmemb, unsigned int size) {
//first malloc the block
unsigned int addr = this->malloc(nmemb * size);
if (addr != HEAP_ERROR) {
//find the newly malloc'ed block and zeroize it
MallocNode *node = findMallocNode(addr); //this should never fail
memset(node->block, 0, node->size);
}
return addr;
}
//emulations heap realloc function
unsigned int EmuHeap::realloc(unsigned int ptr, unsigned int size) {
unsigned int result = HEAP_ERROR;
if (ptr == 0) {
//act like malloc is ptr is NULL
result = this->malloc(size);
}
else {
//find the malloc'ed node
MallocNode *node = findMallocNode(ptr);
//round the new size to a word boundary
size = (size + 3) & 0xFFFFFFFC;
if (node) {
if (size == node->size) {
//no change in size? do nothing
result = ptr;
}
else if (size < node->size) {
//node shrinking, shrink node size and realloc its block
node->size = size;
node->block = (unsigned char*) ::realloc(node->block, size);
result = ptr;
}
else {
//node growing, allocate new block
result = this->malloc(size);
if (result != HEAP_ERROR) {
//find the newly allocated node
MallocNode *newnode = findMallocNode(result);
//copy the old block into the new larger block
memcpy(newnode->block, node->block, node->size);
//free the old block
this->free(ptr);
}
}
}
}
return result;
}
//emulations heap realloc function
unsigned int EmuHeap::realloc(unsigned int ptr, unsigned int size) {
unsigned int result = HEAP_ERROR;
if (ptr == 0) {
//act like malloc if ptr is NULL
result = this->malloc(size);
}
else {
//find the malloc'ed node
MallocNode *node = findMallocNode(ptr);
//round the new size to a word boundary
size = (size + 3) & 0xFFFFFFFC;
if (node) {
if (size == node->size) {
//no change in size? do nothing
result = ptr;
}
else if (size < node->size) {
//node shrinking, shrink node size
node->size = size;
result = ptr;
}
else {
//node growing, allocate new block
result = this->malloc(size);
if (result != HEAP_ERROR) {
//copy the old block into the new larger block
for (unsigned int i = 0; i < node->size; i++) {
patch_byte(result + i, get_byte(ptr + i));
}
//free the old block
this->free(ptr);
}
}
}
}
return result;
}
