godot/core/os/memory.cpp
Pedro J. Estébanez 779693a79b Implement byte-tagging of memory
Using a magic value for memory allocated but uninitialized and another one for memory about-to-be-released. Helps in debugging unitialized members, dangling pointerts, etc.

Disabled by default. Can be enabled for debug builds by defining `DEBUG_MEMORY_TAGGING`.
2017-07-05 10:31:13 +02:00

194 lines
5.2 KiB
C++

/*************************************************************************/
/* memory.cpp */
/*************************************************************************/
/* This file is part of: */
/* GODOT ENGINE */
/* http://www.godotengine.org */
/*************************************************************************/
/* Copyright (c) 2007-2017 Juan Linietsky, Ariel Manzur. */
/* Copyright (c) 2014-2017 Godot Engine contributors (cf. AUTHORS.md) */
/* */
/* Permission is hereby granted, free of charge, to any person obtaining */
/* a copy of this software and associated documentation files (the */
/* "Software"), to deal in the Software without restriction, including */
/* without limitation the rights to use, copy, modify, merge, publish, */
/* distribute, sublicense, and/or sell copies of the Software, and to */
/* permit persons to whom the Software is furnished to do so, subject to */
/* the following conditions: */
/* */
/* The above copyright notice and this permission notice shall be */
/* included in all copies or substantial portions of the Software. */
/* */
/* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, */
/* EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF */
/* MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.*/
/* IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY */
/* CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, */
/* TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE */
/* SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE. */
/*************************************************************************/
#include "memory.h"
#include "copymem.h"
#include "core/safe_refcount.h"
#include "error_macros.h"
#include <stdio.h>
#include <stdlib.h>
void *operator new(size_t p_size, const char *p_description) {
return Memory::alloc_static(p_size, false);
}
void *operator new(size_t p_size, void *(*p_allocfunc)(size_t p_size)) {
return p_allocfunc(p_size);
}
#ifdef DEBUG_ENABLED
size_t Memory::mem_usage = 0;
size_t Memory::max_usage = 0;
#ifdef DEBUG_MEMORY_TAGGING
#define MEM_UNINIT_TAG 0xEA
#define MEM_RELEASED_TAG 0xAE
#endif
#define PREPAD true
#else
#define PREPAD p_pad_align
#endif
uint64_t Memory::alloc_count = 0;
void *Memory::alloc_static(size_t p_bytes, bool p_pad_align) {
void *mem = malloc(p_bytes + (PREPAD ? PAD_ALIGN : 0));
ERR_FAIL_COND_V(!mem, NULL);
atomic_increment(&alloc_count);
if (PREPAD) {
#ifdef DEBUG_ENABLED
mem_usage += p_bytes;
if (mem_usage > max_usage) {
max_usage = mem_usage;
}
#endif
uint64_t *s = (uint64_t *)mem;
*s = p_bytes;
uint8_t *s8 = (uint8_t *)mem + PAD_ALIGN;
#if defined DEBUG_ENABLED && defined DEBUG_MEMORY_TAGGING
memset(s8, MEM_UNINIT_TAG, p_bytes);
#endif
return s8;
} else {
return mem;
}
}
void *Memory::realloc_static(void *p_memory, size_t p_bytes, bool p_pad_align) {
if (p_memory == NULL) {
return alloc_static(p_bytes, p_pad_align);
}
uint8_t *mem = (uint8_t *)p_memory;
if (PREPAD) {
mem -= PAD_ALIGN;
uint64_t *s = (uint64_t *)mem;
if (p_bytes == 0) {
#ifdef DEBUG_ENABLED
mem_usage -= *s;
#ifdef DEBUG_MEMORY_TAGGING
memset(mem, MEM_RELEASED_TAG, PAD_ALIGN + *s);
#endif
#endif
free(mem);
return NULL;
} else {
#if defined DEBUG_ENABLED && defined DEBUG_MEMORY_TAGGING
if (p_bytes < *s) {
memset(mem + PAD_ALIGN + p_bytes, MEM_RELEASED_TAG, *s - p_bytes);
}
#endif
mem = (uint8_t *)realloc(mem, p_bytes + PAD_ALIGN);
ERR_FAIL_COND_V(!mem, NULL);
s = (uint64_t *)mem;
#ifdef DEBUG_ENABLED
mem_usage -= *s;
mem_usage += p_bytes;
#ifdef DEBUG_MEMORY_TAGGING
if (p_bytes > *s) {
memset(mem + PAD_ALIGN + *s, MEM_UNINIT_TAG, p_bytes - *s);
}
#endif
#endif
*s = p_bytes;
return mem + PAD_ALIGN;
}
} else {
mem = (uint8_t *)realloc(mem, p_bytes);
ERR_FAIL_COND_V(mem == NULL && p_bytes > 0, NULL);
return mem;
}
}
void Memory::free_static(void *p_ptr, bool p_pad_align) {
ERR_FAIL_COND(p_ptr == NULL);
uint8_t *mem = (uint8_t *)p_ptr;
if (PREPAD) {
mem -= PAD_ALIGN;
#ifdef DEBUG_ENABLED
const uint64_t s = *((uint64_t *)mem);
mem_usage -= s;
#ifdef DEBUG_MEMORY_TAGGING
memset(mem, MEM_RELEASED_TAG, PAD_ALIGN + s);
#endif
#endif
}
atomic_decrement(&alloc_count);
free(mem);
}
size_t Memory::get_mem_available() {
return 0xFFFFFFFFFFFFF;
}
size_t Memory::get_mem_usage() {
#ifdef DEBUG_ENABLED
return mem_usage;
#else
return 0;
#endif
}
size_t Memory::get_mem_max_usage() {
#ifdef DEBUG_ENABLED
return max_usage;
#else
return 0;
#endif
}
_GlobalNil::_GlobalNil() {
color = 1;
left = this;
right = this;
parent = this;
}
_GlobalNil _GlobalNilClass::_nil;