virtualx-engine/core/rid_handle.cpp
lawnjelly 130cc36a88 Improve locking safety for RID handles builds
Additional locks are added. This is primarily to cover a potential race condition where the pool is resized from another thread during a get operation.
2022-04-23 09:09:50 +01:00

306 lines
10 KiB
C++

/*************************************************************************/
/* rid_handle.cpp */
/*************************************************************************/
/* This file is part of: */
/* GODOT ENGINE */
/* https://godotengine.org */
/*************************************************************************/
/* Copyright (c) 2007-2022 Juan Linietsky, Ariel Manzur. */
/* Copyright (c) 2014-2022 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 "rid_handle.h"
#ifdef RID_HANDLES_ENABLED
#include "core/os/memory.h"
#include "core/print_string.h"
#include "core/ustring.h"
// This define will flag up an error when get() or getptr() is called with a NULL object.
// These calls should more correctly be made as get_or_null().
// #define RID_HANDLE_FLAG_NULL_GETS
RID_Database g_rid_database;
RID_Data::~RID_Data() {
}
void RID_OwnerBase::init_rid() {
// NOOP
}
RID_OwnerBase::~RID_OwnerBase() {
_shutdown = true;
}
void RID_OwnerBase::_rid_print(const char *pszType, String sz, const RID &p_rid) {
String tn = pszType;
print_line(tn + " : " + sz + " " + itos(p_rid._id) + " [ " + itos(p_rid._revision) + " ]");
}
RID_Database::RID_Database() {
// request first element so the handles start from 1
uint32_t dummy;
_pool.request(dummy);
}
RID_Database::~RID_Database() {
}
String RID_Database::_rid_to_string(const RID &p_rid, const PoolElement &p_pe) const {
String s = "RID id=" + itos(p_rid._id);
s += " [ rev " + itos(p_rid._revision) + " ], ";
s += "PE [ rev " + itos(p_pe.revision) + " ] ";
#ifdef RID_HANDLE_ALLOCATION_TRACKING_ENABLED
if (p_pe.filename) {
s += String(p_pe.filename).get_file() + " ";
}
s += "line " + itos(p_pe.line_number);
if (p_pe.previous_filename) {
s += " ( prev ";
s += String(p_pe.previous_filename).get_file() + " ";
s += "line " + itos(p_pe.previous_line_number) + " )";
}
#endif
return s;
}
void RID_Database::preshutdown() {
#ifdef RID_HANDLE_ALLOCATION_TRACKING_ENABLED
for (uint32_t n = 0; n < _pool.active_size(); n++) {
uint32_t id = _pool.get_active_id(n);
// ignore zero as it is a dummy
if (!id) {
continue;
}
PoolElement &pe = _pool[id];
if (pe.data) {
if (pe.data->_owner) {
const char *tn = pe.data->_owner->get_typename();
// does it already exist?
bool found = false;
for (unsigned int i = 0; i < _owner_names.size(); i++) {
if (_owner_names[i] == tn) {
found = true;
pe.owner_name_id = i;
}
}
if (!found) {
pe.owner_name_id = _owner_names.size();
_owner_names.push_back(tn);
}
}
}
}
#endif
}
void RID_Database::register_leak(uint32_t p_line_number, uint32_t p_owner_name_id, const char *p_filename) {
// does the leak exist already?
for (unsigned int n = 0; n < _leaks.size(); n++) {
Leak &leak = _leaks[n];
if ((leak.line_number == p_line_number) && (leak.filename == p_filename) && (leak.owner_name_id == p_owner_name_id)) {
leak.num_objects_leaked += 1;
return;
}
}
Leak leak;
leak.filename = p_filename;
leak.line_number = p_line_number;
leak.owner_name_id = p_owner_name_id;
leak.num_objects_leaked = 1;
_leaks.push_back(leak);
}
void RID_Database::shutdown() {
// free the first dummy element, so we don't report a false leak
_pool.free(0);
// print leaks
if (_pool.active_size()) {
ERR_PRINT("RID_Database leaked " + itos(_pool.active_size()) + " objects at exit.");
#ifdef RID_HANDLE_ALLOCATION_TRACKING_ENABLED
for (uint32_t n = 0; n < _pool.active_size(); n++) {
const PoolElement &pe = _pool.get_active(n);
register_leak(pe.line_number, pe.owner_name_id, pe.filename);
}
#endif
}
#ifdef RID_HANDLE_ALLOCATION_TRACKING_ENABLED
for (uint32_t n = 0; n < _leaks.size(); n++) {
const Leak &leak = _leaks[n];
const char *tn = "RID_Owner unknown";
if (_owner_names.size()) {
tn = _owner_names[leak.owner_name_id];
}
const char *fn = "Filename unknown";
if (leak.filename) {
fn = leak.filename;
}
_err_print_error(tn, fn, leak.line_number, itos(leak.num_objects_leaked) + " RID objects leaked");
}
#endif
_shutdown = true;
}
void RID_Database::handle_make_rid(RID &r_rid, RID_Data *p_data, RID_OwnerBase *p_owner) {
ERR_FAIL_COND_MSG(_shutdown, "RID_Database make_rid use after shutdown.");
ERR_FAIL_COND_MSG(!p_data, "RID_Database make_rid, data is empty.");
bool data_was_empty = true;
_mutex.lock();
PoolElement *pe = _pool.request(r_rid._id);
data_was_empty = !pe->data;
pe->data = p_data;
p_data->_owner = p_owner;
pe->revision = pe->revision + 1;
r_rid._revision = pe->revision;
#ifdef RID_HANDLE_ALLOCATION_TRACKING_ENABLED
// make a note of the previous allocation - this isn't super necessary
// but can pinpoint source allocations when dangling RIDs occur.
pe->previous_filename = pe->filename;
pe->previous_line_number = pe->line_number;
pe->line_number = 0;
pe->filename = nullptr;
#endif
_mutex.unlock();
ERR_FAIL_COND_MSG(!data_was_empty, "RID_Database make_rid, previous data was not empty.");
}
RID_Data *RID_Database::handle_get(const RID &p_rid) const {
RID_Data *data = handle_get_or_null(p_rid);
#ifdef RID_HANDLE_FLAG_NULL_GETS
ERR_FAIL_COND_V_MSG(!data, nullptr, "RID_Database get is NULL");
#endif
return data;
}
RID_Data *RID_Database::handle_getptr(const RID &p_rid) const {
RID_Data *data = handle_get_or_null(p_rid);
#ifdef RID_HANDLE_FLAG_NULL_GETS
ERR_FAIL_COND_V_MSG(!data, nullptr, "RID_Database getptr is NULL");
#endif
return data;
}
RID_Data *RID_Database::handle_get_or_null(const RID &p_rid) const {
if (p_rid.is_valid()) {
ERR_FAIL_COND_V_MSG(_shutdown, nullptr, "RID_Database get_or_null after shutdown.");
MutexLock lock(_mutex);
// The if statement is to allow breakpointing without a recompile.
if (p_rid._id >= _pool.pool_reserved_size()) {
ERR_FAIL_COND_V_MSG(p_rid._id >= _pool.pool_reserved_size(), nullptr, "RID_Database get_or_null, RID id was outside pool size.");
}
const PoolElement &pe = _pool[p_rid._id];
if (pe.revision != p_rid._revision) {
ERR_FAIL_COND_V_MSG(pe.revision != p_rid._revision, nullptr, "RID get_or_null, revision is incorrect, possible dangling RID. " + _rid_to_string(p_rid, pe));
}
return pe.data;
}
return nullptr;
}
bool RID_Database::handle_is_owner(const RID &p_rid, const RID_OwnerBase *p_owner) const {
if (p_rid.is_valid()) {
ERR_FAIL_COND_V_MSG(_shutdown, false, "RID_Database handle_is_owner after shutdown.");
MutexLock lock(_mutex);
// The if statement is to allow breakpointing without a recompile.
if (p_rid._id >= _pool.pool_reserved_size()) {
ERR_FAIL_COND_V_MSG(p_rid._id >= _pool.pool_reserved_size(), false, "RID_Database handle_is_owner, RID id was outside pool size.");
}
const PoolElement &pe = _pool[p_rid._id];
if (pe.revision != p_rid._revision) {
ERR_FAIL_COND_V_MSG(pe.revision != p_rid._revision, false, "RID handle_is_owner, revision is incorrect, possible dangling RID. " + _rid_to_string(p_rid, pe));
}
return pe.data->_owner == p_owner;
}
return false;
}
void RID_Database::handle_free(const RID &p_rid) {
ERR_FAIL_COND_MSG(_shutdown, "RID_Database free after shutdown.");
bool revision_correct = true;
{
MutexLock lock(_mutex);
ERR_FAIL_COND_MSG(p_rid._id >= _pool.pool_reserved_size(), "RID_Database free, RID id was outside pool size.");
PoolElement &pe = _pool[p_rid._id];
revision_correct = pe.revision == p_rid._revision;
// mark the data as zero, which indicates unused element
if (revision_correct) {
pe.data->_owner = nullptr;
pe.data = nullptr;
_pool.free(p_rid._id);
}
}
ERR_FAIL_COND_MSG(!revision_correct, "RID_Database free, revision is incorrect, object possibly freed more than once.");
}
RID RID_Database::prime(const RID &p_rid, int p_line_number, const char *p_filename) {
#ifdef RID_HANDLE_ALLOCATION_TRACKING_ENABLED
if (p_rid.is_valid()) {
ERR_FAIL_COND_V_MSG(_shutdown, p_rid, "RID_Database prime after shutdown.");
ERR_FAIL_COND_V_MSG(p_rid._id >= _pool.pool_reserved_size(), p_rid, "RID_Database prime, RID id was outside pool size.");
// We could also probably get away without using a lock here if purely for debugging, and not for release editor / templates.
MutexLock lock(_mutex);
PoolElement &pe = _pool[p_rid._id];
ERR_FAIL_COND_V_MSG(pe.revision != p_rid._revision, p_rid, "RID_Database prime, revision is incorrect, object possibly freed before use.");
pe.line_number = p_line_number;
pe.filename = p_filename;
}
#endif
return p_rid;
}
#endif // RID_HANDLES_ENABLED