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Avoid interaction issues between resource loading threads

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This commit is contained in:
Pedro J. Estébanez 2023-03-05 01:09:18 +01:00
parent c80a2b4fe9
commit 8983b20ccd
10 changed files with 461 additions and 392 deletions
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47
core/io/resource_format_binary.cpp
View file

@ -445,13 +445,12 @@ Error ResourceLoaderBinary::parse_variant(Variant &r_v) {
WARN_PRINT("Broken external resource! (index out of size)");
r_v = Variant();
} else {
if (external_resources[erindex].cache.is_null()) {
//cache not here yet, wait for it?
if (use_sub_threads) {
Error err;
external_resources.write[erindex].cache = ResourceLoader::load_threaded_get(external_resources[erindex].path, &err);
if (err != OK || external_resources[erindex].cache.is_null()) {
Ref<ResourceLoader::LoadToken> &load_token = external_resources.write[erindex].load_token;
if (load_token.is_valid()) { // If not valid, it's OK since then we know this load accepts broken dependencies.
Error err;
Ref<Resource> res = ResourceLoader::_load_complete(*load_token.ptr(), &err);
if (res.is_null()) {
if (!ResourceLoader::is_cleaning_tasks()) {
if (!ResourceLoader::get_abort_on_missing_resources()) {
ResourceLoader::notify_dependency_error(local_path, external_resources[erindex].path, external_resources[erindex].type);
} else {
@ -459,12 +458,11 @@ Error ResourceLoaderBinary::parse_variant(Variant &r_v) {
ERR_FAIL_V_MSG(error, "Can't load dependency: " + external_resources[erindex].path + ".");
}
}
} else {
r_v = res;
}
}
r_v = external_resources[erindex].cache;
}
} break;
default: {
ERR_FAIL_V(ERR_FILE_CORRUPT);
@ -684,28 +682,13 @@ Error ResourceLoaderBinary::load() {
}
external_resources.write[i].path = path; //remap happens here, not on load because on load it can actually be used for filesystem dock resource remap
if (!use_sub_threads) {
external_resources.write[i].cache = ResourceLoader::load(path, external_resources[i].type);
if (external_resources[i].cache.is_null()) {
if (!ResourceLoader::get_abort_on_missing_resources()) {
ResourceLoader::notify_dependency_error(local_path, path, external_resources[i].type);
} else {
error = ERR_FILE_MISSING_DEPENDENCIES;
ERR_FAIL_V_MSG(error, "Can't load dependency: " + path + ".");
}
}
} else {
Error err = ResourceLoader::load_threaded_request(path, external_resources[i].type, use_sub_threads, ResourceFormatLoader::CACHE_MODE_REUSE, local_path);
if (err != OK) {
if (!ResourceLoader::get_abort_on_missing_resources()) {
ResourceLoader::notify_dependency_error(local_path, path, external_resources[i].type);
} else {
error = ERR_FILE_MISSING_DEPENDENCIES;
ERR_FAIL_V_MSG(error, "Can't load dependency: " + path + ".");
}
external_resources.write[i].load_token = ResourceLoader::_load_start(path, external_resources[i].type, use_sub_threads ? ResourceLoader::LOAD_THREAD_DISTRIBUTE : ResourceLoader::LOAD_THREAD_FROM_CURRENT, ResourceFormatLoader::CACHE_MODE_REUSE);
if (!external_resources[i].load_token.is_valid()) {
if (!ResourceLoader::get_abort_on_missing_resources()) {
ResourceLoader::notify_dependency_error(local_path, path, external_resources[i].type);
} else {
error = ERR_FILE_MISSING_DEPENDENCIES;
ERR_FAIL_V_MSG(error, "Can't load dependency: " + path + ".");
}
}
}

2
core/io/resource_format_binary.h
View file

@ -60,7 +60,7 @@ class ResourceLoaderBinary {
String path;
String type;
ResourceUID::ID uid = ResourceUID::INVALID_ID;
Ref<Resource> cache;
Ref<ResourceLoader::LoadToken> load_token;
};
bool using_named_scene_ids = false;

642
core/io/resource_loader.cpp
View file

@ -202,20 +202,72 @@ void ResourceFormatLoader::_bind_methods() {
///////////////////////////////////
// This should be robust enough to be called redundantly without issues.
void ResourceLoader::LoadToken::clear() {
thread_load_mutex.lock();
Thread *thread_to_destroy = nullptr;
if (!local_path.is_empty()) { // Empty is used for the special case where the load task is not registered.
DEV_ASSERT(thread_load_tasks.has(local_path));
ThreadLoadTask &load_task = thread_load_tasks[local_path];
thread_to_destroy = load_task.thread;
load_task.thread = nullptr;
thread_load_tasks.erase(local_path);
local_path.clear();
}
if (!user_path.is_empty()) {
DEV_ASSERT(user_load_tokens.has(user_path));
user_load_tokens.erase(user_path);
user_path.clear();
}
thread_load_mutex.unlock();
// If thread is unused, destroy it here, locally, now the token data is consistent.
if (thread_to_destroy) {
if (thread_to_destroy->is_started()) {
thread_to_destroy->wait_to_finish();
}
memdelete(thread_to_destroy);
}
}
ResourceLoader::LoadToken::~LoadToken() {
clear();
}
Ref<Resource> ResourceLoader::_load(const String &p_path, const String &p_original_path, const String &p_type_hint, ResourceFormatLoader::CacheMode p_cache_mode, Error *r_error, bool p_use_sub_threads, float *r_progress) {
bool found = false;
load_nesting++;
if (load_paths_stack.size()) {
thread_load_mutex.lock();
HashMap<String, ThreadLoadTask>::Iterator E = thread_load_tasks.find(load_paths_stack[load_paths_stack.size() - 1]);
if (E) {
E->value.sub_tasks.insert(p_path);
}
thread_load_mutex.unlock();
}
load_paths_stack.push_back(p_path);
// Try all loaders and pick the first match for the type hint
bool found = false;
Ref<Resource> res;
for (int i = 0; i < loader_count; i++) {
if (!loader[i]->recognize_path(p_path, p_type_hint)) {
continue;
}
found = true;
Ref<Resource> res = loader[i]->load(p_path, !p_original_path.is_empty() ? p_original_path : p_path, r_error, p_use_sub_threads, r_progress, p_cache_mode);
if (res.is_null()) {
continue;
res = loader[i]->load(p_path, !p_original_path.is_empty() ? p_original_path : p_path, r_error, p_use_sub_threads, r_progress, p_cache_mode);
if (!res.is_null()) {
break;
}
}
load_paths_stack.resize(load_paths_stack.size() - 1);
load_nesting--;
if (!res.is_null()) {
return res;
}
@ -232,47 +284,45 @@ Ref<Resource> ResourceLoader::_load(const String &p_path, const String &p_origin
void ResourceLoader::_thread_load_function(void *p_userdata) {
ThreadLoadTask &load_task = *(ThreadLoadTask *)p_userdata;
load_task.loader_id = Thread::get_caller_id();
if (load_task.cond_var) {
//this is an actual thread, so wait for Ok from semaphore
thread_load_semaphore->wait(); //wait until its ok to start loading
// Thread-safe either if it's the current thread or a brand new one.
if (load_task.first_in_stack) {
if (!load_task.dependent_path.is_empty()) {
load_paths_stack.push_back(load_task.dependent_path);
}
} else {
DEV_ASSERT(load_task.dependent_path.is_empty());
}
load_task.resource = _load(load_task.remapped_path, load_task.remapped_path != load_task.local_path ? load_task.local_path : String(), load_task.type_hint, load_task.cache_mode, &load_task.error, load_task.use_sub_threads, &load_task.progress);
// --
Ref<Resource> res = _load(load_task.remapped_path, load_task.remapped_path != load_task.local_path ? load_task.local_path : String(), load_task.type_hint, load_task.cache_mode, &load_task.error, load_task.use_sub_threads, &load_task.progress);
thread_load_mutex.lock();
load_task.resource = res;
load_task.progress = 1.0; //it was fully loaded at this point, so force progress to 1.0
thread_load_mutex->lock();
if (load_task.error != OK) {
load_task.status = THREAD_LOAD_FAILED;
} else {
load_task.status = THREAD_LOAD_LOADED;
}
if (load_task.cond_var) {
if (load_task.start_next && thread_waiting_count > 0) {
thread_waiting_count--;
//thread loading count remains constant, this ends but another one begins
thread_load_semaphore->post();
} else {
thread_loading_count--; //no threads waiting, just reduce loading count
}
print_lt("END: load count: " + itos(thread_loading_count) + " / wait count: " + itos(thread_waiting_count) + " / suspended count: " + itos(thread_suspended_count) + " / active: " + itos(thread_loading_count - thread_suspended_count));
load_task.cond_var->notify_all();
memdelete(load_task.cond_var);
load_task.cond_var = nullptr;
}
if (load_task.resource.is_valid()) {
load_task.resource->set_path(load_task.local_path);
if (load_task.cache_mode != ResourceFormatLoader::CACHE_MODE_IGNORE) {
load_task.resource->set_path(load_task.local_path);
}
if (load_task.xl_remapped) {
load_task.resource->set_as_translation_remapped(true);
}
#ifdef TOOLS_ENABLED
load_task.resource->set_edited(false);
if (timestamp_on_load) {
uint64_t mt = FileAccess::get_modified_time(load_task.remapped_path);
@ -286,7 +336,16 @@ void ResourceLoader::_thread_load_function(void *p_userdata) {
}
}
thread_load_mutex->unlock();
if (load_nesting == 0) {
thread_active_count--;
if (thread_waiting_count) {
thread_active_cond_var.notify_one();
}
}
print_lt("END: load count: " + itos(thread_active_count + thread_suspended_count) + " / wait count: " + itos(thread_waiting_count) + " / suspended count: " + itos(thread_suspended_count) + " / active: " + itos(thread_active_count));
thread_load_mutex.unlock();
}
static String _validate_local_path(const String &p_path) {
@ -299,91 +358,158 @@ static String _validate_local_path(const String &p_path) {
return ProjectSettings::get_singleton()->localize_path(p_path);
}
}
Error ResourceLoader::load_threaded_request(const String &p_path, const String &p_type_hint, bool p_use_sub_threads, ResourceFormatLoader::CacheMode p_cache_mode, const String &p_source_resource) {
String local_path = _validate_local_path(p_path);
thread_load_mutex->lock();
if (!p_source_resource.is_empty()) {
//must be loading from this resource
if (!thread_load_tasks.has(p_source_resource)) {
thread_load_mutex->unlock();
ERR_FAIL_V_MSG(ERR_INVALID_PARAMETER, "There is no thread loading source resource '" + p_source_resource + "'.");
}
//must not be already added as s sub tasks
if (thread_load_tasks[p_source_resource].sub_tasks.has(local_path)) {
thread_load_mutex->unlock();
ERR_FAIL_V_MSG(ERR_INVALID_PARAMETER, "Thread loading source resource '" + p_source_resource + "' already is loading '" + local_path + "'.");
}
}
if (thread_load_tasks.has(local_path)) {
thread_load_tasks[local_path].requests++;
if (!p_source_resource.is_empty()) {
thread_load_tasks[p_source_resource].sub_tasks.insert(local_path);
}
thread_load_mutex->unlock();
Error ResourceLoader::load_threaded_request(const String &p_path, const String &p_type_hint, bool p_use_sub_threads, ResourceFormatLoader::CacheMode p_cache_mode) {
thread_load_mutex.lock();
if (user_load_tokens.has(p_path)) {
print_verbose("load_threaded_request(): Another threaded load for resource path '" + p_path + "' has been initiated. Not an error.");
user_load_tokens[p_path]->reference(); // Additional request.
thread_load_mutex.unlock();
return OK;
}
user_load_tokens[p_path] = nullptr;
thread_load_mutex.unlock();
Ref<ResourceLoader::LoadToken> token = _load_start(p_path, p_type_hint, p_use_sub_threads ? LOAD_THREAD_DISTRIBUTE : LOAD_THREAD_SPAWN_SINGLE, p_cache_mode);
if (token.is_valid()) {
thread_load_mutex.lock();
token->user_path = p_path;
token->reference(); // First request.
user_load_tokens[p_path] = token.ptr();
print_lt("REQUEST: user load tokens: " + itos(user_load_tokens.size()));
thread_load_mutex.unlock();
return OK;
} else {
return FAILED;
}
}
Ref<Resource> ResourceLoader::load(const String &p_path, const String &p_type_hint, ResourceFormatLoader::CacheMode p_cache_mode, Error *r_error) {
if (r_error) {
*r_error = OK;
}
Ref<LoadToken> load_token = _load_start(p_path, p_type_hint, LOAD_THREAD_FROM_CURRENT, p_cache_mode);
if (!load_token.is_valid()) {
if (r_error) {
*r_error = FAILED;
}
return Ref<Resource>();
}
Ref<Resource> res = _load_complete(*load_token.ptr(), r_error);
return res;
}
Ref<ResourceLoader::LoadToken> ResourceLoader::_load_start(const String &p_path, const String &p_type_hint, LoadThreadMode p_thread_mode, ResourceFormatLoader::CacheMode p_cache_mode) {
String local_path = _validate_local_path(p_path);
Ref<LoadToken> load_token;
bool must_not_register = false;
ThreadLoadTask unregistered_load_task; // Once set, must be valid up to the call to do the load.
ThreadLoadTask *load_task_ptr = nullptr;
bool run_on_current_thread = false;
{
MutexLock thread_load_lock(thread_load_mutex);
if (thread_load_tasks.has(local_path)) {
load_token = Ref<LoadToken>(thread_load_tasks[local_path].load_token);
if (!load_token.is_valid()) {
// The token is dying (reached 0 on another thread).
// Ensure it's killed now so the path can be safely reused right away.
thread_load_tasks[local_path].load_token->clear();
} else {
if (p_cache_mode != ResourceFormatLoader::CACHE_MODE_IGNORE) {
return load_token;
}
}
}
load_token.instantiate();
load_token->local_path = local_path;
//create load task
{
ThreadLoadTask load_task;
ThreadLoadTask load_task;
load_task.requests = 1;
load_task.remapped_path = _path_remap(local_path, &load_task.xl_remapped);
load_task.local_path = local_path;
load_task.type_hint = p_type_hint;
load_task.cache_mode = p_cache_mode;
load_task.use_sub_threads = p_use_sub_threads;
{ //must check if resource is already loaded before attempting to load it in a thread
if (load_task.loader_id == Thread::get_caller_id()) {
thread_load_mutex->unlock();
ERR_FAIL_V_MSG(ERR_INVALID_PARAMETER, "Attempted to load a resource already being loaded from this thread, cyclic reference?");
load_task.remapped_path = _path_remap(local_path, &load_task.xl_remapped);
load_task.load_token = load_token.ptr();
load_task.local_path = local_path;
load_task.type_hint = p_type_hint;
load_task.cache_mode = p_cache_mode;
load_task.use_sub_threads = p_thread_mode == LOAD_THREAD_DISTRIBUTE;
if (p_cache_mode != ResourceFormatLoader::CACHE_MODE_IGNORE) {
Ref<Resource> existing = ResourceCache::get_ref(local_path);
if (existing.is_valid()) {
//referencing is fine
load_task.resource = existing;
load_task.status = THREAD_LOAD_LOADED;
load_task.progress = 1.0;
thread_load_tasks[local_path] = load_task;
return load_token;
}
}
Ref<Resource> existing = ResourceCache::get_ref(local_path);
if (existing.is_valid()) {
//referencing is fine
load_task.resource = existing;
load_task.status = THREAD_LOAD_LOADED;
load_task.progress = 1.0;
// If we want to ignore cache, but there's another task loading it, we can't add this one to the map and we also have to finish unconditionally synchronously.
must_not_register = thread_load_tasks.has(local_path) && p_cache_mode == ResourceFormatLoader::CACHE_MODE_IGNORE;
if (must_not_register) {
load_token->local_path.clear();
unregistered_load_task = load_task;
} else {
thread_load_tasks[local_path] = load_task;
}
load_task_ptr = must_not_register ? &unregistered_load_task : &thread_load_tasks[local_path];
}
if (!p_source_resource.is_empty()) {
thread_load_tasks[p_source_resource].sub_tasks.insert(local_path);
print_lt("REQUEST: load count: " + itos(thread_active_count + thread_suspended_count) + " / wait count: " + itos(thread_waiting_count) + " / suspended count: " + itos(thread_suspended_count) + " / active: " + itos(thread_active_count));
run_on_current_thread = must_not_register || p_thread_mode == LOAD_THREAD_FROM_CURRENT;
if (!run_on_current_thread && thread_active_count >= thread_active_max && load_nesting > 0) {
// No free slots for another thread, but this one is already active, so keep working here.
run_on_current_thread = true;
}
thread_load_tasks[local_path] = load_task;
}
load_task_ptr->first_in_stack = run_on_current_thread ? load_nesting == 0 : true;
ThreadLoadTask &load_task = thread_load_tasks[local_path];
if (load_task_ptr->first_in_stack) {
if (!run_on_current_thread && load_paths_stack.size()) {
// The paths stack is lost across thread boundaries, so we have to remember what was the topmost path.
load_task_ptr->dependent_path = load_paths_stack[load_paths_stack.size() - 1];
}
if (thread_active_count >= thread_active_max) {
// Either the current or a new thread needs to wait for a free slot to become active.
thread_waiting_count++;
do {
thread_active_cond_var.wait(thread_load_lock);
} while (thread_active_count >= thread_active_max);
thread_waiting_count--;
}
thread_active_count++;
}
if (load_task.resource.is_null()) { //needs to be loaded in thread
if (cleaning_tasks) {
load_task_ptr->status = THREAD_LOAD_FAILED;
return load_token;
}
load_task.cond_var = memnew(ConditionVariable);
if (thread_loading_count < thread_load_max) {
thread_loading_count++;
thread_load_semaphore->post(); //we have free threads, so allow one
if (run_on_current_thread) {
load_task_ptr->loader_id = Thread::get_caller_id();
if (must_not_register) {
load_token->res_if_unregistered = load_task_ptr->resource;
}
} else {
thread_waiting_count++;
load_task_ptr->thread = memnew(Thread);
load_task_ptr->loader_id = load_task_ptr->thread->start(_thread_load_function, load_task_ptr);
}
print_lt("REQUEST: load count: " + itos(thread_loading_count) + " / wait count: " + itos(thread_waiting_count) + " / suspended count: " + itos(thread_suspended_count) + " / active: " + itos(thread_loading_count - thread_suspended_count));
load_task.thread = memnew(Thread);
load_task.thread->start(_thread_load_function, &thread_load_tasks[local_path]);
load_task.loader_id = load_task.thread->get_id();
}
thread_load_mutex->unlock();
if (run_on_current_thread) {
_thread_load_function(load_task_ptr);
}
return OK;
return load_token;
}
float ResourceLoader::_dependency_get_progress(const String &p_path) {
@ -409,13 +535,22 @@ float ResourceLoader::_dependency_get_progress(const String &p_path) {
}
ResourceLoader::ThreadLoadStatus ResourceLoader::load_threaded_get_status(const String &p_path, float *r_progress) {
String local_path = _validate_local_path(p_path);
MutexLock thread_load_lock(thread_load_mutex);
thread_load_mutex->lock();
if (!thread_load_tasks.has(local_path)) {
thread_load_mutex->unlock();
if (!user_load_tokens.has(p_path)) {
print_verbose("load_threaded_get_status(): No threaded load for resource path '" + p_path + "' has been initiated or its result has already been collected.");
return THREAD_LOAD_INVALID_RESOURCE;
}
String local_path = _validate_local_path(p_path);
if (!thread_load_tasks.has(local_path)) {
#ifdef DEV_ENABLED
CRASH_NOW();
#endif
// On non-dev, be defensive and at least avoid crashing (at this point at least).
return THREAD_LOAD_INVALID_RESOURCE;
}
ThreadLoadTask &load_task = thread_load_tasks[local_path];
ThreadLoadStatus status;
status = load_task.status;
@ -423,198 +558,115 @@ ResourceLoader::ThreadLoadStatus ResourceLoader::load_threaded_get_status(const
*r_progress = _dependency_get_progress(local_path);
}
thread_load_mutex->unlock();
return status;
}
Ref<Resource> ResourceLoader::load_threaded_get(const String &p_path, Error *r_error) {
String local_path = _validate_local_path(p_path);
MutexLock thread_load_lock(*thread_load_mutex);
if (!thread_load_tasks.has(local_path)) {
if (r_error) {
*r_error = ERR_INVALID_PARAMETER;
}
return Ref<Resource>();
if (r_error) {
*r_error = OK;
}
ThreadLoadTask &load_task = thread_load_tasks[local_path];
Ref<Resource> res;
{
MutexLock thread_load_lock(thread_load_mutex);
if (load_task.status == THREAD_LOAD_IN_PROGRESS) {
if (load_task.loader_id == Thread::get_caller_id()) {
// Load is in progress, but it's precisely this thread the one in charge.
// That means this is a cyclic load.
if (r_error) {
*r_error = ERR_BUSY;
}
return Ref<Resource>();
} else if (!load_task.cond_var) {
// Load is in progress, but a condition variable was never created for it.
// That happens when a load has been initiated with subthreads disabled,
// but now another load thread needs to interact with this one (either
// because of subthreads being used this time, or because it's simply a
// threaded load running on a different thread).
// Since we want to be notified when the load ends, we must create the
// condition variable now.
load_task.cond_var = memnew(ConditionVariable);
}
}
//cond var still exists, meaning it's still loading, request poll
if (load_task.cond_var) {
{
// As we got a cond var, this means we are going to have to wait
// until the sub-resource is done loading
//
// As this thread will become 'blocked' we should "exchange" its
// active status with a waiting one, to ensure load continues.
//
// This ensures loading is never blocked and that is also within
// the maximum number of active threads.
if (thread_waiting_count > 0) {
thread_waiting_count--;
thread_loading_count++;
thread_load_semaphore->post();
load_task.start_next = false; //do not start next since we are doing it here
}
thread_suspended_count++;
print_lt("GET: load count: " + itos(thread_loading_count) + " / wait count: " + itos(thread_waiting_count) + " / suspended count: " + itos(thread_suspended_count) + " / active: " + itos(thread_loading_count - thread_suspended_count));
}
bool still_valid = true;
bool was_thread = load_task.thread;
do {
load_task.cond_var->wait(thread_load_lock);
if (!thread_load_tasks.has(local_path)) { //may have been erased during unlock and this was always an invalid call
still_valid = false;
break;
}
} while (load_task.cond_var); // In case of spurious wakeup.
if (was_thread) {
thread_suspended_count--;
}
if (!still_valid) {
if (!user_load_tokens.has(p_path)) {
print_verbose("load_threaded_get(): No threaded load for resource path '" + p_path + "' has been initiated or its result has already been collected.");
if (r_error) {
*r_error = ERR_INVALID_PARAMETER;
}
return Ref<Resource>();
}
}
Ref<Resource> resource = load_task.resource;
if (r_error) {
*r_error = load_task.error;
}
load_task.requests--;
if (load_task.requests == 0) {
if (load_task.thread) { //thread may not have been used
load_task.thread->wait_to_finish();
memdelete(load_task.thread);
LoadToken *load_token = user_load_tokens[p_path];
if (!load_token) {
// This happens if requested from one thread and rapidly querying from another.
if (r_error) {
*r_error = ERR_BUSY;
}
return Ref<Resource>();
}
res = _load_complete_inner(*load_token, r_error, thread_load_lock);
if (load_token->unreference()) {
memdelete(load_token);
}
thread_load_tasks.erase(local_path);
}
return resource;
print_lt("GET: user load tokens: " + itos(user_load_tokens.size()));
return res;
}
Ref<Resource> ResourceLoader::load(const String &p_path, const String &p_type_hint, ResourceFormatLoader::CacheMode p_cache_mode, Error *r_error) {
Ref<Resource> ResourceLoader::_load_complete(LoadToken &p_load_token, Error *r_error) {
MutexLock thread_load_lock(thread_load_mutex);
return _load_complete_inner(p_load_token, r_error, thread_load_lock);
}
Ref<Resource> ResourceLoader::_load_complete_inner(LoadToken &p_load_token, Error *r_error, MutexLock<SafeBinaryMutex<BINARY_MUTEX_TAG>> &p_thread_load_lock) {
if (r_error) {
*r_error = ERR_CANT_OPEN;
*r_error = OK;
}
String local_path = _validate_local_path(p_path);
if (p_cache_mode != ResourceFormatLoader::CACHE_MODE_IGNORE) {
thread_load_mutex->lock();
//Is it already being loaded? poll until done
if (thread_load_tasks.has(local_path)) {
Error err = load_threaded_request(p_path, p_type_hint);
if (err != OK) {
if (r_error) {
*r_error = err;
}
thread_load_mutex->unlock();
return Ref<Resource>();
}
thread_load_mutex->unlock();
return load_threaded_get(p_path, r_error);
}
//Is it cached?
Ref<Resource> existing = ResourceCache::get_ref(local_path);
if (existing.is_valid()) {
thread_load_mutex->unlock();
if (!p_load_token.local_path.is_empty()) {
if (!thread_load_tasks.has(p_load_token.local_path)) {
#ifdef DEV_ENABLED
CRASH_NOW();
#endif
// On non-dev, be defensive and at least avoid crashing (at this point at least).
if (r_error) {
*r_error = OK;
*r_error = ERR_BUG;
}
return existing; //use cached
}
//load using task (but this thread)
ThreadLoadTask load_task;
load_task.requests = 1;
load_task.local_path = local_path;
load_task.remapped_path = _path_remap(local_path, &load_task.xl_remapped);
load_task.type_hint = p_type_hint;
load_task.cache_mode = p_cache_mode; //ignore
load_task.loader_id = Thread::get_caller_id();
thread_load_tasks[local_path] = load_task;
thread_load_mutex->unlock();
_thread_load_function(&thread_load_tasks[local_path]);
return load_threaded_get(p_path, r_error);
} else {
bool xl_remapped = false;
String path = _path_remap(local_path, &xl_remapped);
if (path.is_empty()) {
ERR_FAIL_V_MSG(Ref<Resource>(), "Remapping '" + local_path + "' failed.");
}
print_verbose("Loading resource: " + path);
float p;
Ref<Resource> res = _load(path, local_path, p_type_hint, p_cache_mode, r_error, false, &p);
if (res.is_null()) {
print_verbose("Failed loading resource: " + path);
return Ref<Resource>();
}
if (xl_remapped) {
res->set_as_translation_remapped(true);
ThreadLoadTask &load_task = thread_load_tasks[p_load_token.local_path];
if (load_task.status == THREAD_LOAD_IN_PROGRESS) {
if (load_task.loader_id == Thread::get_caller_id()) {
// Load is in progress, but it's precisely this thread the one in charge.
// That means this is a cyclic load.
if (r_error) {
*r_error = ERR_BUSY;
}
return Ref<Resource>();
} else if (!load_task.cond_var) {
// This is the first time some thread needs to wait for this one.
load_task.cond_var = memnew(ConditionVariable);
}
// Wait for load to complete.
thread_suspended_count++;
print_lt("GET: load count: " + itos(thread_active_count + thread_suspended_count) + " / wait count: " + itos(thread_waiting_count) + " / suspended count: " + itos(thread_suspended_count) + " / active: " + itos(thread_active_count));
do {
load_task.cond_var->wait(p_thread_load_lock);
DEV_ASSERT(thread_load_tasks.has(p_load_token.local_path) && p_load_token.get_reference_count());
} while (load_task.cond_var);
thread_suspended_count--;
}
#ifdef TOOLS_ENABLED
res->set_edited(false);
if (timestamp_on_load) {
uint64_t mt = FileAccess::get_modified_time(path);
//printf("mt %s: %lli\n",remapped_path.utf8().get_data(),mt);
res->set_last_modified_time(mt);
if (cleaning_tasks) {
load_task.resource = Ref<Resource>();
load_task.error = FAILED;
}
#endif
return res;
Ref<Resource> resource = load_task.resource;
if (r_error) {
*r_error = load_task.error;
}
return resource;
} else {
// Special case of an unregistered task.
// The resource should have been loaded by now.
Ref<Resource> resource = p_load_token.res_if_unregistered;
if (!resource.is_valid()) {
if (r_error) {
*r_error = FAILED;
}
}
return resource;
}
}
@ -958,32 +1010,43 @@ void ResourceLoader::clear_translation_remaps() {
}
void ResourceLoader::clear_thread_load_tasks() {
thread_load_mutex->lock();
// Bring the thing down as quickly as possible without causing deadlocks or leaks.
for (KeyValue<String, ResourceLoader::ThreadLoadTask> &E : thread_load_tasks) {
switch (E.value.status) {
case ResourceLoader::ThreadLoadStatus::THREAD_LOAD_LOADED: {
E.value.resource = Ref<Resource>();
} break;
thread_load_mutex.lock();
cleaning_tasks = true;
case ResourceLoader::ThreadLoadStatus::THREAD_LOAD_IN_PROGRESS: {
if (E.value.thread != nullptr) {
E.value.thread->wait_to_finish();
memdelete(E.value.thread);
E.value.thread = nullptr;
while (true) {
bool none_running = true;
if (thread_load_tasks.size()) {
for (KeyValue<String, ResourceLoader::ThreadLoadTask> &E : thread_load_tasks) {
if (E.value.status == THREAD_LOAD_IN_PROGRESS) {
if (E.value.cond_var) {
E.value.cond_var->notify_all();
memdelete(E.value.cond_var);
E.value.cond_var = nullptr;
}
none_running = false;
}
E.value.resource = Ref<Resource>();
} break;
case ResourceLoader::ThreadLoadStatus::THREAD_LOAD_FAILED:
default: {
// do nothing
}
}
if (none_running) {
break;
}
thread_active_cond_var.notify_all();
thread_load_mutex.unlock();
OS::get_singleton()->delay_usec(1000);
thread_load_mutex.lock();
}
for (KeyValue<String, LoadToken *> &E : user_load_tokens) {
memdelete(E.value);
}
user_load_tokens.clear();
thread_load_tasks.clear();
thread_load_mutex->unlock();
cleaning_tasks = false;
thread_load_mutex.unlock();
}
void ResourceLoader::load_path_remaps() {
@ -1080,21 +1143,20 @@ void ResourceLoader::remove_custom_loaders() {
}
}
void ResourceLoader::initialize() {
thread_load_mutex = memnew(SafeBinaryMutex<BINARY_MUTEX_TAG>);
thread_load_max = OS::get_singleton()->get_processor_count();
thread_loading_count = 0;
thread_waiting_count = 0;
thread_suspended_count = 0;
thread_load_semaphore = memnew(Semaphore);
bool ResourceLoader::is_cleaning_tasks() {
MutexLock lock(thread_load_mutex);
return cleaning_tasks;
}
void ResourceLoader::finalize() {
clear_thread_load_tasks();
memdelete(thread_load_mutex);
memdelete(thread_load_semaphore);
void ResourceLoader::initialize() {
thread_active_max = OS::get_singleton()->get_processor_count();
thread_active_count = 0;
thread_waiting_count = 0;
thread_suspended_count = 0;
}
void ResourceLoader::finalize() {}
ResourceLoadErrorNotify ResourceLoader::err_notify = nullptr;
void *ResourceLoader::err_notify_ud = nullptr;
@ -1105,16 +1167,22 @@ bool ResourceLoader::create_missing_resources_if_class_unavailable = false;
bool ResourceLoader::abort_on_missing_resource = true;
bool ResourceLoader::timestamp_on_load = false;
thread_local int ResourceLoader::load_nesting = 0;
thread_local Vector<String> ResourceLoader::load_paths_stack;
template <>
thread_local uint32_t SafeBinaryMutex<ResourceLoader::BINARY_MUTEX_TAG>::count = 0;
SafeBinaryMutex<ResourceLoader::BINARY_MUTEX_TAG> *ResourceLoader::thread_load_mutex = nullptr;
SafeBinaryMutex<ResourceLoader::BINARY_MUTEX_TAG> ResourceLoader::thread_load_mutex;
HashMap<String, ResourceLoader::ThreadLoadTask> ResourceLoader::thread_load_tasks;
Semaphore *ResourceLoader::thread_load_semaphore = nullptr;
ConditionVariable ResourceLoader::thread_active_cond_var;
int ResourceLoader::thread_loading_count = 0;
int ResourceLoader::thread_active_count = 0;
int ResourceLoader::thread_waiting_count = 0;
int ResourceLoader::thread_suspended_count = 0;
int ResourceLoader::thread_load_max = 0;
int ResourceLoader::thread_active_max = 0;
bool ResourceLoader::cleaning_tasks = false;
HashMap<String, ResourceLoader::LoadToken *> ResourceLoader::user_load_tokens;
SelfList<Resource>::List ResourceLoader::remapped_list;
HashMap<String, Vector<String>> ResourceLoader::translation_remaps;

47
core/io/resource_loader.h
View file

@ -107,9 +107,30 @@ public:
THREAD_LOAD_LOADED
};
enum LoadThreadMode {
LOAD_THREAD_FROM_CURRENT,
LOAD_THREAD_SPAWN_SINGLE,
LOAD_THREAD_DISTRIBUTE,
};
struct LoadToken : public RefCounted {
String local_path;
String user_path;
Ref<Resource> res_if_unregistered;
void clear();
virtual ~LoadToken();
};
static const int BINARY_MUTEX_TAG = 1;
static Ref<LoadToken> _load_start(const String &p_path, const String &p_type_hint, LoadThreadMode p_thread_mode, ResourceFormatLoader::CacheMode p_cache_mode);
static Ref<Resource> _load_complete(LoadToken &p_load_token, Error *r_error);
private:
static Ref<Resource> _load_complete_inner(LoadToken &p_load_token, Error *r_error, MutexLock<SafeBinaryMutex<BINARY_MUTEX_TAG>> &p_thread_load_lock);
static Ref<ResourceFormatLoader> loader[MAX_LOADERS];
static int loader_count;
static bool timestamp_on_load;
@ -129,8 +150,7 @@ private:
static SelfList<Resource>::List remapped_list;
friend class ResourceFormatImporter;
friend class ResourceInteractiveLoader;
// Internal load function.
static Ref<Resource> _load(const String &p_path, const String &p_original_path, const String &p_type_hint, ResourceFormatLoader::CacheMode p_cache_mode, Error *r_error, bool p_use_sub_threads, float *r_progress);
static ResourceLoadedCallback _loaded_callback;
@ -140,9 +160,12 @@ private:
struct ThreadLoadTask {
Thread *thread = nullptr;
Thread::ID loader_id = 0;
bool first_in_stack = false;
ConditionVariable *cond_var = nullptr;
LoadToken *load_token = nullptr;
String local_path;
String remapped_path;
String dependent_path;
String type_hint;
float progress = 0.0;
ThreadLoadStatus status = THREAD_LOAD_IN_PROGRESS;
@ -151,24 +174,28 @@ private:
Ref<Resource> resource;
bool xl_remapped = false;
bool use_sub_threads = false;
bool start_next = true;
int requests = 0;
HashSet<String> sub_tasks;
};
static void _thread_load_function(void *p_userdata);
static SafeBinaryMutex<BINARY_MUTEX_TAG> *thread_load_mutex;
static thread_local int load_nesting;
static thread_local Vector<String> load_paths_stack;
static SafeBinaryMutex<BINARY_MUTEX_TAG> thread_load_mutex;
static HashMap<String, ThreadLoadTask> thread_load_tasks;
static Semaphore *thread_load_semaphore;
static ConditionVariable thread_active_cond_var;
static int thread_active_count;
static int thread_waiting_count;
static int thread_loading_count;
static int thread_suspended_count;
static int thread_load_max;
static int thread_active_max;
static bool cleaning_tasks;
static HashMap<String, LoadToken *> user_load_tokens;
static float _dependency_get_progress(const String &p_path);
public:
static Error load_threaded_request(const String &p_path, const String &p_type_hint = "", bool p_use_sub_threads = false, ResourceFormatLoader::CacheMode p_cache_mode = ResourceFormatLoader::CACHE_MODE_REUSE, const String &p_source_resource = String());
static Error load_threaded_request(const String &p_path, const String &p_type_hint = "", bool p_use_sub_threads = false, ResourceFormatLoader::CacheMode p_cache_mode = ResourceFormatLoader::CACHE_MODE_REUSE);
static ThreadLoadStatus load_threaded_get_status(const String &p_path, float *r_progress = nullptr);
static Ref<Resource> load_threaded_get(const String &p_path, Error *r_error = nullptr);
@ -237,6 +264,8 @@ public:
static void set_create_missing_resources_if_class_unavailable(bool p_enable);
_FORCE_INLINE_ static bool is_creating_missing_resources_if_class_unavailable_enabled() { return create_missing_resources_if_class_unavailable; }
static bool is_cleaning_tasks();
static void initialize();
static void finalize();
};

19
core/os/mutex.h
View file

@ -119,8 +119,25 @@ class MutexLock {
public:
_ALWAYS_INLINE_ explicit MutexLock(const MutexT &p_mutex) :
lock(p_mutex.mutex){};
};
// This specialization is needed so manual locking and MutexLock can be used
// at the same time on a SafeBinaryMutex.
template <int Tag>
class MutexLock<SafeBinaryMutex<Tag>> {
friend class ConditionVariable;
std::unique_lock<std::mutex> lock;
public:
_ALWAYS_INLINE_ explicit MutexLock(const SafeBinaryMutex<Tag> &p_mutex) :
lock(p_mutex.mutex) {
}
SafeBinaryMutex<Tag>::count++;
};
_ALWAYS_INLINE_ ~MutexLock() {
SafeBinaryMutex<Tag>::count--;
};
};
using Mutex = MutexImpl<std::recursive_mutex>; // Recursive, for general use

5
core/os/thread.cpp
View file

@ -66,11 +66,12 @@ void Thread::callback(ID p_caller_id, const Settings &p_settings, Callback p_cal
}
}
void Thread::start(Thread::Callback p_callback, void *p_user, const Settings &p_settings) {
ERR_FAIL_COND_MSG(id != UNASSIGNED_ID, "A Thread object has been re-started without wait_to_finish() having been called on it.");
Thread::ID Thread::start(Thread::Callback p_callback, void *p_user, const Settings &p_settings) {
ERR_FAIL_COND_V_MSG(id != UNASSIGNED_ID, UNASSIGNED_ID, "A Thread object has been re-started without wait_to_finish() having been called on it.");
id = id_counter.increment();
std::thread new_thread(&Thread::callback, id, p_settings, p_callback, p_user);
thread.swap(new_thread);
return id;
}
bool Thread::is_started() const {

2
core/os/thread.h
View file

@ -109,7 +109,7 @@ public:
static Error set_name(const String &p_name);
void start(Thread::Callback p_callback, void *p_user, const Settings &p_settings = Settings());
ID start(Thread::Callback p_callback, void *p_user, const Settings &p_settings = Settings());
bool is_started() const;
///< waits until thread is finished, and deallocates it.
void wait_to_finish();

4
main/main.cpp
View file

@ -3446,6 +3446,8 @@ void Main::cleanup(bool p_force) {
movie_writer->end();
}
ResourceLoader::clear_thread_load_tasks();
ResourceLoader::remove_custom_loaders();
ResourceSaver::remove_custom_savers();
@ -3462,8 +3464,6 @@ void Main::cleanup(bool p_force) {
ResourceLoader::clear_translation_remaps();
ResourceLoader::clear_path_remaps();
ResourceLoader::clear_thread_load_tasks();
ScriptServer::finish_languages();
// Sync pending commands that may have been queued from a different thread during ScriptServer finalization

83
scene/resources/resource_format_text.cpp
View file

@ -150,32 +150,31 @@ Error ResourceLoaderText::_parse_ext_resource(VariantParser::Stream *p_stream, R
String path = ext_resources[id].path;
String type = ext_resources[id].type;
Ref<ResourceLoader::LoadToken> &load_token = ext_resources[id].load_token;
if (ext_resources[id].cache.is_valid()) {
r_res = ext_resources[id].cache;
} else if (use_sub_threads) {
Ref<Resource> res = ResourceLoader::load_threaded_get(path);
if (load_token.is_valid()) { // If not valid, it's OK since then we know this load accepts broken dependencies.
Ref<Resource> res = ResourceLoader::_load_complete(*load_token.ptr(), &err);
if (res.is_null()) {
if (ResourceLoader::get_abort_on_missing_resources()) {
error = ERR_FILE_MISSING_DEPENDENCIES;
error_text = "[ext_resource] referenced nonexistent resource at: " + path;
_printerr();
err = error;
} else {
ResourceLoader::notify_dependency_error(local_path, path, type);
if (!ResourceLoader::is_cleaning_tasks()) {
if (ResourceLoader::get_abort_on_missing_resources()) {
error = ERR_FILE_MISSING_DEPENDENCIES;
error_text = "[ext_resource] referenced non-existent resource at: " + path;
_printerr();
err = error;
} else {
ResourceLoader::notify_dependency_error(local_path, path, type);
}
}
} else {
ext_resources[id].cache = res;
#ifdef TOOLS_ENABLED
//remember ID for saving
res->set_id_for_path(path, id);
#endif
r_res = res;
}
} else {
error = ERR_FILE_MISSING_DEPENDENCIES;
error_text = "[ext_resource] referenced non-loaded resource at: " + path;
_printerr();
err = error;
r_res = Ref<Resource>();
}
} else {
r_res = Ref<Resource>();
}
VariantParser::get_token(p_stream, token, line, r_err_str);
@ -462,48 +461,20 @@ Error ResourceLoaderText::load() {
path = remaps[path];
}
ExtResource er;
er.path = path;
er.type = type;
if (use_sub_threads) {
Error err = ResourceLoader::load_threaded_request(path, type, use_sub_threads, ResourceFormatLoader::CACHE_MODE_REUSE, local_path);
if (err != OK) {
if (ResourceLoader::get_abort_on_missing_resources()) {
error = ERR_FILE_CORRUPT;
error_text = "[ext_resource] referenced broken resource at: " + path;
_printerr();
return error;
} else {
ResourceLoader::notify_dependency_error(local_path, path, type);
}
}
} else {
Ref<Resource> res = ResourceLoader::load(path, type);
if (res.is_null()) {
if (ResourceLoader::get_abort_on_missing_resources()) {
error = ERR_FILE_CORRUPT;
error_text = "[ext_resource] referenced nonexistent resource at: " + path;
_printerr();
return error;
} else {
ResourceLoader::notify_dependency_error(local_path, path, type);
}
ext_resources[id].path = path;
ext_resources[id].type = type;
ext_resources[id].load_token = ResourceLoader::_load_start(path, type, use_sub_threads ? ResourceLoader::LOAD_THREAD_DISTRIBUTE : ResourceLoader::LOAD_THREAD_FROM_CURRENT, ResourceFormatLoader::CACHE_MODE_REUSE);
if (!ext_resources[id].load_token.is_valid()) {
if (ResourceLoader::get_abort_on_missing_resources()) {
error = ERR_FILE_CORRUPT;
error_text = "[ext_resource] referenced non-existent resource at: " + path;
_printerr();
return error;
} else {
#ifdef TOOLS_ENABLED
//remember ID for saving
res->set_id_for_path(local_path, id);
#endif
ResourceLoader::notify_dependency_error(local_path, path, type);
}
er.cache = res;
}
ext_resources[id] = er;
error = VariantParser::parse_tag(&stream, lines, error_text, next_tag, &rp);
if (error) {

2
scene/resources/resource_format_text.h
View file

@ -48,7 +48,7 @@ class ResourceLoaderText {
VariantParser::StreamFile stream;
struct ExtResource {
Ref<Resource> cache;
Ref<ResourceLoader::LoadToken> load_token;
String path;
String type;
};