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authorRĂ©mi Verschelde <remi@verschelde.fr>2022-07-22 13:25:31 +0200
committerGitHub <noreply@github.com>2022-07-22 13:25:31 +0200
commitd2fa9cbdfd43c75cd76917d2c4db26f2489d2717 (patch)
treebb6d9e828c1dfcab7ff102e388a0182702b7a35f /core/object
parent653f95282ccd31a4e38a157bb7845405079de371 (diff)
parent67a260d63f971a6dca2b8716a220831928661085 (diff)
Merge pull request #63141 from reduz/implement-thread-runner
Diffstat (limited to 'core/object')
-rw-r--r--core/object/worker_thread_pool.cpp463
-rw-r--r--core/object/worker_thread_pool.h146
2 files changed, 609 insertions, 0 deletions
diff --git a/core/object/worker_thread_pool.cpp b/core/object/worker_thread_pool.cpp
new file mode 100644
index 0000000000..c276802f99
--- /dev/null
+++ b/core/object/worker_thread_pool.cpp
@@ -0,0 +1,463 @@
+/*************************************************************************/
+/* worker_thread_pool.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 "worker_thread_pool.h"
+
+#include "core/os/os.h"
+
+WorkerThreadPool *WorkerThreadPool::singleton = nullptr;
+
+void WorkerThreadPool::_process_task_queue() {
+ task_mutex.lock();
+ Task *task = task_queue.first()->self();
+ task_queue.remove(task_queue.first());
+ task_mutex.unlock();
+ _process_task(task);
+}
+
+void WorkerThreadPool::_process_task(Task *p_task) {
+ bool low_priority = p_task->low_priority;
+
+ if (p_task->group) {
+ // Handling a group
+ bool do_post = false;
+ if (p_task->native_group_func) {
+ while (true) {
+ uint32_t work_index = p_task->group->index.postincrement();
+ if (work_index >= p_task->group->max) {
+ do_post = work_index == p_task->group->max; // First one reaching max handles semaphore and clean-up.
+ break;
+ }
+ p_task->native_group_func(p_task->native_func_userdata, work_index);
+ }
+
+ } else {
+ Callable::CallError ce;
+ Variant ret;
+ Variant arg;
+ Variant *argptr = &arg;
+ while (true) {
+ uint32_t work_index = p_task->group->index.postincrement();
+ if (work_index >= p_task->group->max) {
+ do_post = work_index == p_task->group->max; // First one reaching max handles semaphore and clean-up.
+ break;
+ }
+ arg = work_index;
+ p_task->callable.call((const Variant **)&argptr, 1, ret, ce);
+ }
+ }
+
+ if (low_priority && use_native_low_priority_threads) {
+ p_task->completed = true;
+ p_task->done_semaphore.post();
+ if (do_post) {
+ p_task->group->completed.set_to(true);
+ }
+ } else {
+ if (do_post) {
+ p_task->group->done_semaphore.post();
+ p_task->group->completed.set_to(true);
+ }
+ uint32_t max_users = p_task->group->tasks_used + 1; // Add 1 because the thread waiting for it is also user. Read before to avoid another thread freeing task after increment.
+ uint32_t finished_users = p_task->group->finished.increment();
+
+ if (finished_users == max_users) {
+ // Get rid of the group, because nobody else is using it.
+ task_mutex.lock();
+ group_allocator.free(p_task->group);
+ task_mutex.unlock();
+ }
+
+ // For groups, tasks get rid of themselves.
+
+ task_mutex.lock();
+ task_allocator.free(p_task);
+ task_mutex.unlock();
+ }
+ } else {
+ if (p_task->native_func) {
+ p_task->native_func(p_task->native_func_userdata);
+ } else {
+ Callable::CallError ce;
+ Variant ret;
+ p_task->callable.call(nullptr, 0, ret, ce);
+ }
+
+ p_task->completed = true;
+ p_task->done_semaphore.post();
+ }
+
+ if (!use_native_low_priority_threads && low_priority) {
+ // A low prioriry task was freed, so see if we can move a pending one to the high priority queue.
+ bool post = false;
+ task_mutex.lock();
+ if (low_priority_task_queue.first()) {
+ Task *low_prio_task = low_priority_task_queue.first()->self();
+ low_priority_task_queue.remove(low_priority_task_queue.first());
+ task_queue.add_last(&low_prio_task->task_elem);
+ post = true;
+ } else {
+ low_priority_threads_used.decrement();
+ }
+ task_mutex.lock();
+ if (post) {
+ task_available_semaphore.post();
+ }
+ }
+}
+
+void WorkerThreadPool::_thread_function(void *p_user) {
+ while (true) {
+ singleton->task_available_semaphore.wait();
+ if (singleton->exit_threads.is_set()) {
+ break;
+ }
+ singleton->_process_task_queue();
+ }
+}
+
+void WorkerThreadPool::_native_low_priority_thread_function(void *p_user) {
+ Task *task = (Task *)p_user;
+ singleton->_process_task(task);
+}
+
+void WorkerThreadPool::_post_task(Task *p_task, bool p_high_priority) {
+ task_mutex.lock();
+ p_task->low_priority = !p_high_priority;
+ if (!p_high_priority && use_native_low_priority_threads) {
+ task_mutex.unlock();
+ p_task->low_priority_thread = native_thread_allocator.alloc();
+ p_task->low_priority_thread->start(_native_low_priority_thread_function, p_task); // Pask task directly to thread.
+
+ } else if (p_high_priority || low_priority_threads_used.get() < max_low_priority_threads) {
+ task_queue.add_last(&p_task->task_elem);
+ if (!p_high_priority) {
+ low_priority_threads_used.increment();
+ }
+ task_mutex.unlock();
+ task_available_semaphore.post();
+ } else {
+ // Too many threads using low priority, must go to queue.
+ low_priority_task_queue.add_last(&p_task->task_elem);
+ task_mutex.unlock();
+ }
+}
+
+WorkerThreadPool::TaskID WorkerThreadPool::add_native_task(void (*p_func)(void *), void *p_userdata, bool p_high_priority, const String &p_description) {
+ task_mutex.lock();
+ // Get a free task
+ Task *task = task_allocator.alloc();
+ TaskID id = last_task++;
+ task->native_func = p_func;
+ task->native_func_userdata = p_userdata;
+ task->description = p_description;
+ tasks.insert(id, task);
+ task_mutex.unlock();
+
+ _post_task(task, p_high_priority);
+
+ return id;
+}
+
+WorkerThreadPool::TaskID WorkerThreadPool::add_task(const Callable &p_action, bool p_high_priority, const String &p_description) {
+ task_mutex.lock();
+ // Get a free task
+ Task *task = task_allocator.alloc();
+ TaskID id = last_task++;
+ task->callable = p_action;
+ task->description = p_description;
+ tasks.insert(id, task);
+ task_mutex.unlock();
+
+ _post_task(task, p_high_priority);
+
+ return id;
+}
+
+bool WorkerThreadPool::is_task_completed(TaskID p_task_id) const {
+ task_mutex.lock();
+ const Task *const *taskp = tasks.getptr(p_task_id);
+ if (!taskp) {
+ task_mutex.unlock();
+ ERR_FAIL_V_MSG(false, "Invalid Task ID"); // Invalid task
+ }
+
+ bool completed = (*taskp)->completed;
+ task_mutex.unlock();
+
+ return completed;
+}
+
+void WorkerThreadPool::wait_for_task_completion(TaskID p_task_id) {
+ task_mutex.lock();
+ Task **taskp = tasks.getptr(p_task_id);
+ if (!taskp) {
+ task_mutex.unlock();
+ ERR_FAIL_MSG("Invalid Task ID"); // Invalid task
+ }
+ Task *task = *taskp;
+
+ if (task->waiting) {
+ String description = task->description;
+ task_mutex.unlock();
+ if (description.is_empty()) {
+ ERR_FAIL_MSG("Another thread is waiting on this task: " + itos(p_task_id)); // Invalid task
+ } else {
+ ERR_FAIL_MSG("Another thread is waiting on this task: " + description + " (" + itos(p_task_id) + ")"); // Invalid task
+ }
+ }
+
+ task->waiting = true;
+
+ task_mutex.unlock();
+
+ if (use_native_low_priority_threads && task->low_priority) {
+ task->low_priority_thread->wait_to_finish();
+ native_thread_allocator.free(task->low_priority_thread);
+ } else {
+ int *index = thread_ids.getptr(Thread::get_caller_id());
+
+ if (index) {
+ // We are an actual process thread, we must not be blocked so continue processing stuff if available.
+ while (true) {
+ if (task->done_semaphore.try_wait()) {
+ // If done, exit
+ break;
+ }
+ if (task_available_semaphore.try_wait()) {
+ // Solve tasks while they are around.
+ _process_task_queue();
+ continue;
+ }
+ OS::get_singleton()->delay_usec(1); // Microsleep, this could be converted to waiting for multiple objects in supported platforms for a bit more performance.
+ }
+ } else {
+ task->done_semaphore.wait();
+ }
+ }
+
+ task_mutex.lock();
+ tasks.erase(p_task_id);
+ task_allocator.free(task);
+ task_mutex.unlock();
+}
+
+WorkerThreadPool::GroupID WorkerThreadPool::add_native_group_task(void (*p_func)(void *, uint32_t), void *p_userdata, int p_elements, int p_tasks, bool p_high_priority, const String &p_description) {
+ ERR_FAIL_COND_V(p_elements <= 0, INVALID_TASK_ID);
+ if (p_tasks < 0) {
+ p_tasks = threads.size();
+ }
+
+ task_mutex.lock();
+ Group *group = group_allocator.alloc();
+ GroupID id = last_task++;
+ group->max = p_elements;
+ group->self = id;
+ group->tasks_used = p_tasks;
+ Task **tasks_posted = (Task **)alloca(sizeof(Task *) * p_tasks);
+ for (int i = 0; i < p_tasks; i++) {
+ Task *task = task_allocator.alloc();
+ task->native_group_func = p_func;
+ task->native_func_userdata = p_userdata;
+ task->description = p_description;
+ task->group = group;
+ tasks_posted[i] = task;
+ // No task ID is used.
+ }
+ groups[id] = group;
+ task_mutex.unlock();
+
+ if (!p_high_priority && use_native_low_priority_threads) {
+ group->low_priority_native_tasks.resize(p_tasks);
+ }
+
+ for (int i = 0; i < p_tasks; i++) {
+ _post_task(tasks_posted[i], p_high_priority);
+ if (!p_high_priority && use_native_low_priority_threads) {
+ group->low_priority_native_tasks[i] = tasks_posted[i];
+ }
+ }
+
+ return id;
+}
+
+WorkerThreadPool::GroupID WorkerThreadPool::add_group_task(const Callable &p_action, int p_elements, int p_tasks, bool p_high_priority, const String &p_description) {
+ ERR_FAIL_COND_V(p_elements <= 0, INVALID_TASK_ID);
+ if (p_tasks < 0) {
+ p_tasks = threads.size();
+ }
+
+ task_mutex.lock();
+ Group *group = group_allocator.alloc();
+ GroupID id = last_task++;
+ group->max = p_elements;
+ group->self = id;
+ group->tasks_used = p_tasks;
+ Task **tasks_posted = (Task **)alloca(sizeof(Task *) * p_tasks);
+ for (int i = 0; i < p_tasks; i++) {
+ Task *task = task_allocator.alloc();
+ task->callable = p_action;
+ task->description = p_description;
+ task->group = group;
+ tasks_posted[i] = task;
+ // No task ID is used.
+ }
+ groups[id] = group;
+ task_mutex.unlock();
+
+ if (!p_high_priority && use_native_low_priority_threads) {
+ group->low_priority_native_tasks.resize(p_tasks);
+ }
+
+ for (int i = 0; i < p_tasks; i++) {
+ _post_task(tasks_posted[i], p_high_priority);
+ if (!p_high_priority && use_native_low_priority_threads) {
+ group->low_priority_native_tasks[i] = tasks_posted[i];
+ }
+ }
+ return id;
+}
+
+bool WorkerThreadPool::is_group_task_completed(GroupID p_group) const {
+ task_mutex.lock();
+ const Group *const *groupp = groups.getptr(p_group);
+ if (!groupp) {
+ task_mutex.unlock();
+ ERR_FAIL_V_MSG(false, "Invalid Group ID");
+ }
+ bool completed = (*groupp)->completed.is_set();
+ task_mutex.unlock();
+ return completed;
+}
+
+void WorkerThreadPool::wait_for_group_task_completion(GroupID p_group) {
+ task_mutex.lock();
+ Group **groupp = groups.getptr(p_group);
+ task_mutex.unlock();
+ if (!groupp) {
+ ERR_FAIL_MSG("Invalid Group ID");
+ }
+ Group *group = *groupp;
+
+ if (group->low_priority_native_tasks.size() > 0) {
+ for (uint32_t i = 0; i < group->low_priority_native_tasks.size(); i++) {
+ group->low_priority_native_tasks[i]->low_priority_thread->wait_to_finish();
+ native_thread_allocator.free(group->low_priority_native_tasks[i]->low_priority_thread);
+ task_mutex.lock();
+ task_allocator.free(group->low_priority_native_tasks[i]);
+ task_mutex.unlock();
+ }
+
+ task_mutex.lock();
+ group_allocator.free(group);
+ task_mutex.unlock();
+ } else {
+ group->done_semaphore.wait();
+
+ uint32_t max_users = group->tasks_used + 1; // Add 1 because the thread waiting for it is also user. Read before to avoid another thread freeing task after increment.
+ uint32_t finished_users = group->finished.increment(); // fetch happens before inc, so increment later.
+
+ if (finished_users == max_users) {
+ // All tasks using this group are gone (finished before the group), so clear the gorup too.
+ task_mutex.lock();
+ group_allocator.free(group);
+ task_mutex.unlock();
+ }
+ }
+
+ groups.erase(p_group); // Threads do not access this, so safe to erase here.
+}
+
+void WorkerThreadPool::init(int p_thread_count, bool p_use_native_threads_low_priority, float p_low_priority_task_ratio) {
+ ERR_FAIL_COND(threads.size() > 0);
+ if (p_thread_count < 0) {
+ p_thread_count = OS::get_singleton()->get_default_thread_pool_size();
+ }
+
+ if (p_use_native_threads_low_priority) {
+ max_low_priority_threads = 0;
+ } else {
+ max_low_priority_threads = CLAMP(p_thread_count * p_low_priority_task_ratio, 1, p_thread_count);
+ }
+
+ use_native_low_priority_threads = p_use_native_threads_low_priority;
+
+ threads.resize(p_thread_count);
+
+ for (uint32_t i = 0; i < threads.size(); i++) {
+ threads[i].index = i;
+ threads[i].thread.start(&WorkerThreadPool::_thread_function, &threads[i]);
+ thread_ids.insert(threads[i].thread.get_id(), i);
+ }
+}
+
+void WorkerThreadPool::finish() {
+ if (threads.size() == 0) {
+ return;
+ }
+
+ task_mutex.lock();
+ SelfList<Task> *E = low_priority_task_queue.first();
+ while (E) {
+ print_error("Task waiting was never re-claimed: " + E->self()->description);
+ E = E->next();
+ }
+ task_mutex.unlock();
+
+ exit_threads.set_to(true);
+
+ for (uint32_t i = 0; i < threads.size(); i++) {
+ task_available_semaphore.post();
+ }
+
+ for (uint32_t i = 0; i < threads.size(); i++) {
+ threads[i].thread.wait_to_finish();
+ }
+
+ threads.clear();
+}
+
+void WorkerThreadPool::_bind_methods() {
+ ClassDB::bind_method(D_METHOD("add_task", "action", "high_priority", "description"), &WorkerThreadPool::add_task, DEFVAL(false), DEFVAL(String()));
+ ClassDB::bind_method(D_METHOD("is_task_completed", "task_id"), &WorkerThreadPool::is_task_completed);
+ ClassDB::bind_method(D_METHOD("wait_for_task_completion", "task_id"), &WorkerThreadPool::wait_for_task_completion);
+
+ ClassDB::bind_method(D_METHOD("add_group_task", "action", "elements", "tasks_needed", "high_priority", "description"), &WorkerThreadPool::add_group_task, DEFVAL(-1), DEFVAL(false), DEFVAL(String()));
+ ClassDB::bind_method(D_METHOD("is_group_task_completed", "group_id"), &WorkerThreadPool::is_group_task_completed);
+ ClassDB::bind_method(D_METHOD("wait_for_group_task_completion", "group_id"), &WorkerThreadPool::wait_for_group_task_completion);
+}
+
+WorkerThreadPool::WorkerThreadPool() {
+ singleton = this;
+}
+
+WorkerThreadPool::~WorkerThreadPool() {
+ finish();
+}
diff --git a/core/object/worker_thread_pool.h b/core/object/worker_thread_pool.h
new file mode 100644
index 0000000000..dfb0050605
--- /dev/null
+++ b/core/object/worker_thread_pool.h
@@ -0,0 +1,146 @@
+/*************************************************************************/
+/* worker_thread_pool.h */
+/*************************************************************************/
+/* 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. */
+/*************************************************************************/
+
+#ifndef WORKER_THREAD_POOL_H
+#define WORKER_THREAD_POOL_H
+
+#include "core/os/memory.h"
+#include "core/os/os.h"
+#include "core/os/semaphore.h"
+#include "core/os/thread.h"
+#include "core/templates/local_vector.h"
+#include "core/templates/paged_allocator.h"
+#include "core/templates/rid.h"
+#include "core/templates/safe_refcount.h"
+
+class WorkerThreadPool : public Object {
+ GDCLASS(WorkerThreadPool, Object)
+public:
+ enum {
+ INVALID_TASK_ID = -1
+ };
+
+ typedef int64_t TaskID;
+ typedef int64_t GroupID;
+
+private:
+ struct Task;
+
+ struct Group {
+ GroupID self;
+ SafeNumeric<uint32_t> index;
+ uint32_t max = 0;
+ Semaphore done_semaphore;
+ SafeFlag completed;
+ SafeNumeric<uint32_t> finished;
+ uint32_t tasks_used = 0;
+ TightLocalVector<Task *> low_priority_native_tasks;
+ };
+
+ struct Task {
+ Callable callable;
+ void (*native_func)(void *) = nullptr;
+ void (*native_group_func)(void *, uint32_t) = nullptr;
+ void *native_func_userdata = nullptr;
+ String description;
+ Semaphore done_semaphore;
+ bool completed = false;
+ Group *group = nullptr;
+ SelfList<Task> task_elem;
+ bool waiting = false; // Waiting for completion
+ bool low_priority = false;
+ Thread *low_priority_thread = nullptr;
+ Task() :
+ task_elem(this) {}
+ };
+
+ PagedAllocator<Task> task_allocator;
+ PagedAllocator<Group> group_allocator;
+ PagedAllocator<Thread> native_thread_allocator;
+
+ SelfList<Task>::List low_priority_task_queue;
+ SelfList<Task>::List task_queue;
+
+ Mutex task_mutex;
+ Semaphore task_available_semaphore;
+
+ struct ThreadData {
+ uint32_t index;
+ Thread thread;
+ };
+
+ TightLocalVector<ThreadData> threads;
+ SafeFlag exit_threads;
+
+ HashMap<Thread::ID, int> thread_ids;
+ HashMap<TaskID, Task *> tasks;
+ HashMap<GroupID, Group *> groups;
+
+ bool use_native_low_priority_threads = false;
+ uint32_t max_low_priority_threads = 0;
+ SafeNumeric<uint32_t> low_priority_threads_used;
+
+ uint64_t last_task = 1;
+
+ static void _thread_function(void *p_user);
+ static void _native_low_priority_thread_function(void *p_user);
+
+ void _process_task_queue();
+ void _process_task(Task *task);
+
+ void _post_task(Task *p_task, bool p_high_priority);
+
+ static WorkerThreadPool *singleton;
+
+protected:
+ static void _bind_methods();
+
+public:
+ TaskID add_native_task(void (*p_func)(void *), void *p_userdata, bool p_high_priority = false, const String &p_description = String());
+ TaskID add_task(const Callable &p_action, bool p_high_priority = false, const String &p_description = String());
+
+ bool is_task_completed(TaskID p_task_id) const;
+ void wait_for_task_completion(TaskID p_task_id);
+
+ GroupID add_native_group_task(void (*p_func)(void *, uint32_t), void *p_userdata, int p_elements, int p_tasks = -1, bool p_high_priority = false, const String &p_description = String());
+ GroupID add_group_task(const Callable &p_action, int p_elements, int p_tasks = -1, bool p_high_priority = false, const String &p_description = String());
+ bool is_group_task_completed(GroupID p_group) const;
+ void wait_for_group_task_completion(GroupID p_group);
+
+ _FORCE_INLINE_ int get_thread_count() const { return threads.size(); }
+
+ static WorkerThreadPool *get_singleton() { return singleton; }
+ void init(int p_thread_count = -1, bool p_use_native_threads_low_priority = true, float p_low_priority_task_ratio = 0.3);
+ void finish();
+ WorkerThreadPool();
+ ~WorkerThreadPool();
+};
+
+#endif // WORKER_THREAD_POOL_H