Modernize Thread

- Based on C++11's `thread` and `thread_local`
- No more need to allocate-deallocate or check for null
- No pointer anymore, just a member variable
- Platform-specific implementations no longer needed (except for the few cases of non-portable functions)
- Simpler for `NO_THREADS`
- Thread ids are now the same across platforms (main is 1; others follow)

1 files changed, 12 insertions, 21 deletions

diff --git a/editor/editor_file_system.cpp b/editor/editor_file_system.cpp
index 76814ea378..4b68de26e7 100644
--- a/editor/editor_file_system.cpp
+++ b/editor/editor_file_system.cpp
@@ -595,7 +595,7 @@ void EditorFileSystem::scan() {
 		return;
 	}
 
-	if (scanning || scanning_changes || thread) {
+	if (scanning || scanning_changes || thread.is_started()) {
 		return;
 	}
 
@@ -619,13 +619,13 @@ void EditorFileSystem::scan() {
 		_queue_update_script_classes();
 		first_scan = false;
 	} else {
-		ERR_FAIL_COND(thread);
+		ERR_FAIL_COND(thread.is_started());
 		set_process(true);
 		Thread::Settings s;
 		scanning = true;
 		scan_total = 0;
 		s.priority = Thread::PRIORITY_LOW;
-		thread = Thread::create(_thread_func, this, s);
+		thread.start(_thread_func, this, s);
 		//tree->hide();
 		//progress->show();
 	}
@@ -1046,7 +1046,7 @@ void EditorFileSystem::_thread_func_sources(void *_userdata) {
 
 void EditorFileSystem::scan_changes() {
 	if (first_scan || // Prevent a premature changes scan from inhibiting the first full scan
-			scanning || scanning_changes || thread) {
+			scanning || scanning_changes || thread.is_started()) {
 		scan_changes_pending = true;
 		set_process(true);
 		return;
@@ -1076,12 +1076,12 @@ void EditorFileSystem::scan_changes() {
 		scanning_changes_done = true;
 		emit_signal("sources_changed", sources_changed.size() > 0);
 	} else {
-		ERR_FAIL_COND(thread_sources);
+		ERR_FAIL_COND(thread_sources.is_started());
 		set_process(true);
 		scan_total = 0;
 		Thread::Settings s;
 		s.priority = Thread::PRIORITY_LOW;
-		thread_sources = Thread::create(_thread_func_sources, this, s);
+		thread_sources.start(_thread_func_sources, this, s);
 	}
 }
 
@@ -1092,17 +1092,14 @@ void EditorFileSystem::_notification(int p_what) {
 
 		} break;
 		case NOTIFICATION_EXIT_TREE: {
-			Thread *active_thread = thread ? thread : thread_sources;
-			if (use_threads && active_thread) {
+			Thread &active_thread = thread.is_started() ? thread : thread_sources;
+			if (use_threads && active_thread.is_started()) {
 				//abort thread if in progress
 				abort_scan = true;
 				while (scanning) {
 					OS::get_singleton()->delay_usec(1000);
 				}
-				Thread::wait_to_finish(active_thread);
-				memdelete(active_thread);
-				thread = nullptr;
-				thread_sources = nullptr;
+				active_thread.wait_to_finish();
 				WARN_PRINT("Scan thread aborted...");
 				set_process(false);
 			}
@@ -1125,9 +1122,7 @@ void EditorFileSystem::_notification(int p_what) {
 
 						set_process(false);
 
-						Thread::wait_to_finish(thread_sources);
-						memdelete(thread_sources);
-						thread_sources = nullptr;
+						thread_sources.wait_to_finish();
 						if (_update_scan_actions()) {
 							emit_signal("filesystem_changed");
 						}
@@ -1135,7 +1130,7 @@ void EditorFileSystem::_notification(int p_what) {
 						_queue_update_script_classes();
 						first_scan = false;
 					}
-				} else if (!scanning && thread) {
+				} else if (!scanning && thread.is_started()) {
 					set_process(false);
 
 					if (filesystem) {
@@ -1143,9 +1138,7 @@ void EditorFileSystem::_notification(int p_what) {
 					}
 					filesystem = new_filesystem;
 					new_filesystem = nullptr;
-					Thread::wait_to_finish(thread);
-					memdelete(thread);
-					thread = nullptr;
+					thread.wait_to_finish();
 					_update_scan_actions();
 					emit_signal("filesystem_changed");
 					emit_signal("sources_changed", sources_changed.size() > 0);
@@ -2080,11 +2073,9 @@ EditorFileSystem::EditorFileSystem() {
 	filesystem = memnew(EditorFileSystemDirectory); //like, empty
 	filesystem->parent = nullptr;
 
-	thread = nullptr;
 	scanning = false;
 	importing = false;
 	use_threads = true;
-	thread_sources = nullptr;
 	new_filesystem = nullptr;
 
 	abort_scan = false;