1 files changed, 112 insertions, 0 deletions
diff --git a/core/templates/command_queue_mt.cpp b/core/templates/command_queue_mt.cpp
new file mode 100644
index 0000000000..a94853a21c
--- /dev/null
+++ b/core/templates/command_queue_mt.cpp
@@ -0,0 +1,112 @@
+/*************************************************************************/
+/*  command_queue_mt.cpp                                                 */
+/*************************************************************************/
+/*                       This file is part of:                           */
+/*                           GODOT ENGINE                                */
+/*                      https://godotengine.org                          */
+/*************************************************************************/
+/* Copyright (c) 2007-2020 Juan Linietsky, Ariel Manzur.                 */
+/* Copyright (c) 2014-2020 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 "command_queue_mt.h"
+
+#include "core/config/project_settings.h"
+#include "core/os/os.h"
+
+void CommandQueueMT::lock() {
+	mutex.lock();
+}
+
+void CommandQueueMT::unlock() {
+	mutex.unlock();
+}
+
+void CommandQueueMT::wait_for_flush() {
+	// wait one millisecond for a flush to happen
+	OS::get_singleton()->delay_usec(1000);
+}
+
+CommandQueueMT::SyncSemaphore *CommandQueueMT::_alloc_sync_sem() {
+	int idx = -1;
+
+	while (true) {
+		lock();
+		for (int i = 0; i < SYNC_SEMAPHORES; i++) {
+			if (!sync_sems[i].in_use) {
+				sync_sems[i].in_use = true;
+				idx = i;
+				break;
+			}
+		}
+		unlock();
+
+		if (idx == -1) {
+			wait_for_flush();
+		} else {
+			break;
+		}
+	}
+
+	return &sync_sems[idx];
+}
+
+bool CommandQueueMT::dealloc_one() {
+tryagain:
+	if (dealloc_ptr == (write_ptr_and_epoch >> 1)) {
+		// The queue is empty
+		return false;
+	}
+
+	uint32_t size = *(uint32_t *)&command_mem[dealloc_ptr];
+
+	if (size == 0) {
+		// End of command buffer wrap down
+		dealloc_ptr = 0;
+		goto tryagain;
+	}
+
+	if (size & 1) {
+		// Still used, nothing can be deallocated
+		return false;
+	}
+
+	dealloc_ptr += (size >> 1) + 8;
+	return true;
+}
+
+CommandQueueMT::CommandQueueMT(bool p_sync) {
+	command_mem_size = GLOBAL_DEF_RST("memory/limits/command_queue/multithreading_queue_size_kb", DEFAULT_COMMAND_MEM_SIZE_KB);
+	ProjectSettings::get_singleton()->set_custom_property_info("memory/limits/command_queue/multithreading_queue_size_kb", PropertyInfo(Variant::INT, "memory/limits/command_queue/multithreading_queue_size_kb", PROPERTY_HINT_RANGE, "1,4096,1,or_greater"));
+	command_mem_size *= 1024;
+	command_mem = (uint8_t *)memalloc(command_mem_size);
+	if (p_sync) {
+		sync = memnew(Semaphore);
+	}
+}
+
+CommandQueueMT::~CommandQueueMT() {
+	if (sync) {
+		memdelete(sync);
+	}
+	memfree(command_mem);
+}