Make Servers truly Thread Safe

-Rendering server now uses a split RID allocate/initialize internally, this allows generating RIDs immediately but initialization to happen later on the proper thread (as rendering APIs generally requiere to call on the right thread).
-RenderingServerWrapMT is no more, multithreading is done in RenderingServerDefault.
-Some functions like texture or mesh creation, when renderer supports it, can register and return immediately (so no waiting for server API to flush, and saving staging and command buffer memory).
-3D physics server changed to be made multithread friendly.
-Added PhysicsServer3DWrapMT to use 3D physics server from multiple threads.
-Disablet Bullet (too much effort to make multithread friendly, this needs to be fixed eventually).

4 files changed, 44 insertions, 33 deletions

diff --git a/scene/2d/cpu_particles_2d.cpp b/scene/2d/cpu_particles_2d.cpp
index b34a9a9ea4..5e6a89fa18 100644
--- a/scene/2d/cpu_particles_2d.cpp
+++ b/scene/2d/cpu_particles_2d.cpp
@@ -60,7 +60,7 @@ void CPUParticles2D::set_amount(int p_amount) {
 	}
 
 	particle_data.resize((8 + 4 + 4) * p_amount);
-	RS::get_singleton()->multimesh_allocate(multimesh, p_amount, RS::MULTIMESH_TRANSFORM_2D, true, true);
+	RS::get_singleton()->multimesh_allocate_data(multimesh, p_amount, RS::MULTIMESH_TRANSFORM_2D, true, true);
 
 	particle_order.resize(p_amount);
 }
diff --git a/scene/2d/joints_2d.cpp b/scene/2d/joints_2d.cpp
index 80445e7e5d..f4f08674c9 100644
--- a/scene/2d/joints_2d.cpp
+++ b/scene/2d/joints_2d.cpp
@@ -65,18 +65,16 @@ void Joint2D::_body_exit_tree(const ObjectID &p_body_id) {
 }
 
 void Joint2D::_update_joint(bool p_only_free) {
-	if (joint.is_valid()) {
-		if (ba.is_valid() && bb.is_valid() && exclude_from_collision) {
-			PhysicsServer2D::get_singleton()->joint_disable_collisions_between_bodies(joint, false);
-		}
-
-		PhysicsServer2D::get_singleton()->free(joint);
-		joint = RID();
-		ba = RID();
-		bb = RID();
+	if (ba.is_valid() && bb.is_valid() && exclude_from_collision) {
+		PhysicsServer2D::get_singleton()->joint_disable_collisions_between_bodies(joint, false);
 	}
 
+	ba = RID();
+	bb = RID();
+	configured = false;
+
 	if (p_only_free || !is_inside_tree()) {
+		PhysicsServer2D::get_singleton()->joint_clear(joint);
 		warning = String();
 		return;
 	}
@@ -88,30 +86,35 @@ void Joint2D::_update_joint(bool p_only_free) {
 	PhysicsBody2D *body_b = Object::cast_to<PhysicsBody2D>(node_b);
 
 	if (node_a && !body_a && node_b && !body_b) {
+		PhysicsServer2D::get_singleton()->joint_clear(joint);
 		warning = TTR("Node A and Node B must be PhysicsBody2Ds");
 		update_configuration_warning();
 		return;
 	}
 
 	if (node_a && !body_a) {
+		PhysicsServer2D::get_singleton()->joint_clear(joint);
 		warning = TTR("Node A must be a PhysicsBody2D");
 		update_configuration_warning();
 		return;
 	}
 
 	if (node_b && !body_b) {
+		PhysicsServer2D::get_singleton()->joint_clear(joint);
 		warning = TTR("Node B must be a PhysicsBody2D");
 		update_configuration_warning();
 		return;
 	}
 
 	if (!body_a || !body_b) {
+		PhysicsServer2D::get_singleton()->joint_clear(joint);
 		warning = TTR("Joint is not connected to two PhysicsBody2Ds");
 		update_configuration_warning();
 		return;
 	}
 
 	if (body_a == body_b) {
+		PhysicsServer2D::get_singleton()->joint_clear(joint);
 		warning = TTR("Node A and Node B must be different PhysicsBody2Ds");
 		update_configuration_warning();
 		return;
@@ -128,7 +131,9 @@ void Joint2D::_update_joint(bool p_only_free) {
 		body_b->force_update_transform();
 	}
 
-	joint = _configure_joint(body_a, body_b);
+	configured = true;
+
+	_configure_joint(joint, body_a, body_b);
 
 	ERR_FAIL_COND_MSG(!joint.is_valid(), "Failed to configure the joint.");
 
@@ -249,6 +254,11 @@ void Joint2D::_bind_methods() {
 }
 
 Joint2D::Joint2D() {
+	joint = PhysicsServer2D::get_singleton()->joint_create();
+}
+
+Joint2D::~Joint2D() {
+	PhysicsServer2D::get_singleton()->free(joint);
 }
 
 ///////////////////////////////////////////////////////////////////////////////
@@ -272,16 +282,15 @@ void PinJoint2D::_notification(int p_what) {
 	}
 }
 
-RID PinJoint2D::_configure_joint(PhysicsBody2D *body_a, PhysicsBody2D *body_b) {
-	RID pj = PhysicsServer2D::get_singleton()->pin_joint_create(get_global_transform().get_origin(), body_a->get_rid(), body_b ? body_b->get_rid() : RID());
-	PhysicsServer2D::get_singleton()->pin_joint_set_param(pj, PhysicsServer2D::PIN_JOINT_SOFTNESS, softness);
-	return pj;
+void PinJoint2D::_configure_joint(RID p_joint, PhysicsBody2D *body_a, PhysicsBody2D *body_b) {
+	PhysicsServer2D::get_singleton()->joint_make_pin(p_joint, get_global_transform().get_origin(), body_a->get_rid(), body_b ? body_b->get_rid() : RID());
+	PhysicsServer2D::get_singleton()->pin_joint_set_param(p_joint, PhysicsServer2D::PIN_JOINT_SOFTNESS, softness);
 }
 
 void PinJoint2D::set_softness(real_t p_softness) {
 	softness = p_softness;
 	update();
-	if (get_joint().is_valid()) {
+	if (is_configured()) {
 		PhysicsServer2D::get_singleton()->pin_joint_set_param(get_joint(), PhysicsServer2D::PIN_JOINT_SOFTNESS, p_softness);
 	}
 }
@@ -323,13 +332,13 @@ void GrooveJoint2D::_notification(int p_what) {
 	}
 }
 
-RID GrooveJoint2D::_configure_joint(PhysicsBody2D *body_a, PhysicsBody2D *body_b) {
+void GrooveJoint2D::_configure_joint(RID p_joint, PhysicsBody2D *body_a, PhysicsBody2D *body_b) {
 	Transform2D gt = get_global_transform();
 	Vector2 groove_A1 = gt.get_origin();
 	Vector2 groove_A2 = gt.xform(Vector2(0, length));
 	Vector2 anchor_B = gt.xform(Vector2(0, initial_offset));
 
-	return PhysicsServer2D::get_singleton()->groove_joint_create(groove_A1, groove_A2, anchor_B, body_a->get_rid(), body_b->get_rid());
+	PhysicsServer2D::get_singleton()->joint_make_groove(p_joint, groove_A1, groove_A2, anchor_B, body_a->get_rid(), body_b->get_rid());
 }
 
 void GrooveJoint2D::set_length(real_t p_length) {
@@ -385,19 +394,17 @@ void DampedSpringJoint2D::_notification(int p_what) {
 	}
 }
 
-RID DampedSpringJoint2D::_configure_joint(PhysicsBody2D *body_a, PhysicsBody2D *body_b) {
+void DampedSpringJoint2D::_configure_joint(RID p_joint, PhysicsBody2D *body_a, PhysicsBody2D *body_b) {
 	Transform2D gt = get_global_transform();
 	Vector2 anchor_A = gt.get_origin();
 	Vector2 anchor_B = gt.xform(Vector2(0, length));
 
-	RID dsj = PhysicsServer2D::get_singleton()->damped_spring_joint_create(anchor_A, anchor_B, body_a->get_rid(), body_b->get_rid());
+	PhysicsServer2D::get_singleton()->joint_make_damped_spring(p_joint, anchor_A, anchor_B, body_a->get_rid(), body_b->get_rid());
 	if (rest_length) {
-		PhysicsServer2D::get_singleton()->damped_spring_joint_set_param(dsj, PhysicsServer2D::DAMPED_SPRING_REST_LENGTH, rest_length);
+		PhysicsServer2D::get_singleton()->damped_spring_joint_set_param(p_joint, PhysicsServer2D::DAMPED_SPRING_REST_LENGTH, rest_length);
 	}
-	PhysicsServer2D::get_singleton()->damped_spring_joint_set_param(dsj, PhysicsServer2D::DAMPED_SPRING_STIFFNESS, stiffness);
-	PhysicsServer2D::get_singleton()->damped_spring_joint_set_param(dsj, PhysicsServer2D::DAMPED_SPRING_DAMPING, damping);
-
-	return dsj;
+	PhysicsServer2D::get_singleton()->damped_spring_joint_set_param(p_joint, PhysicsServer2D::DAMPED_SPRING_STIFFNESS, stiffness);
+	PhysicsServer2D::get_singleton()->damped_spring_joint_set_param(p_joint, PhysicsServer2D::DAMPED_SPRING_DAMPING, damping);
 }
 
 void DampedSpringJoint2D::set_length(real_t p_length) {
@@ -412,7 +419,7 @@ real_t DampedSpringJoint2D::get_length() const {
 void DampedSpringJoint2D::set_rest_length(real_t p_rest_length) {
 	rest_length = p_rest_length;
 	update();
-	if (get_joint().is_valid()) {
+	if (is_configured()) {
 		PhysicsServer2D::get_singleton()->damped_spring_joint_set_param(get_joint(), PhysicsServer2D::DAMPED_SPRING_REST_LENGTH, p_rest_length ? p_rest_length : length);
 	}
 }
@@ -424,7 +431,7 @@ real_t DampedSpringJoint2D::get_rest_length() const {
 void DampedSpringJoint2D::set_stiffness(real_t p_stiffness) {
 	stiffness = p_stiffness;
 	update();
-	if (get_joint().is_valid()) {
+	if (is_configured()) {
 		PhysicsServer2D::get_singleton()->damped_spring_joint_set_param(get_joint(), PhysicsServer2D::DAMPED_SPRING_STIFFNESS, p_stiffness);
 	}
 }
@@ -436,7 +443,7 @@ real_t DampedSpringJoint2D::get_stiffness() const {
 void DampedSpringJoint2D::set_damping(real_t p_damping) {
 	damping = p_damping;
 	update();
-	if (get_joint().is_valid()) {
+	if (is_configured()) {
 		PhysicsServer2D::get_singleton()->damped_spring_joint_set_param(get_joint(), PhysicsServer2D::DAMPED_SPRING_DAMPING, p_damping);
 	}
 }
diff --git a/scene/2d/joints_2d.h b/scene/2d/joints_2d.h
index 887155c6ea..3607a6c176 100644
--- a/scene/2d/joints_2d.h
+++ b/scene/2d/joints_2d.h
@@ -46,6 +46,7 @@ class Joint2D : public Node2D {
 	real_t bias = 0.0;
 
 	bool exclude_from_collision = true;
+	bool configured = false;
 	String warning;
 
 protected:
@@ -54,10 +55,12 @@ protected:
 	void _update_joint(bool p_only_free = false);
 
 	void _notification(int p_what);
-	virtual RID _configure_joint(PhysicsBody2D *body_a, PhysicsBody2D *body_b) = 0;
+	virtual void _configure_joint(RID p_joint, PhysicsBody2D *body_a, PhysicsBody2D *body_b) = 0;
 
 	static void _bind_methods();
 
+	_FORCE_INLINE_ bool is_configured() const { return configured; }
+
 public:
 	virtual String get_configuration_warning() const override;
 
@@ -75,6 +78,7 @@ public:
 
 	RID get_joint() const { return joint; }
 	Joint2D();
+	~Joint2D();
 };
 
 class PinJoint2D : public Joint2D {
@@ -84,7 +88,7 @@ class PinJoint2D : public Joint2D {
 
 protected:
 	void _notification(int p_what);
-	virtual RID _configure_joint(PhysicsBody2D *body_a, PhysicsBody2D *body_b) override;
+	virtual void _configure_joint(RID p_joint, PhysicsBody2D *body_a, PhysicsBody2D *body_b) override;
 	static void _bind_methods();
 
 public:
@@ -102,7 +106,7 @@ class GrooveJoint2D : public Joint2D {
 
 protected:
 	void _notification(int p_what);
-	virtual RID _configure_joint(PhysicsBody2D *body_a, PhysicsBody2D *body_b) override;
+	virtual void _configure_joint(RID p_joint, PhysicsBody2D *body_a, PhysicsBody2D *body_b) override;
 	static void _bind_methods();
 
 public:
@@ -125,7 +129,7 @@ class DampedSpringJoint2D : public Joint2D {
 
 protected:
 	void _notification(int p_what);
-	virtual RID _configure_joint(PhysicsBody2D *body_a, PhysicsBody2D *body_b) override;
+	virtual void _configure_joint(RID p_joint, PhysicsBody2D *body_a, PhysicsBody2D *body_b) override;
 	static void _bind_methods();
 
 public:
diff --git a/scene/2d/skeleton_2d.cpp b/scene/2d/skeleton_2d.cpp
index 48e44e01a1..5728230a8c 100644
--- a/scene/2d/skeleton_2d.cpp
+++ b/scene/2d/skeleton_2d.cpp
@@ -182,7 +182,7 @@ void Skeleton2D::_update_bone_setup() {
 	}
 
 	bone_setup_dirty = false;
-	RS::get_singleton()->skeleton_allocate(skeleton, bones.size(), true);
+	RS::get_singleton()->skeleton_allocate_data(skeleton, bones.size(), true);
 
 	bones.sort(); //sorty so they are always in the same order/index