Modernize atomics

- Based on C++11's `atomic`
- Reworked `SafeRefCount` (based on the rewrite by @hpvb)
- Replaced free atomic functions by the new `SafeNumeric<T>`
- Replaced wrong cases of `volatile bool` by the new `SafeFlag`
- Platform-specific implementations no longer needed

Co-authored-by: Hein-Pieter van Braam-Stewart <hp@tmm.cx>

12 files changed, 155 insertions, 129 deletions

diff --git a/scene/2d/audio_stream_player_2d.cpp b/scene/2d/audio_stream_player_2d.cpp
index 79624bf3bf..6d8d6058eb 100644
--- a/scene/2d/audio_stream_player_2d.cpp
+++ b/scene/2d/audio_stream_player_2d.cpp
@@ -35,14 +35,14 @@
 #include "scene/main/window.h"
 
 void AudioStreamPlayer2D::_mix_audio() {
-	if (!stream_playback.is_valid() || !active ||
+	if (!stream_playback.is_valid() || !active.is_set() ||
 			(stream_paused && !stream_paused_fade_out)) {
 		return;
 	}
 
-	if (setseek >= 0.0) {
-		stream_playback->start(setseek);
-		setseek = -1.0; //reset seek
+	if (setseek.get() >= 0.0) {
+		stream_playback->start(setseek.get());
+		setseek.set(-1.0); //reset seek
 	}
 
 	//get data
@@ -57,7 +57,8 @@ void AudioStreamPlayer2D::_mix_audio() {
 	stream_playback->mix(buffer, pitch_scale, buffer_size);
 
 	//write all outputs
-	for (int i = 0; i < output_count; i++) {
+	int oc = output_count.get();
+	for (int i = 0; i < oc; i++) {
 		Output current = outputs[i];
 
 		//see if current output exists, to keep volume ramp
@@ -130,14 +131,14 @@ void AudioStreamPlayer2D::_mix_audio() {
 		prev_outputs[i] = current;
 	}
 
-	prev_output_count = output_count;
+	prev_output_count = oc;
 
 	//stream is no longer active, disable this.
 	if (!stream_playback->is_playing()) {
-		active = false;
+		active.clear();
 	}
 
-	output_ready = false;
+	output_ready.clear();
 	stream_paused_fade_in = false;
 	stream_paused_fade_out = false;
 }
@@ -168,7 +169,7 @@ void AudioStreamPlayer2D::_notification(int p_what) {
 	if (p_what == NOTIFICATION_INTERNAL_PHYSICS_PROCESS) {
 		//update anything related to position first, if possible of course
 
-		if (!output_ready) {
+		if (!output_ready.is_set()) {
 			List<Viewport *> viewports;
 			Ref<World2D> world_2d = get_world_2d();
 			ERR_FAIL_COND(world_2d.is_null());
@@ -240,19 +241,19 @@ void AudioStreamPlayer2D::_notification(int p_what) {
 				}
 			}
 
-			output_count = new_output_count;
-			output_ready = true;
+			output_count.set(new_output_count);
+			output_ready.set();
 		}
 
 		//start playing if requested
-		if (setplay >= 0.0) {
-			setseek = setplay;
-			active = true;
-			setplay = -1;
+		if (setplay.get() >= 0.0) {
+			setseek.set(setplay.get());
+			active.set();
+			setplay.set(-1);
 		}
 
 		//stop playing if no longer active
-		if (!active) {
+		if (!active.is_set()) {
 			set_physics_process_internal(false);
 			emit_signal("finished");
 		}
@@ -267,8 +268,8 @@ void AudioStreamPlayer2D::set_stream(Ref<AudioStream> p_stream) {
 	if (stream_playback.is_valid()) {
 		stream_playback.unref();
 		stream.unref();
-		active = false;
-		setseek = -1;
+		active.clear();
+		setseek.set(-1);
 	}
 
 	if (p_stream.is_valid()) {
@@ -311,29 +312,29 @@ void AudioStreamPlayer2D::play(float p_from_pos) {
 	}
 
 	if (stream_playback.is_valid()) {
-		setplay = p_from_pos;
-		output_ready = false;
+		setplay.set(p_from_pos);
+		output_ready.clear();
 		set_physics_process_internal(true);
 	}
 }
 
 void AudioStreamPlayer2D::seek(float p_seconds) {
 	if (stream_playback.is_valid()) {
-		setseek = p_seconds;
+		setseek.set(p_seconds);
 	}
 }
 
 void AudioStreamPlayer2D::stop() {
 	if (stream_playback.is_valid()) {
-		active = false;
+		active.clear();
 		set_physics_process_internal(false);
-		setplay = -1;
+		setplay.set(-1);
 	}
 }
 
 bool AudioStreamPlayer2D::is_playing() const {
 	if (stream_playback.is_valid()) {
-		return active || setplay >= 0;
+		return active.is_set() || setplay.get() >= 0;
 	}
 
 	return false;
@@ -341,8 +342,9 @@ bool AudioStreamPlayer2D::is_playing() const {
 
 float AudioStreamPlayer2D::get_playback_position() {
 	if (stream_playback.is_valid()) {
-		if (setseek >= 0.0) {
-			return setseek;
+		float ss = setseek.get();
+		if (ss >= 0.0) {
+			return ss;
 		}
 		return stream_playback->get_playback_position();
 	}
@@ -383,7 +385,7 @@ void AudioStreamPlayer2D::_set_playing(bool p_enable) {
 }
 
 bool AudioStreamPlayer2D::_is_active() const {
-	return active;
+	return active.is_set();
 }
 
 void AudioStreamPlayer2D::_validate_property(PropertyInfo &property) const {
diff --git a/scene/2d/audio_stream_player_2d.h b/scene/2d/audio_stream_player_2d.h
index 6fb8cc414c..21f524c703 100644
--- a/scene/2d/audio_stream_player_2d.h
+++ b/scene/2d/audio_stream_player_2d.h
@@ -31,6 +31,7 @@
 #ifndef AUDIO_STREAM_PLAYER_2D_H
 #define AUDIO_STREAM_PLAYER_2D_H
 
+#include "core/templates/safe_refcount.h"
 #include "scene/2d/node_2d.h"
 #include "servers/audio/audio_stream.h"
 #include "servers/audio_server.h"
@@ -52,8 +53,8 @@ private:
 	};
 
 	Output outputs[MAX_OUTPUTS];
-	volatile int output_count = 0;
-	volatile bool output_ready = false;
+	SafeNumeric<int> output_count;
+	SafeFlag output_ready;
 
 	//these are used by audio thread to have a reference of previous volumes (for ramping volume and avoiding clicks)
 	Output prev_outputs[MAX_OUTPUTS];
@@ -63,9 +64,9 @@ private:
 	Ref<AudioStream> stream;
 	Vector<AudioFrame> mix_buffer;
 
-	volatile float setseek = -1.0;
-	volatile bool active = false;
-	volatile float setplay = -1.0;
+	SafeNumeric<float> setseek{ -1.0 };
+	SafeFlag active;
+	SafeNumeric<float> setplay{ -1.0 };
 
 	float volume_db = 0.0;
 	float pitch_scale = 1.0;
diff --git a/scene/3d/audio_stream_player_3d.cpp b/scene/3d/audio_stream_player_3d.cpp
index dd77221a3f..72392be5bd 100644
--- a/scene/3d/audio_stream_player_3d.cpp
+++ b/scene/3d/audio_stream_player_3d.cpp
@@ -138,15 +138,15 @@ void AudioStreamPlayer3D::_calc_output_vol(const Vector3 &source_dir, real_t tig
 }
 
 void AudioStreamPlayer3D::_mix_audio() {
-	if (!stream_playback.is_valid() || !active ||
+	if (!stream_playback.is_valid() || !active.is_set() ||
 			(stream_paused && !stream_paused_fade_out)) {
 		return;
 	}
 
 	bool started = false;
-	if (setseek >= 0.0) {
-		stream_playback->start(setseek);
-		setseek = -1.0; //reset seek
+	if (setseek.get() >= 0.0) {
+		stream_playback->start(setseek.get());
+		setseek.set(-1.0); //reset seek
 		started = true;
 	}
 
@@ -160,14 +160,14 @@ void AudioStreamPlayer3D::_mix_audio() {
 	}
 
 	// Mix if we're not paused or we're fading out
-	if ((output_count > 0 || out_of_range_mode == OUT_OF_RANGE_MIX)) {
+	if ((output_count.get() > 0 || out_of_range_mode == OUT_OF_RANGE_MIX)) {
 		float output_pitch_scale = 0.0;
-		if (output_count) {
+		if (output_count.get()) {
 			//used for doppler, not realistic but good enough
-			for (int i = 0; i < output_count; i++) {
+			for (int i = 0; i < output_count.get(); i++) {
 				output_pitch_scale += outputs[i].pitch_scale;
 			}
-			output_pitch_scale /= float(output_count);
+			output_pitch_scale /= float(output_count.get());
 		} else {
 			output_pitch_scale = 1.0;
 		}
@@ -176,7 +176,7 @@ void AudioStreamPlayer3D::_mix_audio() {
 	}
 
 	//write all outputs
-	for (int i = 0; i < output_count; i++) {
+	for (int i = 0; i < output_count.get(); i++) {
 		Output current = outputs[i];
 
 		//see if current output exists, to keep volume ramp
@@ -285,14 +285,14 @@ void AudioStreamPlayer3D::_mix_audio() {
 		prev_outputs[i] = current;
 	}
 
-	prev_output_count = output_count;
+	prev_output_count = output_count.get();
 
 	//stream is no longer active, disable this.
 	if (!stream_playback->is_playing()) {
-		active = false;
+		active.clear();
 	}
 
-	output_ready = false;
+	output_ready.clear();
 	stream_paused_fade_in = false;
 	stream_paused_fade_out = false;
 }
@@ -360,7 +360,7 @@ void AudioStreamPlayer3D::_notification(int p_what) {
 	if (p_what == NOTIFICATION_INTERNAL_PHYSICS_PROCESS) {
 		//update anything related to position first, if possible of course
 
-		if (!output_ready) {
+		if (!output_ready.is_set()) {
 			Vector3 linear_velocity;
 
 			//compute linear velocity for doppler
@@ -596,19 +596,19 @@ void AudioStreamPlayer3D::_notification(int p_what) {
 				}
 			}
 
-			output_count = new_output_count;
-			output_ready = true;
+			output_count.set(new_output_count);
+			output_ready.set();
 		}
 
 		//start playing if requested
-		if (setplay >= 0.0) {
-			setseek = setplay;
-			active = true;
-			setplay = -1;
+		if (setplay.get() >= 0.0) {
+			setseek.set(setplay.get());
+			active.set();
+			setplay.set(-1);
 		}
 
 		//stop playing if no longer active
-		if (!active) {
+		if (!active.is_set()) {
 			set_physics_process_internal(false);
 			emit_signal("finished");
 		}
@@ -623,8 +623,8 @@ void AudioStreamPlayer3D::set_stream(Ref<AudioStream> p_stream) {
 	if (stream_playback.is_valid()) {
 		stream_playback.unref();
 		stream.unref();
-		active = false;
-		setseek = -1;
+		active.clear();
+		setseek.set(-1);
 	}
 
 	if (p_stream.is_valid()) {
@@ -683,29 +683,29 @@ void AudioStreamPlayer3D::play(float p_from_pos) {
 	}
 
 	if (stream_playback.is_valid()) {
-		setplay = p_from_pos;
-		output_ready = false;
+		setplay.set(p_from_pos);
+		output_ready.clear();
 		set_physics_process_internal(true);
 	}
 }
 
 void AudioStreamPlayer3D::seek(float p_seconds) {
 	if (stream_playback.is_valid()) {
-		setseek = p_seconds;
+		setseek.set(p_seconds);
 	}
 }
 
 void AudioStreamPlayer3D::stop() {
 	if (stream_playback.is_valid()) {
-		active = false;
+		active.clear();
 		set_physics_process_internal(false);
-		setplay = -1;
+		setplay.set(-1);
 	}
 }
 
 bool AudioStreamPlayer3D::is_playing() const {
 	if (stream_playback.is_valid()) {
-		return active || setplay >= 0;
+		return active.is_set() || setplay.get() >= 0;
 	}
 
 	return false;
@@ -713,8 +713,9 @@ bool AudioStreamPlayer3D::is_playing() const {
 
 float AudioStreamPlayer3D::get_playback_position() {
 	if (stream_playback.is_valid()) {
-		if (setseek >= 0.0) {
-			return setseek;
+		float ss = setseek.get();
+		if (ss >= 0.0) {
+			return ss;
 		}
 		return stream_playback->get_playback_position();
 	}
@@ -755,7 +756,7 @@ void AudioStreamPlayer3D::_set_playing(bool p_enable) {
 }
 
 bool AudioStreamPlayer3D::_is_active() const {
-	return active;
+	return active.is_set();
 }
 
 void AudioStreamPlayer3D::_validate_property(PropertyInfo &property) const {
diff --git a/scene/3d/audio_stream_player_3d.h b/scene/3d/audio_stream_player_3d.h
index 33ed758749..70c535bd89 100644
--- a/scene/3d/audio_stream_player_3d.h
+++ b/scene/3d/audio_stream_player_3d.h
@@ -31,6 +31,7 @@
 #ifndef AUDIO_STREAM_PLAYER_3D_H
 #define AUDIO_STREAM_PLAYER_3D_H
 
+#include "core/templates/safe_refcount.h"
 #include "scene/3d/node_3d.h"
 #include "scene/3d/velocity_tracker_3d.h"
 #include "servers/audio/audio_filter_sw.h"
@@ -80,8 +81,8 @@ private:
 	};
 
 	Output outputs[MAX_OUTPUTS];
-	volatile int output_count = 0;
-	volatile bool output_ready = false;
+	SafeNumeric<int> output_count;
+	SafeFlag output_ready;
 
 	//these are used by audio thread to have a reference of previous volumes (for ramping volume and avoiding clicks)
 	Output prev_outputs[MAX_OUTPUTS];
@@ -91,9 +92,9 @@ private:
 	Ref<AudioStream> stream;
 	Vector<AudioFrame> mix_buffer;
 
-	volatile float setseek = -1.0;
-	volatile bool active = false;
-	volatile float setplay = -1.0;
+	SafeNumeric<float> setseek{ -1.0 };
+	SafeFlag active;
+	SafeNumeric<float> setplay{ -1.0 };
 
 	AttenuationModel attenuation_model = ATTENUATION_INVERSE_DISTANCE;
 	float unit_db = 0.0;
diff --git a/scene/3d/cpu_particles_3d.cpp b/scene/3d/cpu_particles_3d.cpp
index 979c6424b8..d22d7ff3ab 100644
--- a/scene/3d/cpu_particles_3d.cpp
+++ b/scene/3d/cpu_particles_3d.cpp
@@ -1074,7 +1074,7 @@ void CPUParticles3D::_update_particle_data_buffer() {
 		ptr += 20;
 	}
 
-	can_update = true;
+	can_update.set();
 }
 
 void CPUParticles3D::_set_redraw(bool p_redraw) {
@@ -1103,9 +1103,9 @@ void CPUParticles3D::_set_redraw(bool p_redraw) {
 void CPUParticles3D::_update_render_thread() {
 	MutexLock lock(update_mutex);
 
-	if (can_update) {
+	if (can_update.is_set()) {
 		RS::get_singleton()->multimesh_set_buffer(multimesh, particle_data);
-		can_update = false; //wait for next time
+		can_update.clear(); //wait for next time
 	}
 }
 
@@ -1167,7 +1167,7 @@ void CPUParticles3D::_notification(int p_what) {
 				ptr += 20;
 			}
 
-			can_update = true;
+			can_update.set();
 		}
 	}
 }
@@ -1468,6 +1468,21 @@ CPUParticles3D::CPUParticles3D() {
 	set_param(PARAM_HUE_VARIATION, 0);
 	set_param(PARAM_ANIM_SPEED, 0);
 	set_param(PARAM_ANIM_OFFSET, 0);
+	set_emission_shape(EMISSION_SHAPE_POINT);
+	set_emission_sphere_radius(1);
+	set_emission_box_extents(Vector3(1, 1, 1));
+
+	set_gravity(Vector3(0, -9.8, 0));
+
+	for (int i = 0; i < PARAM_MAX; i++) {
+		set_param_randomness(Parameter(i), 0);
+	}
+
+	for (int i = 0; i < PARTICLE_FLAG_MAX; i++) {
+		particle_flags[i] = false;
+	}
+
+	set_color(Color(1, 1, 1, 1));
 }
 
 CPUParticles3D::~CPUParticles3D() {
diff --git a/scene/3d/cpu_particles_3d.h b/scene/3d/cpu_particles_3d.h
index 4af959a7bf..10ac32622d 100644
--- a/scene/3d/cpu_particles_3d.h
+++ b/scene/3d/cpu_particles_3d.h
@@ -32,6 +32,7 @@
 #define CPU_PARTICLES_H
 
 #include "core/templates/rid.h"
+#include "core/templates/safe_refcount.h"
 #include "scene/3d/visual_instance_3d.h"
 
 class CPUParticles3D : public GeometryInstance3D {
@@ -142,7 +143,7 @@ private:
 
 	Transform inv_emission_transform;
 
-	volatile bool can_update = false;
+	SafeFlag can_update;
 
 	DrawOrder draw_order = DRAW_ORDER_INDEX;
 
diff --git a/scene/audio/audio_stream_player.cpp b/scene/audio/audio_stream_player.cpp
index ec0a4b8696..7957571ab7 100644
--- a/scene/audio/audio_stream_player.cpp
+++ b/scene/audio/audio_stream_player.cpp
@@ -99,7 +99,7 @@ void AudioStreamPlayer::_mix_audio() {
 		use_fadeout = false;
 	}
 
-	if (!stream_playback.is_valid() || !active ||
+	if (!stream_playback.is_valid() || !active.is_set() ||
 			(stream_paused && !stream_paused_fade)) {
 		return;
 	}
@@ -112,24 +112,24 @@ void AudioStreamPlayer::_mix_audio() {
 		return;
 	}
 
-	if (setstop) {
+	if (setstop.is_set()) {
 		_mix_internal(true);
 		stream_playback->stop();
-		setstop = false;
+		setstop.clear();
 	}
 
-	if (setseek >= 0.0 && !stop_has_priority) {
+	if (setseek.get() >= 0.0 && !stop_has_priority.is_set()) {
 		if (stream_playback->is_playing()) {
 			//fade out to avoid pops
 			_mix_internal(true);
 		}
 
-		stream_playback->start(setseek);
-		setseek = -1.0; //reset seek
+		stream_playback->start(setseek.get());
+		setseek.set(-1.0); //reset seek
 		mix_volume_db = volume_db; //reset ramp
 	}
 
-	stop_has_priority = false;
+	stop_has_priority.clear();
 
 	_mix_internal(false);
 }
@@ -143,8 +143,8 @@ void AudioStreamPlayer::_notification(int p_what) {
 	}
 
 	if (p_what == NOTIFICATION_INTERNAL_PROCESS) {
-		if (!active || (setseek < 0 && !stream_playback->is_playing())) {
-			active = false;
+		if (!active.is_set() || (setseek.get() < 0 && !stream_playback->is_playing())) {
+			active.clear();
 			set_process_internal(false);
 			emit_signal("finished");
 		}
@@ -169,7 +169,7 @@ void AudioStreamPlayer::_notification(int p_what) {
 void AudioStreamPlayer::set_stream(Ref<AudioStream> p_stream) {
 	AudioServer::get_singleton()->lock();
 
-	if (active && stream_playback.is_valid() && !stream_paused) {
+	if (active.is_set() && stream_playback.is_valid() && !stream_paused) {
 		//changing streams out of the blue is not a great idea, but at least
 		//lets try to somehow avoid a click
 
@@ -196,9 +196,9 @@ void AudioStreamPlayer::set_stream(Ref<AudioStream> p_stream) {
 	if (stream_playback.is_valid()) {
 		stream_playback.unref();
 		stream.unref();
-		active = false;
-		setseek = -1;
-		setstop = false;
+		active.clear();
+		setseek.set(-1);
+		setstop.clear();
 	}
 
 	if (p_stream.is_valid()) {
@@ -237,29 +237,29 @@ float AudioStreamPlayer::get_pitch_scale() const {
 void AudioStreamPlayer::play(float p_from_pos) {
 	if (stream_playback.is_valid()) {
 		//mix_volume_db = volume_db; do not reset volume ramp here, can cause clicks
-		setseek = p_from_pos;
-		stop_has_priority = false;
-		active = true;
+		setseek.set(p_from_pos);
+		stop_has_priority.clear();
+		active.set();
 		set_process_internal(true);
 	}
 }
 
 void AudioStreamPlayer::seek(float p_seconds) {
 	if (stream_playback.is_valid()) {
-		setseek = p_seconds;
+		setseek.set(p_seconds);
 	}
 }
 
 void AudioStreamPlayer::stop() {
-	if (stream_playback.is_valid() && active) {
-		setstop = true;
-		stop_has_priority = true;
+	if (stream_playback.is_valid() && active.is_set()) {
+		setstop.set();
+		stop_has_priority.set();
 	}
 }
 
 bool AudioStreamPlayer::is_playing() const {
 	if (stream_playback.is_valid()) {
-		return active && !setstop; //&& stream_playback->is_playing();
+		return active.is_set() && !setstop.is_set(); //&& stream_playback->is_playing();
 	}
 
 	return false;
@@ -267,8 +267,9 @@ bool AudioStreamPlayer::is_playing() const {
 
 float AudioStreamPlayer::get_playback_position() {
 	if (stream_playback.is_valid()) {
-		if (setseek >= 0.0) {
-			return setseek;
+		float ss = setseek.get();
+		if (ss >= 0.0) {
+			return ss;
 		}
 		return stream_playback->get_playback_position();
 	}
@@ -317,7 +318,7 @@ void AudioStreamPlayer::_set_playing(bool p_enable) {
 }
 
 bool AudioStreamPlayer::_is_active() const {
-	return active;
+	return active.is_set();
 }
 
 void AudioStreamPlayer::set_stream_paused(bool p_pause) {
diff --git a/scene/audio/audio_stream_player.h b/scene/audio/audio_stream_player.h
index ab98d41302..d8f83ee38d 100644
--- a/scene/audio/audio_stream_player.h
+++ b/scene/audio/audio_stream_player.h
@@ -31,6 +31,7 @@
 #ifndef AUDIO_STREAM_PLAYER_H
 #define AUDIO_STREAM_PLAYER_H
 
+#include "core/templates/safe_refcount.h"
 #include "scene/main/node.h"
 #include "servers/audio/audio_stream.h"
 
@@ -49,12 +50,12 @@ private:
 	Ref<AudioStream> stream;
 	Vector<AudioFrame> mix_buffer;
 	Vector<AudioFrame> fadeout_buffer;
-	bool use_fadeout = false;
+	bool use_fadeout;
 
-	volatile float setseek = -1.0;
-	volatile bool active = false;
-	volatile bool setstop = false;
-	volatile bool stop_has_priority = false;
+	SafeNumeric<float> setseek{ -1.0 };
+	SafeFlag active;
+	SafeFlag setstop;
+	SafeFlag stop_has_priority;
 
 	float mix_volume_db = 0.0;
 	float pitch_scale = 1.0;
diff --git a/scene/main/http_request.cpp b/scene/main/http_request.cpp
index 384e7d2652..ce7d6ef13c 100644
--- a/scene/main/http_request.cpp
+++ b/scene/main/http_request.cpp
@@ -49,7 +49,7 @@ Error HTTPRequest::_parse_url(const String &p_url) {
 	got_response = false;
 	body_len = -1;
 	body.resize(0);
-	downloaded = 0;
+	downloaded.set(0);
 	redirections = 0;
 
 	String url_lower = url.to_lower();
@@ -159,9 +159,9 @@ Error HTTPRequest::request_raw(const String &p_url, const Vector<String> &p_cust
 
 	requesting = true;
 
-	if (use_threads) {
-		thread_done = false;
-		thread_request_quit = false;
+	if (use_threads.is_set()) {
+		thread_done.clear();
+		thread_request_quit.clear();
 		client->set_blocking_mode(true);
 		thread.start(_thread_func, this);
 	} else {
@@ -186,7 +186,7 @@ void HTTPRequest::_thread_func(void *p_userdata) {
 	if (err != OK) {
 		hr->call_deferred("_request_done", RESULT_CANT_CONNECT, 0, PackedStringArray(), PackedByteArray());
 	} else {
-		while (!hr->thread_request_quit) {
+		while (!hr->thread_request_quit.is_set()) {
 			bool exit = hr->_update_connection();
 			if (exit) {
 				break;
@@ -195,7 +195,7 @@ void HTTPRequest::_thread_func(void *p_userdata) {
 		}
 	}
 
-	hr->thread_done = true;
+	hr->thread_done.set();
 }
 
 void HTTPRequest::cancel_request() {
@@ -205,10 +205,10 @@ void HTTPRequest::cancel_request() {
 		return;
 	}
 
-	if (!use_threads) {
+	if (!use_threads.is_set()) {
 		set_process_internal(false);
 	} else {
-		thread_request_quit = true;
+		thread_request_quit.set();
 		thread.wait_to_finish();
 	}
 
@@ -236,7 +236,7 @@ bool HTTPRequest::_handle_response(bool *ret_value) {
 	List<String> rheaders;
 	client->get_response_headers(&rheaders);
 	response_headers.resize(0);
-	downloaded = 0;
+	downloaded.set(0);
 	for (List<String>::Element *E = rheaders.front(); E; E = E->next()) {
 		response_headers.push_back(E->get());
 	}
@@ -276,7 +276,7 @@ bool HTTPRequest::_handle_response(bool *ret_value) {
 				got_response = false;
 				body_len = -1;
 				body.resize(0);
-				downloaded = 0;
+				downloaded.set(0);
 				redirections = new_redirs;
 				*ret_value = false;
 				return true;
@@ -389,7 +389,7 @@ bool HTTPRequest::_update_connection() {
 			client->poll();
 
 			PackedByteArray chunk = client->read_response_body_chunk();
-			downloaded += chunk.size();
+			downloaded.add(chunk.size());
 
 			if (file) {
 				const uint8_t *r = chunk.ptr();
@@ -402,13 +402,13 @@ bool HTTPRequest::_update_connection() {
 				body.append_array(chunk);
 			}
 
-			if (body_size_limit >= 0 && downloaded > body_size_limit) {
+			if (body_size_limit >= 0 && downloaded.get() > body_size_limit) {
 				call_deferred("_request_done", RESULT_BODY_SIZE_LIMIT_EXCEEDED, response_code, response_headers, PackedByteArray());
 				return true;
 			}
 
 			if (body_len >= 0) {
-				if (downloaded == body_len) {
+				if (downloaded.get() == body_len) {
 					call_deferred("_request_done", RESULT_SUCCESS, response_code, response_headers, body);
 					return true;
 				}
@@ -478,7 +478,7 @@ void HTTPRequest::_request_done(int p_status, int p_code, const PackedStringArra
 
 void HTTPRequest::_notification(int p_what) {
 	if (p_what == NOTIFICATION_INTERNAL_PROCESS) {
-		if (use_threads) {
+		if (use_threads.is_set()) {
 			return;
 		}
 		bool done = _update_connection();
@@ -497,11 +497,11 @@ void HTTPRequest::_notification(int p_what) {
 
 void HTTPRequest::set_use_threads(bool p_use) {
 	ERR_FAIL_COND(get_http_client_status() != HTTPClient::STATUS_DISCONNECTED);
-	use_threads = p_use;
+	use_threads.set_to(p_use);
 }
 
 bool HTTPRequest::is_using_threads() const {
-	return use_threads;
+	return use_threads.is_set();
 }
 
 void HTTPRequest::set_accept_gzip(bool p_gzip) {
@@ -555,7 +555,7 @@ int HTTPRequest::get_max_redirects() const {
 }
 
 int HTTPRequest::get_downloaded_bytes() const {
-	return downloaded;
+	return downloaded.get();
 }
 
 int HTTPRequest::get_body_size() const {
diff --git a/scene/main/http_request.h b/scene/main/http_request.h
index 5525ea7912..92b0ff28e9 100644
--- a/scene/main/http_request.h
+++ b/scene/main/http_request.h
@@ -34,6 +34,7 @@
 #include "core/io/http_client.h"
 #include "core/os/file_access.h"
 #include "core/os/thread.h"
+#include "core/templates/safe_refcount.h"
 #include "node.h"
 #include "scene/main/timer.h"
 
@@ -74,7 +75,7 @@ private:
 	bool request_sent = false;
 	Ref<HTTPClient> client;
 	PackedByteArray body;
-	volatile bool use_threads = false;
+	SafeFlag use_threads;
 	bool accept_gzip = true;
 
 	bool got_response = false;
@@ -86,7 +87,7 @@ private:
 	FileAccess *file = nullptr;
 
 	int body_len = -1;
-	volatile int downloaded = 0;
+	SafeNumeric<int> downloaded;
 	int body_size_limit = -1;
 
 	int redirections = 0;
@@ -107,8 +108,8 @@ private:
 	bool has_header(const PackedStringArray &p_headers, const String &p_header_name);
 	String get_header_value(const PackedStringArray &p_headers, const String &header_name);
 
-	volatile bool thread_done = false;
-	volatile bool thread_request_quit = false;
+	SafeFlag thread_done;
+	SafeFlag thread_request_quit;
 
 	Thread thread;
 
diff --git a/scene/resources/visual_shader.cpp b/scene/resources/visual_shader.cpp
index a296156bf5..d8e63e47be 100644
--- a/scene/resources/visual_shader.cpp
+++ b/scene/resources/visual_shader.cpp
@@ -1400,11 +1400,11 @@ bool VisualShader::has_func_name(RenderingServer::ShaderMode p_mode, const Strin
 }
 
 void VisualShader::_update_shader() const {
-	if (!dirty) {
+	if (!dirty.is_set()) {
 		return;
 	}
 
-	dirty = false;
+	dirty.clear();
 
 	StringBuilder global_code;
 	StringBuilder global_code_per_node;
@@ -1590,11 +1590,11 @@ void VisualShader::_update_shader() const {
 }
 
 void VisualShader::_queue_update() {
-	if (dirty) {
+	if (dirty.is_set()) {
 		return;
 	}
 
-	dirty = true;
+	dirty.set();
 	call_deferred("_update_shader");
 }
 
@@ -1614,7 +1614,7 @@ void VisualShader::_input_type_changed(Type p_type, int p_id) {
 }
 
 void VisualShader::rebuild() {
-	dirty = true;
+	dirty.set();
 	_update_shader();
 }
 
@@ -1668,6 +1668,7 @@ void VisualShader::_bind_methods() {
 }
 
 VisualShader::VisualShader() {
+	dirty.set();
 	for (int i = 0; i < TYPE_MAX; i++) {
 		Ref<VisualShaderNodeOutput> output;
 		output.instance();
diff --git a/scene/resources/visual_shader.h b/scene/resources/visual_shader.h
index f3f3caf15e..ef724c7650 100644
--- a/scene/resources/visual_shader.h
+++ b/scene/resources/visual_shader.h
@@ -32,6 +32,7 @@
 #define VISUAL_SHADER_H
 
 #include "core/string/string_builder.h"
+#include "core/templates/safe_refcount.h"
 #include "scene/gui/control.h"
 #include "scene/resources/shader.h"
 
@@ -99,7 +100,7 @@ private:
 
 	static RenderModeEnums render_mode_enums[];
 
-	volatile mutable bool dirty = true;
+	mutable SafeFlag dirty;
 	void _queue_update();
 
 	union ConnectionKey {