PTY output not shown without GUI activity

[lihop]

I also encountered another problem, but I don't know if it can be related to this one.

With the same setup (scene with Terminal,Pty and other input nodes) if I execute a command with sudo the terminal screen do not show the command output, to force a refresh I need to press a key or click on other input field to switch focus.

The same command executed without sudo works as expected, the screen show the output.

ping www.google.com works
sudo ping www.google.com doesn't work

Originally posted by @ConteZero in #51 (comment)

[lihop]

@ConteZero I am not able to reproduce this issue in the test scene:

However, I faced a similar issue when developing the integrated terminal EditorPlugin.

When making the integrated terminal for editor I noticed that the output would not update unless moving the cursor to focus on another panel or after some other type of gui activity (e.g. button click, scroll, cursor blink, etc.). The output from PTY is only updated by calling poll() in _process():

godot-xterm/addons/godot_xterm/nodes/pty/unix/pty_unix.gd

Lines 129 to 131 in 2acb93f

	func _process(_delta):
	if _pipe:
	_pipe.poll()

In editor, _process() is not continuously called unless the editor setting 'update continuously' is set to on:

However, this issue affected all command output regardless of whether it had sudo or not:

My workaround was to add a timer to regularly call poll() on the underlying pipe:

godot-xterm/addons/godot_xterm/editor_plugins/terminal/editor_terminal.gd

Lines 54 to 66 in 3b7bdfc

	# In editor _process is not called continuously unless the "Update Continuously"
	# editor setting is enabled. This setting is disabled by default and uses 100%
	# of one core when enabled, so best to leave it off and use a timer instead.
	add_child(timer)
	timer.wait_time = 0.025
	timer.connect("timeout", self, "_poll")
	timer.start()
	func _poll():
	if pty and pty.has_method("get_master"):
	pty.get_master().poll()
	update()

I now notice that _physics_process() is called continuously in editor, so I will consider moving the poll from _process() to _physics_process() or adding a process_mode property (like Timer has) to choose between the two.

Could you try changing func _process(_delta) in addons/godot_xterm/nodes/pty/unix/pty_unix.gd to func _physics_process(_delta), or force a regular update by calling pty.get_master().poll() with a timer?

Also, on the off chance that the issue isn't related to the PTY node, but rather the update functions of the Terminal node, you could try setting the update_mode property of Terminal to All (although this will have a slight performance penalty).

If none of these suggestions fix the problem, then I would be interested in more details about your scene setup and operating system version/environment to try and reproduce the issue and figure out why sudo commands might affect the output differently.

[ConteZero]

After doing same code changes to my project now I have the same update problem with and without sudo (update_mode is set to All), probably the differences between the two modes were caused by something wrong with my code.

Luckily your suggestion solves the problem, I've added to my terminal.gd:

func _on_PTY_data_received(data):
#	parsing 'data' code
	_poll()


func _poll():
	if visible and pty and pty.has_method("get_master"): 
		pty.get_master().poll() 
		update()

Thanks for your help.

[lihop]

After digging a bit deeper, I have found that simply adding update() at the end of terminal's write function fixes the issue I outlined above, and removes the need for a timer with the editor plugin.

@ConteZero Would you be able to undo the changes you made above and, in terminal.gd, change this code:

func write(data) -> void:
	assert(data is String or data is PoolByteArray)

	# Will be cleared when _flush() is called after VisualServer emits the "frame_pre_draw" signal.
	_buffer.push_back(data)

to this:

func write(data) -> void:
	assert(data is String or data is PoolByteArray)

	# Will be cleared when _flush() is called after VisualServer emits the "frame_pre_draw" signal.
	_buffer.push_back(data)
	update()

and let me know if that also fixes the problem?

[ConteZero]

I did various tests using _poll(), initially seemed to have solved the problem, instead I found that sometimes some data was not written on the terminal screen.

For now your last solution seems to work well, the only drawback is that it slowdown the execution when the terminal is not visible.
I've changed it to:

func write(data) -> void:
	assert(data is String or data is PoolByteArray)

	# Will be cleared when _flush() is called after VisualServer emits the "frame_pre_draw" signal.
	_buffer.push_back(data)
	if visible:
		update()

This change avoid the slowdown but I don't know if it's right and if it can have unwanted side effects.

[lihop]

For now your last solution seems to work well, the only drawback is that it slowdown the execution when the terminal is not visible.

@ConteZero Could you try the last solution but with the terminal's update_mode set to the default of Auto rather than All? I'm curious to know if it will still slowdown execution.

Otherwise, I can't think of any unwanted side effect that calling update() only if visible would have.

[ConteZero]

There are no speed differences between update_mode Auto and All.