BGE python thread or socket problem: script stopped between 2 lines #43990

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jimy-byerley · 2015-03-14T09:24:40+01:00

jimy-byerley commented

2015-03-14 09:24:40 +01:00

I wrote a simple module to use easely the python TCP socket to create game. With it it is possible to synchronize some object's rotation, location, properties, ...
But when I test it, there is a problem.
BGE seems to be stopping the scrit during the execution or anything like this.
I start the server (server-test.py) on python 3.2 in a shell
I open client-test.blend with blender 2.73 and I launch the game.
the client connect himself to the server, and normaly sends sync requests, but the script is stopped just at line 46 of file client.py
and it continues when I stop the BGE !

Here is my work BGE-bug-socket.zip

the server console output is then :

[('192.168.1.10', 45619)]
{}
[('192.168.1.10', 45619)]
{}
[('192.168.1.10', 45619)]
{}
getpacket: 'registerloc\x00Cube'
getpacket: 'registerrot\x00Cube'
getpacket: 'registerprop\x00Cube\x00prop'
send 'setloc\x000\x000\x000\x00Cube'
send 'setrot\x000\x000\x000\x00Cube'
send 'setprop\x00Cube\x00prop\x00None'
send 'setloc\x000\x000\x000\x00Cube'
send 'setrot\x000\x000\x000\x00Cube'
send 'setprop\x00Cube\x00prop\x00None'
send 'setloc\x000\x000\x000\x00Cube'
Exception in thread Thread-1:
Traceback (most recent call last):
  File "/usr/lib/python3.2/threading.py", line 740, in _bootstrap_inner
    self.run()
  File "/home/jimy/tron-reboot/server/BGE-bug-socket/server.py", line 140, in run
    if data.position : self.sendall('setloc\0%d\0%d\0%d\0%s' % (data.position[0], data.position[1], data.position[2], obj))
  File "/home/jimy/tron-reboot/server/BGE-bug-socket/basic_connection.py", line 206, in sendall
    self.send(i, data)
  File "/home/jimy/tron-reboot/server/BGE-bug-socket/basic_connection.py", line 202, in send
    self.tunnels[index].send('{}{}{}'.format(START_MARK, str(data), END_MARK).encode())
socket.error: [Errno 32] Broken pipe

[('192.168.1.10', 45619)]
{'Cube': {pos=(0, 0, 0),         rot=(0, 0, 0),  parent=False,   properties={'prop': None}}}
[('192.168.1.10', 45619)]
{'Cube': {pos=(0, 0, 0),         rot=(0, 0, 0),  parent=False,   properties={'prop': None}}}
^CTraceback (most recent call last):
  File "server-test.py", line 12, in <module>
    sleep(1)
KeyboardInterrupt

All is normal on this side : when the server receive the requests, it starts synching.

The client continue execution only after the BGE stopped (after Blender Game Engine Finished)
The client side get :

Blender Game Engine Started
send queued
Blender Game Engine Finished
queue
send 'registerloc\x00Cube'
queue
send 'registerrot\x00Cube'
queue
send 'registerprop\x00Cube\x00prop'
receiving
getpacket
no packet
send queued
receiving
getpacket
getpacket: 'setloc\x000\x000\x000\x00Cube'
confirmed
Writing: /tmp/client-test.crash.txt
/usr/local/bin/blender : ligne 2 : 17951 Erreur de segmentation  /usr/local/share/blender/blender "$@"

Please help me !
I am on a important game project and I need multiplayer (tron-R {reboot|reloaded} .

jimy.byerley@gmail.com

I wrote a simple module to use easely the python TCP socket to create game. With it it is possible to synchronize some object's rotation, location, properties, ... But when I test it, there is a problem. BGE seems to be stopping the scrit during the execution or anything like this. I start the server (server-test.py) on python 3.2 in a shell I open client-test.blend with blender 2.73 and I launch the game. the client connect himself to the server, and normaly sends sync requests, but the script is stopped just at line 46 of file client.py and it continues when I stop the BGE ! Here is my work [BGE-bug-socket.zip](https://archive.blender.org/developer/F151233/BGE-bug-socket.zip) the server console output is then : ``` [('192.168.1.10', 45619)] {} [('192.168.1.10', 45619)] {} [('192.168.1.10', 45619)] {} getpacket: 'registerloc\x00Cube' getpacket: 'registerrot\x00Cube' getpacket: 'registerprop\x00Cube\x00prop' send 'setloc\x000\x000\x000\x00Cube' send 'setrot\x000\x000\x000\x00Cube' send 'setprop\x00Cube\x00prop\x00None' send 'setloc\x000\x000\x000\x00Cube' send 'setrot\x000\x000\x000\x00Cube' send 'setprop\x00Cube\x00prop\x00None' send 'setloc\x000\x000\x000\x00Cube' Exception in thread Thread-1: Traceback (most recent call last): File "/usr/lib/python3.2/threading.py", line 740, in _bootstrap_inner self.run() File "/home/jimy/tron-reboot/server/BGE-bug-socket/server.py", line 140, in run if data.position : self.sendall('setloc\0%d\0%d\0%d\0%s' % (data.position[0], data.position[1], data.position[2], obj)) File "/home/jimy/tron-reboot/server/BGE-bug-socket/basic_connection.py", line 206, in sendall self.send(i, data) File "/home/jimy/tron-reboot/server/BGE-bug-socket/basic_connection.py", line 202, in send self.tunnels[index].send('{}{}{}'.format(START_MARK, str(data), END_MARK).encode()) socket.error: [Errno 32] Broken pipe [('192.168.1.10', 45619)] {'Cube': {pos=(0, 0, 0), rot=(0, 0, 0), parent=False, properties={'prop': None}}} [('192.168.1.10', 45619)] {'Cube': {pos=(0, 0, 0), rot=(0, 0, 0), parent=False, properties={'prop': None}}} ^CTraceback (most recent call last): File "server-test.py", line 12, in <module> sleep(1) KeyboardInterrupt ``` All is normal on this side : when the server receive the requests, it starts synching. The client continue execution only after the BGE stopped (after Blender Game Engine Finished) The client side get : ``` Blender Game Engine Started send queued Blender Game Engine Finished queue send 'registerloc\x00Cube' queue send 'registerrot\x00Cube' queue send 'registerprop\x00Cube\x00prop' receiving getpacket no packet send queued receiving getpacket getpacket: 'setloc\x000\x000\x000\x00Cube' confirmed Writing: /tmp/client-test.crash.txt /usr/local/bin/blender : ligne 2 : 17951 Erreur de segmentation /usr/local/share/blender/blender "$@" ``` Please help me ! I am on a important game project and I need multiplayer ([tron-R {reboot|reloaded} ](http://blenderartists.org/forum/showthread.php?362226-Tron-R-reboot-reloaded-An-open-source-openworld-of-tron). jimy.byerley@gmail.com

jimy-byerley commented

2015-03-14 09:24:40 +01:00

Changed status to: 'Open'

jimy-byerley commented

2015-03-14 09:24:40 +01:00

Added subscribers: @jimy-byerley, @mont29, @JorgeBernalMartinez

Jorge Bernal commented

2015-03-16 02:41:44 +01:00

I can not connect to the server.

Blender Game Engine Started
Python script error - object 'Cube', controller 'Python':
Traceback (most recent call last):
  File "setup", line 6, in <module>
  File "/home/lordloki/Pruebas/BGE-bug-socket/basic_connection.py", line 17, in __init__
    self.tunnel.connect(addr)
OSError: [Errno 113] No route to host
Blender Game Engine Finished

Anyway, this doesn't seem a BGE bug. It seems threading bug in the client-server code

I can not connect to the server. ``` Blender Game Engine Started Python script error - object 'Cube', controller 'Python': Traceback (most recent call last): File "setup", line 6, in <module> File "/home/lordloki/Pruebas/BGE-bug-socket/basic_connection.py", line 17, in __init__ self.tunnel.connect(addr) OSError: [Errno 113] No route to host Blender Game Engine Finished ``` Anyway, this doesn't seem a BGE bug. It seems threading bug in the client-server code

jimy-byerley commented

2015-03-16 16:23:17 +01:00

There is an updated version of my test (now, client ip is detected automaticaly to work on localhost: client-test.blend).
BGE-bug-socket.zip

There is an updated version of my test (now, client ip is detected automaticaly to work on localhost: client-test.blend). [BGE-bug-socket.zip](https://archive.blender.org/developer/F152178/BGE-bug-socket.zip)

Jorge Bernal commented

2015-03-16 23:53:13 +01:00

You have the issue in file client.py line 49:

self.send(self.queue[0])

the crash comes from same file, line 59:

scene = bge.logic.getCurrentScene()

but it is normal because you want to accede to the scene after the game engine is finished.

Has you tried to get help from blenderartists? I don't see that the issue is related with bge itself.

You have the issue in file client.py line 49: ``` self.send(self.queue[0]) ``` the crash comes from same file, line 59: ``` scene = bge.logic.getCurrentScene() ``` but it is normal because you want to accede to the scene after the game engine is finished. Has you tried to get help from blenderartists? I don't see that the issue is related with bge itself.

jimy-byerley commented

2015-03-17 10:48:17 +01:00

My problem in not the crash of blender, but the pause in the script between line 46 and 47 (the client prints 'queue' only after the game was stopped by user.
I also tested it using Wireshark, no packet are sent before the client was stopped.

I will try to find some help on blenderartist, in case it is not a bug from BGE.

My problem in not the crash of blender, but the pause in the script between line 46 and 47 (the client prints 'queue' only after the game was stopped by user. I also tested it using Wireshark, no packet are sent before the client was stopped. I will try to find some help on blenderartist, in case it is not a bug from BGE.

Jorge Bernal commented

2015-03-17 14:54:32 +01:00

Changed status from 'Open' to: 'Archived'

Jorge Bernal closed this issue

2015-03-17 14:54:32 +01:00

Jorge Bernal self-assigned this 2015-03-17 14:54:32 +01:00

Jorge Bernal commented

2015-03-17 14:54:32 +01:00

I saw at blenderartists that the issue was related to the use of blocking sockets instead of non-blocking sockets.

Then, I close the bug report as BGE is not affected.

Thanks for reporting.

I saw at blenderartists that the issue was related to the use of blocking sockets instead of non-blocking sockets. Then, I close the bug report as BGE is not affected. Thanks for reporting.

Dalai Felinto commented

2015-03-17 15:25:11 +01:00

Added subscriber: @dfelinto

Dalai Felinto commented

2015-03-17 15:25:11 +01:00

people should ALWAYS use preemptive/non-blocking sockets with the BGE, since there is no real python threading available there

jimy-byerley commented

2015-03-17 18:15:52 +01:00

Don't close !
I use non blocking sockets for transmission (basic_connection.py : line 18) and anyway, it is when I send a mail that the script is stopped, but just between 2 code lines witout any network usage.

As you see up, script prints "send queued" from client.py line 46.
Then, the script was stopped. After "Game engine finished", the script prints "queue" from client.py line 48.
And so the 'Client.send()' method was not called before.

For me the scripts stops at line 47 from file client.py :

for i in range(len(self.queue)):

I didn't find this issue anywhere else, I it the reason why I report it.

Don't close ! I use non blocking sockets for transmission (basic_connection.py : line 18) and anyway, it is when I send a mail that the script is stopped, but just between 2 code lines witout any network usage. As you see up, script prints "send queued" from client.py line 46. Then, the script was stopped. After "Game engine finished", the script prints "queue" from client.py line 48. And so the 'Client.send()' method was not called before. For me the scripts stops at line 47 from file client.py : ``` for i in range(len(self.queue)): ``` I didn't find this issue anywhere else, I it the reason why I report it.

Jorge Bernal commented

2015-03-17 19:57:23 +01:00

Changed status from 'Archived' to: 'Open'

Jorge Bernal reopened this issue

2015-03-17 19:57:23 +01:00

Jorge Bernal commented

2015-03-17 19:57:23 +01:00

Sorry for closing.

It was a coincident that someone asked for the same issue at the same time, at blenderartists: http://blenderartists.org/forum/showthread.php?365621-Sending-data-via-sockets

Sorry for closing. It was a coincident that someone asked for the same issue at the same time, at blenderartists: http://blenderartists.org/forum/showthread.php?365621-Sending-data-via-sockets

Jorge Bernal commented

2015-03-28 20:20:18 +01:00

If you find a solution and the problem is not related to bge, please report it here.

jimy-byerley commented

2015-03-30 16:06:29 +02:00

I found no solution yet, it is why I am here. But of course, if I find I will report it.

Jorge Bernal removed their assignment 2015-04-05 17:59:00 +02:00

Angus Hollands was assigned by Jorge Bernal

2015-05-17 02:54:07 +02:00

Jorge Bernal commented

2015-05-17 02:54:07 +02:00

Agoose, could you check it?

Angus Hollands commented

2015-05-17 14:59:47 +02:00

I've read through the code, and It's too hard to follow and quickly find a solution.
However, it seems pretty clear that this is simply a threading issue, which is probably due to a lock somewhere being held (or another thread taking all the processing). It's hard to discern from this file, but I've happily used threads in my own projects with no issue (TCP).

I would advise not to use boolean variables as locks, as they won't function correctly. Neither would I advise accessing the BGE API from a separate thread, as it won't function as expected, especially global state like getCurrentScene() / getCurrentController(). Instead use a queue (queue.Queue) to send data (position copy, orientation copy, ...) to/from BGE.

I've read through the code, and It's too hard to follow and quickly find a solution. However, it seems pretty clear that this is simply a threading issue, which is probably due to a lock somewhere being held (or another thread taking all the processing). It's hard to discern from this file, but I've happily used threads in my own projects with no issue (TCP). I would advise not to use boolean variables as locks, as they won't function correctly. Neither would I advise accessing the BGE API from a separate thread, as it won't function as expected, especially global state like getCurrentScene() / getCurrentController(). Instead use a queue (queue.Queue) to send data (position copy, orientation copy, ...) to/from BGE.

Angus Hollands commented

2015-05-17 15:00:06 +02:00

Changed status from 'Open' to: 'Archived'

Angus Hollands closed this issue

2015-05-17 15:00:06 +02:00

jimy-byerley commented

2015-06-21 09:24:42 +02:00

I recently tried blender 2.75 RC2, Blender doesn't crash when I press ESCAPE (but it is not the interesting point). I have the same problem : The script stops at the same line and continue only when BGE is ended (in blender interface).

I recently tried blender **2.75** RC2, Blender doesn't crash when I press ESCAPE (but it is not the interesting point). I have the same problem : The script stops at the same line and continue only when BGE is ended (in blender interface).

jimy-byerley commented

2015-06-21 09:27:22 +02:00

I use threads for accessing the BGE in my main project: Tron-R
And it never made any problem.

I use threads for accessing the BGE in my main project: [Tron-R ](http://blenderartists.org/forum/showthread.php?362226-Tron-R-reboot-reloaded-An-open-source-openworld-of-tron) And it never made any problem.

eson commented

2016-12-14 12:39:15 +01:00

Added subscriber: @esoneson

eson commented

2016-12-14 12:39:15 +01:00

I just ran in to this problem myself and can confirm that it still exists, It is also looking like it is a blender problem and not a bug in the threading as my code is working in a pure python console window.

to produce this problem you need to creat a thread, run it using .start(). Inside of the thread, try to use any tcp socket commands, the commands won't be executed until you exit blender GE. if you run the thread using .run() everything is working. this is as .run() don't start a new thread but instead run the content inside the current one (the main loop)

Before i found this thread I posted a question about this HERE assuming I where doing something wrong in my python code.

I just ran in to this problem myself and can confirm that it still exists, It is also looking like it is a blender problem and not a bug in the threading as my code is working in a pure python console window. to produce this problem you need to creat a thread, run it using .start(). Inside of the thread, try to use any tcp socket commands, the commands won't be executed until you exit blender GE. if you run the thread using .run() everything is working. this is as .run() don't start a new thread but instead run the content inside the current one (the main loop) Before i found this thread I posted a question about this [HERE ](http://stackoverflow.com/questions/41137366/python-client-recv-only-reciving-on-exit-inside-bge) assuming I where doing something wrong in my python code.

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BGE python thread or socket problem: script stopped between 2 lines #43990