Init fails on RaspberryPi 2 about ofxlibwebsockets

[robotconscience]

Ah! Are you working with the master branch? Just realized I updated to the newest libwebsockets but only compiled for mac and win. Compiling libwebsockets is pretty simple; if you're able to do that and submit a PR I'd be really grateful!

1. Clone libwebsockets
2. Build LWS:

cd /path/to/libwebsockets
mkdir build
cd build
cmake .. -DLWS_IPV6=OFF
make

1. Move compiled lib into ofxLibwebsockets/libs/libwebsockets/lib/linuxarmv6l

[timonsku]

That seems to work, I made a PR. Though the RPI2 is ARMv7 not 6 so I added it to linuxarmv7l.

[timonsku]

While it now initializes it still seems to have some bugs.
When I use any of the server example I get:
[warning] [ofxLibwebsockets] protocol is null
The browser side (chrome) says:
websocket connection CLOSED
If I then reload the page the server is not reachable anymore from the browser and I get:

[warning] [ofxLibwebsockets] Failed to send HTTP file /home/pi/of_v20150504_linuxarmv7l_release/addons/ofxLibwebsockets/example_server_sharedcanvas/bin/data/web/index.html for /index.html

[robotconscience]

Can you set ofLogLevel to OF_LOG_VERBOSE and post your trace here?

[timonsku]

When I load the page this gets printed. Though weirdly now it doesn't show that the connection closed, the web page just does nothing, no matter how often I reload. Without setting the log level it goes back to the previous behavior. It seems that only the index.html gets transfered in OF_LOG_VERBOSE.

It goes-> nothing happens -> hard refresh -> connection closed -> hard refresh -> index.html can't be sent anymore.

[verbose] [ofxLibwebsockets] LWS_CALLBACK_GET_THREAD_ID
[verbose] [ofxLibwebsockets] LWS_CALLBACK_GET_THREAD_ID
[verbose] [ofxLibwebsockets] LWS_CALLBACK_FILTER_NETWORK_CONNECTION
[verbose] [ofxLibwebsockets] LWS_CALLBACK_WSI_CREATE
[verbose] [ofxLibwebsockets] LWS_CALLBACK_SERVER_NEW_CLIENT_INSTANTIATED
[verbose] [ofxLibwebsockets] LWS_CALLBACK_LOCK_POLL
[verbose] [ofxLibwebsockets] LWS_CALLBACK_ADD_POLL_FD
[verbose] [ofxLibwebsockets] LWS_CALLBACK_UNLOCK_POLL
[verbose] [ofxLibwebsockets] LWS_CALLBACK_GET_THREAD_ID
[verbose] [ofxLibwebsockets] LWS_CALLBACK_FILTER_HTTP_CONNECTION
[verbose] [ofxLibwebsockets] LWS_CALLBACK_HTTP
[verbose] [ofxLibwebsockets] LWS_CALLBACK_HTTP_FILE_COMPLETION
[verbose] [ofxLibwebsockets] LWS_CALLBACK_CLOSED_HTTP
[verbose] [ofxLibwebsockets] LWS_CALLBACK_LOCK_POLL
[verbose] [ofxLibwebsockets] LWS_CALLBACK_DEL_POLL_FD
[verbose] [ofxLibwebsockets] LWS_CALLBACK_UNLOCK_POLL
[verbose] [ofxLibwebsockets] LWS_CALLBACK_CLOSED_HTTP
[verbose] [ofxLibwebsockets] LWS_CALLBACK_WSI_DESTROY
[verbose] [ofxLibwebsockets] LWS_CALLBACK_GET_THREAD_ID
[verbose] [ofxLibwebsockets] LWS_CALLBACK_GET_THREAD_ID
[verbose] [ofxLibwebsockets] LWS_CALLBACK_FILTER_NETWORK_CONNECTION
[verbose] [ofxLibwebsockets] LWS_CALLBACK_WSI_CREATE
[verbose] [ofxLibwebsockets] LWS_CALLBACK_SERVER_NEW_CLIENT_INSTANTIATED
[verbose] [ofxLibwebsockets] LWS_CALLBACK_LOCK_POLL
[verbose] [ofxLibwebsockets] LWS_CALLBACK_ADD_POLL_FD
[verbose] [ofxLibwebsockets] LWS_CALLBACK_UNLOCK_POLL
[verbose] [ofxLibwebsockets] LWS_CALLBACK_GET_THREAD_ID
[verbose] [ofxLibwebsockets] LWS_CALLBACK_FILTER_HTTP_CONNECTION
[verbose] [ofxLibwebsockets] LWS_CALLBACK_HTTP
[warning] [ofxLibwebsockets] Failed to send HTTP file /home/pi/of_v20150504_linuxarmv7l_release/addons/ofxLibwebsockets/example_server_sharedcanvas/bin/data/web/favicon.ico for /favicon.ico
[verbose] [ofxLibwebsockets] LWS_CALLBACK_LOCK_POLL
[verbose] [ofxLibwebsockets] LWS_CALLBACK_DEL_POLL_FD
[verbose] [ofxLibwebsockets] LWS_CALLBACK_UNLOCK_POLL
[verbose] [ofxLibwebsockets] LWS_CALLBACK_CLOSED_HTTP
[verbose] [ofxLibwebsockets] LWS_CALLBACK_WSI_DESTROY
[verbose] [ofxLibwebsockets] LWS_CALLBACK_GET_THREAD_ID
[verbose] [ofxLibwebsockets] LWS_CALLBACK_GET_THREAD_ID
[verbose] [ofxLibwebsockets] LWS_CALLBACK_GET_THREAD_ID
[verbose] [ofxLibwebsockets] LWS_CALLBACK_GET_THREAD_ID

[robotconscience]

Hm! Ok, try this:
In Reactor.cpp (ofxLibwebsockets/libs/ofxLibwebsockets/src), add these lines:

// top of file, after #include Reactor.h
#include "ofxLibwebsockets/Util.h"

//line 114, AFTER
/*
            if (conn == NULL){
                ofLog(OF_LOG_WARNING, "[ofxLibwebsockets] connection is null ");
            } else {
                ofLog(OF_LOG_WARNING, "[ofxLibwebsockets] protocol is null");
            }
*/
// ADD:
ofLog( OF_LOG_WARNING, "[ofxLibwebsockets] "+ getCallbackReason(reason) );

Now see what LWS event is occurring at the null protocol.

[timonsku]

[warning] [ofxLibwebsockets] protocol is null
[warning] [ofxLibwebsockets] LWS_CALLBACK_ESTABLISHED
[warning] [ofxLibwebsockets] protocol is null
[warning] [ofxLibwebsockets] LWS_CALLBACK_SERVER_WRITEABLE
[warning] [ofxLibwebsockets] protocol is null
[warning] [ofxLibwebsockets] LWS_CALLBACK_CLOSED
[warning] [ofxLibwebsockets] Failed to send HTTP file /home/pi/of_v20150504_linuxarmv7l_release/addons/ofxLibwebsockets/example_server_sharedcanvas/bin/data/web/favicon.ico for /favicon.ico
[warning] [ofxLibwebsockets] Failed to send HTTP file /home/pi/of_v20150504_linuxarmv7l_release/addons/ofxLibwebsockets/example_server_sharedcanvas/bin/data/web/index.html for /index.html

[robotconscience]

Hm! Can you try two things for me?

1. Test the libwebsocket examples on your RPi
2. Change ~line 110 to this:

            if (conn == NULL){
                ofLog(OF_LOG_WARNING, "[ofxLibwebsockets] connection is null ");
            } else if (conn->ws == NULL) {
                ofLog(OF_LOG_WARNING, "[ofxLibwebsockets] websocket is null");
            } else {
                ofLog(OF_LOG_WARNING, "[ofxLibwebsockets] protocol is null");
            }

and print what's happening?

It's sometimes OK that the protocol is null, but something weird is happening with the websocket creation, I think.

[timonsku]

The libwebsocket examples are working fine.
Replacing that code results in a complete crash of the app ending with this as soons as I load the page in the browser:

[warning] [ofxLibwebsockets] protocol is null
[warning] [ofxLibwebsockets] LWS_CALLBACK_ESTABLISHED
Segmentation fault

[robotconscience]

Oof. That doesn't make a ton of sense, but you can try changing

} else if (conn->ws == NULL) {

to

} else if (conn != NULL && conn->ws == NULL) {

Last test: can you try creating a separate html app and connecting to the websocket server? You can even test in Chrome directly through the debugger console by pasting

var ws = new WebSocket("ws://locahost:9093"); 
ws.onmessage = function(m){ console.log(m); } 
ws.onclose = function(){ console.log("closed");}

when your app is running...

[timonsku]

Unfortunately the same behavior with the snippet, with the only exception that I of course don't get any errors about not being able to send the index.html.
Changing the if statement doesn't change anything either.

Chrome output:

var ws = new WebSocket("ws://192.168.2.110:9092"); 
ws.onmessage = function(m){ console.log(m); } 
ws.onclose = function(){ console.log("closed");}

<- function ws.onclose()
VM5531:4 closed

[robotconscience]

OK! The if statement won't fix anything, just trying to get to the bottom of your problem. I had suspected it was with libwebsocket's http server but now I don't think so. I unfortunately do not have an RPi 1 or 2 to test with and can't replicate the errors on OS X.

Something's happening internally with libwebsockets that's different on RPi.

Last thing to try is building from the exact commit I used:
warmcat/libwebsockets@c67dace

[timonsku]

Tried to do that aswell but same outcome, very weird.

[robotconscience]

Can you try using the latest build of the library AND swapping out
ofxLibwebsockets/libs/libwebsockets/include/libwebsockets.h for the one that compiles with the lib?

I'm still pretty sure it's an internal libwebsockets error, but all I can do is suggest fixes! Apologies, all RPi stuff is contributed and not maintained by me.

[timonsku]

That works! I had to fix a function call in reactor.cpp but that was about it.
Though I also had to include the lws_config.h that got build. The only libwebsockets.h I could find was in /libwebsockets/lib/ not in the build directory.

I'll make a pull request. I also changed the sharedcanvas example though you might not want to merge that ofAppGlutWindow doesn't seem to be supported on the Pi. Wouldn't link properly if I left that in, maybe I'm just missing a library.

E: looks like GLUT isnt really supported on the Pi
https://www.raspberrypi.org/forums/viewtopic.php?f=33&t=72654