multiple definition of `websockets2_generic::WebsocketsServer::~WebsocketsServer()' in websocket2_generic library

[pchan1401-ICIL]

HI.

I’m using ‘adafruit feather m0’ board with w5500 and I succeed to run example code “SAMD-Ethernet-Client”. Also, I communicate server using websocket2_generic library. Then I want to separate code into two files.

While I was trying to make separate WebSocket header file using websockets2_generic library, I face weird error. I try to figure out it, but It was very complicated with my codes. Thus, I remove all of my code except necessary things such as “#define” and “#include”.

I have four files which is

SAMD-Ethernet-Client.ino EthernetWebSocketsClient.h EthernetWebSocketsClient.cpp defines.h

As the file name, I use the example code. defines.h is almost same with example code. I just remove unnecessary global values. Other files are same below.

SAMD-Ethernet-Client.ino

#include "EthernetWebSocketsClient.h"

void setup()
{}

void loop()
{}

EthernetWebSocketsClient.h

#ifndef EWC_H
#define EWC_H

#include "defines.h"
#include <WebSockets2_Generic.h>

#endif

EthernetWebSocketsClient.cpp

#include "EthernetWebSocketsClient.h"

As I mentioned before, I remove all the code. Those are the full code. When compiling, it shows error like below

c:/users/chanyoung/appdata/local/arduino15/packages/adafruit/tools/arm-none-eabi-gcc/9-2019q4/bin/../lib/gcc/arm-none-eabi/9.2.1/../../../../arm-none-eabi/bin/ld.exe: C:\Users\CHANYO~1\AppData\Local\Temp\arduino_build_4918\sketch\SAMD-Ethernet-Client.ino.cpp.o: in function std::function<void (websockets2_generic::WebsocketsClient&, websockets2_generic::WebsocketsMessage)>::operator bool() const': C:\Arduino\libraries\WebSockets2_Generic-master\src/Tiny_Websockets_Generic/internals/wscrypto/sha1.hpp:73: multiple definition ofwebsockets2_generic::WebsocketsServer::~WebsocketsServer()'; C:\Users\CHANYO~1\AppData\Local\Temp\arduino_build_4918\sketch\EthernetWebSocketsClient.cpp.o:C:\Arduino\libraries\WebSockets2_Generic-master\src/WebSockets2_Generic_Server.hpp:182: first defined here c:/users/chanyoung/appdata/local/arduino15/packages/adafruit/tools/arm-none-eabi-gcc/9-2019q4/bin/../lib/gcc/arm-none-eabi/9.2.1/../../../../arm-none-eabi/bin/ld.exe: C:\Users\CHANYO~1\AppData\Local\Temp\arduino_build_4918\sketch\SAMD-Ethernet-Client.ino.cpp.o: in function std::function<void (websockets2_generic::WebsocketsClient&, websockets2_generic::WebsocketsMessage)>::operator bool() const': C:\Arduino\libraries\WebSockets2_Generic-master\src/Tiny_Websockets_Generic/internals/wscrypto/sha1.hpp:73: multiple definition ofwebsockets2_generic::WebsocketsServer::~WebsocketsServer()'; C:\Users\CHANYO~1\AppData\Local\Temp\arduino_build_4918\sketch\EthernetWebSocketsClient.cpp.o:C:\Arduino\libraries\WebSockets2_Generic-master\src/WebSockets2_Generic_Server.hpp:182: first defined here c:/users/chanyoung/appdata/local/arduino15/packages/adafruit/tools/arm-none-eabi-gcc/9-2019q4/bin/../lib/gcc/arm-none-eabi/9.2.1/../../../../arm-none-eabi/bin/ld.exe: C:\Users\CHANYO~1\AppData\Local\Temp\arduino_build_4918\sketch\SAMD-Ethernet-Client.ino.cpp.o: in function `websockets2_generic::WebsocketsServer::~WebsocketsServer()':

It shows multiple definition.

I change codes in EthernetWebSocketsClient.h, SAMD-Ethernet-Client.ino.

SAMD-Ethernet-Client.ino

#ifndef EWC_H
#define EWC_H

#endif

SAMD-Ethernet-Client.ino

#include "defines.h"
#include <WebSockets2_Generic.h>

#include "EthernetWebSocketsClient.h"

void setup()
{}

void loop()
{}

I just change the location of

#include "defines.h"
#include <WebSockets2_Generic.h>

Then, I succeed to compile and linking.

I want to implement websocket functions in EthernetWebSocketsClient.cpp file. Thus, EthernetWebSocketsClient.h include websocket2_generic library.

How can I include websocket2_generic library in EthernetWebSocketsClient.h file.

[khoih-prog]

@pchan1401-ICIL

Thanks for using the library. The problems you experienced happened because the complicated feature of the libraries.

You can use either solutions as follows:

1. Better implementation

SAMD-Ethernet-Client.ino EthernetWebSocketsClient.h EthernetWebSocketsClient_Impl.h defines.h

SAMD-Ethernet-Client.ino

#include "defines.h"

#include <WebSockets2_Generic.h>

#include "EthernetWebSocketsClient.h"

using namespace websockets2_generic;

void setup()
{}

void loop()
{}

EthernetWebSocketsClient.h

#ifndef EWC_H
#define EWC_H

#include "EthernetWebSocketsClient_Impl.h"    

#endif

EthernetWebSocketsClient_Impl.h

#ifndef EWC_Impl_H
#define EWC_Impl_H

#endif

---

2. Another implementation

SAMD-Ethernet-Client.ino EthernetWebSocketsClient.h EthernetWebSocketsClient.cpp defines.h

SAMD-Ethernet-Client.ino

#include "defines.h"

#include <WebSockets2_Generic.h>

#include "EthernetWebSocketsClient.h"

using namespace websockets2_generic;

void setup()
{}

void loop()
{}

EthernetWebSocketsClient.h

#ifndef EWC_H
#define EWC_H

#endif

EthernetWebSocketsClient.cpp

#include "EthernetWebSocketsClient.h"

---

If you are OK with any implementation, please post the result for other people to follow. It's complicated to explain all, it's better for you to research why if OK.

[khoih-prog]

This is the terminal output when running the same example on SAMD21 SeeedStudio XIAO Mo

Starting WebSockets2_Generic SAMD-Ethernet-Client on SEEED_XIAO_M0
Ethernet using W5x00 and Ethernet Library
[SETUP] BOOT WAIT 2
[SETUP] BOOT WAIT 1
_pinCS = 0
W5100 init, using SS_PIN_DEFAULT = 10, new ss_pin = 10, W5100Class::ss_pin = 1
W5100::init: W5500, SSIZE =4096
WebSockets Client IP address: 192.168.2.126
Connecting to WebSockets Server @192.168.2.81
[WS] WebsocketsClient::generateHandshake: base64Authorization = 
[WS] WebsocketsClient::generateHandshake: handshake = GET / HTTP/1.1
Host: 192.168.2.81
Sec-WebSocket-Key: MDEyMzQ1Njc4OWFiY2RlZg==
Upgrade: websocket
Connection: Upgrade
Sec-WebSocket-Version: 13
User-Agent: TinyWebsockets Client
Authorization: Basic 
Origin: https://github.com/khoih-prog/Websockets2_Generic

[WS] WebsocketsClient::connect: base64Authorization = 
[WS] WebsocketsClient::doestStartsWith: str = HTTP/1.1 101 Switching Protocols

[WS] WebsocketsClient::doestStartsWith: prefix = HTTP/1.1 101
[WS] WebsocketsClient::generateHandshake: key = Connection
[WS] WebsocketsClient::generateHandshake: value = Upgrade
[WS] WebsocketsClient::generateHandshake: key = Upgrade
[WS] WebsocketsClient::generateHandshake: value = websocket
[WS] WebsocketsClient::generateHandshake: key = Sec-WebSocket-Version
[WS] WebsocketsClient::generateHandshake: value = 13
[WS] WebsocketsClient::generateHandshake: key = Sec-WebSocket-Accept
[WS] WebsocketsClient::generateHandshake: value = BACScCJPNqyz+UBoqMH89VmURoA=
Connnection Opened
Connected!
Got Message: Echo: Hello to Server from SEEED_XIAO_M0
Connnection Closed

[pchan1401-ICIL]

Thank you for offering nice library. but your answer is slightly way off with my expection.

I'm using folder named SAMD-Ethernet-Client In this folder there are four files.

SAMD-Ethernet-Client.ino EthernetWebSocketsClient.h EthernetWebSocketsClient.cpp defines.h

I want to use library in EthernetWebSocketsClient.h not SAMD-Ethernet-Client.ino file.

Thus, "#include " should in EthernetWebSocketsClient.h

Putting "#include " into .ino file is successful. Also, I already run the examlpe code with my board. In addition, I succed to connect websocket server.

However, I want to make saperate file EthernetWebSocketsClient.h which using websocket library for code management.

For more easy explanation. Here is an example.

EthernetWebSocketsClient.h

#ifndef EWC_H
#define EWC_H

#include "defines.h"
#include <WebSockets2_Generic.h>

using namespace websockets2_generic;

class EWCTest
{
 public :
  void init();
 private :
  WebsocketsClient client;
};

#endif

Thank you for your reply.

[khoih-prog]

You can use this solution as follows:

---

SAMD-Ethernet-Client.ino EthernetWebSocketsClient.h EthernetWebSocketsClient_Impl.h defines.h

---

SAMD-Ethernet-Client.ino

#include "EthernetWebSocketsClient.h"

using namespace websockets2_generic;

void setup()
{}

void loop()
{}

---

EthernetWebSocketsClient.h

#ifndef EWC_H
#define EWC_H

#include "defines.h"
#include <WebSockets2_Generic.h>

using namespace websockets2_generic;

class EWCTest
{
 public :
  void init();
 private :
  WebsocketsClient client;
};

#include "EthernetWebSocketsClient_Impl.h"

#endif

---

EthernetWebSocketsClient_Impl.h

#ifndef EWC_Impl_H
#define EWC_Impl_H

#endif

---

[pchan1401-ICIL]

It works

Thaks a lot.

But what is the reason it makes error with ".cpp" file?

[khoih-prog]

That's left for you to research and investigate.

Thanks for confirming the solution.

[pchan1401-ICIL]

Thank you for your reply