Panic: concurrent write to websocket connection when sending WebSocket events (0.7.2)

[tuGusz]

Welcome!

• Yes, I have searched for similar issues on GitHub and found none.

What did you do?

O erro ocorreu durante a utilização normal da EvolutionGo
A aplicação estava conectada ao WhatsApp e processando eventos normalmente quando, em determinado momento, ocorreu um panic que encerrou completamente o processo.
Eu consegui identificar um passo exato para reproduzir o problema de forma consistente, ele ocorreu durante o processamento simultâneo de eventos. Principalmente quando estamos recebendo muita mensagem e lendo mensagem.
Mas identifiquei que quando usamos o evento para restaurar o histórico de conversas, caso ultrapasse mais de 50 mensagens de acordo com os logs, ele da Panic e encerra e todas as instancias são desconectadas

Pelo stack trace, o panic acontece dentro de websocketProducer.Produce(), durante a chamada de WriteJSON() da biblioteca Gorilla WebSocket.

What did you expect?

Esperava que a aplicação continuasse processando e enviando os eventos normalmente, sem encerrar o processo.
Mesmo com múltiplos eventos sendo processados ao mesmo tempo, a escrita na conexão WebSocket deveria ser sincronizada para evitar concorrência.

What did you observe instead of what you expected?

A aplicação encerra com o seguinte panic:

panic: concurrent write to websocket connection

O stack trace indica que múltiplas goroutines estão tentando escrever simultaneamente na mesma conexão WebSocket, resultando no encerramento da EvolutionGo.

Stack trace:

panic: concurrent write to websocket connection

goroutine 969 [running]:
github.com/gorilla/websocket.(*messageWriter).flushFrame(0xc0013019e0, 0x1, {0x0?, 0x47c305?, 0x30?})
        /go/pkg/mod/github.com/gorilla/websocket@v1.5.3/conn.go:617 +0x4af
github.com/gorilla/websocket.(*messageWriter).Close(0x7453cc47d201?)
        /go/pkg/mod/github.com/gorilla/websocket@v1.5.3/conn.go:731 +0x35
github.com/gorilla/websocket.(*Conn).beginMessage(0xc0017329a0, 0xc00158d800, 0x1)
        /go/pkg/mod/github.com/gorilla/websocket@v1.5.3/conn.go:480 +0x37
github.com/gorilla/websocket.(*Conn).NextWriter(0xc0017329a0, 0x1)
        /go/pkg/mod/github.com/gorilla/websocket@v1.5.3/conn.go:520 +0x3f
github.com/gorilla/websocket.(*Conn).WriteJSON(0x171ece0?, {0x171ece0, 0xc00158d7d0})
        /go/pkg/mod/github.com/gorilla/websocket@v1.5.3/json.go:24 +0x34
github.com/evolution-foundation/evolution-go/pkg/events/websocket.(*websocketProducer).Produce(0xc000590d00, {0xc0013e4db0, 0x2c}, {0xc0011c0480, 0x206, 0xc0016b9dd0?}, {0xc00004dc20, 0x24}, {0xc00004dc50, 0x24})
        /build/pkg/events/websocket/websocket_producer.go:127 +0x42a
github.com/evolution-foundation/evolution-go/pkg/whatsmeow/service.(*whatsmeowService).sendToQueueOrWebhook(0xc0001fce10, 0xc000176a00, {0xc0013e4db0, 0x2c}, {0xc0011c0480, 0x206, 0x240})
        /build/pkg/whatsmeow/service/whatsmeow.go:2305 +0x4f9
github.com/evolution-foundation/evolution-go/pkg/whatsmeow/service.(*whatsmeowService).CallWebhook(0xc0001fce10, 0xc000176a00, {0xc0013e4db0, 0x2c}, {0xc0011c0480, 0x206, 0x240})
        /build/pkg/whatsmeow/service/whatsmeow.go:2191 +0x242b
created by github.com/evolution-foundation/evolution-go/pkg/whatsmeow/service.(*MyClient).myEventHandler in goroutine 967
        /build/pkg/whatsmeow/service/whatsmeow.go:2098 +0x997e
...

Screenshots/Videos

No response

Which version are you using?

0.7.2

What is your environment?

Linux

If applicable, paste the log output

Sistema Operacional: Linux
Implantação: Docker
WebSocket: Habilitado
2026/07/03 09:31:20 [INFO] [] subscriptions [MESSAGE SEND_MESSAGE READ_RECEIPT PRESENCE HISTORY_SYNC CHAT_PRESENCE CALL CONNECTION LABEL CONTACT GROUP NEWSLETTER QRCODE BUTTON_CLICK] eventType Receipt
2026/07/03 09:31:20 [INFO] [] Event received of type Receipt
panic: concurrent write to websocket connection

goroutine 969 [running]:
github.com/gorilla/websocket.(*messageWriter).flushFrame(0xc0013019e0, 0x1, {0x0?, 0x47c305?, 0x30?})
/go/pkg/mod/github.com/gorilla/websocket@v1.5.3/conn.go:617 +0x4af
github.com/gorilla/websocket.(*messageWriter).Close(0x7453cc47d201?)
/go/pkg/mod/github.com/gorilla/websocket@v1.5.3/conn.go:731 +0x35
github.com/gorilla/websocket.(*Conn).beginMessage(0xc0017329a0, 0xc00158d800, 0x1)
/go/pkg/mod/github.com/gorilla/websocket@v1.5.3/conn.go:480 +0x37
github.com/gorilla/websocket.(*Conn).NextWriter(0xc0017329a0, 0x1)
/go/pkg/mod/github.com/gorilla/websocket@v1.5.3/conn.go:520 +0x3f
github.com/gorilla/websocket.(*Conn).WriteJSON(0x171ece0?, {0x171ece0, 0xc00158d7d0})
/go/pkg/mod/github.com/gorilla/websocket@v1.5.3/json.go:24 +0x34
github.com/evolution-foundation/evolution-go/pkg/events/websocket.(*websocketProducer).Produce(0xc000590d00, {0xc0013e4db0, 0x2c}, {0xc0011c0480, 0x206, 0xc0016b9dd0?}, {0xc00004dc20, 0x24}, {0xc00004dc50, 0x24})
/build/pkg/events/websocket/websocket_producer.go:127 +0x42a
github.com/evolution-foundation/evolution-go/pkg/whatsmeow/service.(*whatsmeowService).sendToQueueOrWebhook(0xc0001fce10, 0xc000176a00, {0xc0013e4db0, 0x2c}, {0xc0011c0480, 0x206, 0x240})
/build/pkg/whatsmeow/service/whatsmeow.go:2305 +0x4f9
github.com/evolution-foundation/evolution-go/pkg/whatsmeow/service.(*whatsmeowService).CallWebhook(0xc0001fce10, 0xc000176a00, {0xc0013e4db0, 0x2c}, {0xc0011c0480, 0x206, 0x240})
/build/pkg/whatsmeow/service/whatsmeow.go:2191 +0x242b
created by github.com/evolution-foundation/evolution-go/pkg/whatsmeow/service.(*MyClient).myEventHandler in goroutine 967
/build/pkg/whatsmeow/service/whatsmeow.go:2098 +0x997e

Additional Notes

Na versão 0.7.0 isso não ocorria

[tuGusz]

Com base nos logs é um erro concurrent write to websocket connection. Parece que uma goroutine tenta enviar um evento de Receipt pelo Websocket no exato momento em que outra rotina está processando um download de mídia ou um volume grande do HistorySync. Será que está faltando um bloqueio Mutex na escrita do Websocket?

Se alguém tiver uma solução para compartilhar com a comunidade!

2026/07/03 11:34:53 [INFO] [uuid] ===== MESSAGE RECEIVED ===== ID: [CENSURADO], From: [CENSURADO]@lid, Type: media, Size: 121332 bytes
2026/07/03 11:34:53 [INFO] [uuid] Detected LID/WhatsApp JID swap case - Sender: [CENSURADO]:71@lid, SenderAlt: [CENSURADO]:71@s.whatsapp.net
2026/07/03 11:34:53 [INFO] [uuid] JID swap completed - New Sender: [CENSURADO]@s.whatsapp.net, New Chat: [CENSURADO]@s.whatsapp.net
2026/07/03 11:34:53 [INFO] [uuid] Processing media message - ID: [CENSURADO]
2026/07/03 11:34:53 [INFO] [uuid] Downloading document - ID: [CENSURADO], FileName: [ARQUIVO_CENSURADO].pdf, Size: 121332 bytes
2026/07/03 11:34:56 [INFO] [uuid] Media download successful - ID: [CENSURADO]
2026/07/03 11:35:11 [INFO] [uuid] Event received of type Receipt
2026/07/03 11:35:11 [INFO] [uuid] Message sent to websocket successfully
panic: concurrent write to websocket connection

goroutine 10157 [running]:
github.com/gorilla/websocket.(*messageWriter).flushFrame(0xc00268ed50, 0x1, {0x0?, 0x47c305?, 0x30?})
/go/pkg/mod/github.com/gorilla/websocket@v1.5.3/conn.go:617 +0x4af
github.com/gorilla/websocket.(*messageWriter).Close(0x517001?)
/go/pkg/mod/github.com/gorilla/websocket@v1.5.3/conn.go:731 +0x35
github.com/gorilla/websocket.(*Conn).beginMessage(0xc00191e9a0, 0xc002446600, 0x1)
/go/pkg/mod/github.com/gorilla/websocket@v1.5.3/conn.go:480 +0x37
github.com/gorilla/websocket.(*Conn).NextWriter(0xc00191e9a0, 0x1)
/go/pkg/mod/github.com/gorilla/websocket@v1.5.3/conn.go:520 +0x3f
github.com/gorilla/websocket.(*Conn).WriteJSON(0x171ece0?, {0x171ece0, 0xc0024465d0})
/go/pkg/mod/github.com/gorilla/websocket@v1.5.3/json.go:24 +0x34
github.com/evolution-foundation/evolution-go/pkg/events/websocket.(*websocketProducer).Produce(0xc00013a940, {0xc002069b30, 0x2c}, {0xc002430900, 0x206, 0xc0006a5dd0?}, {0xc000697b30, 0x24}, {0xc000697b60, 0x24})
/build/pkg/events/websocket/websocket_producer.go:127 +0x42a
github.com/evolution-foundation/evolution-go/pkg/whatsmeow/service.(*whatsmeowService).sendToQueueOrWebhook(0xc0001fca50, 0xc00151ec80, {0xc002069b30, 0x2c}, {0xc002430900, 0x206, 0x240})
/build/pkg/whatsmeow/service/whatsmeow.go:2305 +0x4f9
github.com/evolution-foundation/evolution-go/pkg/whatsmeow/service.(*whatsmeowService).CallWebhook(0xc0001fca50, 0xc00151ec80, {0xc002069b30, 0x2c}, {0xc002430900, 0x206, 0x240})
/build/pkg/whatsmeow/service/whatsmeow.go:2191 +0x242b