Closing syncer causes panics

[janekolszak]

Hi!
Calling Close() closes internal channels, but it doesn't prevent sends on those internal channels.
Because of that I randomly see:

panic: send on closed channel

goroutine 68 [running]:
github.com/everFinance/arsyncer.(*Syncer).pollingBlock(0xc000178180)
        /home/jan/work/redstone/syncer/.gopath~/pkg/mod/github.com/ever!finance/arsyncer@v1.1.4/syncer.go:138 +0x506
created by github.com/everFinance/arsyncer.(*Syncer).Run
        /home/jan/work/redstone/syncer/.gopath~/pkg/mod/github.com/ever!finance/arsyncer@v1.1.4/syncer.go:83 +0x97

[zyjblockchain]

This is normal, close must be closed channel

[janekolszak]

Could you check if arsyncer.Close() was called and avoid writing to a closed channel?

[zyjblockchain]

Could you check if arsyncer.Close() was called and avoid writing to a closed channel?
It's just an exit process, we don't expect this method to be called during the code run, this method is only applicable inside the program exit process

[zyjblockchain]

You cannot call this method to pause arsyncer, arsyncer does not have a pause function

[janekolszak]

Yes, I'm calling Close() only when our service is closing, but this isn't the problem.

The problem is that arsyncer is crashing the service when Close() is called.
I call Close() and wait till the SubscribeTx channel is closed. This way I'm sure all transactions pending in the channel get processed before our service is stopped.

Right now I call Close(), arsyncer is crashing and all pending data is lost.

Would you accept a PR?

[zyjblockchain]

yes you can push a PR about this problem