concurrent map read and map write

[NDagestad]

How have you installed cordless

• Arch User Repository
• Snap
• scoop
• brew
• go get
• git clone & go build .

What happened

If a server is marked read while cordless is open (from a phone app or desktop or something) it sometimes crashes.

How do you reproduce this bug

It is not reliably reproducible as it seems to be a race condition, but to make it happen, one should mark a server as read while discord is open

Error output

https://paste.git.dagestad.fr/~nicolai/ffb3bc8af04cedc092be1d69215fd6cf843e19e3

Hints on what could've happened

In ´readstate/readmarkers.go´ line 220 ´data´ is read and probably written to at the same time from another thread.

System information

Key	Value
OS	Arch
Architecture	amd64
Go version	go1.15 linux/amd64

[Bios-Marcel]

I've added locking. If this occurs again, please reopen the issue.

[NDagestad]

I imagine that would fix the issue, thanks 👍