database/sql: conn() can cause a deadlock #2542
Description
by samuel.stauffer:
What steps will reproduce the problem? 1. open a db 2. close the db 3. exec a query (returns error that db is closed) 4. exec a query - causes deadlock What is the expected output? All goroutines deadlocked What do you see instead? The same error about db being closed Which compiler are you using (5g, 6g, 8g, gccgo)? 8g (though unrelated to compiler) Which operating system are you using? Linux/Ubuntu Which revision are you using? (hg identify) 5ea674d1b2ba+ tip Please provide any additional information below. conn() in exp/sql/sql.go:135 can return leaving db.mu locked if db.closed is true. This is unlikely to show up in use as it requires ignoring the "closed" error and trying again anyway.