From 897080d5cbb1793f8ad3ef5fb7c6fafba2e97d42 Mon Sep 17 00:00:00 2001 From: Daniel Theophanes Date: Sat, 23 Sep 2017 15:30:46 -0700 Subject: database/sql: prevent race in driver by locking dc in Next Database drivers should be called from a single goroutine to ease driver's design. If a driver chooses to handle context cancels internally it may do so. The sql package violated this agreement when calling Next or NextResultSet. It was possible for a concurrent rollback triggered from a context cancel to call a Tx.Rollback (which takes a driver connection lock) while a Rows.Next is in progress (which does not tack the driver connection lock). The current internal design of the sql package is each call takes roughly two locks: a closemu lock which prevents an disposing of internal resources (assigning nil or removing from lists) and a driver connection lock that prevents calling driver code from multiple goroutines. Fixes #21117 Change-Id: Ie340dc752a503089c27f57ffd43e191534829360 Reviewed-on: https://go-review.googlesource.com/65731 Reviewed-by: Ian Lance Taylor --- src/database/sql/fakedb_test.go | 1 + 1 file changed, 1 insertion(+) (limited to 'src/database/sql/fakedb_test.go') diff --git a/src/database/sql/fakedb_test.go b/src/database/sql/fakedb_test.go index 4dcd096ca4..8e77df4ace 100644 --- a/src/database/sql/fakedb_test.go +++ b/src/database/sql/fakedb_test.go @@ -943,6 +943,7 @@ type rowsCursor struct { } func (rc *rowsCursor) touchMem() { + rc.parentMem.touchMem() rc.line++ } -- cgit v1.3-5-g9baa