[release-branch.go1.11] database/sql: correctly report MaxIdleClosed stat

Previously the MaxIdleClosed counter was incremented when added
to the free connection list, rather then when it wasn't added
to the free connection list. Flip this logic to correct.

Fixes #28325

Change-Id: I405302c14fb985369dab48fbe845e5651afc4ccf
Reviewed-on: https://go-review.googlesource.com/c/138578
Run-TryBot: Daniel Theophanes <kardianos@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
(cherry picked from commit 7db509e682891f3bc501c7b23e32e02c64893557)
Reviewed-on: https://go-review.googlesource.com/c/146697
Run-TryBot: Brad Fitzpatrick <bradfitz@golang.org>
Reviewed-by: Andrew Bonventre <andybons@golang.org>
Reviewed-by: Daniel Theophanes <kardianos@gmail.com>

diff --git a/src/database/sql/sql.go b/src/database/sql/sql.go
index 36179855db2b6d247e7258913222fc6794bc72ad..44840b879834e40312f22df1ae883929b0090b7d 100644 (file)
--- a/src/database/sql/sql.go
+++ b/src/database/sql/sql.go
@@ -1322,11 +1322,13 @@ func (db *DB) putConnDBLocked(dc *driverConn, err error) bool {
                        err:  err,
                }
                return true
-       } else if err == nil && !db.closed && db.maxIdleConnsLocked() > len(db.freeConn) {
-               db.freeConn = append(db.freeConn, dc)
+       } else if err == nil && !db.closed {
+               if db.maxIdleConnsLocked() > len(db.freeConn) {
+                       db.freeConn = append(db.freeConn, dc)
+                       db.startCleanerLocked()
+                       return true
+               }
                db.maxIdleClosed++
-               db.startCleanerLocked()
-               return true
        }
        return false
 }

diff --git a/src/database/sql/sql_test.go b/src/database/sql/sql_test.go
index f194744aefe727b0b0e51039de90c0fb29ac4345..e52091c3afd0c36d46ba4c9baaa32d840ddd033f 100644 (file)
--- a/src/database/sql/sql_test.go
+++ b/src/database/sql/sql_test.go
@@ -3415,6 +3415,58 @@ func TestConnectionLeak(t *testing.T) {
        wg.Wait()
 }
 
+func TestStatsMaxIdleClosedZero(t *testing.T) {
+       db := newTestDB(t, "people")
+       defer closeDB(t, db)
+
+       db.SetMaxOpenConns(1)
+       db.SetMaxIdleConns(1)
+       db.SetConnMaxLifetime(0)
+
+       preMaxIdleClosed := db.Stats().MaxIdleClosed
+
+       for i := 0; i < 10; i++ {
+               rows, err := db.Query("SELECT|people|name|")
+               if err != nil {
+                       t.Fatal(err)
+               }
+               rows.Close()
+       }
+
+       st := db.Stats()
+       maxIdleClosed := st.MaxIdleClosed - preMaxIdleClosed
+       t.Logf("MaxIdleClosed: %d", maxIdleClosed)
+       if maxIdleClosed != 0 {
+               t.Fatal("expected 0 max idle closed conns, got: ", maxIdleClosed)
+       }
+}
+
+func TestStatsMaxIdleClosedTen(t *testing.T) {
+       db := newTestDB(t, "people")
+       defer closeDB(t, db)
+
+       db.SetMaxOpenConns(1)
+       db.SetMaxIdleConns(0)
+       db.SetConnMaxLifetime(0)
+
+       preMaxIdleClosed := db.Stats().MaxIdleClosed
+
+       for i := 0; i < 10; i++ {
+               rows, err := db.Query("SELECT|people|name|")
+               if err != nil {
+                       t.Fatal(err)
+               }
+               rows.Close()
+       }
+
+       st := db.Stats()
+       maxIdleClosed := st.MaxIdleClosed - preMaxIdleClosed
+       t.Logf("MaxIdleClosed: %d", maxIdleClosed)
+       if maxIdleClosed != 10 {
+               t.Fatal("expected 0 max idle closed conns, got: ", maxIdleClosed)
+       }
+}
+
 type nvcDriver struct {
        fakeDriver
        skipNamedValueCheck bool