go/src/database/sql/sql.go, branch go1.8.7

[release-branch.go1.8] database/sql: ensure releaseConn is defined before a possible close

2017-05-23T19:41:50Z

Applies https://golang.org/cl/42139 to the go1.8 release branch. Also correct two minor issues detected with go vet. Fixes #20217 Change-Id: I2c41af9497493598fbcfc140439b4e25b9bb7e72 Reviewed-on: https://go-review.googlesource.com/42532 Run-TryBot: Brad Fitzpatrick TryBot-Result: Gobot Gobot Reviewed-by: Chris Broadfoot

[release-branch.go1.8] database/sql: ensure driverConns are closed if not returned to pool

2017-02-10T17:53:36Z

Previously if a connection was requested but timed out during the request and when acquiring the db.Lock the connection request is fulfilled and the request is unable to be returned to the connection pool, then then driver connection would not be closed. No tests were added or modified because I was unable to determine how to trigger this situation without something invasive. Change-Id: I9d4dc680e3fdcf63d79d212174a5b8b313f363f1 Reviewed-on: https://go-review.googlesource.com/36641 Reviewed-by: Russ Cox Reviewed-on: https://go-review.googlesource.com/36714 Run-TryBot: Russ Cox TryBot-Result: Gobot Gobot Reviewed-by: Brad Fitzpatrick

[release-branch.go1.8] database/sql: do not exhaust connection pool on conn request timeout

2017-02-10T17:53:29Z

Previously if a context was canceled while it was waiting for a connection request, that connection request would leak. To prevent this remove the pending connection request if the context is canceled and ensure no connection has been sent on the channel. This requires a change to how the connection requests are represented in the DB. Fixes #18995 Change-Id: I9a274b48b8f4f7ca46cdee166faa38f56d030852 Reviewed-on: https://go-review.googlesource.com/36563 Reviewed-by: Russ Cox Run-TryBot: Russ Cox TryBot-Result: Gobot Gobot Reviewed-on: https://go-review.googlesource.com/36613 Reviewed-by: Brad Fitzpatrick

[release-branch.go1.8] database/sql: record the context error in Rows if canceled

2017-02-09T03:47:26Z

Previously it was intended that Rows.Scan would return an error and Rows.Err would return nil. This was problematic because drivers could not differentiate between a normal Rows.Close or a context cancel close. The alternative is to require drivers to return a Scan to return an error if the driver is closed while there are still rows to be read. This is currently not how several drivers currently work and may be difficult to detect when there are additional rows. At the same time guard the the Rows.lasterr and prevent a close while a Rows operation is active. For the drivers that do not have Context methods, do not check for context cancelation after the operation, but before for any operation that may modify the database state. Fixes #18961 Change-Id: I49a25318ecd9f97a35d5b50540ecd850c01cfa5e Reviewed-on: https://go-review.googlesource.com/36485 Reviewed-by: Russ Cox Run-TryBot: Russ Cox TryBot-Result: Gobot Gobot Reviewed-on: https://go-review.googlesource.com/36614 Reviewed-by: Brad Fitzpatrick

database/sql: fix race when canceling queries immediately

2017-01-26T06:25:37Z

Previously the following could happen, though in practice it would be rare. Goroutine 1: (*Tx).QueryContext begins a query, passing in userContext Goroutine 2: (*Tx).awaitDone starts to wait on the context derived from the passed in context Goroutine 1: (*Tx).grabConn returns a valid (*driverConn) The (*driverConn) passes to (*DB).queryConn Goroutine 3: userContext is canceled Goroutine 2: (*Tx).awaitDone unblocks and calls (*Tx).rollback (*driverConn).finalClose obtains dc.Mutex (*driverConn).finalClose sets dc.ci = nil Goroutine 1: (*DB).queryConn obtains dc.Mutex in withLock ctxDriverPrepare accepts dc.ci which is now nil ctxCriverPrepare panics on the nil ci The fix for this is to guard the Tx methods with a RWLock holding it exclusivly when closing the Tx and holding a read lock when executing a query. Fixes #18719 Change-Id: I37aa02c37083c9793dabd28f7f934a1c5cbc05ea Reviewed-on: https://go-review.googlesource.com/35550 Run-TryBot: Brad Fitzpatrick TryBot-Result: Gobot Gobot Reviewed-by: Brad Fitzpatrick

all: fix misspellings

2017-01-07T16:53:25Z

Change-Id: I429637ca91f7db4144f17621de851a548dc1ce76 Reviewed-on: https://go-review.googlesource.com/34923 Reviewed-by: Ian Lance Taylor Reviewed-by: Daniel Martí Run-TryBot: Ian Lance Taylor TryBot-Result: Gobot Gobot

database/sql: prevent Tx.rollback from racing Tx.close

2017-01-02T20:21:02Z

Previously Tx.done was being set in close, but in a Tx rollback and Commit are the real closing methods, and Tx.close is just a helper common to both. Prior to this change a multiple rollback statements could be called, one would enter close and begin closing it while the other was still in rollback breaking it. Fix that by setting done in rollback and Commit, not in Tx.close. Fixes #18429 Change-Id: Ie274f60c2aa6a4a5aa38e55109c05ea9d4fe0223 Reviewed-on: https://go-review.googlesource.com/34716 Reviewed-by: Brad Fitzpatrick Run-TryBot: Brad Fitzpatrick TryBot-Result: Gobot Gobot

database/sql: do not store Tx options in Context

2016-12-14T18:13:13Z

Drivers which previously supported tip will need to update to this revision before release. Fixes #18284 Change-Id: I70b8e7afff1558a8b5348885ce9f50e067c72ee9 Reviewed-on: https://go-review.googlesource.com/34330 Run-TryBot: Daniel Theophanes Reviewed-by: Brad Fitzpatrick TryBot-Result: Gobot Gobot

database/sql: use complete sentences in new docs

2016-12-09T20:19:06Z

Change-Id: Icb842a80cab2b07b9ace1e8e14c4a19c48a92c43 Reviewed-on: https://go-review.googlesource.com/34247 Reviewed-by: Ian Lance Taylor Reviewed-by: Daniel Theophanes

database/sql: document that drivers may not return right after cancel

2016-12-09T03:15:22Z

Fixes #18168 Change-Id: Idbfe3d4daedd93c7caf6f1770ecd988e9af39949 Reviewed-on: https://go-review.googlesource.com/34144 Reviewed-by: Brad Fitzpatrick