From 3620d996cf112c2a7419c909b46f2e2c4f100461 Mon Sep 17 00:00:00 2001
From: Fabian Reinartz <fab.reinartz@gmail.com>
Date: Sat, 13 Feb 2016 09:21:40 +0100
Subject: [PATCH] Serialize all database accesses

---
 provider/sqlite/sqlite.go | 35 ++++++++++++++++++++++++++++++++---
 1 file changed, 32 insertions(+), 3 deletions(-)

diff --git a/provider/sqlite/sqlite.go b/provider/sqlite/sqlite.go
index 5e0809e4..069d0e99 100644
--- a/provider/sqlite/sqlite.go
+++ b/provider/sqlite/sqlite.go
@@ -30,16 +30,21 @@ CREATE INDEX IF NOT EXISTS alerts_end     ON alerts (ends_at);
 CREATE INDEX IF NOT EXISTS alerts_updated ON alerts (updated_at);
 `
 
+var dbmtx sync.Mutex
+
 type Alerts struct {
 	db *sql.DB
 
-	pmtx, mtx sync.RWMutex
+	mtx       sync.RWMutex
 	listeners map[int]chan *types.Alert
 	next      int
 	insertCh  chan *types.Alert
 }
 
 func NewAlerts(db *sql.DB) (*Alerts, error) {
+	dbmtx.Lock()
+	defer dbmtx.Unlock()
+
 	tx, err := db.Begin()
 	if err != nil {
 		return nil, err
@@ -120,6 +125,9 @@ func (a *Alerts) GetPending() provider.AlertIterator {
 }
 
 func (a *Alerts) getPending() ([]*types.Alert, error) {
+	dbmtx.Lock()
+	defer dbmtx.Unlock()
+
 	// Get the last instance for each alert.
 	rows, err := a.db.Query(`
 		SELECT a1.labels, a1.annotations, a1.starts_at, a1.ends_at, a1.updated_at, a1.timeout
@@ -173,8 +181,8 @@ func (a *Alerts) Get(model.Fingerprint) (*types.Alert, error) {
 
 // Put implements the Alerts interface.
 func (a *Alerts) Put(alerts ...*types.Alert) error {
-	a.pmtx.Lock()
-	defer a.pmtx.Unlock()
+	dbmtx.Lock()
+	defer dbmtx.Unlock()
 
 	tx, err := a.db.Begin()
 	if err != nil {
@@ -337,6 +345,9 @@ type Notifies struct {
 }
 
 func NewNotifies(db *sql.DB) (*Notifies, error) {
+	dbmtx.Lock()
+	defer dbmtx.Unlock()
+
 	tx, err := db.Begin()
 	if err != nil {
 		return nil, err
@@ -352,6 +363,9 @@ func NewNotifies(db *sql.DB) (*Notifies, error) {
 
 // Get implements the Notifies interface.
 func (n *Notifies) Get(dest string, fps ...model.Fingerprint) ([]*types.NotifyInfo, error) {
+	dbmtx.Lock()
+	defer dbmtx.Unlock()
+
 	var result []*types.NotifyInfo
 
 	for _, fp := range fps {
@@ -388,6 +402,9 @@ func (n *Notifies) Get(dest string, fps ...model.Fingerprint) ([]*types.NotifyIn
 
 // Set implements the Notifies interface.
 func (n *Notifies) Set(ns ...*types.NotifyInfo) error {
+	dbmtx.Lock()
+	defer dbmtx.Unlock()
+
 	tx, err := n.db.Begin()
 	if err != nil {
 		return err
@@ -455,6 +472,9 @@ type Silences struct {
 
 // NewSilences returns a new Silences based on the provided SQL DB.
 func NewSilences(db *sql.DB, mk types.Marker) (*Silences, error) {
+	dbmtx.Lock()
+	defer dbmtx.Unlock()
+
 	tx, err := db.Begin()
 	if err != nil {
 		return nil, err
@@ -490,6 +510,9 @@ func (s *Silences) Mutes(lset model.LabelSet) bool {
 
 // All implements the Silences interface.
 func (s *Silences) All() ([]*types.Silence, error) {
+	dbmtx.Lock()
+	defer dbmtx.Unlock()
+
 	rows, err := s.db.Query(`
 		SELECT id, matchers, starts_at, ends_at, created_at, created_by, comment
 		FROM silences 
@@ -535,6 +558,9 @@ func (s *Silences) All() ([]*types.Silence, error) {
 
 // Set impelements the Silences interface.
 func (s *Silences) Set(sil *types.Silence) (uint64, error) {
+	dbmtx.Lock()
+	defer dbmtx.Unlock()
+
 	mb, err := json.Marshal(sil.Silence.Matchers)
 	if err != nil {
 		return 0, err
@@ -590,6 +616,9 @@ func (s *Silences) Del(sid uint64) error {
 
 // Get implements the Silences interface.
 func (s *Silences) Get(sid uint64) (*types.Silence, error) {
+	dbmtx.Lock()
+	defer dbmtx.Unlock()
+
 	row := s.db.QueryRow(`
 		SELECT id, matchers, starts_at, ends_at, created_at, created_by, comment
 		FROM silences