Use Promise Disposer for lock, + cleanup

gosuper/gosuper/main_test.go

@@ -22,7 +22,7 @@ func TestPurge(t *testing.T) {
 
 	if err = os.MkdirAll(dataPath, 0755); err != nil {
 		t.Fatal("Could not create test directory for purge")
-	} else if err = ioutil.WriteFile(dataPath+"/test", []byte("test"), 777); err != nil {
+	} else if err = ioutil.WriteFile(dataPath+"/test", []byte("test"), 0777); err != nil {
 		t.Fatal("Could not create test file for purge")
 	}
 

gosuper/supertest/super_test.go

@@ -42,31 +42,29 @@ func TestPurge(t *testing.T) {
 	appId := config.ApplicationId
 	dataPath := "/resin-data/" + appId
 
-	if err := ioutil.WriteFile(dataPath+"/test", []byte("test"), 777); err != nil {
+	if err := ioutil.WriteFile(dataPath+"/test", []byte("test"), 0777); err != nil {
 		t.Fatal("Could not create test file for purge")
 	} else if request, err := http.NewRequest("POST", supervisorAddress+"/v1/purge?apikey=bananas", strings.NewReader(`{"appId": "`+appId+`"}`)); err != nil {
 		t.Fatal(err)
 	} else {
 		request.Header.Set("Content-Type", "application/json")
-
-		if response, err := http.DefaultClient.Do(request); err != nil {
+		response, err := http.DefaultClient.Do(request)
+		defer response.Body.Close()
+		if err != nil {
 			t.Fatal(err)
 		} else if response.StatusCode != http.StatusOK {
 			t.Errorf("Expected 200, got %d", response.StatusCode)
-			defer response.Body.Close()
 			if contents, err := ioutil.ReadAll(response.Body); err != nil {
 				t.Fatal(err)
 			} else {
 				t.Fatalf("Response: %s", contents)
 			}
 		} else {
-			defer response.Body.Close()
 			if contents, err := ioutil.ReadAll(response.Body); err != nil {
 				t.Fatal(err)
 			} else if !strings.EqualFold(string(contents), `{"Status":"OK","Error":""}`) {
 				t.Errorf("Purge response didn't match the expected JSON, got: %s", contents)
 			}
-
 			if dirContents, err := ioutil.ReadDir(dataPath); err != nil {
 				t.Errorf("Could not read the data path after purge: %s", err)
 			} else if len(dirContents) > 0 {

src/api.coffee

@@ -67,21 +67,20 @@ module.exports = (secret) ->
 		utils.mixpanelTrack('Purge /data', appId)
 		if !appId?
 			return res.status(400).send('Missing app id')
-		app = null
 		knex('app').select().where({ appId })
-		.then ([ appFromDB ]) ->
-			if !appFromDB?
+		.then ([ app ]) ->
+			if !app?
 				throw new Error('App not found')
-			app = appFromDB
-			application.lockUpdatesAsync()
-		.tap ->
-			application.kill(app)
-		.then (release) ->
-			request.post config.gosuperAddress + '/v1/purge', { json: true, body: applicationId: appId }, ->
-				application.start(app)
+			Promise.using application.lockUpdates(), ->
+				application.kill(app)
 				.then ->
-					release()
-			.pipe(res)
+					new Promise (resolve, reject) ->
+						request.post(config.gosuperAddress + '/v1/purge', { json: true, body: applicationId: appId })
+						.on 'error', reject
+						.on 'response', -> resolve()
+						.pipe(res)
+				.finally ->
+					application.start(app)
 		.catch (err) ->
 			res.status(503).send(err?.message or err or 'Unknown error')
 

src/application.coffee

@@ -242,9 +242,10 @@ getEnvironment = do ->
 			console.error("Failed to get environment for device #{deviceId}, app #{appId}. #{err}")
 			throw err
 
-lock = new Lock()
-exports.lockUpdates = lockUpdates = lock.async.writeLock
-exports.lockUpdatesAsync = lockUpdatesAsync = Promise.promisify(lockUpdates)
+exports.lockUpdates = lockUpdates = do ->
+	_lock = new Lock()
+	_lockUpdates = Promise.promisify(_lock.async.writeLock)
+	return -> _lockUpdates().disposer (release) -> release()
 
 # 0 - Idle
 # 1 - Updating
@@ -325,27 +326,24 @@ exports.update = update = ->
 				app = remoteApps[imageId]
 				fetch(app)
 			.then ->
-				lockUpdatesAsync()
-			.tap ->
-				# Then delete all the ones to remove in one go
-				Promise.map toBeRemoved, (imageId) ->
-					kill(apps[imageId])
-			.tap ->
-				# Then install the apps and add each to the db as they succeed
-				installingPromises = toBeInstalled.map (imageId) ->
-					app = remoteApps[imageId]
-					start(app)
-				# And remove/recreate updated apps and update db as they succeed
-				updatingPromises = toBeUpdated.map (imageId) ->
-					localApp = apps[imageId]
-					app = remoteApps[imageId]
-					logSystemEvent(logTypes.updateApp, app)
-					kill(localApp)
+				Promise.using lockUpdates(), ->
+					# Then delete all the ones to remove in one go
+					Promise.map toBeRemoved, (imageId) ->
+						kill(apps[imageId])
 					.then ->
-						start(app)
-				Promise.all(installingPromises.concat(updatingPromises))
-			.then (release) ->
-				release()
+						# Then install the apps and add each to the db as they succeed
+						installingPromises = toBeInstalled.map (imageId) ->
+							app = remoteApps[imageId]
+							start(app)
+						# And remove/recreate updated apps and update db as they succeed
+						updatingPromises = toBeUpdated.map (imageId) ->
+							localApp = apps[imageId]
+							app = remoteApps[imageId]
+							logSystemEvent(logTypes.updateApp, app)
+							kill(localApp)
+							.then ->
+								start(app)
+						Promise.all(installingPromises.concat(updatingPromises))
 	.then ->
 		failedUpdates = 0
 		# We cleanup here as we want a point when we have a consistent apps/images state, rather than potentially at a