serialize app state saves

fixes #3543

app/index.js

@@ -63,6 +63,7 @@ const flash = require('../js/flash')
 const contentSettings = require('../js/state/contentSettings')
 const privacy = require('../js/state/privacy')
 const basicAuth = require('./browser/basicAuth')
+const async = require('async')
 
 // Used to collect the per window state when shutting down the application
 let perWindowState = []
@@ -85,6 +86,10 @@ const prefsRestartLastValue = {}
 
 const unsafeTestMasterKey = 'c66af15fc6555ebecf7cee3a5b82c108fd3cb4b587ab0b299d28e39c79ecc708'
 
+const sessionStoreQueue = async.queue((task, callback) => {
+  task(callback)
+}, 1)
+
 /**
  * Gets the master key for encrypting login credentials from the OS keyring.
  */
@@ -164,24 +169,34 @@ const saveIfAllCollected = (forceSave) => {
         }
       }
     }
+    sessionStoreQueue.push(saveAppState.bind(null, appState))
+  }
+}
 
-    const logSaveAppStateError = (e) => {
-      console.error('Error saving app state: ', e)
-    }
-    SessionStore.saveAppState(appState, shuttingDown).catch(logSaveAppStateError).then(() => {
-      if (shuttingDown) {
-        sessionStateStoreCompleteOnQuit = true
-        // If there's an update to apply, then do it here.
-        // Otherwise just quit.
-        if (appState.updates && (appState.updates.status === UpdateStatus.UPDATE_APPLYING_NO_RESTART ||
-            appState.updates.status === UpdateStatus.UPDATE_APPLYING_RESTART)) {
-          Updater.quitAndInstall()
-        } else {
-          app.quit()
-        }
+const logSaveAppStateError = (e) => {
+  console.error('Error saving app state: ', e)
+}
+
+const saveAppState = (appState, cb) => {
+  SessionStore.saveAppState(appState, shuttingDown).catch((e) => {
+    logSaveAppStateError(e)
+    cb()
+  }).then(() => {
+    if (shuttingDown) {
+      sessionStateStoreCompleteOnQuit = true
+      // If there's an update to apply, then do it here.
+      // Otherwise just quit.
+      if (appState.updates && (appState.updates.status === UpdateStatus.UPDATE_APPLYING_NO_RESTART ||
+          appState.updates.status === UpdateStatus.UPDATE_APPLYING_RESTART)) {
+        Updater.quitAndInstall()
+      } else {
+        app.quit()
       }
-    })
-  }
+      // no callback here because we don't want to get a partial write during shutdown
+    } else {
+      cb()
+    }
+  })
 }
 
 /**
@@ -279,7 +294,7 @@ app.on('ready', () => {
 
     e.preventDefault()
 
-    clearTimeout(initiateSessionStateSave)
+    clearInterval(initiateSessionStateSave)
     initiateSessionStateSave(true)
 
     // Just in case a window is not responsive, we don't want to wait forever.

package.json

@@ -77,6 +77,7 @@
   "dependencies": {
     "abp-filter-parser-cpp": "1.1.x",
     "acorn": "3.2.0",
+    "async": "^2.0.1",
     "electron-localshortcut": "^0.6.0",
     "electron-prebuilt": "brave/electron-prebuilt",
     "electron-squirrel-startup": "^1.0.0",
@@ -92,8 +93,8 @@
     "ledger-client": "^0.8.55",
     "ledger-publisher": "^0.8.57",
     "lru_cache": "^1.0.0",
-    "random-lib": "2.1.0",
     "qr-image": "^3.1.0",
+    "random-lib": "2.1.0",
     "react": "^15.0.1",
     "react-dom": "^15.0.1",
     "react-stickynode": "1.1.x",