The process cannot access the file because it is being used by another process

[EvenAR]

Hello,

I have tried to follow the steps provided in the readme. However, when the updater is finished I get the following message in updater.log:

2017/03/30 18:55:09 C:\Users\Even\AppData\Roaming\vnpc2\VNPCv2.exe: creating new file: open C:\Users\Even\AppData\Roaming\vnpc2\VNPCv2.exe: The process cannot access the file because it is being used by another process.

Am I doing something wrong in my code? I assume the reason is that my NW client is not 100% closed when the updater is trying to replace VNPCv2.exe.

This is the code I use to start the update:

if(newUpdate) {
	alert("Update found! I will now download the update...");

	var url = global.va.getUpdateUrl();
	var TMP_DIR = require('os').tmpdir() + "/vnpcUpdate";

	var download = require('download-file')
	
	download(url, { directory: TMP_DIR, filename: "update.zip" }, function(err){
		const shell = nw.require('shelljs');
		const path = nw.require('path');

		const APPDIR = path.dirname(process.execPath);
		const UPDATER_BIN = TMP_DIR + '/updater.exe';
		
		shell.cp(APPDIR + '/updater.exe', UPDATER_BIN);
		shell.chmod(755 & ~process.umask(), UPDATER_BIN);

		const spawn = require('child_process').spawn;
		alert("Update downloaded. I will now quit in order to install the new update.");

		spawn(UPDATER_BIN, [
			'--bundle', 'update.zip',
			'--inst-dir', APPDIR
		], {
			cwd: path.dirname(UPDATER_BIN),
			detached: true,
			stdio: 'ignore'
		}).unref();
		
		nw.App.quit();
	});
}

updater.exe is built using GOOS=windows GOARCH=386 go build -ldflags "-s -w -H=windowsgui" -o updater.exe nwjs-autoupdater with the <requestedExecutionLevel level="asInvoker" uiAccess="false"/> set in the manifest-file.

I have also tried with <requestedExecutionLevel level="requireAdministrator" uiAccess="false"/>, however this gives me this error in my application when trying to execute the updater:

Error: spawn EACCES
unless I run my app "As administrator" - In that case I get the same problem as described earlier.

My application executable (VNPCv2.exe) is built using nw-builder

[weiluenju]

I have same issue and my error message is:

2018/04/10 16:36:04 open C:...\d3dcompiler_47.dll: The process cannot access the file because it is being used by another process.

[adityagesh]

Add 1 or 2 second sleep to main.go file and then build the updater.

package main

import (
	"flag"
	"log"
	"os"
	"path/filepath"
	"time"
	"github.com/skratchdot/open-golang/open"
	"nwjs-autoupdater/updater"
)

func main() {
	var bundle, instDir, appName string

	flag.StringVar(&bundle, "bundle", "", "Path to the update package")
	flag.StringVar(&instDir, "inst-dir", "", "Path to the application install dir")
	flag.StringVar(&appName, "app-name", "my_app", "Application executable name")
	flag.Parse()

	cwd, _ := os.Getwd()
	logfile, err := os.Create(filepath.Join(cwd, "updater.log"))
	if err != nil {
		panic(err)
	}
	defer logfile.Close()

	time.Sleep(2 * time.Second)

	logger := log.New(logfile, "", log.LstdFlags)

	var appExec string;
	err, appExec = updater.Update(bundle, instDir, appName)
	if err != nil {
		logger.Fatal(err)
	}

	open.Start(appExec)
}

[SuperKirik]

I added 8 sec sleep in updater, but sometimes some files from nw app are still in use and as a result update crashes trying replace files with the error 'Acccess Denied'. Now for example it happaned with 'd3dcompiler_47.dll' file.

Despite it happens quite rare, it is stiil very upleasure... Anybody knows the way to prevent the issue for sure?

[d3x0r]

Windows does allow renaming exes/dlls which are in use... so you can move the file out of the way, and then use the https://learn.microsoft.com/en-us/windows/win32/api/winbase/nf-winbase-movefileexa function 'If dwFlags specifies MOVEFILE_DELAY_UNTIL_REBOOT and lpNewFileName is NULL, MoveFileEx registers the lpExistingFileName file to be deleted when the system restarts. I' Though I suppose it becomes trickier if you do multiple updates inbetween reboots or in a single session....