How to unlock the file after AWS S3 Helper uploading file?

Yes the stream upload locks the file till it finishes, Try either of 2,

$client = AWS::createClient('s3');$fileContent = file_get_contents($temp_path);$result = $client->putObject(array(    'Bucket'     => self::$bucketName,    'Key'        => 'screenshot/testing.png',    'Body'       => $fileContent,    'ACL'        => 'public-read')););unlink($temp_path);

or

$client = AWS::createClient('s3');$fileContent = file_get_contents($temp_path);$result = $client->putObject(array(    'Bucket'     => self::$bucketName,    'Key'        => 'screenshot/testing.png',    'Body'       => $fileContent,    'ACL'        => 'public-read')););gc_collect_cycles();unlink($temp_path);

When you're using SourceFile option at putObject S3Client opens a file, but doesn't close it after operation.

In most cases you just can unset $client and/or $result to close opened files.But unfortunately not in this case.

Use Body option instead of the SourceFile.

// temp file$file = fopen($temp_path, "r");// use resource, not a path$result = $client->putObject(array(        'Bucket'     => self::$bucketName,        'Key'        => 'screenshot/testing.png',        'Body'       => $file,        'ACL'        => 'public-read'    )););fclose($file);unlink($temp_path);

EDIT: I just noticed the string in your $temp_path begins with a "/" slash character. This beginning slash typically starts at the root directory of the website, are you sure this is the correct location? Use the getcwd() command in PHP to find out what folder PHP thinks it is inside of.

I understand you believe the permissions are correct but in light of the "Permission denied" error I still believe it is telling you something relevant.

I see you are trying to chown the directory, did you perhaps mean to chmod it? If you can SSH to your server and run this command you may have more luck:

chmod -R 777 /(your-website-dir/screenshot_temp

Or even try changing the "chown" to "chmod" in your PHP code.