Multiple AF.upload cannot be concurrent

[baiyidjp]

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What did you do?

When I use AF.upload to initiate multiple upload tasks, the multiple upload tasks are always executed serially. As a result, other requests I want to execute after the upload is successful must also be executed after all uploads are completed. In other words, upload seems to be blocking other requests. But this is not the case when I use AFNetwork

What did you expect to happen?

When I use AF.upload to initiate multiple upload tasks, they can be executed concurrently without blocking other requests.

What happened instead?

Blocking other requests

Alamofire Environment

**Alamofire Version: 5.8.1
**Dependency Manager: cocoapods
**Xcode Version: 15.1
**Swift Version: Swift 5
**Platform(s) Running Alamofire: 17.1
**macOS Version Running Xcode: 14.2.1

Demo Project

        DispatchQueue.global().async {
            AF.upload(
                    multipartFormData: {
                        $0.append(fileData, withName: name, fileName: fileName, mimeType: mimeType)
                    },
                    to: uploadURL,
                    headers: headers)
                .responseDecodable(of: APIResponse<APIResult>.self) { response in
                    DispatchQueue.main.async {
                        /// other request
                    }
                }
        }

[jshier]

There's nothing in Alamofire that triggers this behavior. If you're seeing this it's likely URLSession is attempting to optimize your connectivity or otherwise preventing the app from overloading the network connections. Or it may be that your server doesn't allow multiple uploads at the same time.

P.S. The DispatchQueue usage you have here is unnecessary. Neither the global() or the call back to main does anything. Alamofire completion handlers are on main by default.