Prevent Plugin from Locking when Heavy Processing + Adding Process Indicator [Multithreading?]

Audio Plugins
1

Hi everyone,

I’m creating an ARA plugin that makes use of ARA’s ability to read entire audiosources at once, which I am using CURL to be processed through the network and receive processed audio data. Basically, I am extracting the audio from the DAW as a .wav file, sending it via CURL for processing, receiving back a processed .wav file, then playing it back.

The issue I’m facing right now is that when the CURL call is happening, the plugin/DAW sort of “locks up” and I get the spinning wheel of death on my mac, during which I can’t perform any action on the plugin/DAW. The process is quite heavy so it takes up to a minute when making this call on a 3 minute long-ish wav file.

My question may be a bit broad, but what would be the best way to 1) prevent the plugin/DAW from locking up during this CURL call and 2) display a sort of “progress bar” that indicates how much of the processing is done? I have a pretty good idea about 2) but I’m mostly looking for an answer for 1). Should I be doing some kind of multi-thread processing? If so, what’s the best way to approach multi-threading in JUCE?

Any kind of pointers will help, thank you very much.

2

I’m not very familiar with what you try to achieve, but it seems that the DAW hangs because you are running a heavy task on the Message Thread. You indeed should not do that.

Instead, you should run this task on a separate thread. You can use a simple std::thread and detach it. But since you also want a progress bar, you should look at Juce’s ThreadWithProgressWindow. It does exactly what you want.

Careful though, you say you are building a plugin, so you might want to avoid popup windows, especially modal ones like ThreadWithProgressWindow. So maybe you should instead bake a progress bar inside your already existing plugin editor.

3

Thanks! Your advice is a lot of help.

4

Instead of curl you could also have a look at DownloadTask, which is designed to download in the background and you can use the Listener to display progress.