Dispatching delegates in designated queues

[philips77]

This PR should solve issue #249.
CC @DevAndArtist

There are still 3 calls for main dispatch queue. Do you have an idea how to solve it? I guess I should use the queue used for central manager to be consistent.

[philips77]

Ok, I guess that's it. Could you check if it works for you? Or at least if the API will work for you?

[DevAndArtist]

@philips77 thank you for the effort, I will add it tomorrow to our project and check how it behaves. Btw. I scanned over the patches and haven't seen any use of dispatchPrecondition, how did you verified the queue on which the code is being run?

[philips77]

The main reason for not using it is that I don't know how to use this method :)
I assume that all CBCentralManager and CBPeripheral delegate calls are done on a queue given in CBCentralManager connector. All other calls in the lib are called from one of the delegate methods, except from starting dfu, where the current queue is used, it delayed called, where I use the same queue explicitly. Isn't that enough?

[philips77]

Hello, any updates on this? I watched a video and I'm now pro in dispatchPrecondition, but still don't think it's necessary due to what I said earlier.

[DevAndArtist]

@philips77 not yet. I'm currently fixing other parts of our library which prevent me from being able to compile the project. I'll try to test your patch by the end of the day, I hope, and report back.

If you're interested to read more about dispatchPrecondition here is a Swift thread where I asked for some more clarifications: https://forums.swift.org/t/what-is-the-default-target-queue-for-a-serial-queue/18094

[philips77]

Other thing, dispatchPrecondition is available on iOS 10+ while DFU is now supported on 9.0+ (after migrating Zip -> ZipFramework in #251).

[philips77]

I'm thinking about merging the PR tomorrow and releasing 4.3.0 if you have no objections.

[DevAndArtist]

I finally updated to project to test the changes but I'm hitting an issue:

dyld: Library not loaded: @rpath/ZIPFoundation.framework/ZIPFoundation
  Referenced from: /private/var/containers/Bundle/Application/D5798A54-60A6-4F27-9BC1-F3E9AD9164B5/App.app/Frameworks/iOSDFULibrary.framework/iOSDFULibrary
  Reason: image not found

Should I include the new dependency manually or are the projects dependencies messed up? (I'm using carthage to include the DFU lib.)

You are missing a cartfile with the new dependency to ZIPFoundation, otherwise Carthage has now idea that this project depends on it.

[DevAndArtist]

Resolved the dependency here and the framework gets added into the app bundle, but I'm hitting the next issue and unable to run the app.

dyld: Library not loaded: @rpath/ZIPFoundation.framework/ZIPFoundation
  Referenced from: /private/var/containers/Bundle/Application/6768A1C7-5C6E-471B-9969-F84AEFE42EA3/App.app/Frameworks/iOSDFULibrary.framework/iOSDFULibrary
  Reason: Incompatible library version: iOSDFULibrary requires version 1.0.0 or later, but ZIPFoundation provides version 0.0.0

I'm currently out of ideas why this issue happens. I cleared Derived Data and clean build the project.

[DevAndArtist]

I resolved the issue above, it's an issue ZIPFoundation has, I'm not sure if my PR will be approved. I found the solution in a different project after searching the web for it: jpsim/Yams#131

I fixed the issue here:
weichsel/ZIPFoundation#91

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In your case you still need to add a cartfile so Carthage can pull ZIPFoundation.

[philips77]

I've created cartfile with

github "weichsel/ZIPFoundation" ~> 0.9

in the main directory. Is there anything else needed for me to push?

[philips77]

Btw, we didn't have cartfile before switching to ZipFoundation, or at least I don't see it. Was it working for you before, or you had to include that dependency in your cartfile?

[DevAndArtist]

That's a good question. To be honest I'm not sure how Carthage previously pulled Zip.framework. It just didn't worked for me this time.

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I'm fixing some internal dispatchPrecondition cases related to the changes made here. Give me an hour or so, I'll report if I could flash without issues.

[DevAndArtist]

Okay I could flash multiple times without any issues. Feel free to merge.

[philips77]

I've added Cartfile. Is that the right place for it?

[DevAndArtist]

Looks good on my end, Carthage can now pull ZIPFoundation correctly, the only requirement for the project to run correctly is them to merge my PR.