Fixing threading-related hang during initialization in urgent mode #10958
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wowlocal
commented
Mar 15, 2023
…gent mode This commit resolves a threading issue in the FIRCLSInstallIdentifierModel class that caused a 10-second hang during Crashlytics initialization in urgent mode. The issue was caused by a semaphore that was used in a main thread, which blocked the main thread's execution and prevented completion of the installation ID check within the designated time limit. To address this issue, the code was updated to check whether the current thread is the main thread, and if so, eliminate usage of the semaphore entirely. Instead, a runloop spinning mechanism was introduced, which allows dispatch_async to notify the thread to resume execution.
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Hey @wowlocal, I made a change to this PR in a new one: https://github.com/firebase/firebase-ios-sdk/pull/11216/files. I put the rationale in the description. I am for some reason unable to run your new test using Swift Package Manager. Are you able to run it? |
The resourcePath behaves differently when using SPM. |
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Closing in favor of #11216 |
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This commit fixes a threading issue in the FIRCLSInstallIdentifierModel class that caused a 10-second hang during Crashlytics initialization in urgent mode. The issue was caused by a semaphore that was waiting for a completion handler to unblock it, but the completion handler was waiting for the main thread to call dispatch_async, resulting in a deadlock. To solve this problem, the code was updated to use a runloop spinning mechanism instead of the semaphore when running on the main thread. This allows dispatch_async to notify the thread to resume execution without blocking it.
Changes include: