This repository was archived by the owner on Oct 20, 2024. It is now read-only.
Fix an "unrecognized selector sent to instance" crash#79
Open
eunikolsky wants to merge 1 commit intozwopple:developfrom
Open
Fix an "unrecognized selector sent to instance" crash#79eunikolsky wants to merge 1 commit intozwopple:developfrom
eunikolsky wants to merge 1 commit intozwopple:developfrom
Conversation
An app using `PocketSocket` crashes occasionally with this information: ``` Fatal Exception: NSInvalidArgumentException -[SomeDelegate webSocketDidFlushOutput:]: unrecognized selector sent to instance 0x123456789 0 CoreFoundation 0x88881ad8c __exceptionPreprocess … 5 PocketSocket 0x8888d5004 __43-[PSWebSocket notifyDelegateDidFlushOutput]_block_invoke (PSWebSocket.m:668) 6 libdispatch.dylib 0x88880caa0 _dispatch_call_block_and_release … ``` The `notifyDelegateDidFlushOutput` function checks if the delegate responds to the `webSocketDidFlushOutput:` selector before sending it. The only possible cause for the crash is when the delegate changes between the check and the call because the function is not atomic. Added `testChangingDelegateWhileFlushingOutputShouldNotCrashWithUnrecognizedSelector` can reproduce the crash very quickly and consistently. The fix here is to capture the delegate strongly while the function is running to work with the same instance. The patch fixes the crash in all similar places in `PSWebSocket`, as well as in `PSWebSocketServer`.
This file contains hidden or bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
Sign up for free
to subscribe to this conversation on GitHub.
Already have an account?
Sign in.
1 participant
Add this suggestion to a batch that can be applied as a single commit.This suggestion is invalid because no changes were made to the code.Suggestions cannot be applied while the pull request is closed.Suggestions cannot be applied while viewing a subset of changes.Only one suggestion per line can be applied in a batch.Add this suggestion to a batch that can be applied as a single commit.Applying suggestions on deleted lines is not supported.You must change the existing code in this line in order to create a valid suggestion.Outdated suggestions cannot be applied.This suggestion has been applied or marked resolved.Suggestions cannot be applied from pending reviews.Suggestions cannot be applied on multi-line comments.Suggestions cannot be applied while the pull request is queued to merge.Suggestion cannot be applied right now. Please check back later.
An app using
PocketSocketcrashes occasionally with this information:The
notifyDelegateDidFlushOutputfunction checks if the delegateresponds to the
webSocketDidFlushOutput:selector before sending it.The only possible cause for the crash is when the delegate changes
between the check and the call because the function is not atomic. Added
testChangingDelegateWhileFlushingOutputShouldNotCrashWithUnrecognizedSelectorcan reproduce the crash very quickly and consistently.
The fix here is to capture the delegate strongly while the function is
running to work with the same instance. The patch fixes the crash in all
similar places in
PSWebSocket, as well as inPSWebSocketServer.