There is one xpc server and two xpc clients (clientA and clientB). When clientB sends a message to the xpc server, xpc server fills a value for dummyString in it's memory and I want clientA to know that dummyString got updated and also the new value for this dummyString. The updation of dummyString is not something that happens often. Two options we tried: Have a timer for 5 seconds in clientA and keep polling and request for the value of this dummyString. Setup a darwin notification in server that gets posted whenever dummyString is being updated. clientA receives requests for dummyString value only when it observes a notification being posted. Which of these two approaches causes the least delay for clientA to know the updated value of dummyString?

I have 2 XPC clients and an XPC server. One of the XPC clients is a binary-helper that serves as a native messaging host for the browserExtension. The other XPC client sends a specific event to the XPC server, which then triggers a Darwin notification. The binary-helper observes this Darwin notification and sends a response to the browserExtension. Currently, we're considering two options to communicate the response from binary-helper to browserExtension: Polling: Every 5 seconds, the browserExtension checks for a response. Darwin Notifications: The binary-helper sends a message to the browserExtension as soon as it observes the Darwin notification. I'm wondering if Darwin notifications are fast enough to reliably deliver this response to the browserExtension in real time, or if polling would be a more reliable approach. Any insights or experiences with using Darwin notifications in a similar scenario would be greatly appreciated.

I'm using libxpc in a C server and Swift client. I set up a code-signing requirement in the server using xpc_connection_set_peer_code_signing_requirement(). However, when the client doesn't meet the requirement, the server just closes the connection, and I get XPC_ERROR_CONNECTION_INTERRUPTED on the client side instead of XPC_ERROR_PEER_CODE_SIGNING_REQUIREMENT, making debugging harder. What I want: To receive XPC_ERROR_PEER_CODE_SIGNING_REQUIREMENT on the client when code-signing fails, for better debugging. What I’ve tried: Using xpc_connection_set_peer_code_signing_requirement(), but it causes the connection to be dropped immediately. Questions: Why does the server close the connection without sending the expected error? How can I receive the correct error on the client side? Are there any other methods for debugging code-signing failures with libxpc? Thanks for any insights!

This is the functionality I am trying to achieve with libxpc: There's one xpc server and two xpc clients. When the xpc server receives a particular dictionary item from clientB, the server needs to send a response to both clientA and clientB. This is the approach I am currently using: First, clientA creates a dictionary item that indicates that this item is from clientA. Now, clientA sends this dictionary to server. When server receives this item, it stores the connection instance with clientA in a global variable. Next, when clientB sends a particular dictionary item, server uses this global variable where it perviously stored clientA's connection instance to send a response back to clientA, alongside clientB. Only one edge case I can see is that when clientA closes this connection instance, server will be trying to send a response to an invalidated connection. Question: Is this approach recommended? Any edge cases I should be aware of? Is there any better way to achieve this functionality?