How to get a unique POSIX message queue?

Question

I am working on a simple parallel application in which I want to use a single process to store information about the status of a workflow family. It seems relatively easy to set up a POSIX message queue in which all worker bees can send periodic updates to the state support service. My problem? The POSIX message queue must have a name. I do not want to choose a name; all I care about is getting a unique message queue, just as I would use SYSV's message queues with IPC_PRIVATE. For a unique file name I could use mkstemp(3)or for a unique open file descriptor that I could use tmpfile(3). How do I get a unique POSIX message queue?

Answer 1

I do not want to choose a name; all I care about is getting a unique message queue, just as I would use SYSV message queues with IPC_PRIVATE

Well, with POSIX message queues, you need to specify a name, but you do not need to save it and do not allow other users to use the same queue under this name.

IPC_PRIVATE facial expressions

Take that mkstempand tmpfiledo under the hood. Borrow any of the tmp / temp naming algorithms to create something / reasonably_unique, mq_openit is O_CREAT | O_EXCL and then mq_unlinkit. Then, the child worker processes can inherit the message queue descriptor.

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