Pthread Condvars: POSIX Compliance and the Priority Inheritance Gap

Explore the intricacies of Pthread Condvars and their compliance with POSIX standards in this 55-minute conference talk presented by Darren Hart from Intel and Torvald Riegel from RedHat. Delve into the challenges of using condvars in real-time applications, particularly the issue of non-configurable internal locking for Priority Inheritance (PI). Examine the current state of glibc patches providing non-POSIX extensions for PI configuration and their relationship with the PREEMPT_RT Linux kernel. Investigate the newly discovered POSIX non-compliance in glibc's condvar implementation and its implications for supporting PI. Engage in a discussion about potential solutions, including modifications to existing operations or the introduction of new PI futex operations. Gain insights from kernel developers experienced in core locking mechanisms, system library developers, and real-time applications developers as they explore paths towards a POSIX-compliant solution that supports Priority Inheritance.