#signals

Thread-safe is not reentrant, and the difference bites

The Qt handler contract asked for a reentrant function, not just a thread-safe one, and a std::mutex gives you the second without the first. A demo shows a thread-safe counter and a reentrant recursion that needs a recursive_mutex. The precise taxonomy: reentrant implies thread-safe, never the reverse. Episode 8 of the concurrent I/O series.

• #concurrency
• #reentrancy
• #threads
• #signals