pika 0.15.0

New features

• async_rw_mutex has been moved to a public header: pika/async_rw_mutex.hpp. The functionality is still experimental in the pika::execution::experimental namespace. async_rw_mutex_access_type and async_rw_mutex_access_wrapper have also been moved out of the detail namespace. (#655)

Breaking changes

• The any_sender and unique_any_sender operator bool(), which can be used to check whether the sender contains a valid sender, is now explicit to avoid accidental conversions. (#653)
• Scheduler idling was disabled by default. This typically improves performance. If performance is less important than resource usage idling may be beneficial to enable explicitly. (#661)
• The CMake option PIKA_WITH_THREAD_CUMULATIVE_COUNTS was disabled by default. This often improves performance. (#662)
• Thread guard pages were disabled by default. This often improves performance. They can still be enabled at runtime with the configuration option pika.stacks.use_guard_pages=1 to debug e.g. stack overflows. (#663)
• The fast_idle and delay_exit scheduler modes were completely removed as they added overhead and were not used in any meaningful way in the scheduler. (#664)
• The ability to run background threads in the scheduler was completely removed. (#665, #668)

Bugfixes

• Fixed an inconsistent preprocessor guard that affected Apple M1 and M2 systems. (#657)
• Fixed preprocessor guards to enable deadlock detection in debug builds. The deadlock detection was never enabled previously. (#658)
• Thread deadlock detection will now correctly print potentially deadlocked threads. (#659)