Commit a23661d2 authored by Committed by Simon MarlowBrowse files
STM: Only wake up once
Previously, threads blocked on an STM retry would be sent a wakeup message each time an unpark was requested. This could result in the accumulation of a large number of wake-up messages, which would slow wake-up once the sleeping thread is finally scheduled. Here, we introduce a new closure type, STM_AWOKEN, which marks a TSO which has been sent a wake-up message, allowing us to send only one wakeup.