Condition is designed to check the current value when a consumer wakes up. That's fine when state only moves forward, but it falls apart when transitions are fast. When the setter changes state, it calls notify_all(), which schedules wakeups for every waiting consumer. But in a single-threaded event loop, no consumer actually runs until the current coroutine yields. If the value changes again before that happens, consumers wake up and re-evaluate their predicate against the current value, not the value that triggered the notification. The predicate fails and the consumer goes back to sleep, potentially forever.
新世纪开初十年，我多次赴日本访学，从东京到西京（京都）、九州，向北到仙台，走遍了知名的国立大学，也到过那些著名的私立大学，接触了许多做中国研究的学者，以及在日本留学、定居的中国学人，其间议论到日本大学的教师职位聘任。。体育直播对此有专业解读
"error": {，这一点在PDF资料中也有详细论述
// Nothing executes until iteration begins
Kristen Wiig, Palm Royale