On Tue, Jul 25, 2017 at 5:47 AM, Petr Jelinek <petr.jeli...@2ndquadrant.com> wrote: > As a side note, the ConditionVariablePrepareToSleep()'s comment could be > improved because currently it says the only advantage is that we skip > double-test in the beginning of ConditionVariableSleep(). But that's not > true, it's essential for preventing race conditions like the one above > because it puts the current process into waiting list so we can be sure > it will be signaled on broadcast once ConditionVariablePrepareToSleep() > has been called.
But if you don't call ConditionVariablePrepareToSleep() before calling ConditionVariableSleep(), then the first call to the latter will call the former and return without doing anything else. So I don't see how this can ever go wrong if you're using these primitives as documented. -- Robert Haas EnterpriseDB: http://www.enterprisedb.com The Enterprise PostgreSQL Company -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers
