On 3 September 2012 08:10, Daniel Farina <dan...@heroku.com> wrote: > http://doxygen.postgresql.org/xlog_8c_source.html#l08197 > > On line 8197 of xlog.c: > > 08194 /* Get a local copy of the last safe checkpoint record. */ > 08195 SpinLockAcquire(&xlogctl->info_lck); > 08196 lastCheckPointRecPtr = xlogctl->lastCheckPointRecPtr; > 08197 memcpy(&lastCheckPoint, &XLogCtl->lastCheckPoint, > sizeof(CheckPoint)); > 08198 SpinLockRelease(&xlogctl->info_lck); > > Note the use of capital XLogCtl->lastCheckPoint, which is not the > volatile pointer.
That looks like a bug to me. Come to think of it, the whole convention of using a lower-case variant of the original pointer variable name seems like a foot-gun, given the harmful and indeed very subtle consequences of making this error. I count 98 SpinLockAcquire() call sites (of which only a minority use this convention, which is mostly within xlog.c, I think). Is it worth instituting an alternative convention to make this kind of misuse more obvious? This went unnoticed since February 2009. -- Peter Geoghegan http://www.2ndQuadrant.com/ PostgreSQL Development, 24x7 Support, Training and Services -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers
