On Thu, Jan 23, 2025 at 2:17 PM Amit Kapila <amit.kapil...@gmail.com> wrote: > > On Wed, Jan 22, 2025 at 9:21 AM Peter Smith <smithpb2...@gmail.com> wrote: > > > > On Wed, Jan 22, 2025 at 5:36 AM Masahiko Sawada <sawada.m...@gmail.com> > > wrote: > > > > > > On Sun, Jan 19, 2025 at 7:53 PM Amit Kapila <amit.kapil...@gmail.com> > > > wrote: > > > > > > > > On Fri, Jan 17, 2025 at 11:19 PM Masahiko Sawada > > > > <sawada.m...@gmail.com> wrote: > > > > > > > > > > On Wed, Jan 15, 2025 at 4:43 PM Peter Smith <smithpb2...@gmail.com> > > > > > wrote: > > > > > > > > > > > > My thoughts are that any consistency improvement is a step in the > > > > > > right direction so even "don't increase the consistency much" is > > > > > > still > > > > > > better than nothing. > > > > > > > > > > I agree that doing something is better than nothing. The proposed > > > > > idea, having RBTXN_IS_PREPARED prefix for all related flags, improves > > > > > the consistency in terms of names, but I'm not sure this is the right > > > > > direction. For example, RBTXN_IS_PREPARED_SKIPPED is quite confusing > > > > > to me. I think this name implies "this is a prepared transaction but > > > > > is skipped", but I don't think it conveys the meaning well. In > > > > > addition to that, if we add RBTXN_IS_PREPARED flag also for skipped > > > > > prepared transactions, we would end up with doing like: > > > > > > > > > > txn->txn_flags |= (RBTXN_IS_PREPARED | RBTXN_IS_PREPARED_SKIPPED); > > > > > > > > > > Which seems quite redundant. It makes more sense to me to do like: > > > > > > > > > > txn->txn_flags |= (RBTXN_IS_PREPARED | RBTXN_SKIPPED_PREPARE); > > > > > > > > > > I'd like to avoid a situation like where we rename these names just > > > > > for better consistency in terms of names and later rename them to > > > > > better names for other reasons again and again. > > > > > > > > > > > > > Sounds reasonable. We agree with just changing RBTXN_PREPARE to > > > > RBTXN_IS_PREPARED and its corresponding macro. The next step is to > > > > update the patch to reflect the same. > > > > > > Right. I've attached the updated patches. > > > > > > > Some review comments for v15-0002. > > > > ====== > > Commit message > > > > typo /RBTXN_IS_PREAPRE/RBTXN_IS_PREPARE/ > > > > ====== > > > > I'm not trying to be pedantic, but there seems to be something strange > > about the combination usage of these PREPARE constants, which raises > > lots of questions for me... > > > > For example. > > I had thought RBTXN_SKIPPED_PREPARE meant it is a prepared tx AND it is > > skipped > > I had thought RBTXN_SENT_PREPARE meant it is a prepared tx AND it is sent > > > > So I was surprised that the patch makes this change: > > - txn->txn_flags |= RBTXN_SKIPPED_PREPARE; > > + txn->txn_flags |= (RBTXN_IS_PREPARED | RBTXN_SKIPPED_PREPARE); > > > > because, if we cannot infer that RBTXN_SKIPPED_PREPARE *must* mean it > > is a prepared transaction then why does that constant even have > > "PREPARE" in its name at all instead of just being called > > RBTXN_SKIPPED? > > > > e.g., either of these makes sense to me: > > txn->txn_flags |= (RBTXN_IS_PREPARED | RBTXN_SKIPPED); > > txn->txn_flags |= RBTXN_SKIPPED_PREPARE; > > > > But this combination seemed odd: > > txn->txn_flags |= (RBTXN_IS_PREPARED | RBTXN_SKIPPED_PREPARE); > > > > Also, this code (below) seems to be treating those macros as > > unrelated, but IIUC we know that rbtxn_skip_prepared(txn) is not > > possible unless rbtxn_is_prepared(txn) is true. > > > > - if (rbtxn_prepared(txn) || rbtxn_skip_prepared(txn)) > > + if (rbtxn_is_prepared(txn) || rbtxn_skip_prepared(txn)) > > continue; > > > > ~~ > > > > Furthermore, if we cannot infer that RBTXN_SKIPPED_PREPARE *must* also > > be a prepared transaction, then why aren't the macros changed to match > > that interpretation? > > > > e.g. > > > > /* prepare for this transaction skipped? */ > > #define rbtxn_skip_prepared(txn) \ > > ( \ > > ((txn)->txn_flags & RBTXN_IS_PREPARED != 0) && \ > > ((txn)->txn_flags & RBTXN_SKIPPED_PREPARE != 0) \ > > ) > > > > /* Has a prepare or stream_prepare already been sent? */ > > #define rbtxn_sent_prepare(txn) \ > > ( \ > > ((txn)->txn_flags & RBTXN_IS_PREPARED != 0) && \ > > ((txn)->txn_flags & RBTXN_SENT_PREPARE != 0) \ > > ) > > > > ~~~ > > > > I think a to fix all this might be to enforce the RBTXN_IS_PREPARED > > bitflag is set also for RBTXN_SKIPPED_PREPARE and RBTXN_SENT_PREPARE > > constants, removing the ambiguity about how exactly to interpret those > > two constants. > > > > e.g. something like > > > > #define RBTXN_IS_PREPARED 0x0040 > > #define RBTXN_SKIPPED_PREPARE (0x0080 | RBTXN_IS_PREPARED) > > #define RBTXN_SENT_PREPARE (0x0200 | RBTXN_IS_PREPARED) > > > > I think the better way would be to ensure that where we set > RBTXN_SENT_PREPARE or RBTXN_SKIPPED_PREPARE, the transaction is a > prepared one (RBTXN_IS_PREPARED must be already set). It should be > already the case for RBTXN_SENT_PREPARE but we can ensure the same for > RBTXN_SKIPPED_PREPARE as well. > > Will that address your concern? Does anyone else have an opinion on this > matter?
Yes that would be OK, but should also add some clarifying comments in the "reorderbuffer.h" like: #define RBTXN_SKIPPED_PREPARE 0x0080 /* this flag can only be set for RBTXN_IS_PREPARED transactions */ #define RBTXN_SENT_PREPARE 0x0200 /* this flag can only be set for RBTXN_IS_PREPARED transactions */ ====== Kind Regards, Peter Smith. Fujitsu Australia
