Re: inline newNode()
От | Bruce Momjian |
---|---|
Тема | Re: inline newNode() |
Дата | |
Msg-id | 200210090435.g994Z6B07015@candle.pha.pa.us обсуждение исходный текст |
Ответ на | Re: inline newNode() (Tom Lane <tgl@sss.pgh.pa.us>) |
Ответы |
Re: inline newNode()
Re: inline newNode() |
Список | pgsql-patches |
Tom Lane wrote: > Bruce Momjian <pgman@candle.pha.pa.us> writes: > > Right, palloc shouldn't. I was thinking of having another version of > > palloc that _does_ clear out memory, and calling that from a newNode() > > macro. We already know palloc is going to call MemoryContextAlloc, so > > we could have a pallocC() that calls a new MemoryContextAllocC() that > > would call the underlying memory allocation function, then do the loop > > like MemSet to clear it. > > But if the MemSet is inside the called function then it cannot reduce > the if-tests to a compile-time decision to invoke the word-zeroing loop. > We want the MemSet to be expanded at the newNode call site, where the > size of the allocated memory is a compile-time constant. I can easily do the tests in the MemSet macro, but I can't do a loop in a macro that has to return a value; I need while(). Though a loop in a new fuction will not be as fast as a MemSet macro, I think it will be better than what we have now with newNode only because newNode will be a macro and not a function anymore, i.e. the MemSet will happen in the function called by pallocC and not in newNode anymore, and there will be zero code bloat. I wish I saw another way. -- Bruce Momjian | http://candle.pha.pa.us pgman@candle.pha.pa.us | (610) 359-1001 + If your life is a hard drive, | 13 Roberts Road + Christ can be your backup. | Newtown Square, Pennsylvania 19073
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