Re: synchronized code
От | Felipe Schnack |
---|---|
Тема | Re: synchronized code |
Дата | |
Msg-id | 1042060306.12254.155.camel@desenv1.ritterdosreis.br обсуждение исходный текст |
Ответ на | Re: synchronized code ("Michael Paesold" <mpaesold@gmx.at>) |
Ответы |
Re: synchronized code
Re: synchronized code |
Список | pgsql-jdbc |
yuck! I think this implementation is kinda gross (can you send me this source? Just curious). Just imagine using preparedstatements, you will allocate a big internal buffer (to store the "PREPARE", etc command) and then just execute much smaller "EXECUTE" calls. Well, what we have to decide is what is better: - Create and destroy StringBuffer objects. This adds object creation overhead (as far as I know this isn't a problem) and gc overhead (I have no idea if it's costly) - Continue the way it is, or: use a unique StringBuffer, that is synchronized in every use (maybe it's better now, but historically a costly operation, AFAIK) and have its contents reset every time (IMHO a bad programming pratice - easily someone will forget to do it - and as pointed out by Michael, not very effective). My opinion is quite clear, isn't it? On Wed, 2003-01-08 at 18:16, Michael Paesold wrote: > Felipe Schnack <felipes@ritterdosreis.br> wrote: > > > Is... but what got better with JVM 1.4 was synch'ing not object > > creation, so you're basically saying I'm correct? :-) > > I think it depends on the virtual machine, but I'm no expert. > > I just had a look at the latest StringBuffer sources. What setLength(0) > does, is to wipe the whole buffer with null-bytes ('\0') in a loop! Although > I have no idea why it is done, it seems to be very inefficient. Especially > when you think of the fact, that this single StringBuffer will grow, > everytime a bigger string is put into it. It seams that sb.delete(0, > sb.length); is much more efficient. It just resets the internal length > counter? > > Any comments? > > Regards, > Michael Paesold > -- Felipe Schnack Analista de Sistemas felipes@ritterdosreis.br Cel.: (51)91287530 Linux Counter #281893 Centro Universitário Ritter dos Reis http://www.ritterdosreis.br ritter@ritterdosreis.br Fone/Fax.: (51)32303341
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