Re: libpq WSACleanup is not needed
От | James Mansion |
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Тема | Re: libpq WSACleanup is not needed |
Дата | |
Msg-id | 497652C9.8060708@mansionfamily.plus.com обсуждение исходный текст |
Ответ на | Re: libpq WSACleanup is not needed (Andrew Chernow <ac@esilo.com>) |
Ответы |
Re: libpq WSACleanup is not needed
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Список | pgsql-hackers |
Andrew Chernow wrote: > The only problem is how to detect the first connection. In a threaded > environment you'd have to perform locking in connectdb, which is > probably not going to fly. Well, if you do an atomic test for a flag being zero, and if so then enter a critsec, do the init iff you're the first in, and then set the flag on the way out, then:- most times, you'll just have the atomic test- other times, you have a short critsec I can't see that being a big deal considering you're about to resolve the server hostname and then do a TCP/IP connect. My understanding is that if you do WSAStartup and WSACleanup scoped to each connection then:- the internal counting means that only the 0 -> 1 and 1 -> 0 transitions are expensive- libpq will only incur the cost if the application didn't do it already So it seems that the cost is incurred by an application that:- makes no other use of winsock (or also does startup/cleanupoften)- does not retain a connection (or pool) but creates and closes a single connection often How many applications are there that match this pattern? Isn't it enough just to tell the user to do WSAStartup and WSACleanup in main() if they find they have a performance problem? Surely most Windows programs effectively do that anyway, often as a side effect of using a framework. James
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