Re: ecpg threading vs win32

Magnus Hagander <magnus(at)hagander(dot)net> wrote:

> This patch replaces the pthreads code in ecpg with native win32 threads,
> in order to make it threadsafe. The idea is not to have to download the
> non-standard pthreads library on windows.
>
> Does it seem like it should be doing the right thing? Does somebody have
> a good test-case where ecpg breaks when not built thread-safe? (which
> would then also break when built thread-safe with a broken implementation)

I have two questions about thread-safe ecpg.

Q1. Don't you use CRITICAL_SECTION instead of Mutex (CreateMutex)?
I've heard there is a performance benefit in CRITICAL_SECTION.
If the mutex is shared only in one process, CS might be a better solution.
http://japan.internet.com/developer/img/article/873/17801.gif
http://world.std.com/~jmhart/csmutx.htm

Q2. Do we need to use PQescapeStringConn() instead of PQescapeString()?
PQescapeString() is used to escape literals, and the documentation says
PQescapeStringConn() should be used in multi-threaded client programs.
http://momjian.us/main/writings/pgsql/sgml/libpq-exec.html#LIBPQ-EXEC-ESCAPE-STRING
| PQescapeString can be used safely in single-threaded client programs
| that work with only one PostgreSQL connection at a time

Regards,
---
ITAGAKI Takahiro
NTT Open Source Software Center