mirror/postgresql
2
0
Fork 0
mirror of https://git.postgresql.org/git/postgresql.git synced 2025-02-05 19:09:58 +08:00
Code Issues Packages Projects Releases Wiki Activity

Document a gotcha that happens on Windows when using libpq's new event

Browse Source 
procedure support: it's possible to get confused because exported procedures
have two different addresses.  Per Andrew Chernow.
This commit is contained in:
Tom Lane 2008-11-14 22:58:51 +00:00
parent 772eedb6bb
commit 07c179a82b
1 changed files with 14 additions and 1 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

15
doc/src/sgml/libpq.sgml
View File

@ -1,4 +1,4 @@
<!-- $PostgreSQL: pgsql/doc/src/sgml/libpq.sgml,v 1.269 2008/11/13 09:45:24 mha Exp $ -->
<!-- $PostgreSQL: pgsql/doc/src/sgml/libpq.sgml,v 1.270 2008/11/14 22:58:51 tgl Exp $ -->
<chapter id="libpq">
<title><application>libpq</application> - C Library</title>
@ -5255,6 +5255,19 @@ int eventproc(PGEventId evtId, void *evtInfo, void *passThrough)
<structname>PGconn</>. This is because the address of the procedure
is used as a lookup key to identify the associated instance data.
</para>
<caution>
<para>
On Windows, functions can have two different addresses: one visible
from outside a DLL and another visible from inside the DLL. One
should be careful that only one of these addresses is used with
<application>libpq</>'s event-procedure functions, else confusion will
result. The simplest rule for writing code that will work is to
ensure that event procedures are declared <literal>static</>. If the
procedure's address must be available outside its own source file,
expose a separate function to return the address.
</para>
</caution>
</listitem>
</varlistentry>
</variablelist>