Bug #818: pg_Connect() doesn't return unique connection
| From: | bschaffner at accentonline dot com | Date: | Mon, 05 Oct 1998 14:36:43 +0000 |
| Subject: | Bug #818: pg_Connect() doesn't return unique connection | ||
| Groups: | php.dev | ||
| Request: | Send a blank email to php-dev+get-1674@lists.php.net to get a copy of this message | ||
From: bschaffner@accentonline.com
Operating system: FreeBSD 2.2.6
PHP version: 3.0.4
PHP Bug Type: PostgreSQL related
Bug description: pg_Connect() doesn't return unique connection
pg_Connect() doesn't always return a unique connection identifier. This is a problem for code
that uses nested
connections, or code that "hides" connections by using
objects.
One work-around is to not explicitly call pg_Close() from the nested connection. The other is to do
away with this feature - because it smells a lot like pg_pConnect().
Here's a small piece of code:
<?
$HOST = "localhost";
$PORT = "5432";
$DATABASE = "template1";
function Nested() {
global $HOST, $PORT, $DATABASE;
$conn = pg_Connect($HOST, $PORT, "", "", $DATABASE);
if ($conn) {
echo "Nested id: $conn\n";
pg_Close($conn);
}
}
function SomeFunc() {
global $HOST, $PORT, $DATABASE;
$conn = pg_Connect($HOST, $PORT, "", "", $DATABASE);
if ($conn) {
echo "First id: $conn\n";
Nested();
pg_Close($conn);
}
}
SomeFunc();
?>
Running this code yields:
First id: 1
Nested id: 1
<br>
<b>Warning</b>: 1 is not a PostgreSQL link index in <b>foo.php3</b> on line
<b>23</b><br>
The expected output is:
First id: 1
Nested id: 2
The cause is the lookup performed inside pg_Connect(). Whenever a connection is established,
it's stored in a hash table. Then, when a new connection is requested, the connection
parameters are looked up in the hash table, and if a match is found, an existing connection id is
returned. You can see this behaviour by changing one of the above pg_Connect() lines to:
$conn = pg_Connect("127.0.0.1", $PORT, "", "", $DATABASE);
This will cause the lookup to fail because localhost looks different from 127.0.0.1 in the lookup.
I have a feeling this may be something leftover from before pg_pConnect()...
-Brian Schaffner-
--
PHP Development Mailing List http://www.php.net/
To unsubscribe send an empty message to php-dev-unsubscribe@lists.php.net
For help: php-dev-help@lists.php.net