ID: 36469
Comment by: levi at alliancesoftware dot com dot au
Reported By: levi at alliancesoftware dot com dot au
Status: No Feedback
Bug Type: PostgreSQL related
Operating System: FC3
PHP Version: 5.1.2
Assigned To: helly
New Comment:
Edit: We gave up on Postgres for that project, but had to revisit this
recently; the issue still exists but it seems the cause is actually that
pg_connection_busy() stays true for some time after a query that causes
any sort of postgres error.
Tested additionally with
x86_64/FC10 + PHP [5.2.9 | 5.2.11 | 5.3.0] + Postgres 8.3
#!/usr/bin/php
<?php
$connStr = sprintf("host=%s dbname=%s user=%s password=%s",
'localhost', 'testlevi', 'levi', 'levi');
($dbConn = pg_connect($connStr)) or die("Could not connect");
@pg_query($dbConn, "drop table thisTableExists");
@pg_query($dbConn, "drop table thisTableDoesNotExist");
pg_query($dbConn, "create table thisTableExists (x varchar(255))")
|| die("Can't create table");
pg_query($dbConn, "insert into thisTableExists values ('foo')") ||
die("Can't insert first row");
pg_query($dbConn, "insert into thisTableExists values ('foo2')") ||
die("Can't insert second row");
$loopCount = 0;
while (true) {
// First 20 queries are completely valid; after that we try
invalid queries
$sql = ($loopCount < 20)
? "select * from thisTableExists; select * from
thisTableExists;"
: "select * from thisTableExists; select * from
thisTableDoesNotExist;";
// Issue the queries
pg_send_query($dbConn, $sql);
// Check first result
$result1 = pg_get_result($dbConn);
$rowCount1 = pg_num_rows($result1);
if ($rowCount1 != 2) die("Bad result set returned (1)");
// Check the second result
$result2 = pg_get_result($dbConn);
$rowCount2 = pg_num_rows($result2);
$expectedRowCount = ($loopCount >= 20) ? 0 : 2;
if ($rowCount2 != $expectedRowCount) die("Bad result set
returned (2)");
if (pg_connection_busy($dbConn)) {
echo (pg_connection_status($dbConn) ==
PGSQL_CONNECTION_OK) ? '+' : '-';
while (pg_connection_busy($dbConn)) {
echo '!';
usleep(1);
}
}
echo ".";
$loopCount++;
}
?>
Expected output:
........................... etc
Actual output:
....................+!.+!.+...............+.+!!!!!!!!!!!!!!!!!!!!!!!!!!!!!.....+!.+!.+!.+
Comments for anyone else experiencing this:
It seems pg_get_result() correctly waits until results are ready, but
even after pg_get_result() returns, if there was an error in the query
then pg_connection_busy() will stay true for some time.
Previous Comments:
------------------------------------------------------------------------
[2008-11-10 01:00:01] php-bugs at lists dot php dot net
No feedback was provided for this bug for over a week, so it is
being suspended automatically. If you are able to provide the
information that was originally requested, please do so and change
the status of the bug back to "Open".
------------------------------------------------------------------------
[2008-11-02 12:31:20] [email protected]
Please try using this CVS snapshot:
http://snaps.php.net/php5.2-latest.tar.gz
For Windows:
http://windows.php.net/snapshots/
------------------------------------------------------------------------
[2006-02-23 02:35:30] levi at alliancesoftware dot com dot au
I have tried and can repeat the error on the following:
Fedora Core 2 (x86):
PHP 5.0.4* PG 8.1*
PHP 5.1.2* PG 8.1*
Fedora Core 3 (x86-64):
PHP 5.0.4** PG 8.1*
PHP 5.1.2* PG 8.1*
* = compiled from source
** = system RPM
I also doublechecked that the connection only says its busy if the
previous query had an error (ie change the query to a valid SELECT and
it doesn't happen)
------------------------------------------------------------------------
[2006-02-22 10:57:52] [email protected]
What PG version are you using and did you try to upgrade it (and
rebuild PHP with the upgraded libs) ?
------------------------------------------------------------------------
[2006-02-21 08:18:22] levi at alliancesoftware dot com dot au
Description:
------------
According to the pg_connection_busy documentation, if pg_get_result is
called on a pg_send_query that is currently executing, it should block
until results become available.
Occasionally this does not happen if the query had an error in it.
Reproduce code:
---------------
#!/usr/local/bin/php51
<?php
$connStr = sprintf("host=%s dbname=%s user=%s password=%s",
'localhost', 'testdb', 'liam', 'liam');
$dbconn = pg_connect($connStr) or die("Could not connect");
$i = 0;
while (!pg_connection_busy($dbconn)) {
pg_send_query($dbconn, 'i am a syntax error');
pg_get_result($dbconn);
$i++;
}
echo "got a busy signal after $i commands";
?>
Expected result:
----------------
(Loops forever)
Actual result:
--------------
got a busy signal after 221 commands
(actual count varies, but always returns within 1 second. Approximately
1/3 of the time it gives a "happy" run and will loop forever)
Note that if the SQL statement was a valid statement, I cannot get the
erroneous behaviour to occur.
------------------------------------------------------------------------
--
Edit this bug report at http://bugs.php.net/?id=36469&edit=1
