PHP 8.5.0 Alpha 1 available for testing

pg_connect_poll

(PHP 5 >= 5.6.0, PHP 7, PHP 8)

pg_connect_poll Prueba el estado de un intento de conexión asíncrona a PostgreSQL en curso

Descripción

pg_connect_poll(PgSql\Connection $connection): int

La función pg_connect_poll() prueba el estado de una conexión PostgreSQL creada al llamar a la función pg_connect() con la opción PGSQL_CONNECT_ASYNC.

Parámetros

connection

An PgSql\Connection instance.

Valores devueltos

Devuelve la constante PGSQL_POLLING_FAILED, PGSQL_POLLING_READING, PGSQL_POLLING_WRITING, PGSQL_POLLING_OK, o la constante PGSQL_POLLING_ACTIVE.

Historial de cambios

Versión Descripción
8.1.0 The connection parameter expects an PgSql\Connection instance now; previously, a recurso was expected.
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User Contributed Notes 1 note

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5
VLroyrenn
6 years ago
So the documentation on this function is pretty barebones (as is the case for a lot of thin PHP wrappers around C functions), but from what I've gathered by reading the libpq doc and trying various things, you should probably know the following :

* Polling the connection while the underlying socket is busy will cause the connection (or at least the polling, I'm not sure) to fail.
* As stated by the libpq documentation, "do not assume that the socket remains the same across PQconnectPoll calls"
* The socket will become ready after every change in connection status, so the connection must be polled multiple times until the function returns "polling_ok" or "polling_failed".
* "polling_active" can never be returned by libpq and has literally never been used anywhere ever, it has been an unused constant since day 1.

What you need to do is use pg_socket get a PHP stream object corresponding to the current socket and wait after it before polling, like so:

<?php
function pg_wait_connection_ready($conn) {
assert(is_resource($conn));
assert(get_resource_type($conn) === "pgsql link" || get_resource_type($conn) === "pgsql link persistent");

// "On the first iteration, i.e. if you have yet to call PQconnectPoll, behave as if it last returned PGRES_POLLING_WRITING."
$poll_outcome = PGSQL_POLLING_WRITING;

while (
true) {
$socket = [pg_socket($conn)]; // "Caution: do not assume that the socket remains the same across PQconnectPoll calls."
$null = [];

if (
$poll_outcome === PGSQL_POLLING_READING) {
stream_select($socket, $null, $null, 5);
$poll_outcome = pg_connect_poll($conn);
} else if (
$poll_outcome === PGSQL_POLLING_WRITING) {
stream_select($null, $socket, $null, 5);
$poll_outcome = pg_connect_poll($conn);
} else {
break;
}
}
}

$db = pg_connect($conn_string, PGSQL_CONNECT_ASYNC);
// Do things while the connection is getting ready
pg_wait_connection_ready($db);
pg_query($sql);
?>
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