/**
* MySQL version of DBLockManager that supports shared locks.
*
- * All lock servers must have the innodb table defined in locking/filelocks.sql.
+ * Do NOT use this on connection handles that are also being used for anything
+ * else as the transaction isolation will be wrong and all the other changes will
+ * get rolled back when the locks release!
+ *
+ * All lock servers must have the innodb table defined in maintenance/locking/filelocks.sql.
* All locks are non-blocking, which avoids deadlocks.
*
* @ingroup LockManager
$keys[] = $key;
$data[] = [ 'fls_key' => $key, 'fls_session' => $this->session ];
if ( !isset( $this->locksHeld[$path][self::LOCK_EX] ) ) {
- $checkEXKeys[] = $key;
+ $checkEXKeys[] = $key; // this has no EX lock on $key itself
}
}
$db->insert( 'filelocks_shared', $data, __METHOD__, [ 'IGNORE' ] );
# Actually do the locking queries...
if ( $type == self::LOCK_SH ) { // reader locks
- $blocked = false;
# Bail if there are any existing writers...
if ( count( $checkEXKeys ) ) {
- $blocked = $db->selectField( 'filelocks_exclusive', '1',
+ $blocked = $db->selectField(
+ 'filelocks_exclusive',
+ '1',
[ 'fle_key' => $checkEXKeys ],
__METHOD__
);
+ } else {
+ $blocked = false;
}
# Other prospective writers that haven't yet updated filelocks_exclusive
# will recheck filelocks_shared after doing so and bail due to this entry.
# Bail if there are any existing writers...
# This may detect readers, but the safe check for them is below.
# Note: if two writers come at the same time, both bail :)
- $blocked = $db->selectField( 'filelocks_shared', '1',
+ $blocked = $db->selectField(
+ 'filelocks_shared',
+ '1',
[ 'fls_key' => $keys, "fls_session != $encSession" ],
__METHOD__
);
# Block new readers/writers...
$db->insert( 'filelocks_exclusive', $data, __METHOD__ );
# Bail if there are any existing readers...
- $blocked = $db->selectField( 'filelocks_shared', '1',
+ $blocked = $db->selectField(
+ 'filelocks_shared',
+ '1',
[ 'fls_key' => $keys, "fls_session != $encSession" ],
__METHOD__
);