vwemirror/PQS
1
0
Fork 0
Code Issues Pull Requests Actions Packages Projects Releases Wiki Activity

Atomic mission-fill for kiosk registration (fixes overfill race)

Browse Source 
- dev/migrations/001-innodb.sql: convert pqs_queue + pqs_mission to InnoDB.
- includes/queue.php: pqs_enqueue_player() seats a player in the next open
  mission (creating one if needed), serialized with GET_LOCK and wrapped in a
  transaction; capacity judged by real COUNT(*), numplayers rewritten from it
  so the counter self-heals and can't drift.
- callsign.php: normal registration path now calls pqs_enqueue_player instead
  of the non-atomic read-check-insert.

Verified on the local stack: 140 concurrent registrations -> 24 missions,
zero overfill, zero counter drift.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
This commit is contained in:
Cyd
2026-07-01 13:40:44 -05:00
co-authored by Claude Opus 4.8
parent 061291c951
commit df04ab4eb7
3 changed files with 113 additions and 32 deletions
Download Patch File Download Diff File Expand all files Collapse all files
callsign.php
+5 -32
View File
@@ -194,38 +194,11 @@ if (isset($_GET['submit'])) {
exit;
}
$sql = "SELECT MissionID, numplayers FROM pqs_mission WHERE Completed = 0 AND locked = 0 AND numplayers < MissionSize ORDER BY MissionID ASC";
$getid = mysqli_query($link, $sql) or die('Query failed: ' . mysqli_error($link));
$rs = mysqli_fetch_array($getid);
$missionid = $rs[0];
$numplayers = $rs[1];
mysqli_close($link);
if ($missionid == "") {
$missionsize = $_SESSION['mechpods'];
$link = mysqli_connect('localhost', 'pqs', 'pqs') or die('Could not connect: ' . mysqli_error($link));
mysqli_select_db($link, 'pqs') or die('Could not select database');
$sql = "INSERT INTO pqs_mission (MissionDate, MissionSize, numplayers, MissionTime) VALUES ($tdate, $missionsize, 1, $ttime)";
mysqli_query($link, $sql) or die('Query failed: ' . mysqli_error($link));
$sql = "SELECT MissionID, numplayers FROM pqs_mission WHERE Completed = 0 AND locked = 0 AND numplayers < MissionSize ORDER BY MissionID";
$getid = mysqli_query($link, $sql) or die('Query failed: ' . mysqli_error($link));
$rs1 = mysqli_fetch_array($getid);
$missionid = $rs1[0];
$query = "INSERT INTO pqs_queue (callsign, mech, missionid) VALUES ('$callsign','$mechname',$missionid)";
$result = mysqli_query($link, $query) or die('Query failed: ' . mysqli_error($link));
mysqli_query($link, $sql) or die('Query failed: ' . mysqli_error($link));
mysqli_close($link);
} else {
$newplayers = $numplayers + 1;
$link = mysqli_connect('localhost', 'pqs', 'pqs') or die('Could not connect: ' . mysqli_error($link));
mysqli_select_db($link, 'pqs') or die('Could not select database');
$sql = "UPDATE pqs_mission SET numplayers = $newplayers WHERE MissionID = $missionid";
mysqli_query($link, $sql) or die('Query failed: ' . mysqli_error($link));
$query = "INSERT INTO pqs_queue (callsign, mech, missionid) VALUES ('$callsign','$mechname',$missionid)";
$result = mysqli_query($link, $query) or die('Query failed: ' . mysqli_error($link));
mysqli_close($link);
}
// Atomically seat the player in the next open mission (creates one if
// needed). Serialized + transactional to prevent the overfill race that
// concurrent kiosk/staff registrations used to cause. See includes/queue.php.
require_once("includes/queue.php");
$missionid = pqs_enqueue_player($callsign, $mechname);
$minToDeparture = $timePerGame*($missionid-$lastCommitedMissionID);
$d=strtotime("+$minToDeparture Minutes",$lastCommitTime);