From da9e071d7dddfe008da0cf8d9b67f85342558424 Mon Sep 17 00:00:00 2001
From: f0o <f0o@librenms.org>
Date: Wed, 2 Sep 2015 14:46:42 +0100
Subject: [PATCH] Revert all PHP-Based MySQL Locks introduced in #1584

---
 discovery.php                  | 13 +------------
 includes/dbFacile.mysql.php    | 30 ------------------------------
 includes/dbFacile.mysqli.php   | 29 -----------------------------
 includes/sql-schema/update.php |  8 --------
 poller.php                     | 17 +++--------------
 5 files changed, 4 insertions(+), 93 deletions(-)

diff --git a/discovery.php b/discovery.php
index c72013ec7..3006399ff 100755
--- a/discovery.php
+++ b/discovery.php
@@ -105,19 +105,8 @@ if ($config['distributed_poller'] === true) {
     $where .= ' AND poller_group IN('.$config['distributed_poller_group'].')';
 }
 
-echo 'Checking for MySQL Locks:';
-while (!dbCheckLock('schema_update')) {
-    echo '.';
-    sleep(1);
-}
-echo PHP_EOL;
-
 foreach (dbFetch("SELECT * FROM `devices` WHERE status = 1 AND disabled = 0 $where ORDER BY device_id DESC") as $device) {
-    if (dbGetLock('discovering.' . $device['device_id'])) {
-        register_shutdown_function('dbReleaseLock','discovering.'.$device['device_id']);
-        discover_device($device, $options);
-        dbReleaseLock('discovering.' . $device['device_id']);
-    }
+    discover_device($device, $options);
 }
 
 $end      = utime();
diff --git a/includes/dbFacile.mysql.php b/includes/dbFacile.mysql.php
index 7b75aa9fb..0d1d7150c 100644
--- a/includes/dbFacile.mysql.php
+++ b/includes/dbFacile.mysql.php
@@ -59,36 +59,6 @@ function dbQuery($sql, $parameters=array()) {
 }//end dbQuery()
 
 
-/*
- * Aquire a lock on a string
- * */
-function dbGetLock($data, $timeout = 0) {
-	$sql = 'SELECT GET_LOCK(\'' . $data . '\',' . $timeout . ')';
-	$result = dbFetchCell($sql);
-	return $result;
-}
-
-
-/*
- * Check a lock on a string
- * */
-function dbCheckLock($data) {
-    $sql = 'SELECT IS_FREE_LOCK(\'' . $data . '\')';
-    $result = dbFetchCell($sql);
-    return $result;
-}
-
-
-/*
- * Release a lock on a string
- * */
-function dbReleaseLock($data) {
-    $sql = 'SELECT RELEASE_LOCK(\'' . $data . '\')';
-    $result = dbFetchCell($sql);
-    return $result;
-}
-
-
 /*
  * Passed an array and a table name, it attempts to insert the data into the table.
  * Check for boolean false to determine whether insert failed
diff --git a/includes/dbFacile.mysqli.php b/includes/dbFacile.mysqli.php
index d7016368d..2408ca990 100644
--- a/includes/dbFacile.mysqli.php
+++ b/includes/dbFacile.mysqli.php
@@ -59,35 +59,6 @@ function dbQuery($sql, $parameters=array()) {
 }//end dbQuery()
 
 
-/*
- * Aquire a lock on a string
- * */
-function dbGetLock($data, $timeout = 0) {
-	$sql = 'SELECT GET_LOCK(\'' . $data . '\',' . $timeout . ')';
-	$result = dbFetchCell($sql);
-	return $result;
-}
-
-
-/*
- * Check a lock on a string
- * */
-function dbCheckLock($data) {
-    $sql = 'SELECT IS_FREE_LOCK(\'' . $data . '\')';
-    $result = dbFetchCell($sql);
-    return $result;
-}
-
-
-/*
- * Release a lock on a string
- * */
-function dbReleaseLock($data) {
-    $sql = 'SELECT RELEASE_LOCK(\'' . $data . '\')';
-    $result = dbFetchCell($sql);
-    return $result;
-}
-
 /*
  * Passed an array and a table name, it attempts to insert the data into the table.
  * Check for boolean false to determine whether insert failed
diff --git a/includes/sql-schema/update.php b/includes/sql-schema/update.php
index 93fe7eb6b..505082615 100644
--- a/includes/sql-schema/update.php
+++ b/includes/sql-schema/update.php
@@ -91,13 +91,6 @@ if ($tmp[0] <= $db_rev) {
     return;
 }
 
-if (!dbGetLock('schema_update')) {
-    echo "Schema update already in progress. Exiting\n";
-    exit(1);
-} //end if
-
-register_shutdown_function('dbReleaseLock','schema_update');
-
 foreach ($filelist as $file) {
     list($filename,$extension) = explode('.', $file, 2);
     if ($filename > $db_rev) {
@@ -168,4 +161,3 @@ if ($updating) {
     echo "-- Done\n";
 }
 
-dbReleaseLock('schema_update');
diff --git a/poller.php b/poller.php
index 265486b2a..6412c37be 100755
--- a/poller.php
+++ b/poller.php
@@ -100,13 +100,6 @@ if (isset($options['r'])) {
     $config['norrd'] = true;
 }
 
-echo 'Checking for MySQL Locks:';
-while (!dbCheckLock('schema_update')) {
-    echo '.';
-    sleep(1);
-}
-echo PHP_EOL;
-
 rrdtool_pipe_open($rrd_process, $rrd_pipes);
 
 echo "Starting polling run:\n\n";
@@ -117,13 +110,9 @@ if (!isset($query)) {
 
 foreach (dbFetch($query) as $device) {
     $device = dbFetchRow("SELECT * FROM `devices` WHERE `device_id` = '".$device['device_id']."'");
-    if (dbGetLock('polling.' . $device['device_id'])) {
-        register_shutdown_function('dbReleaseLock','polling.'.$device['device_id']);
-        poll_device($device, $options);
-        RunRules($device['device_id']);
-        echo "\r\n";
-        dbReleaseLock('polling.' . $device['device_id']);
-    }
+    poll_device($device, $options);
+    RunRules($device['device_id']);
+    echo "\r\n";
     $polled_devices++;
 }