Changeset 36349

Timestamp:

01/19/2016 05:06:46 AM (9 years ago)

Author:

dd32

Message:

Core Upgrader: Add a locking mechanism to avoid two concurrent updates of WordPress occuring.

Fixes #34878

Location:

trunk/src/wp-admin

Files:

• includes/class-wp-upgrader.php (modified) (9 diffs)
• update-core.php (modified) (1 diff)

trunk/src/wp-admin/includes/class-wp-upgrader.php

@@ -752 +752 @@
     }
 
+    /**
+     * Create a Lock using WordPress options.
+     *
+     * @since 4.5.0
+     * @access public
+     *
+     * @param string $lock_name       The name of this unique lock.
+     * @param int    $release_timeout The duration in seconds to respect an existing lock. Default: 1 hour.
+     * @return bool
+     */
+    public function create_lock( $lock_name, $release_timeout = null ) {
+        global $wpdb;
+        if ( ! $release_timeout ) {
+            $release_timeout = HOUR_IN_SECONDS;
+        }
+        $lock_option = $lock_name . '.lock';
+
+        // Try to lock
+        $lock_result = $wpdb->query( $wpdb->prepare( "INSERT IGNORE INTO `$wpdb->options` ( `option_name`, `option_value`, `autoload` ) VALUES (%s, %s, 'no') /* LOCK */", $lock_option, time() ) );
+
+        if ( ! $lock_result ) {
+            $lock_result = get_option( $lock_option );
+
+            // If we couldn't create a lock, and there isn't a lock, bail
+            if ( ! $lock_result ) {
+                return false;
+            }
+
+            // Check to see if the lock is still valid
+            if ( $lock_result > ( time() - $release_timeout ) ) {
+                return false;
+            }
+
+            // There must exist an expired lock, clear it and re-gain it.
+            $this->release_lock( $lock_name );
+
+            return $this->create_lock( $lock_name, $release_timeout );
+        }
+
+        // Update the lock, as by this point we've definitely got a lock, just need to fire the actions
+        update_option( $lock_option, time() );
+
+        return true;
+    }
+
+    /**
+     * Release a lock created by `WP_Upgrader::create_lock()`.
+     *
+     * @since 4.5.0
+     * @access public
+     *
+     * @param string $lock_name The name of this unique lock.
+     * @return bool
+     */
+    public function release_lock( $lock_name ) {
+        return delete_option( $lock_name . '.lock' );
+    }
+
 }
 
@@ -2169 +2227 @@
     public function upgrade_strings() {
         $this->strings['up_to_date'] = __('WordPress is at the latest version.');
+        $this->strings['locked'] = __('Another update is currently in progress.');
         $this->strings['no_package'] = __('Update package not available.');
         $this->strings['downloading_package'] = __('Downloading update from <span class="code">%s</span>&#8230;');
@@ -2253 +2312 @@
             $to_download = 'full';
 
+        // Lock to prevent multiple Core Updates occuring
+        $lock = $this->create_lock( 'core_updater', 15 * MINUTE_IN_SECONDS );
+        if ( ! $lock ) {
+            return new WP_Error( 'locked', $this->strings['locked'] );
+        }
+
         $download = $this->download_package( $current->packages->$to_download );
-        if ( is_wp_error($download) )
+        if ( is_wp_error( $download ) ) {
+            $this->release_lock( 'core_updater' );
             return $download;
+        }
 
         $working_dir = $this->unpack_package( $download );
-        if ( is_wp_error($working_dir) )
+        if ( is_wp_error( $working_dir ) ) {
+            $this->release_lock( 'core_updater' );
             return $working_dir;
+        }
 
         // Copy update-core.php from the new version into place.
         if ( !$wp_filesystem->copy($working_dir . '/wordpress/wp-admin/includes/update-core.php', $wp_dir . 'wp-admin/includes/update-core.php', true) ) {
             $wp_filesystem->delete($working_dir, true);
+            $this->release_lock( 'core_updater' );
             return new WP_Error( 'copy_failed_for_update_core_file', __( 'The update cannot be installed because we will be unable to copy some files. This is usually due to inconsistent file permissions.' ), 'wp-admin/includes/update-core.php' );
         }
@@ -2270 +2340 @@
         require_once( ABSPATH . 'wp-admin/includes/update-core.php' );
 
-        if ( ! function_exists( 'update_core' ) )
+        if ( ! function_exists( 'update_core' ) ) {
+            $this->release_lock( 'core_updater' );
             return new WP_Error( 'copy_failed_space', $this->strings['copy_failed_space'] );
+        }
 
         $result = update_core( $working_dir, $wp_dir );
@@ -2345 +2417 @@
             wp_version_check( $stats );
         }
+
+        $this->release_lock( 'core_updater' );
 
         return $result;
@@ -2939 +3013 @@
         }
 
-        // Core doesn't output this, so let's append it so we don't get confused.
         if ( 'core' == $type ) {
+            if ( is_wp_error( $upgrade_result ) && ( 'up_to_date' == $upgrade_result->get_error_code() || 'locked' == $upgrade_result->get_error_code() ) ) {
+                // These aren't actual errors, treat it as a skipped-update instead to avoid triggering the post-core update failure routines.
+                return false;
+            }
+
+            // Core doesn't output this, so let's append it so we don't get confused.
             if ( is_wp_error( $upgrade_result ) ) {
                 $skin->error( __( 'Installation Failed' ), $upgrade_result );
@@ -2976 +3055 @@
             return;
 
-        $lock_name = 'auto_updater.lock';
-
-        // Try to lock
-        $lock_result = $wpdb->query( $wpdb->prepare( "INSERT IGNORE INTO `$wpdb->options` ( `option_name`, `option_value`, `autoload` ) VALUES (%s, %s, 'no') /* LOCK */", $lock_name, time() ) );
-
-        if ( ! $lock_result ) {
-            $lock_result = get_option( $lock_name );
-
-            // If we couldn't create a lock, and there isn't a lock, bail
-            if ( ! $lock_result )
-                return;
-
-            // Check to see if the lock is still valid
-            if ( $lock_result > ( time() - HOUR_IN_SECONDS ) )
-                return;
-        }
-
-        // Update the lock, as by this point we've definitely got a lock, just need to fire the actions
-        update_option( $lock_name, time() );
+        if ( ! $this->create_lock( 'auto_updater' ) )
+            return;
 
         // Don't automatically run these thins, as we'll handle it ourselves
@@ -3093 +3155 @@
         }
 
-        // Clear the lock
-        delete_option( $lock_name );
+        $this->release_lock( 'auto_updater' );
     }
 
@@ -3164 +3225 @@
          */
         $send = true;
-        $transient_failures = array( 'incompatible_archive', 'download_failed', 'insane_distro' );
+        $transient_failures = array( 'incompatible_archive', 'download_failed', 'insane_distro', 'locked' );
         if ( in_array( $error_code, $transient_failures ) && ! get_site_option( 'auto_core_update_failed' ) ) {
             wp_schedule_single_event( time() + HOUR_IN_SECONDS, 'wp_maybe_auto_update' );

trunk/src/wp-admin/update-core.php

@@ -485 +485 @@
     if ( is_wp_error($result) ) {
         show_message($result);
-        if ('up_to_date' != $result->get_error_code() )
+        if ( 'up_to_date' != $result->get_error_code() && 'locked' != $result->get_error_code() )
             show_message( __('Installation Failed') );
         echo '</div>';