diff options
| author | Andreas Fischer <bantu@phpbb.com> | 2010-10-27 13:06:21 +0200 |
|---|---|---|
| committer | Andreas Fischer <bantu@phpbb.com> | 2010-10-27 13:06:21 +0200 |
| commit | 6ff403c9f8fd19e5ddf81fdf3e8bb27018b519b9 (patch) | |
| tree | 8e5aacbf527f94c9af9b64470d5ee141c396ff86 /phpBB/includes/functions_messenger.php | |
| parent | 832b09d60d79bf2795e1fbbfc7a0f4bda8b66931 (diff) | |
| parent | 981970024701bd1e740056c595c959afd5a85ba0 (diff) | |
| download | forums-6ff403c9f8fd19e5ddf81fdf3e8bb27018b519b9.tar forums-6ff403c9f8fd19e5ddf81fdf3e8bb27018b519b9.tar.gz forums-6ff403c9f8fd19e5ddf81fdf3e8bb27018b519b9.tar.bz2 forums-6ff403c9f8fd19e5ddf81fdf3e8bb27018b519b9.tar.xz forums-6ff403c9f8fd19e5ddf81fdf3e8bb27018b519b9.zip | |
Merge branch 'ticket/cs278/9061' into develop-olympus
* ticket/cs278/9061:
[ticket/9061] Simplify conditional statements by reworking the logic.
[ticket/9061] Fixed a race condition in queue locking.
Diffstat (limited to 'phpBB/includes/functions_messenger.php')
| -rw-r--r-- | phpBB/includes/functions_messenger.php | 87 |
1 files changed, 68 insertions, 19 deletions
diff --git a/phpBB/includes/functions_messenger.php b/phpBB/includes/functions_messenger.php index bb0d88ec1b..b5c87094c0 100644 --- a/phpBB/includes/functions_messenger.php +++ b/phpBB/includes/functions_messenger.php @@ -632,6 +632,64 @@ class queue } /** + * Obtains exclusive lock on queue cache file. + * Returns resource representing the lock + */ + function lock() + { + // For systems that can't have two processes opening + // one file for writing simultaneously + if (file_exists($this->cache_file . '.lock')) + { + $mode = 'rb'; + } + else + { + $mode = 'wb'; + } + + $lock_fp = @fopen($this->cache_file . '.lock', $mode); + + if ($mode == 'wb') + { + if (!$lock_fp) + { + // Two processes may attempt to create lock file at the same time. + // Have the losing process try opening the lock file again for reading + // on the assumption that the winning process created it + $mode = 'rb'; + $lock_fp = @fopen($this->cache_file . '.lock', $mode); + } + else + { + // Only need to set mode when the lock file is written + @chmod($this->cache_file . '.lock', 0666); + } + } + + if ($lock_fp) + { + @flock($lock_fp, LOCK_EX); + } + + return $lock_fp; + } + + /** + * Releases lock on queue cache file, using resource obtained from lock() + */ + function unlock($lock_fp) + { + // lock() will return null if opening lock file, and thus locking, failed. + // Accept null values here so that client code does not need to check them + if ($lock_fp) + { + @flock($lock_fp, LOCK_UN); + fclose($lock_fp); + } + } + + /** * Process queue * Using lock file */ @@ -639,24 +697,16 @@ class queue { global $db, $config, $phpEx, $phpbb_root_path, $user; - set_config('last_queue_run', time(), true); + $lock_fp = $this->lock(); - // Delete stale lock file - if (file_exists($this->cache_file . '.lock') && !file_exists($this->cache_file)) - { - @unlink($this->cache_file . '.lock'); - return; - } + set_config('last_queue_run', time(), true); - if (!file_exists($this->cache_file) || (file_exists($this->cache_file . '.lock') && filemtime($this->cache_file) > time() - $config['queue_interval'])) + if (!file_exists($this->cache_file) || filemtime($this->cache_file) > time() - $config['queue_interval']) { + $this->unlock($lock_fp); return; } - $fp = @fopen($this->cache_file . '.lock', 'wb'); - fclose($fp); - @chmod($this->cache_file . '.lock', 0777); - include($this->cache_file); foreach ($this->queue_data as $object => $data_ary) @@ -720,6 +770,7 @@ class queue break; default: + $this->unlock($lock_fp); return; } @@ -745,8 +796,6 @@ class queue if (!$result) { - @unlink($this->cache_file . '.lock'); - messenger::error('EMAIL', $err_msg); continue 2; } @@ -790,16 +839,14 @@ class queue { if ($fp = @fopen($this->cache_file, 'wb')) { - @flock($fp, LOCK_EX); fwrite($fp, "<?php\nif (!defined('IN_PHPBB')) exit;\n\$this->queue_data = unserialize(" . var_export(serialize($this->queue_data), true) . ");\n\n?>"); - @flock($fp, LOCK_UN); fclose($fp); phpbb_chmod($this->cache_file, CHMOD_READ | CHMOD_WRITE); } } - @unlink($this->cache_file . '.lock'); + $this->unlock($lock_fp); } /** @@ -812,6 +859,8 @@ class queue return; } + $lock_fp = $this->lock(); + if (file_exists($this->cache_file)) { include($this->cache_file); @@ -831,13 +880,13 @@ class queue if ($fp = @fopen($this->cache_file, 'w')) { - @flock($fp, LOCK_EX); fwrite($fp, "<?php\nif (!defined('IN_PHPBB')) exit;\n\$this->queue_data = unserialize(" . var_export(serialize($this->data), true) . ");\n\n?>"); - @flock($fp, LOCK_UN); fclose($fp); phpbb_chmod($this->cache_file, CHMOD_READ | CHMOD_WRITE); } + + $this->unlock($lock_fp); } } |