I see in our muc/config.php this section:
'definitionmappings' => array (
0 => array (
'store' => 'Redis',
'definition' => 'core/coursemodinfo',
'sort' => 1,
),
),
'locks' => array (
'cachelock_file_default' => array (
'name' => 'cachelock_file_default',
'type' => 'cachelock_file',
'dir' => 'filelocks',
'default' => true,
),
),
It seems to me that the locks are being written to the filesystem instead of to the caching server?
Or am I wrong? I was searching in the code for the error thrown, and I only found it in the
caching module of file caching, that's why I am confused about these config settings.
Here's the code in the php file /[www root]/cache/locks/file/lib.php:
public function lock($key, $ownerid, $block = false) {
// Get the name of the lock file we want to use.
$lockfile = $this->get_lock_file($key);
// Attempt to create a handle to the lock file.
// Mode xb is the secret to this whole function.
// x = Creates the file and opens it for writing. If the file already exists fopen returns false and a warning is thrown.
// b = Forces binary mode.
$result = @fopen($lockfile, 'xb');
// Check if we could create the file or not.
if ($result === false) {
// Lock exists already.
if ($this->maxlife !== null && !array_key_exists($key, $this->locks)) {
$mtime = filemtime($lockfile);
if ($mtime < time() - $this->maxlife) {
$this->unlock($key, true);
$result = $this->lock($key, false);
if ($result) {
return true;
}
}
}
if ($block) {
// OK we are blocking. We had better sleep and then retry to lock.
$iterations = 0;
$maxiterations = $this->blockattempts;
while (($result = $this->lock($key, false)) === false) {
// Usleep causes the application to cleep to x microseconds.
// Before anyone asks there are 1'000'000 microseconds to a second.
usleep(rand(1000, 50000)); // Sleep between 1 and 50 milliseconds.
$iterations++;
if ($iterations > $maxiterations) {
// BOOM! We've exceeded the maximum number of iterations we want to block for.
throw new cache_exception('ex_unabletolock');
}
}
}
return false;
} else {
// We have the lock.
fclose($result);
$this->locks[$key] = $lockfile;
return true;
}
}
