Make retry timeout configurable

README.md

@@ -16,6 +16,8 @@ Set:
   - It can also be `hostname:port` if you want to use other port different than `6379` (Default)
 * `$CFG->lock_factory` to `'\\local_redislock\\lock\\redis_lock_factory'` in your config file.
 * `$CFG->local_redislock_auth` with your Redis server's password string.
+* `$CFG->local_redislock_retry_timeout` the time in ms to sleep between attempts to claim the lock (Default: 750)
+* `$CFG->local_redislock_retry_jitter` amount of random jitter in ms to add/subtract from `$CFG->local_redislock_retry_timeout`. (Default: 250)
 
 ## Flags
 

classes/lock/redis_lock_factory.php

@@ -94,6 +94,8 @@ public function __construct($type, \Redis $redis = null, $logging = null) {
         $this->redisserver = $CFG->local_redislock_redis_server ?? null;
         $this->shareconnection = empty($CFG->local_redislock_disable_shared_connection);
         $this->auth = $CFG->local_redislock_redis_auth ?? null;
+        $this->lockretry = ($CFG->local_redislock_retry_timeout ?? 750) * 1000;
+        $this->lockretry_jitter = ($CFG->local_redislock_retry_jitter ?? 250) * 1000;
         if (is_null($redis)) {
             shared_redis_connection::get_instance()->add_factory();
             $redis = $this->bootstrap_redis();
@@ -202,7 +204,7 @@ public function get_lock($resource, $timeout, $maxlifetime = 86400) {
             }
 
             if (!$locked && $timeout !== 0) {
-                usleep(rand(500000, 1000000)); // Sleep between 0.5 and 1 second.
+                usleep(rand($this->lockretry - $this->lockretry_jitter, $this->lockretry + $this->lockretry_jitter));
             }
         } while (!$locked && $now < $giveuptime);
 
@@ -262,7 +264,7 @@ public function release_lock(lock $lock) {
                 $this->redis = $this->bootstrap_redis();
 
                 // Sleep the loop for a bit so we don't spam connections.
-                usleep(rand(500000, 1000000));
+                usleep(rand($this->lockretry - $this->lockretry_jitter, $this->lockretry + $this->lockretry_jitter));
             }
         } while ($exception);