[9.x] Make throttle lock acquisition retry time configurable (#41516)

* Make throttle lock acquisition attempt retry time configurable

Depending on context, 750ms can be a long time to wait between retries
for a throttle.  We are making the retry time configurable so that users
can tune the throttling further.

All changes are backwards compatible.

I set the unit as milliseconds because this seemed like the natural time
unit to use.  Seconds would require floats which felt dirty.  That being
said, it's not consistent with the unit used for `->every` and `->block`
on the builder.  So I'm open to changing it for consistency.

```php
Redis::throttle('my-key')
    ->allow(5)
    ->every(10)
    ->retryWait(100)
    ->then(static fn () => echo "hello!");
```

* formatting

Co-authored-by: Taylor Otwell <[email protected]>

Author: timmartin19

src/Illuminate/Redis/Limiters/DurationLimiter.php

@@ -70,11 +70,12 @@ public function __construct($redis, $name, $maxLocks, $decay)
      *
      * @param  int  $timeout
      * @param  callable|null  $callback
+     * @param  int  $sleep
      * @return mixed
      *
      * @throws \Illuminate\Contracts\Redis\LimiterTimeoutException
      */
-    public function block($timeout, $callback = null)
+    public function block($timeout, $callback = null, $sleep = 750)
     {
         $starting = time();
 
@@ -83,7 +84,7 @@ public function block($timeout, $callback = null)
                 throw new LimiterTimeoutException;
             }
 
-            usleep(750 * 1000);
+            usleep($sleep * 1000);
         }
 
         if (is_callable($callback)) {

src/Illuminate/Redis/Limiters/DurationLimiterBuilder.php

@@ -44,6 +44,13 @@ class DurationLimiterBuilder
      */
     public $timeout = 3;
 
+    /**
+     * The number of milliseconds to wait between attempts to acquire the lock.
+     *
+     * @var int
+     */
+    public $sleep = 750;
+
     /**
      * Create a new builder instance.
      *
@@ -96,6 +103,19 @@ public function block($timeout)
         return $this;
     }
 
+    /**
+     * The number of milliseconds to wait between lock acquisition attempts.
+     *
+     * @param  int  $sleep
+     * @return $this
+     */
+    public function sleep($sleep)
+    {
+        $this->sleep = $sleep;
+
+        return $this;
+    }
+
     /**
      * Execute the given callback if a lock is obtained, otherwise call the failure callback.
      *
@@ -110,7 +130,7 @@ public function then(callable $callback, callable $failure = null)
         try {
             return (new DurationLimiter(
                 $this->connection, $this->name, $this->maxLocks, $this->decay
-            ))->block($this->timeout, $callback);
+            ))->block($this->timeout, $callback, $this->sleep);
         } catch (LimiterTimeoutException $e) {
             if ($failure) {
                 return $failure($e);