fix: use random_int instead of mt_rand for retry jitter (#3221)

Author: yenfryherrerafeliz

.changes/nextrelease/fix-backoff-delay.json

@@ -0,0 +1,7 @@
+[
+    {
+        "type": "enhancement",
+        "category": "",
+        "description": "Enhance exponential delay calculation to reduce the possibilities of having 0 as the delay."
+    }
+]

src/RetryMiddlewareV2.php

@@ -6,6 +6,7 @@
 use Aws\Retry\QuotaManager;
 use Aws\Retry\RateLimiter;
 use Aws\Retry\RetryHelperTrait;
+use Exception;
 use GuzzleHttp\Exception\RequestException;
 use GuzzleHttp\Promise;
 use Psr\Http\Message\RequestInterface;
@@ -200,7 +201,7 @@ public function __invoke(CommandInterface $cmd, RequestInterface $req)
                     $value->prependMonitoringEvent($event);
                 }
             }
-            if ($value instanceof \Exception || $value instanceof \Throwable) {
+            if ($value instanceof Exception || $value instanceof \Throwable) {
                 if (!$decider($attempts, $cmd, $value)) {
                     return Promise\Create::rejectionFor(
                         $this->bindStatsToReturn($value, $requestStats)
@@ -245,7 +246,14 @@ public function __invoke(CommandInterface $cmd, RequestInterface $req)
      */
     public function exponentialDelayWithJitter($attempts)
     {
-        $rand = mt_rand() / mt_getrandmax();
+        $max = mt_getrandmax();
+        try {
+            $rand = random_int(0, $max) / $max;
+        } catch (Exception $_) {
+            // fallback to prevent failing
+            $rand = mt_rand(0, $max) / $max;
+        }
+
         return min(1000 * $rand * pow(2, $attempts) , $this->maxBackoff);
     }
 
@@ -287,7 +295,7 @@ private static function isRetryable(
             }
         }
 
-        if ($result instanceof \Exception || $result instanceof \Throwable) {
+        if ($result instanceof Exception || $result instanceof \Throwable) {
             $isError = true;
         } else {
             $isError = false;