Add getter for ActivityPrototype::$factory

src/Internal/Workflow/WorkflowContext.php

@@ -63,6 +63,7 @@
 use Temporal\Workflow\ChildWorkflowStubInterface;
 use Temporal\Workflow\ContinueAsNewOptions;
 use Temporal\Workflow\ExternalWorkflowStubInterface;
+use Temporal\Workflow\MutexInterface;
 use Temporal\Workflow\WorkflowContextInterface;
 use Temporal\Workflow\WorkflowExecution;
 use Temporal\Workflow\WorkflowInfo;
@@ -309,7 +310,7 @@ public function panic(\Throwable $failure = null): PromiseInterface
     public function continueAsNew(
         string $type,
         array $args = [],
-        ContinueAsNewOptions $options = null
+        ContinueAsNewOptions $options = null,
     ): PromiseInterface {
         return $this->callsInterceptor->with(
             function (ContinueAsNewInput $input): PromiseInterface {
@@ -632,6 +633,21 @@ public function uuid7(?DateTimeInterface $dateTime = null): PromiseInterface
         return $this->sideEffect(static fn(): UuidInterface => \Ramsey\Uuid\Uuid::uuid7($dateTime));
     }
 
+    public function mutex(string $name): MutexInterface
+    {
+        // todo
+    }
+
+    public function conditionalMutex(string $name, PromiseInterface|callable ...$lockConditions): MutexInterface
+    {
+        // todo
+    }
+
+    public function runLocked(string|MutexInterface $name, callable $callable): PromiseInterface
+    {
+        // todo
+    }
+
     /**
      * @internal
      */

src/Workflow.php

@@ -28,8 +28,10 @@
 use Temporal\Workflow\ChildWorkflowStubInterface;
 use Temporal\Workflow\ContinueAsNewOptions;
 use Temporal\Workflow\ExternalWorkflowStubInterface;
+use Temporal\Workflow\MutexInterface;
 use Temporal\Workflow\ScopedContextInterface;
 use Temporal\Workflow\UpdateContext;
+use Temporal\Workflow\WorkflowContextInterface;
 use Temporal\Workflow\WorkflowExecution;
 use Temporal\Workflow\WorkflowInfo;
 use Temporal\Internal\Support\DateInterval;
@@ -970,4 +972,87 @@ public static function uuid7(?DateTimeInterface $dateTime = null): PromiseInterf
 
         return $context->uuid7($dateTime);
     }
+
+    /**
+     * Get a mutex by name or create a new one.
+     *
+     * If a mutex is yielded without calling `lock()`, the Workflow will continue
+     * only when the lock is released.
+     *
+     * ```php
+     * yield Workflow::mutex('my-mutex');
+     * ```
+     *
+     * Now to continue only when the lock is acquired:
+     *
+     * ```php
+     * yield Workflow::mutex('my-mutex')->lock();
+     * ```
+     *
+     * Note: in this case, if the lock is already acquired, the Workflow will be blocked until it's released
+     *
+     * @param non-empty-string $name The name of the mutex.
+     */
+    public static function mutex(string $name): MutexInterface
+    {
+        /** @var WorkflowContextInterface $context */
+        $context = self::getCurrentContext();
+
+        return $context->mutex($name);
+    }
+
+    /**
+     * Create a conditional mutex that is locked when any of the conditions are met.
+     *
+     * @param non-empty-string $name
+     *
+     * Example:
+     *
+     * Monitor when the number of threads exceeds 10:
+     *
+     * ```php
+     * #[WorkflowMethod]
+     * function start() {
+     *     // Register a conditional mutex that will be locked when the number of threads exceeds 10
+     *     Workflow::conditionalMutex(
+     *         'limit',
+     *         fn() => count($this->threads) > 10,
+     *     );
+     *     // ...
+     * }
+     *
+     * #[SignalMethod]
+     * function addTask(Task $task) {
+     *     yield Workflow::runLocked('limit', function() {
+     *         $key = array_key_last($this->threads) + 1;
+     *         yield $this->threads[$key] = Workflow::executeChildWorkflow(...);
+     *         unset($this->threads[$key]);
+     *     });
+     * }
+     * ```
+     */
+    public function conditionalMutex(string $name, PromiseInterface|callable ...$lockConditions): MutexInterface
+    {
+        /** @var WorkflowContextInterface $context */
+        $context = self::getCurrentContext();
+
+        return $context->conditionalMutex($name, ...$lockConditions);
+    }
+
+    /**
+     * Run a function when the mutex is released.
+     * The mutex is locked for the duration of the function if it's not a conditional mutex.
+     * Conditional mutexes are locked only when all conditions are met.
+     *
+     * @see Workflow::conditionalMutex()
+     *
+     * @param non-empty-string|MutexInterface $name Mutex name or instance.
+     */
+    public function runLocked(string|MutexInterface $name, callable $callable): PromiseInterface
+    {
+        /** @var WorkflowContextInterface $context */
+        $context = self::getCurrentContext();
+
+        return $context->runLocked($name, $callable);
+    }
 }

src/Workflow/MutexInterface.php

@@ -0,0 +1,21 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Temporal\Workflow;
+
+use React\Promise\PromiseInterface;
+
+interface MutexInterface
+{
+    /**
+     * @return non-empty-string The name of the mutex.
+     */
+    public function getName(): string;
+
+    public function lock(): PromiseInterface;
+
+    public function unlock(): void;
+
+    public function isLocked(): bool;
+}

src/Workflow/WorkflowContextInterface.php

@@ -375,4 +375,27 @@ public function uuid4(): PromiseInterface;
      * @return PromiseInterface<UuidInterface>
      */
     public function uuid7(?DateTimeInterface $dateTime = null): PromiseInterface;
+
+    /**
+     * Get a mutex by name or create a new one.
+     *
+     * @param non-empty-string $name The name of the mutex.
+     */
+    public function mutex(string $name): MutexInterface;
+
+    /**
+     * Create a conditional mutex.
+     *
+     * @param non-empty-string $name
+     */
+    public function conditionalMutex(string $name, PromiseInterface|callable ...$lockConditions): MutexInterface;
+
+    /**
+     * Run a function when the mutex is released.
+     * The mutex is locked for the duration of the function if it's not a conditional mutex.
+     * Conditional mutexes are locked only when all conditions are met.
+     *
+     * @param non-empty-string|MutexInterface $name Mutex name or instance.
+     */
+    public function runLocked(string|MutexInterface $name, callable $callable): PromiseInterface;
 }