feat: more parallel execution options (#249)

ecsact/runtime/common.h

@@ -381,6 +381,23 @@ typedef enum {
 	ECSACT_SYS_NOTIFY_ONREMOVE,
 } ecsact_system_notify_setting;
 
+typedef enum ecsact_parallel_execution {
+	/**
+	 * Let implementation decide parallel execution.
+	 */
+	ECSACT_PAR_EXEC_AUTO = 0,
+
+	/**
+	 * Hint to implementation that parallel execution is preferred.
+	 */
+	ECSACT_PAR_EXEC_PREFERRED = 1,
+
+	/**
+	 * Disallow implementation to use parallel execution.
+	 */
+	ECSACT_PAR_EXEC_DENY = 2,
+} ecsact_parallel_execution;
+
 /**
  * Flags for generates component set
  */

ecsact/runtime/dynamic.h

@@ -474,13 +474,13 @@ ECSACT_DYNAMIC_API_FN(void, ecsact_set_entity_execution_status)
 );
 
 /**
- * Set a _hint_ that the system may process entities in parallel. This is
- * only a _hint_. The runtime implementation may choose to not run in parallel.
+ * Sets the systems parallel execution setting.
+ * @SEE: ecsact_parallel_execution
  */
 ECSACT_DYNAMIC_API_FN(void, ecsact_set_system_parallel_execution)
 ( //
-	ecsact_system_like_id system_like_id,
-	bool                  parallel_execution
+	ecsact_system_like_id     system_like_id,
+	ecsact_parallel_execution parallel_execution
 );
 
 /**

ecsact/runtime/meta.h

@@ -477,7 +477,10 @@ ECSACT_META_API_FN(int32_t, ecsact_meta_get_lazy_iteration_rate)
  * Check if a system/action can run on multiple entities in parallel. This is
  * only a _hint_. The runtime implementation may choose to not run in parallel.
  */
-ECSACT_META_API_FN(bool, ecsact_meta_get_system_parallel_execution)
+ECSACT_META_API_FN(
+	ecsact_parallel_execution,
+	ecsact_meta_get_system_parallel_execution
+)
 ( //
 	ecsact_system_like_id system_like_id
 );

ecsact/runtime/meta.hh

@@ -641,4 +641,13 @@ ECSACT_ALWAYS_INLINE auto main_package() -> std::optional<ecsact_package_id> {
 	return main_pkg_id;
 }
 
+template<typename SystemLikeID>
+ECSACT_ALWAYS_INLINE auto get_system_parallel_execution( //
+	SystemLikeID id
+) -> ecsact_parallel_execution {
+	return ecsact_meta_get_system_parallel_execution(
+		ecsact_id_cast<ecsact_system_like_id>(id)
+	);
+}
+
 } // namespace ecsact::meta