dsmethod.c

h内核

			  this_walk_state->method_node);
	if (ACPI_FAILURE (status)) {
		return_ACPI_STATUS (status);
	}

	if (!(obj_desc->method.method_flags & AML_METHOD_INTERNAL_ONLY)) {
		/* 1) Parse: Create a new walk state for the preempting walk */

		next_walk_state = acpi_ds_create_walk_state (obj_desc->method.owning_id,
				  op, obj_desc, NULL);
		if (!next_walk_state) {
			return_ACPI_STATUS (AE_NO_MEMORY);
		}

		/* Create and init a Root Node */

		op = acpi_ps_create_scope_op ();
		if (!op) {
			status = AE_NO_MEMORY;
			goto cleanup;
		}

		status = acpi_ds_init_aml_walk (next_walk_state, op, method_node,
				  obj_desc->method.aml_start, obj_desc->method.aml_length,
				  NULL, 1);
		if (ACPI_FAILURE (status)) {
			acpi_ds_delete_walk_state (next_walk_state);
			goto cleanup;
		}

		/* Begin AML parse */

		status = acpi_ps_parse_aml (next_walk_state);
		acpi_ps_delete_parse_tree (op);
	}

	/* 2) Execute: Create a new state for the preempting walk */

	next_walk_state = acpi_ds_create_walk_state (obj_desc->method.owning_id,
			  NULL, obj_desc, thread);
	if (!next_walk_state) {
		status = AE_NO_MEMORY;
		goto cleanup;
	}
	/*
	 * The resolved arguments were put on the previous walk state's operand
	 * stack.  Operands on the previous walk state stack always
	 * start at index 0.
	 * Null terminate the list of arguments
	 */
	this_walk_state->operands [this_walk_state->num_operands] = NULL;

	info.parameters = &this_walk_state->operands[0];
	info.parameter_type = ACPI_PARAM_ARGS;

	status = acpi_ds_init_aml_walk (next_walk_state, NULL, method_node,
			  obj_desc->method.aml_start, obj_desc->method.aml_length,
			  &info, 3);
	if (ACPI_FAILURE (status)) {
		goto cleanup;
	}

	/*
	 * Delete the operands on the previous walkstate operand stack
	 * (they were copied to new objects)
	 */
	for (i = 0; i < obj_desc->method.param_count; i++) {
		acpi_ut_remove_reference (this_walk_state->operands [i]);
		this_walk_state->operands [i] = NULL;
	}

	/* Clear the operand stack */

	this_walk_state->num_operands = 0;

	ACPI_DEBUG_PRINT ((ACPI_DB_DISPATCH,
		"Starting nested execution, newstate=%p\n", next_walk_state));

	if (obj_desc->method.method_flags & AML_METHOD_INTERNAL_ONLY) {
		status = obj_desc->method.implementation (next_walk_state);
		return_ACPI_STATUS (status);
	}

	return_ACPI_STATUS (AE_OK);


	/* On error, we must delete the new walk state */

cleanup:
	if (next_walk_state && (next_walk_state->method_desc)) {
		/* Decrement the thread count on the method parse tree */

	   next_walk_state->method_desc->method.thread_count--;
	}
	(void) acpi_ds_terminate_control_method (next_walk_state);
	acpi_ds_delete_walk_state (next_walk_state);
	return_ACPI_STATUS (status);
}


/*******************************************************************************
 *
 * FUNCTION:    acpi_ds_restart_control_method
 *
 * PARAMETERS:  walk_state          - State for preempted method (caller)
 *              return_desc         - Return value from the called method
 *
 * RETURN:      Status
 *
 * DESCRIPTION: Restart a method that was preempted by another (nested) method
 *              invocation.  Handle the return value (if any) from the callee.
 *
 ******************************************************************************/

acpi_status
acpi_ds_restart_control_method (
	struct acpi_walk_state          *walk_state,
	union acpi_operand_object       *return_desc)
{
	acpi_status                     status;


	ACPI_FUNCTION_TRACE_PTR ("ds_restart_control_method", walk_state);


	ACPI_DEBUG_PRINT ((ACPI_DB_DISPATCH,
		"****Restart [%4.4s] Op %p return_value_from_callee %p\n",
		(char *) &walk_state->method_node->name, walk_state->method_call_op,
		return_desc));

	ACPI_DEBUG_PRINT ((ACPI_DB_DISPATCH,
		"    return_from_this_method_used?=%X res_stack %p Walk %p\n",
		walk_state->return_used,
		walk_state->results, walk_state));

	/* Did the called method return a value? */

	if (return_desc) {
		/* Are we actually going to use the return value? */

		if (walk_state->return_used) {
			/* Save the return value from the previous method */

			status = acpi_ds_result_push (return_desc, walk_state);
			if (ACPI_FAILURE (status)) {
				acpi_ut_remove_reference (return_desc);
				return_ACPI_STATUS (status);
			}

			/*
			 * Save as THIS method's return value in case it is returned
			 * immediately to yet another method
			 */
			walk_state->return_desc = return_desc;
		}
		else {
			/*
			 * Delete the return value if it will not be used by the
			 * calling method
			 */
			acpi_ut_remove_reference (return_desc);
		}
	}

	return_ACPI_STATUS (AE_OK);
}


/*******************************************************************************
 *
 * FUNCTION:    acpi_ds_terminate_control_method
 *
 * PARAMETERS:  walk_state          - State of the method
 *
 * RETURN:      Status
 *
 * DESCRIPTION: Terminate a control method.  Delete everything that the method
 *              created, delete all locals and arguments, and delete the parse
 *              tree if requested.
 *
 ******************************************************************************/

acpi_status
acpi_ds_terminate_control_method (
	struct acpi_walk_state          *walk_state)
{
	union acpi_operand_object       *obj_desc;
	struct acpi_namespace_node      *method_node;
	acpi_status                     status;


	ACPI_FUNCTION_TRACE_PTR ("ds_terminate_control_method", walk_state);


	if (!walk_state) {
		return (AE_BAD_PARAMETER);
	}

	/* The current method object was saved in the walk state */

	obj_desc = walk_state->method_desc;
	if (!obj_desc) {
		return_ACPI_STATUS (AE_OK);
	}

	/* Delete all arguments and locals */

	acpi_ds_method_data_delete_all (walk_state);

	/*
	 * Lock the parser while we terminate this method.
	 * If this is the last thread executing the method,
	 * we have additional cleanup to perform
	 */
	status = acpi_ut_acquire_mutex (ACPI_MTX_PARSER);
	if (ACPI_FAILURE (status)) {
		return_ACPI_STATUS (status);
	}

	/* Signal completion of the execution of this method if necessary */

	if (walk_state->method_desc->method.semaphore) {
		status = acpi_os_signal_semaphore (
				  walk_state->method_desc->method.semaphore, 1);
		if (ACPI_FAILURE (status)) {
			ACPI_REPORT_ERROR (("Could not signal method semaphore\n"));
			status = AE_OK;

			/* Ignore error and continue cleanup */
		}
	}

	if (walk_state->method_desc->method.thread_count) {
		ACPI_DEBUG_PRINT ((ACPI_DB_DISPATCH,
			"*** Not deleting method namespace, there are still %d threads\n",
			walk_state->method_desc->method.thread_count));
	}

	if (!walk_state->method_desc->method.thread_count) {
		/*
		 * Support to dynamically change a method from not_serialized to
		 * Serialized if it appears that the method is written foolishly and
		 * does not support multiple thread execution.  The best example of this
		 * is if such a method creates namespace objects and blocks.  A second
		 * thread will fail with an AE_ALREADY_EXISTS exception
		 *
		 * This code is here because we must wait until the last thread exits
		 * before creating the synchronization semaphore.
		 */
		if ((walk_state->method_desc->method.concurrency == 1) &&
			(!walk_state->method_desc->method.semaphore)) {
			status = acpi_os_create_semaphore (1,
					 1,
					 &walk_state->method_desc->method.semaphore);
		}

		/*
		 * There are no more threads executing this method.  Perform
		 * additional cleanup.
		 *
		 * The method Node is stored in the walk state
		 */
		method_node = walk_state->method_node;

		/*
		 * Delete any namespace entries created immediately underneath
		 * the method
		 */
		status = acpi_ut_acquire_mutex (ACPI_MTX_NAMESPACE);
		if (ACPI_FAILURE (status)) {
			return_ACPI_STATUS (status);
		}

		if (method_node->child) {
			acpi_ns_delete_namespace_subtree (method_node);
		}

		/*
		 * Delete any namespace entries created anywhere else within
		 * the namespace
		 */
		acpi_ns_delete_namespace_by_owner (walk_state->method_desc->method.owning_id);
		status = acpi_ut_release_mutex (ACPI_MTX_NAMESPACE);
		if (ACPI_FAILURE (status)) {
			return_ACPI_STATUS (status);
		}
	}

	status = acpi_ut_release_mutex (ACPI_MTX_PARSER);
	return_ACPI_STATUS (status);
}