fw_fcp: check generation of response transaction

In 1394TA AV/C specification, at bus reset, AV/C transaction should be
aborted. In Linux FireWire subsystem, the event of bus reset can be
delayed enough after the successful response of AV/C transaction. It
is just possible to check the aborted transaction only at handling
the response.

This commit adds generation argument to responded signal, then check
request generation and response generation for being aborted.

Signed-off-by: Takashi Sakamoto <[email protected]>

samples/common/__init__.py

@@ -173,8 +173,8 @@ def listen_region(node: Hinawa.FwNode):
     resp.release()
 
 
-def handle_responded(fcp: Hinawa.FwFcp, tstamp: int, frame: list, length: int,
-                     args: tuple[Hinawa.FwNode, Hinawa.CycleTime]):
+def handle_responded(fcp: Hinawa.FwFcp, generation: int, tstamp: int, frame: list,
+                     length: int, args: tuple[Hinawa.FwNode, Hinawa.CycleTime]):
     node, cycle_time = args
     print('Event responded: length {}'.format(length))
     try:

src/fw_fcp.c

@@ -166,6 +166,7 @@ static void hinawa_fw_fcp_class_init(HinawaFwFcpClass *klass)
 	/**
 	 * HinawaFwFcp::responded:
 	 * @self: A [class@FwFcp].
+	 * @generation: The generation of bus topology.
 	 * @tstamp: The time stamp at which the request arrived for the response of FCP
 	 *	    transaction.
 	 * @frame: (array length=frame_size)(element-type guint8): The array with elements for byte
@@ -190,9 +191,9 @@ static void hinawa_fw_fcp_class_init(HinawaFwFcpClass *klass)
 			     G_SIGNAL_RUN_LAST,
 			     G_STRUCT_OFFSET(HinawaFwFcpClass, responded),
 			     NULL, NULL,
-			     hinawa_sigs_marshal_VOID__UINT_POINTER_UINT,
+			     hinawa_sigs_marshal_VOID__UINT_UINT_POINTER_UINT,
 			     G_TYPE_NONE,
-			     3, G_TYPE_UINT, G_TYPE_POINTER, G_TYPE_UINT);
+			     4, G_TYPE_UINT, G_TYPE_UINT, G_TYPE_POINTER, G_TYPE_UINT);
 }
 
 static void node_history_init(struct node_history *history);
@@ -305,6 +306,7 @@ enum waiter_state {
 
 struct waiter {
 	enum waiter_state state;
+	guint generation;
 	guint8 *frame;
 	guint frame_size;
 	guint tstamp;
@@ -313,8 +315,8 @@ struct waiter {
 	LIST_ENTRY(waiter) list;
 };
 
-static void handle_responded_signal(HinawaFwFcp *self, guint tstamp, const guint8 *frame,
-				    guint frame_size)
+static void handle_responded_signal(HinawaFwFcp *self, guint generation, guint tstamp,
+				    const guint8 *frame, guint frame_size)
 {
 	HinawaFwFcpPrivate *priv = hinawa_fw_fcp_get_instance_private(self);
 	struct waiter *w;
@@ -326,6 +328,7 @@ static void handle_responded_signal(HinawaFwFcp *self, guint tstamp, const guint
 
 		if (w->frame[1] == frame[1] && w->frame[2] == frame[2]) {
 			w->state = WAITER_STATE_RESPONDED;
+			w->generation = generation;
 			w->tstamp = tstamp;
 
 			if (frame_size <= w->frame_size)
@@ -377,6 +380,7 @@ gboolean hinawa_fw_fcp_avc_transaction_with_tstamp(HinawaFwFcp *self,
 	HinawaFwFcpPrivate *priv;
 	struct waiter w;
 	gulong handler_id;
+	guint generation;
 	gint64 expiration;
 	gboolean result;
 
@@ -412,6 +416,7 @@ gboolean hinawa_fw_fcp_avc_transaction_with_tstamp(HinawaFwFcp *self,
 	g_mutex_unlock(&priv->transactions_mutex);
 
 	// Finish transaction for command frame.
+	g_object_get(G_OBJECT(priv->node), "generation", &generation, NULL);
 	expiration = g_get_monotonic_time() + timeout_ms * G_TIME_SPAN_MILLISECOND;
 	result = hinawa_fw_fcp_command_with_tstamp(self, cmd, cmd_size, tstamp, timeout_ms, error);
 	if (!result) {
@@ -421,13 +426,13 @@ gboolean hinawa_fw_fcp_avc_transaction_with_tstamp(HinawaFwFcp *self,
 	}
 deferred:
 	while (w.state == WAITER_STATE_PENDING) {
-		// NOTE: Timeout at bus-reset, illegally.
 		if (!g_cond_wait_until(&w.cond, &w.mutex, expiration))
 			break;
 	}
 
 	// It's a deffered transaction, wait again.
-	if (w.state == WAITER_STATE_RESPONDED && w.frame[0] == AVC_STATUS_INTERIM) {
+	if (w.state == WAITER_STATE_RESPONDED && w.generation == generation &&
+	    w.frame[0] == AVC_STATUS_INTERIM) {
 		w.state = WAITER_STATE_PENDING;
 		w.frame[0] = 0x00;
 		w.frame_size = *resp_size;
@@ -445,18 +450,17 @@ gboolean hinawa_fw_fcp_avc_transaction_with_tstamp(HinawaFwFcp *self,
 
 	switch (w.state) {
 	case WAITER_STATE_RESPONDED:
-		if (w.frame_size > *resp_size) {
+		if (w.generation != generation) {
+			generate_local_error(error, HINAWA_FW_FCP_ERROR_ABORTED);
+			result = FALSE;
+		} else if (w.frame_size > *resp_size) {
 			generate_local_error(error, HINAWA_FW_FCP_ERROR_LARGE_RESP);
 			result = FALSE;
 		} else {
 			*resp_size = w.frame_size;
 			tstamp[2] = w.tstamp;
 		}
 		break;
-	case WAITER_STATE_ABORTED:
-		generate_local_error(error, HINAWA_FW_FCP_ERROR_ABORTED);
-		result = FALSE;
-		break;
 	case WAITER_STATE_PENDING:
 	default:
 		generate_local_error(error, HINAWA_FW_FCP_ERROR_TIMEOUT);
@@ -620,7 +624,7 @@ static HinawaFwRcode handle_requested_signal(HinawaFwResp *resp, HinawaFwTcode t
 		// Emit the event only when the source node is the target node.
 		if (recorded) {
 			g_signal_emit(self, fw_fcp_sigs[FW_FCP_SIG_TYPE_RESPONDED], 0,
-				      tstamp, frame, length);
+				      generation, tstamp, frame, length);
 		}
 	}
 

src/fw_fcp.h

@@ -20,6 +20,7 @@ struct _HinawaFwFcpClass {
 	/**
 	 * HinawaFwFcpClass::responded:
 	 * @self: A [class@FwFcp].
+	 * @generation: The generation of bus topology.
 	 * @tstamp: The time stamp at which the request arrived for the response for FCP
 	 *	    transaction.
 	 * @frame: (array length=frame_size)(element-type guint8): The array with elements for byte
@@ -30,7 +31,8 @@ struct _HinawaFwFcpClass {
 	 *
 	 * Since: 3.0
 	 */
-	void (*responded)(HinawaFwFcp *self, guint tstamp, const guint8 *frame, guint frame_size);
+	void (*responded)(HinawaFwFcp *self, guint generation, guint tstamp, const guint8 *frame,
+			  guint frame_size);
 };
 
 HinawaFwFcp *hinawa_fw_fcp_new(void);

src/hinawa_sigs_marshal.list

@@ -1,3 +1,3 @@
 VOID:ENUM,UINT,UINT,POINTER,UINT
-VOID:UINT,POINTER,UINT
+VOID:UINT,UINT,POINTER,UINT
 ENUM:ENUM,UINT64,UINT,UINT,UINT,UINT,UINT,POINTER,UINT