[PATCH 3/6] flow: Introduce flow_foreach_sidei() macro

[David Gibson <david@gibson.dropbear.id.au>]

We have a handful of places where we use a loop to step through each side
of a flow or flows, and we're probably going to have mroe in future.
Introduce a macro to implement this loop for convenience.

Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
---
 flow_table.h | 6 ++++++
 tcp_splice.c | 6 +++---
 2 files changed, 9 insertions(+), 3 deletions(-)

diff --git a/flow_table.h b/flow_table.h
index 8a5f8f25..4f5d041c 100644
--- a/flow_table.h
+++ b/flow_table.h
@@ -41,6 +41,12 @@ union flow {
 extern unsigned flow_first_free;
 extern union flow flowtab[];
 
+/**
+ * flow_foreach_sidei() - 'for' type macro to step through each side of flow
+ * @sidei_:	Takes value INISIDE, then TGTSIDE
+ */
+#define flow_foreach_sidei(sidei_) \
+	for ((sidei_) = INISIDE; (sidei_) < SIDES; (sidei_)++)
 
 /** flow_idx() - Index of flow from common structure
  * @f:	Common flow fields pointer
diff --git a/tcp_splice.c b/tcp_splice.c
index 8bc68a1a..5a9325b1 100644
--- a/tcp_splice.c
+++ b/tcp_splice.c
@@ -263,7 +263,7 @@ bool tcp_splice_flow_defer(struct tcp_splice_conn *conn)
 	if (!(conn->flags & CLOSING))
 		return false;
 
-	for (sidei = 0; sidei < SIDES; sidei++) {
+	flow_foreach_sidei(sidei) {
 		/* Flushing might need to block: don't recycle them. */
 		if (conn->pipe[sidei][0] >= 0) {
 			close(conn->pipe[sidei][0]);
@@ -299,7 +299,7 @@ static int tcp_splice_connect_finish(const struct ctx *c,
 	unsigned sidei;
 	int i = 0;
 
-	for (sidei = 0; sidei < SIDES; sidei++) {
+	flow_foreach_sidei(sidei) {
 		for (; i < TCP_SPLICE_PIPE_POOL_SIZE; i++) {
 			if (splice_pipe_pool[i][0] >= 0) {
 				SWAP(conn->pipe[sidei][0],
@@ -820,7 +820,7 @@ void tcp_splice_timer(const struct ctx *c, struct tcp_splice_conn *conn)
 
 	ASSERT(!(conn->flags & CLOSING));
 
-	for (sidei = 0; sidei < SIDES; sidei++) {
+	flow_foreach_sidei(sidei) {
 		uint8_t set = sidei == 0 ? RCVLOWAT_SET_0 : RCVLOWAT_SET_1;
 		uint8_t act = sidei == 0 ? RCVLOWAT_ACT_0 : RCVLOWAT_ACT_1;
 
-- 
@@ -263,7 +263,7 @@ bool tcp_splice_flow_defer(struct tcp_splice_conn *conn)
 	if (!(conn->flags & CLOSING))
 		return false;
 
-	for (sidei = 0; sidei < SIDES; sidei++) {
+	flow_foreach_sidei(sidei) {
 		/* Flushing might need to block: don't recycle them. */
 		if (conn->pipe[sidei][0] >= 0) {
 			close(conn->pipe[sidei][0]);
@@ -299,7 +299,7 @@ static int tcp_splice_connect_finish(const struct ctx *c,
 	unsigned sidei;
 	int i = 0;
 
-	for (sidei = 0; sidei < SIDES; sidei++) {
+	flow_foreach_sidei(sidei) {
 		for (; i < TCP_SPLICE_PIPE_POOL_SIZE; i++) {
 			if (splice_pipe_pool[i][0] >= 0) {
 				SWAP(conn->pipe[sidei][0],
@@ -820,7 +820,7 @@ void tcp_splice_timer(const struct ctx *c, struct tcp_splice_conn *conn)
 
 	ASSERT(!(conn->flags & CLOSING));
 
-	for (sidei = 0; sidei < SIDES; sidei++) {
+	flow_foreach_sidei(sidei) {
 		uint8_t set = sidei == 0 ? RCVLOWAT_SET_0 : RCVLOWAT_SET_1;
 		uint8_t act = sidei == 0 ? RCVLOWAT_ACT_0 : RCVLOWAT_ACT_1;
 
-- 
2.45.2