From: Felix Fietkau <nbd@openwrt.org>
Date: Sat, 5 Feb 2011 19:50:08 +0000 (+0100)
Subject: fix message buffering
X-Git-Url: https://git.librecmc.org/?a=commitdiff_plain;h=a84c6cac9a8e57cfdbedb82f96e38079e3871995;p=oweals%2Fubus.git

fix message buffering
---

diff --git a/ubusd.c b/ubusd.c
index 798761d..a1636aa 100644
--- a/ubusd.c
+++ b/ubusd.c
@@ -90,31 +90,56 @@ static int ubus_msg_writev(int fd, struct ubus_msg_buf *ub, int offset)
 	}
 }
 
+static void ubus_msg_enqueue(struct ubus_client *cl, struct ubus_msg_buf *ub)
+{
+	if (cl->tx_queue[cl->txq_tail])
+		return;
+
+	cl->tx_queue[cl->txq_tail] = ub;
+	cl->txq_tail = (cl->txq_tail + 1) % ARRAY_SIZE(cl->tx_queue);
+}
+
 /* takes the msgbuf reference */
-void ubus_msg_send(struct ubus_client *cl, struct ubus_msg_buf *ub)
+void ubus_msg_send(struct ubus_client *cl, struct ubus_msg_buf *ub, bool free)
 {
 	int written;
 
-	if (cl->buf_head)
-		goto queue;
+	if (!cl->tx_queue[cl->txq_cur]) {
+		written = ubus_msg_writev(cl->sock.fd, ub, 0);
+		if (written >= ub->len + sizeof(ub->hdr))
+			goto out;
+
+		if (written < 0)
+			written = 0;
 
-	written = ubus_msg_writev(cl->sock.fd, ub, 0);
-	if (written > 0 && written < ub->len + sizeof(ub->hdr)) {
-		cl->buf_head_ofs = written;
+		cl->txq_ofs = written;
 
 		/* get an event once we can write to the socket again */
 		uloop_fd_add(&cl->sock, ULOOP_READ | ULOOP_WRITE | ULOOP_EDGE_TRIGGER);
-		goto queue;
 	}
+	ubus_msg_enqueue(cl, ub);
 
-	ubus_msg_free(ub);
-	return;
+out:
+	if (free)
+		ubus_msg_free(ub);
+}
 
-queue:
-	ub = ubus_msg_unshare(ub);
-	ub->next = NULL;
-	*cl->buf_tail = ub;
-	cl->buf_tail = &ub->next;
+static struct ubus_msg_buf *ubus_msg_head(struct ubus_client *cl)
+{
+	return cl->tx_queue[cl->txq_cur];
+}
+
+static void ubus_msg_dequeue(struct ubus_client *cl)
+{
+	struct ubus_msg_buf *ub = ubus_msg_head(cl);
+
+	if (!ub)
+		return;
+
+	ubus_msg_free(ub);
+	cl->txq_ofs = 0;
+	cl->tx_queue[cl->txq_cur] = NULL;
+	cl->txq_cur = (cl->txq_cur + 1) % ARRAY_SIZE(cl->tx_queue);
 }
 
 static void handle_client_disconnect(struct ubus_client *cl)
@@ -126,6 +151,9 @@ static void handle_client_disconnect(struct ubus_client *cl)
 		ubusd_free_object(obj);
 	}
 
+	while (ubus_msg_head(cl))
+		ubus_msg_dequeue(cl);
+
 	ubus_free_id(&clients, &cl->id);
 	uloop_fd_delete(&cl->sock);
 	close(cl->sock.fd);
@@ -138,11 +166,10 @@ static void client_cb(struct uloop_fd *sock, unsigned int events)
 	struct ubus_msg_buf *ub;
 
 	/* first try to tx more pending data */
-	while (cl->buf_head) {
-		struct ubus_msg_buf *ub = cl->buf_head;
+	while ((ub = ubus_msg_head(cl))) {
 		int written;
 
-		written = ubus_msg_writev(sock->fd, ub, cl->buf_head_ofs);
+		written = ubus_msg_writev(sock->fd, ub, cl->txq_ofs);
 		if (written < 0) {
 			switch(errno) {
 			case EINTR:
@@ -156,19 +183,16 @@ static void client_cb(struct uloop_fd *sock, unsigned int events)
 		if (written == 0)
 			break;
 
-		cl->buf_head_ofs += written;
-		if (cl->buf_head_ofs < ub->len + sizeof(ub->hdr))
+		cl->txq_ofs += written;
+		if (cl->txq_ofs < ub->len + sizeof(ub->hdr))
 			break;
 
-		cl->buf_head_ofs = 0;
-		cl->buf_head = ub->next;
-		if (!cl->buf_head)
-			cl->buf_tail = &cl->buf_head;
+		ubus_msg_dequeue(cl);
 	}
 
 	/* prevent further ULOOP_WRITE events if we don't have data
 	 * to send anymore */
-	if (!cl->buf_head && (events & ULOOP_WRITE))
+	if (!ubus_msg_head(cl) && (events & ULOOP_WRITE))
 		uloop_fd_add(sock, ULOOP_READ | ULOOP_EDGE_TRIGGER);
 
 retry:
@@ -220,7 +244,7 @@ retry:
 	}
 
 out:
-	if (!sock->eof || cl->buf_head)
+	if (!sock->eof || ubus_msg_head(cl))
 		return;
 
 disconnect:
diff --git a/ubusd.h b/ubusd.h
index c82896c..cb6bba0 100644
--- a/ubusd.h
+++ b/ubusd.h
@@ -14,7 +14,6 @@
 #define UBUS_OBJ_HASH_BITS	4
 
 struct ubus_msg_buf {
-	struct ubus_msg_buf *next;
 	uint32_t refcount; /* ~0: uses external data buffer */
 	struct ubus_msghdr hdr;
 	struct blob_attr *data;
@@ -25,22 +24,17 @@ struct ubus_client {
 	struct ubus_id id;
 	struct uloop_fd sock;
 
+	struct list_head objects;
+
+	struct ubus_msg_buf *tx_queue[UBUSD_CLIENT_BACKLOG];
+	unsigned int txq_cur, txq_tail, txq_ofs;
+
+	struct ubus_msg_buf *pending_msg;
+	int pending_msg_offset;
 	struct {
 		struct ubus_msghdr hdr;
 		struct blob_attr data;
 	} hdrbuf;
-
-	struct list_head objects;
-
-	int pending_msg_offset;
-	struct ubus_msg_buf *pending_msg;
-
-	unsigned int buf_head_ofs;
-	struct ubus_msg_buf *buf_head;
-	struct ubus_msg_buf **buf_tail;
-
-	struct ubus_msg_buf *requests[UBUSD_CLIENT_BACKLOG];
-	unsigned int req_head, req_tail;
 };
 
 struct ubus_path {
@@ -49,7 +43,7 @@ struct ubus_path {
 };
 
 struct ubus_msg_buf *ubus_msg_new(void *data, int len, bool shared);
-void ubus_msg_send(struct ubus_client *cl, struct ubus_msg_buf *ub);
+void ubus_msg_send(struct ubus_client *cl, struct ubus_msg_buf *ub, bool free);
 struct ubus_msg_buf *ubus_msg_ref(struct ubus_msg_buf *ub);
 void ubus_msg_free(struct ubus_msg_buf *ub);
 
diff --git a/ubusd_proto.c b/ubusd_proto.c
index 2e84556..3333330 100644
--- a/ubusd_proto.c
+++ b/ubusd_proto.c
@@ -58,14 +58,14 @@ bool ubusd_send_hello(struct ubus_client *cl)
 		return false;
 
 	ubus_msg_init(ub, UBUS_MSG_HELLO, 0, cl->id.id);
-	ubus_msg_send(cl, ub);
+	ubus_msg_send(cl, ub, true);
 	return true;
 }
 
 static int ubusd_send_pong(struct ubus_client *cl, struct ubus_msg_buf *ub, struct blob_attr **attr)
 {
 	ub->hdr.type = UBUS_MSG_DATA;
-	ubus_msg_send(cl, ubus_msg_ref(ub));
+	ubus_msg_send(cl, ub, false);
 	return 0;
 }
 
@@ -86,7 +86,7 @@ static int ubusd_handle_publish(struct ubus_client *cl, struct ubus_msg_buf *ub,
 	if (!ub)
 		return UBUS_STATUS_NO_DATA;
 
-	ubus_msg_send(cl, ub);
+	ubus_msg_send(cl, ub, true);
 	return 0;
 }
 
@@ -111,7 +111,7 @@ static void ubusd_send_obj(struct ubus_client *cl, struct ubus_msg_buf *ub, stru
 	if (!ub)
 		return;
 
-	ubus_msg_send(cl, ub);
+	ubus_msg_send(cl, ub, true);
 }
 
 static int ubusd_handle_lookup(struct ubus_client *cl, struct ubus_msg_buf *ub, struct blob_attr **attr)
@@ -195,7 +195,7 @@ static int ubusd_handle_invoke(struct ubus_client *cl, struct ubus_msg_buf *ub,
 
 	ub->hdr.type = UBUS_MSG_INVOKE;
 	ub->hdr.peer = cl->id.id;
-	ubus_msg_send(obj->client, ub);
+	ubus_msg_send(obj->client, ub, true);
 
 	return -1;
 }
@@ -221,7 +221,7 @@ static int ubusd_handle_response(struct ubus_client *cl, struct ubus_msg_buf *ub
 		goto error;
 
 	ub->hdr.peer = blob_get_int32(attr[UBUS_ATTR_OBJID]);
-	ubus_msg_send(cl, ub);
+	ubus_msg_send(cl, ub, true);
 	return -1;
 
 error:
@@ -260,7 +260,7 @@ void ubusd_receive_message(struct ubus_client *cl, struct ubus_msg_buf *ub)
 	ubus_msg_free(ub);
 
 	*retmsg_data = htonl(ret);
-	ubus_msg_send(cl, ubus_msg_ref(retmsg));
+	ubus_msg_send(cl, retmsg, false);
 }
 
 static void __init ubusd_proto_init(void)