From f545cc75f7caa5afa9a8f5a937344010d4d58e7d Mon Sep 17 00:00:00 2001
From: Mikkel Kamstrup Erlandsen
Date: Wed, 19 Mar 2014 14:41:22 +0100
Subject: device: more aggresively send ACKs when receiving TCP data
Before this it seemed that we only ever sent ACK when
timing out... Looks like a perf double when reading.
---
src/device.c | 115 ++++++++++++++++++++++++++++++++++-------------------------
1 file changed, 66 insertions(+), 49 deletions(-)
diff --git a/src/device.c b/src/device.c
index 15f829b..1297a85 100644
--- a/src/device.c
+++ b/src/device.c
@@ -2,6 +2,7 @@
usbmuxd - iPhone/iPod Touch USB multiplex server daemon
Copyright (C) 2009 Hector Martin "marcan" <hector@marcansoft.com>
+Copyright (C) 2014 Mikkel Kamstrup Erlandsen <mikkel.kamstrup@xamarin.com>
This program is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
@@ -126,6 +127,41 @@ static uint64_t mstime64(void)
return tv.tv_sec * 1000 + tv.tv_usec / 1000;
}
+static struct mux_device* get_mux_device_for_id(int device_id)
+{
+ struct mux_device *dev = NULL;
+ pthread_mutex_lock(&device_list_mutex);
+ FOREACH(struct mux_device *cdev, &device_list) {
+ if(cdev->id == device_id) {
+ dev = cdev;
+ break;
+ }
+ } ENDFOREACH
+ pthread_mutex_unlock(&device_list_mutex);
+
+ return dev;
+}
+
+static struct mux_connection* get_mux_connection(int device_id, struct mux_client *client)
+{
+ struct mux_connection *conn = NULL;
+ pthread_mutex_lock(&device_list_mutex);
+ FOREACH(struct mux_device *dev, &device_list) {
+ if(dev->id == device_id) {
+ FOREACH(struct mux_connection *lconn, &dev->connections) {
+ if(lconn->client == client) {
+ conn = lconn;
+ break;
+ }
+ } ENDFOREACH
+ break;
+ }
+ } ENDFOREACH
+ pthread_mutex_unlock(&device_list_mutex);
+
+ return conn;
+}
+
static int get_next_device_id(void)
{
while(1) {
@@ -274,15 +310,7 @@ static void connection_teardown(struct mux_connection *conn)
int device_start_connect(int device_id, uint16_t dport, struct mux_client *client)
{
- struct mux_device *dev = NULL;
- pthread_mutex_lock(&device_list_mutex);
- FOREACH(struct mux_device *cdev, &device_list) {
- if(cdev->id == device_id) {
- dev = cdev;
- break;
- }
- } ENDFOREACH
- pthread_mutex_unlock(&device_list_mutex);
+ struct mux_device *dev = get_mux_device_for_id(device_id);
if(!dev) {
usbmuxd_log(LL_WARNING, "Attempted to connect to nonexistent device %d", device_id);
return -RESULT_BADDEV;
@@ -369,6 +397,19 @@ static void update_connection(struct mux_connection *conn)
client_set_events(conn->client, conn->events);
}
+static int send_tcp_ack(struct mux_connection *conn)
+{
+ if(send_tcp(conn, TH_ACK, NULL, 0) < 0) {
+ usbmuxd_log(LL_ERROR, "Error sending TCP ACK (%d->%d)", conn->sport, conn->dport);
+ connection_teardown(conn);
+ return -1;
+ }
+
+ update_connection(conn);
+
+ return 0;
+}
+
/**
* Flush input and output buffers for a client connection.
*
@@ -380,21 +421,7 @@ static void update_connection(struct mux_connection *conn)
*/
void device_client_process(int device_id, struct mux_client *client, short events)
{
- // Find the connection for the given device_id
- struct mux_connection *conn = NULL;
- pthread_mutex_lock(&device_list_mutex);
- FOREACH(struct mux_device *dev, &device_list) {
- if(dev->id == device_id) {
- FOREACH(struct mux_connection *lconn, &dev->connections) {
- if(lconn->client == client) {
- conn = lconn;
- break;
- }
- } ENDFOREACH
- break;
- }
- } ENDFOREACH
- pthread_mutex_unlock(&device_list_mutex);
+ struct mux_connection *conn = get_mux_connection(device_id, client);
if(!conn) {
usbmuxd_log(LL_WARNING, "Could not find connection for device %d client %p", device_id, client);
@@ -405,8 +432,8 @@ void device_client_process(int device_id, struct mux_client *client, short event
int res;
int size;
if(events & POLLOUT) {
- // Client is ready to receive data, send what we have
- // in the client's connection buffer
+ // Client is ready to receive data, send what we have
+ // in the client's connection buffer
size = client_write(conn->client, conn->ib_buf, conn->ib_size);
if(size <= 0) {
usbmuxd_log(LL_DEBUG, "error writing to client (%d)", size);
@@ -422,8 +449,8 @@ void device_client_process(int device_id, struct mux_client *client, short event
}
}
if(events & POLLIN) {
- // There is inbound trafic on the client socket,
- // convert it to tcp and send to the device
+ // There is inbound trafic on the client socket,
+ // convert it to tcp and send to the device
size = client_read(conn->client, conn->ob_buf, conn->sendable);
if(size <= 0) {
if (size < 0) {
@@ -475,23 +502,12 @@ static void connection_device_input(struct mux_connection *conn, unsigned char *
void device_abort_connect(int device_id, struct mux_client *client)
{
- pthread_mutex_lock(&device_list_mutex);
- FOREACH(struct mux_device *dev, &device_list) {
- if(dev->id == device_id) {
- FOREACH(struct mux_connection *conn, &dev->connections) {
- if(conn->client == client) {
- connection_teardown(conn);
- pthread_mutex_unlock(&device_list_mutex);
- return;
- }
- } ENDFOREACH
- pthread_mutex_unlock(&device_list_mutex);
- usbmuxd_log(LL_WARNING, "Attempted to abort for nonexistent connection for device %d", device_id);
- return;
- }
- } ENDFOREACH
- pthread_mutex_unlock(&device_list_mutex);
- usbmuxd_log(LL_WARNING, "Attempted to abort connection for nonexistent device %d", device_id);
+ struct mux_connection *conn = get_mux_connection(device_id, client);
+ if (conn) {
+ connection_teardown(conn);
+ } else {
+ usbmuxd_log(LL_WARNING, "Attempted to abort for nonexistent connection for device %d", device_id);
+ }
}
static void device_version_input(struct mux_device *dev, struct version_header *vh)
@@ -543,6 +559,7 @@ static void device_tcp_input(struct mux_device *dev, struct tcphdr *th, unsigned
return;
}
+ // Find the connection on this device that has the right sport and dport
FOREACH(struct mux_connection *lconn, &dev->connections) {
if(lconn->sport == sport && lconn->dport == dport) {
conn = lconn;
@@ -603,6 +620,9 @@ static void device_tcp_input(struct mux_device *dev, struct tcphdr *th, unsigned
connection_teardown(conn);
} else {
connection_device_input(conn, payload, payload_length);
+
+ // Device likes it best when we are prompty ACKing data
+ send_tcp_ack(conn);
}
}
}
@@ -866,10 +886,7 @@ void device_check_timeouts(void)
(conn->flags & CONN_ACK_PENDING) &&
(ct - conn->last_ack_time) > ACK_TIMEOUT) {
usbmuxd_log(LL_DEBUG, "Sending ACK due to expired timeout (%" PRIu64 " -> %" PRIu64 ")", conn->last_ack_time, ct);
- if(send_tcp(conn, TH_ACK, NULL, 0) < 0) {
- usbmuxd_log(LL_ERROR, "Error sending TCP ACK to device %d (%d->%d)", dev->id, conn->sport, conn->dport);
- connection_teardown(conn);
- }
+ send_tcp_ack(conn);
}
} ENDFOREACH
}
--
cgit v1.1-32-gdbae