[Qemu-devel] [RFC PATCH v4 09/15] net: introduce lock to protect NetQueue

[Liu Ping Fan <qemulist@gmail.com>]

From: Liu Ping Fan <pingfank@linux.vnet.ibm.com>

NetQueue will be accessed by nc and its peers at the same time,
need lock to protect it.

Signed-off-by: Liu Ping Fan <pingfank@linux.vnet.ibm.com>
---
 net/queue.c |   11 +++++++++++
 1 files changed, 11 insertions(+), 0 deletions(-)

diff --git a/net/queue.c b/net/queue.c
index 859d02a..2856c1d 100644
--- a/net/queue.c
+++ b/net/queue.c
@@ -53,6 +53,7 @@ struct NetQueue {
     uint32_t nq_maxlen;
     uint32_t nq_count;
 
+    QemuMutex lock;
     QTAILQ_HEAD(packets, NetPacket) packets;
 
     unsigned delivering : 1;
@@ -68,6 +69,7 @@ NetQueue *qemu_new_net_queue(void *opaque)
     queue->nq_maxlen = 10000;
     queue->nq_count = 0;
 
+    qemu_mutex_init(&queue->lock);
     QTAILQ_INIT(&queue->packets);
 
     queue->delivering = 0;
@@ -107,7 +109,9 @@ static void qemu_net_queue_append(NetQueue *queue,
     memcpy(packet->data, buf, size);
 
     queue->nq_count++;
+    qemu_mutex_lock(&queue->lock);
     QTAILQ_INSERT_TAIL(&queue->packets, packet, entry);
+    qemu_mutex_unlock(&queue->lock);
 }
 
 static void qemu_net_queue_append_iov(NetQueue *queue,
@@ -142,7 +146,9 @@ static void qemu_net_queue_append_iov(NetQueue *queue,
     }
 
     queue->nq_count++;
+    qemu_mutex_lock(&queue->lock);
     QTAILQ_INSERT_TAIL(&queue->packets, packet, entry);
+    qemu_mutex_unlock(&queue->lock);
 }
 
 static ssize_t qemu_net_queue_deliver(NetQueue *queue,
@@ -229,6 +235,7 @@ void qemu_net_queue_purge(NetQueue *queue, NetClientState *from)
 {
     NetPacket *packet, *next;
 
+    qemu_mutex_lock(&queue->lock);
     QTAILQ_FOREACH_SAFE(packet, &queue->packets, entry, next) {
         if (packet->sender == from) {
             QTAILQ_REMOVE(&queue->packets, packet, entry);
@@ -236,10 +243,12 @@ void qemu_net_queue_purge(NetQueue *queue, NetClientState *from)
             g_free(packet);
         }
     }
+    qemu_mutex_unlock(&queue->lock);
 }
 
 bool qemu_net_queue_flush(NetQueue *queue)
 {
+    qemu_mutex_lock(&queue->lock);
     while (!QTAILQ_EMPTY(&queue->packets)) {
         NetPacket *packet;
         int ret;
@@ -256,6 +265,7 @@ bool qemu_net_queue_flush(NetQueue *queue)
         if (ret == 0) {
             queue->nq_count++;
             QTAILQ_INSERT_HEAD(&queue->packets, packet, entry);
+            qemu_mutex_unlock(&queue->lock);
             return false;
         }
 
@@ -265,5 +275,6 @@ bool qemu_net_queue_flush(NetQueue *queue)
 
         g_free(packet);
     }
+    qemu_mutex_unlock(&queue->lock);
     return true;
 }
-- 
1.7.4.4