[dpdk-dev,12/12] lib/librte_vhost: support calling rte_vhost_driver_register after rte_vhost_driver_session_start

diff --git a/lib/librte_vhost/vhost_user/fd_man.c b/lib/librte_vhost/vhost_user/fd_man.c
index 929fbc3..e86615d 100644
--- a/lib/librte_vhost/vhost_user/fd_man.c
+++ b/lib/librte_vhost/vhost_user/fd_man.c
@@ -145,6 +145,8 @@  fdset_add(struct fdset *pfdset, int fd, fd_cb rcb, fd_cb wcb, void *dat)
 	if (pfdset == NULL || fd == -1)
 		return -1;
 
+	pthread_mutex_lock(&pfdset->fd_mutex);
+
 	/* Find a free slot in the list. */
 	i = fdset_find_free_slot(pfdset);
 	if (i == -1)
@@ -153,6 +155,8 @@  fdset_add(struct fdset *pfdset, int fd, fd_cb rcb, fd_cb wcb, void *dat)
 	fdset_add_fd(pfdset, i, fd, rcb, wcb, dat);
 	pfdset->num++;
 
+	pthread_mutex_unlock(&pfdset->fd_mutex);
+
 	return 0;
 }
 
@@ -164,12 +168,19 @@  fdset_del(struct fdset *pfdset, int fd)
 {
 	int i;
 
+	if (pfdset == NULL || fd == -1)
+		return;
+
+	pthread_mutex_lock(&pfdset->fd_mutex);
+
 	i = fdset_find_fd(pfdset, fd);
 	if (i != -1 && fd != -1) {
 		pfdset->fd[i].fd = -1;
 		pfdset->fd[i].rcb = pfdset->fd[i].wcb = NULL;
 		pfdset->num--;
 	}
+
+	pthread_mutex_unlock(&pfdset->fd_mutex);
 }
 
 /**
@@ -183,6 +194,9 @@  fdset_event_dispatch(struct fdset *pfdset)
 	int i, maxfds;
 	struct fdentry *pfdentry;
 	int num = MAX_FDS;
+	fd_cb rcb, wcb;
+	void *dat;
+	int fd;
 
 	if (pfdset == NULL)
 		return;
@@ -190,18 +204,31 @@  fdset_event_dispatch(struct fdset *pfdset)
 	while (1) {
 		FD_ZERO(&rfds);
 		FD_ZERO(&wfds);
+		pthread_mutex_lock(&pfdset->fd_mutex);
+
 		maxfds = fdset_fill(&rfds, &wfds, pfdset);
-		if (maxfds == -1)
-			return;
+		if (maxfds == -1) {
+			pthread_mutex_unlock(&pfdset->fd_mutex);
+			sleep(1);
+			continue;
+		}
+
+		pthread_mutex_unlock(&pfdset->fd_mutex);
 
 		select(maxfds + 1, &rfds, &wfds, NULL, NULL);
 
 		for (i = 0; i < num; i++) {
+			pthread_mutex_lock(&pfdset->fd_mutex);
 			pfdentry = &pfdset->fd[i];
-			if (pfdentry->fd >= 0 && FD_ISSET(pfdentry->fd, &rfds) && pfdentry->rcb)
-				pfdentry->rcb(pfdentry->fd, pfdentry->dat);
-			if (pfdentry->fd >= 0 && FD_ISSET(pfdentry->fd, &wfds) && pfdentry->wcb)
-				pfdentry->wcb(pfdentry->fd, pfdentry->dat);
+			fd = pfdentry->fd;
+			rcb = pfdentry->rcb;
+			wcb = pfdentry->wcb;
+			dat = pfdentry->dat;
+			pthread_mutex_unlock(&pfdset->fd_mutex);
+			if (fd >= 0 && FD_ISSET(fd, &rfds) && rcb)
+				rcb(fd, dat);
+			if (fd >= 0 && FD_ISSET(fd, &wfds) && wcb)
+				wcb(fd, dat);
 		}
 	}
 }
diff --git a/lib/librte_vhost/vhost_user/fd_man.h b/lib/librte_vhost/vhost_user/fd_man.h
index 26b4619..4ebae57 100644
--- a/lib/librte_vhost/vhost_user/fd_man.h
+++ b/lib/librte_vhost/vhost_user/fd_man.h
@@ -34,6 +34,7 @@ 
 #ifndef _FD_MAN_H_
 #define _FD_MAN_H_
 #include <stdint.h>
+#include <pthread.h>
 
 #define MAX_FDS 1024
 
@@ -48,6 +49,7 @@  struct fdentry {
 
 struct fdset {
 	struct fdentry fd[MAX_FDS];
+	pthread_mutex_t fd_mutex;
 	int num;	/* current fd number of this fdset */
 };
 
diff --git a/lib/librte_vhost/vhost_user/vhost-net-user.c b/lib/librte_vhost/vhost_user/vhost-net-user.c
index 44ef398..e6df8a8 100644
--- a/lib/librte_vhost/vhost_user/vhost-net-user.c
+++ b/lib/librte_vhost/vhost_user/vhost-net-user.c
@@ -41,6 +41,7 @@ 
 #include <sys/socket.h>
 #include <sys/un.h>
 #include <errno.h>
+#include <pthread.h>
 
 #include <rte_log.h>
 #include <rte_virtio_net.h>
@@ -60,10 +61,18 @@  struct connfd_ctx {
 };
 
 #define MAX_VHOST_SERVER 1024
-static struct {
+struct _vhost_server {
 	struct vhost_server *server[MAX_VHOST_SERVER];
-	struct fdset fdset;	/**< The fd list this vhost server manages. */
-} g_vhost_server;
+	struct fdset fdset;
+};
+
+static struct _vhost_server g_vhost_server = {
+	.fdset = {
+		.fd = { [0 ... MAX_FDS - 1] = {-1, NULL, NULL, NULL} },
+		.fd_mutex = PTHREAD_MUTEX_INITIALIZER,
+		.num = 0
+	},
+};
 
 static int vserver_idx;
 
@@ -423,10 +432,8 @@  rte_vhost_driver_register(const char *path)
 {
 	struct vhost_server *vserver;
 
-	if (vserver_idx == 0) {
-		fdset_init(&g_vhost_server.fdset);
+	if (vserver_idx == 0)
 		ops = get_virtio_net_callbacks();
-	}
 	if (vserver_idx == MAX_VHOST_SERVER)
 		return -1;