socket: socket disconnect should wait for poller thread exit

When SSL is enabled or if "transport.socket.own-thread" option is set
then socket_poller is run as different thread. Currently during
disconnect or PARENT_DOWN scenario we don't wait for this thread
to terminate. PARENT_DOWN will disconnect the socket layer and
cleanup resources used by socket_poller.

Therefore before disconnect we should wait for poller thread to exit.

Change-Id: I71f984b47d260ffd979102f180a99a0bed29f0d6
BUG: 1404181
Signed-off-by: Rajesh Joseph <rjoseph@redhat.com>
Reviewed-on: http://review.gluster.org/16141
Smoke: Gluster Build System <jenkins@build.gluster.org>
NetBSD-regression: NetBSD Build System <jenkins@build.gluster.org>
CentOS-regression: Gluster Build System <jenkins@build.gluster.org>
Reviewed-by: Kaushal M <kaushal@redhat.com>
Reviewed-by: Raghavendra Talur <rtalur@redhat.com>
Reviewed-by: Raghavendra G <rgowdapp@redhat.com>

1 files changed, 81 insertions, 17 deletions

diff --git a/rpc/rpc-transport/socket/src/socket.c b/rpc/rpc-transport/socket/src/socket.c
index 36388548937..d05dc4189aa 100644
--- a/rpc/rpc-transport/socket/src/socket.c
+++ b/rpc/rpc-transport/socket/src/socket.c
@@ -2344,7 +2344,7 @@ out:
         return ret;
 }
 
-static int socket_disconnect (rpc_transport_t *this);
+static int socket_disconnect (rpc_transport_t *this, gf_boolean_t wait);
 
 /* reads rpc_requests during pollin */
 static int
@@ -2375,7 +2375,7 @@ socket_event_handler (int fd, int idx, void *data,
                         EINPROGRESS or ENOENT, so nothing more to do, fail
                         reading/writing anything even if poll_in or poll_out
                         is set */
-                        ret = socket_disconnect (this);
+                        ret = socket_disconnect (this, _gf_false);
 
                         /* Force ret to be -1, as we are officially done with
                         this socket */
@@ -2424,6 +2424,13 @@ socket_poller (void *ctx)
          * conditionally
          */
         THIS = this->xl;
+        GF_REF_GET (priv);
+
+        if (priv->ot_state == OT_PLEASE_DIE) {
+                gf_log (this->name, GF_LOG_DEBUG, "socket_poller is exiting "
+                        "because socket state is OT_PLEASE_DIE");
+                goto err;
+        }
 
         priv->ot_state = OT_RUNNING;
 
@@ -2494,6 +2501,13 @@ socket_poller (void *ctx)
 			break;
 		}
 
+                if (priv->ot_state == OT_PLEASE_DIE) {
+                        gf_log (this->name, GF_LOG_DEBUG,
+                                "OT_PLEASE_DIE on %p (exiting socket_poller)",
+                                this);
+                        break;
+                }
+
 		if (pfd[1].revents & POLL_MASK_INPUT) {
 			ret = socket_event_poll_in(this);
 			if (ret >= 0) {
@@ -2507,7 +2521,6 @@ socket_poller (void *ctx)
                                 gf_log (this->name, GF_LOG_TRACE,
                                         "OT_IDLE on %p (input request)",
                                         this);
-                                priv->ot_state = OT_IDLE;
                                 break;
                         }
 		}
@@ -2524,7 +2537,6 @@ socket_poller (void *ctx)
                                 gf_log (this->name, GF_LOG_TRACE,
                                         "OT_IDLE on %p (output request)",
                                         this);
-                                priv->ot_state = OT_IDLE;
                                 break;
                         }
 		}
@@ -2561,22 +2573,24 @@ socket_poller (void *ctx)
 err:
 	/* All (and only) I/O errors should come here. */
         pthread_mutex_lock(&priv->lock);
+        {
+                __socket_teardown_connection (this);
+                sys_close (priv->sock);
+                priv->sock = -1;
 
-        __socket_teardown_connection (this);
-        sys_close (priv->sock);
-        priv->sock = -1;
-
-        sys_close (priv->pipe[0]);
-        sys_close (priv->pipe[1]);
-        priv->pipe[0] = -1;
-        priv->pipe[1] = -1;
-
-        priv->ot_state = OT_IDLE;
+                sys_close (priv->pipe[0]);
+                sys_close (priv->pipe[1]);
+                priv->pipe[0] = -1;
+                priv->pipe[1] = -1;
 
+                priv->ot_state = OT_IDLE;
+        }
         pthread_mutex_unlock(&priv->lock);
 
         rpc_transport_notify (this, RPC_TRANSPORT_DISCONNECT, this);
 
+        GF_REF_PUT (priv);
+
         rpc_transport_unref (this);
 
 	return NULL;
@@ -2848,16 +2862,39 @@ out:
 
 
 static int
-socket_disconnect (rpc_transport_t *this)
+socket_disconnect (rpc_transport_t *this, gf_boolean_t wait)
 {
-        socket_private_t *priv = NULL;
-        int               ret = -1;
+        socket_private_t *priv   = NULL;
+        int               ret    = -1;
+        char              a_byte = 'r';
 
         GF_VALIDATE_OR_GOTO ("socket", this, out);
         GF_VALIDATE_OR_GOTO ("socket", this->private, out);
 
         priv = this->private;
 
+        if (wait && priv->own_thread) {
+                pthread_mutex_lock (&priv->cond_lock);
+                {
+                        GF_REF_PUT (priv);
+                        /* Change the state to OT_PLEASE_DIE so that
+                         * socket_poller can exit. */
+                        priv->ot_state = OT_PLEASE_DIE;
+                        /* Write something into the pipe so that poller
+                         * thread can wake up.*/
+                        if (sys_write (priv->pipe[1], &a_byte, 1) < 1) {
+                                gf_log (this->name, GF_LOG_WARNING,
+                                                "write error on pipe");
+                        }
+
+                        /* Wait for socket_poller to exit */
+                        if (!priv->own_thread_done)
+                                pthread_cond_wait (&priv->cond,
+                                                   &priv->cond_lock);
+                }
+                pthread_mutex_unlock (&priv->cond_lock);
+        }
+
         pthread_mutex_lock (&priv->lock);
         {
                 ret = __socket_disconnect (this);
@@ -2937,6 +2974,7 @@ socket_connect (rpc_transport_t *this, int port)
 
         pthread_mutex_lock (&priv->lock);
         {
+                priv->own_thread_done = _gf_false;
                 if (priv->sock != -1) {
                         gf_log_callingfn (this->name, GF_LOG_TRACE,
                                           "connect () called on transport "
@@ -3805,6 +3843,26 @@ init_openssl_mt (void)
         SSL_load_error_strings();
 }
 
+void
+socket_poller_mayday (void *data)
+{
+        socket_private_t *priv = (socket_private_t *)data;
+
+        if (priv == NULL)
+                return;
+
+        pthread_mutex_lock (&priv->cond_lock);
+        {
+                /* Signal waiting threads before exiting from socket_poller */
+                if (!priv->own_thread_done) {
+                        gf_log ("socket", GF_LOG_TRACE, "priv->cond SIGNALED");
+                        pthread_cond_signal (&priv->cond);
+                        priv->own_thread_done = _gf_true;
+                }
+        }
+        pthread_mutex_unlock (&priv->cond_lock);
+}
+
 static int
 socket_init (rpc_transport_t *this)
 {
@@ -3835,6 +3893,10 @@ socket_init (rpc_transport_t *this)
         memset(priv,0,sizeof(*priv));
 
         pthread_mutex_init (&priv->lock, NULL);
+        pthread_mutex_init (&priv->cond_lock, NULL);
+        pthread_cond_init (&priv->cond, NULL);
+
+        GF_REF_INIT (priv, socket_poller_mayday);
 
         priv->sock = -1;
         priv->idx = -1;
@@ -4265,6 +4327,8 @@ fini (rpc_transport_t *this)
                         "transport %p destroyed", this);
 
                 pthread_mutex_destroy (&priv->lock);
+                pthread_mutex_destroy (&priv->cond_lock);
+                pthread_cond_destroy (&priv->cond);
 		if (priv->ssl_private_key) {
 			GF_FREE(priv->ssl_private_key);
 		}