From: Christian Babeux <christian.babeux@efficios.com>
Date: Mon, 3 Dec 2012 03:09:28 +0000 (-0500)
Subject: Cygwin: Fix fd hangup in thread_manage_apps of sessiond
X-Git-Url: http://git.lttng.org/?p=lttng-tools.git;a=commitdiff_plain;h=268ec049968538c7a3176159fc992b07ebe69af1

Cygwin: Fix fd hangup in thread_manage_apps of sessiond

The fd hangup is not properly detected in the thread that manage
applications in the sessiond.

A read is done on the fd and if we encounter EOF, we force the
removal of the fd from the set.

Signed-off-by: Christian Babeux <christian.babeux@efficios.com>
---

diff --git a/src/bin/lttng-sessiond/main.c b/src/bin/lttng-sessiond/main.c
index d735be833..722549554 100644
--- a/src/bin/lttng-sessiond/main.c
+++ b/src/bin/lttng-sessiond/main.c
@@ -1287,16 +1287,27 @@ static void *thread_manage_apps(void *data)
 				 * At this point, we know that a registered application made
 				 * the event at poll_wait.
 				 */
-				if (revents & (LPOLLERR | LPOLLHUP | LPOLLRDHUP)) {
-					/* Removing from the poll set */
-					ret = lttng_poll_del(&events, pollfd);
-					if (ret < 0) {
-						goto error;
-					}
 
-					/* Socket closed on remote end. */
-					ust_app_unregister(pollfd);
-					break;
+				if (revents & (LPOLLIN | LPOLLERR | LPOLLHUP | LPOLLRDHUP)) {
+					ssize_t readlen;
+					char dummy;
+
+					do {
+						readlen = read(pollfd, &dummy, 1);
+					} while (readlen == -1 && errno == EINTR);
+
+					if (readlen == 0) {
+						/* Removing from the poll set */
+						ret = lttng_poll_del(&events, pollfd);
+						if (ret < 0) {
+							goto error;
+						}
+
+						/* Socket closed on remote end. */
+						ust_app_unregister(pollfd);
+						break;
+
+					}
 				}
 			}
 		}