From: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Date: Tue, 8 Nov 2011 14:42:17 +0000 (-0500)
Subject: UST consumer: perform buffer flush on hang up
X-Git-Tag: v2.0-pre15~148
X-Git-Url: https://git.lttng.org/?p=lttng-tools.git;a=commitdiff_plain;h=d056b47720cf547dd8c4ca59076ffcd215d58f2c

UST consumer: perform buffer flush on hang up

Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
---

diff --git a/include/lttng/lttng-consumer.h b/include/lttng/lttng-consumer.h
index 256293b81..6f893a53a 100644
--- a/include/lttng/lttng-consumer.h
+++ b/include/lttng/lttng-consumer.h
@@ -118,6 +118,7 @@ struct lttng_consumer_stream {
 	/* For UST */
 	struct lttng_ust_lib_ring_buffer *buf;
 	int cpu;
+	int hangup_flush_done;
 };
 
 /*
diff --git a/include/lttng/lttng-ustconsumer.h b/include/lttng/lttng-ustconsumer.h
index 90d6588b9..217c592d7 100644
--- a/include/lttng/lttng-ustconsumer.h
+++ b/include/lttng/lttng-ustconsumer.h
@@ -70,6 +70,8 @@ int lttng_ustconsumer_read_subbuffer(struct lttng_consumer_stream *stream,
 		struct lttng_consumer_local_data *ctx);
 int lttng_ustconsumer_on_recv_stream(struct lttng_consumer_stream *stream);
 
+void lttng_ustconsumer_on_stream_hangup(struct lttng_consumer_stream *stream);
+
 #else /* HAVE_LIBLTTNG_UST_CTL */
 
 static inline
@@ -146,6 +148,11 @@ int lttng_ustconsumer_on_recv_stream(struct lttng_consumer_stream *stream)
 	return -ENOSYS;
 }
 
+static inline
+void lttng_ustconsumer_on_stream_hangup(struct lttng_consumer_stream *stream)
+{
+}
+
 #endif /* HAVE_LIBLTTNG_UST_CTL */
 
 #endif /* _LTTNG_USTCONSUMER_H */
diff --git a/liblttng-consumer/lttng-consumer.c b/liblttng-consumer/lttng-consumer.c
index de15dd3b7..54338e800 100644
--- a/liblttng-consumer/lttng-consumer.c
+++ b/liblttng-consumer/lttng-consumer.c
@@ -847,7 +847,21 @@ void *lttng_consumer_thread_poll_fds(void *data)
 				num_hup++;
 			} else if ((pollfd[i].revents & POLLHUP) &&
 					!(pollfd[i].revents & POLLIN)) {
-				DBG("Polling fd %d tells it has hung up.", pollfd[i].fd);
+				if (consumer_data.type == LTTNG_CONSUMER_UST) {
+					DBG("Polling fd %d tells it has hung up. Attempting flush and read.",
+						pollfd[i].fd);
+					if (!local_stream[i]->hangup_flush_done) {
+						lttng_ustconsumer_on_stream_hangup(local_stream[i]);
+						/* try reading after flush */
+						ret = ctx->on_buffer_ready(local_stream[i], ctx);
+						/* it's ok to have an unavailable sub-buffer */
+						if (ret == EAGAIN) {
+							ret = 0;
+						}
+					}
+				} else {
+					DBG("Polling fd %d tells it has hung up.", pollfd[i].fd);
+				}
 				consumer_del_stream(local_stream[i]);
 				num_hup++;
 			}
diff --git a/liblttng-ustconsumer/lttng-ustconsumer.c b/liblttng-ustconsumer/lttng-ustconsumer.c
index 29f735249..806ebd3c0 100644
--- a/liblttng-ustconsumer/lttng-ustconsumer.c
+++ b/liblttng-ustconsumer/lttng-ustconsumer.c
@@ -175,6 +175,7 @@ int lttng_ustconsumer_recv_cmd(struct lttng_consumer_local_data *ctx,
 				msg.u.channel.mmap_len,
 				msg.u.channel.max_sb_size);
 		if (new_channel == NULL) {
+			fprintf(stderr, "AAAAA\n");
 			lttng_consumer_send_error(ctx, CONSUMERD_OUTFD_ERROR);
 			goto end_nosignal;
 		}
@@ -217,6 +218,7 @@ int lttng_ustconsumer_recv_cmd(struct lttng_consumer_local_data *ctx,
 				msg.u.stream.output,
 				msg.u.stream.path_name);
 		if (new_stream == NULL) {
+			fprintf(stderr, "BBBBBB\n");
 			lttng_consumer_send_error(ctx, CONSUMERD_OUTFD_ERROR);
 			goto end;
 		}
@@ -281,6 +283,11 @@ int lttng_ustconsumer_allocate_channel(struct lttng_consumer_channel *chan)
 	return 0;
 }
 
+void lttng_ustconsumer_on_stream_hangup(struct lttng_consumer_stream *stream)
+{
+	ustctl_flush_buffer(stream->chan->handle, stream->buf, 0);
+}
+
 void lttng_ustconsumer_del_channel(struct lttng_consumer_channel *chan)
 {
 	ustctl_unmap_channel(chan->handle);