From: Julien Desfossez <jdesfossez@efficios.com>
Date: Mon, 11 Dec 2017 21:42:20 +0000 (-0500)
Subject: Dedicated function to wakeup the consumer metadata pipe
X-Git-Tag: v2.11.0-rc1~357
X-Git-Url: https://git.lttng.org./?a=commitdiff_plain;h=5b8eb761b650749a164de120f014b0cb6c218cf2;p=lttng-tools.git

Dedicated function to wakeup the consumer metadata pipe

Extract the logic to wakeup the consumer metadata pipe to a dedicated
function, it will be used after a rotation in UST.

Signed-off-by: Julien Desfossez <jdesfossez@efficios.com>
Signed-off-by: Jérémie Galarneau <jeremie.galarneau@efficios.com>
---

diff --git a/src/common/consumer/consumer-metadata-cache.c b/src/common/consumer/consumer-metadata-cache.c
index 6b15375e1..ac83443a9 100644
--- a/src/common/consumer/consumer-metadata-cache.c
+++ b/src/common/consumer/consumer-metadata-cache.c
@@ -105,6 +105,31 @@ end:
 	return ret;
 }
 
+/*
+ * Write a character on the metadata poll pipe to wake the metadata thread.
+ * Returns 0 on success, -1 on error.
+ */
+int consumer_metadata_wakeup_pipe(const struct lttng_consumer_channel *channel)
+{
+	int ret = 0;
+	const char dummy = 'c';
+
+	if (channel->monitor && channel->metadata_stream) {
+		ssize_t write_ret;
+
+		write_ret = lttng_write(channel->metadata_stream->ust_metadata_poll_pipe[1],
+				&dummy, 1);
+		if (write_ret < 1) {
+			PERROR("Wake-up UST metadata pipe");
+			ret = -1;
+			goto end;
+		}
+	}
+
+end:
+	return ret;
+}
+
 /*
  * Write metadata to the cache, extend the cache if necessary. We support
  * overlapping updates, but they need to be contiguous. Send the
@@ -118,7 +143,6 @@ int consumer_metadata_cache_write(struct lttng_consumer_channel *channel,
 		char *data)
 {
 	int ret = 0;
-	int size_ret;
 	struct consumer_metadata_cache *cache;
 
 	assert(channel);
@@ -144,18 +168,8 @@ int consumer_metadata_cache_write(struct lttng_consumer_channel *channel,
 
 	memcpy(cache->data + offset, data, len);
 	if (offset + len > cache->max_offset) {
-		char dummy = 'c';
-
 		cache->max_offset = offset + len;
-		if (channel->monitor && channel->metadata_stream) {
-			size_ret = lttng_write(channel->metadata_stream->ust_metadata_poll_pipe[1],
-					&dummy, 1);
-			if (size_ret < 1) {
-				ERR("Wakeup UST metadata pipe");
-				ret = -1;
-				goto end;
-			}
-		}
+		ret = consumer_metadata_wakeup_pipe(channel);
 	}
 
 end:
diff --git a/src/common/consumer/consumer-metadata-cache.h b/src/common/consumer/consumer-metadata-cache.h
index 7dcf6976f..d1ca0be2c 100644
--- a/src/common/consumer/consumer-metadata-cache.h
+++ b/src/common/consumer/consumer-metadata-cache.h
@@ -52,5 +52,6 @@ int consumer_metadata_cache_allocate(struct lttng_consumer_channel *channel);
 void consumer_metadata_cache_destroy(struct lttng_consumer_channel *channel);
 int consumer_metadata_cache_flushed(struct lttng_consumer_channel *channel,
 		uint64_t offset, int timer);
+int consumer_metadata_wakeup_pipe(const struct lttng_consumer_channel *channel);
 
 #endif /* CONSUMER_METADATA_CACHE_H */