X-Git-Url: http://git.liburcu.org/?p=lttng-modules.git;a=blobdiff_plain;f=src%2Flttng-events.c;h=2b72621cf2d6fccacaed54e3c8dde1159500ddb5;hp=3b9b907beb85196b36301cbb6df6456ab195b23b;hb=3e75e2a7f7693107faa58606538f80a4faf73fe6;hpb=0193412d9db9b24752bd1fbcabc7d1cc74c270c4

diff --git a/src/lttng-events.c b/src/lttng-events.c
index 3b9b907b..2b72621c 100644
--- a/src/lttng-events.c
+++ b/src/lttng-events.c
@@ -1673,7 +1673,7 @@ int lttng_metadata_output_channel(struct lttng_metadata_stream *stream,
 			reserve_len);
 	stream->transport->ops.event_commit(&ctx);
 	stream->metadata_in += reserve_len;
-	if (reserve_len < len || stream->metadata_cache->producing != 0)
+	if (reserve_len < len)
 		stream->coherent = false;
 	else
 		stream->coherent = true;
@@ -1689,18 +1689,21 @@ end:
 static
 void lttng_metadata_begin(struct lttng_session *session)
 {
-	mutex_lock(&session->metadata_cache->lock);
-	session->metadata_cache->producing++;
-	mutex_unlock(&session->metadata_cache->lock);
+	if (atomic_inc_return(&session->metadata_cache->producing) == 1)
+		mutex_lock(&session->metadata_cache->lock);
 }
 
 static
 void lttng_metadata_end(struct lttng_session *session)
 {
-	mutex_lock(&session->metadata_cache->lock);
-	WARN_ON_ONCE(!session->metadata_cache->producing);
-	session->metadata_cache->producing--;
-	mutex_unlock(&session->metadata_cache->lock);
+	WARN_ON_ONCE(!atomic_read(&session->metadata_cache->producing));
+	if (atomic_dec_return(&session->metadata_cache->producing) == 0) {
+		struct lttng_metadata_stream *stream;
+
+		mutex_unlock(&session->metadata_cache->lock);
+		list_for_each_entry(stream, &session->metadata_cache->metadata_stream, list)
+			wake_up_interruptible(&stream->read_wait);
+	}
 }
 
 /*
@@ -1717,7 +1720,6 @@ int lttng_metadata_printf(struct lttng_session *session,
 	char *str;
 	size_t len;
 	va_list ap;
-	struct lttng_metadata_stream *stream;
 
 	WARN_ON_ONCE(!READ_ONCE(session->active));
 
@@ -1728,8 +1730,7 @@ int lttng_metadata_printf(struct lttng_session *session,
 		return -ENOMEM;
 
 	len = strlen(str);
-	mutex_lock(&session->metadata_cache->lock);
-	session->metadata_cache->producing++;
+	WARN_ON_ONCE(!atomic_read(&session->metadata_cache->producing));
 	if (session->metadata_cache->metadata_written + len >
 			session->metadata_cache->cache_alloc) {
 		char *tmp_cache_realloc;
@@ -1755,18 +1756,11 @@ int lttng_metadata_printf(struct lttng_session *session,
 			session->metadata_cache->metadata_written,
 			str, len);
 	session->metadata_cache->metadata_written += len;
-	session->metadata_cache->producing--;
-	mutex_unlock(&session->metadata_cache->lock);
 	kfree(str);
 
-	list_for_each_entry(stream, &session->metadata_cache->metadata_stream, list)
-		wake_up_interruptible(&stream->read_wait);
-
 	return 0;
 
 err:
-	session->metadata_cache->producing--;
-	mutex_unlock(&session->metadata_cache->lock);
 	kfree(str);
 	return -ENOMEM;
 }