From: David Goulet <dgoulet@efficios.com>
Date: Mon, 20 Aug 2012 21:12:51 +0000 (-0400)
Subject: Merge duplicate code in consumer for destroy relayd
X-Git-Tag: v2.1.0-rc2~8
X-Git-Url: https://git.lttng.org./?a=commitdiff_plain;h=a6ba4fe1a8217fd5cb9e286b4d88a9252c0d5d06;p=lttng-tools.git

Merge duplicate code in consumer for destroy relayd

Kernel and UST were using the same exact code for the DESTROY_RELAYD
command received from the session daemon.

Signed-off-by: David Goulet <dgoulet@efficios.com>
---

diff --git a/src/common/consumer.c b/src/common/consumer.c
index 363fa4eda..2ee6c3313 100644
--- a/src/common/consumer.c
+++ b/src/common/consumer.c
@@ -201,6 +201,25 @@ void consumer_destroy_relayd(struct consumer_relayd_sock_pair *relayd)
 	call_rcu(&relayd->node.head, consumer_rcu_free_relayd);
 }
 
+/*
+ * Flag a relayd socket pair for destruction. Destroy it if the refcount
+ * reaches zero.
+ *
+ * RCU read side lock MUST be aquired before calling this function.
+ */
+void consumer_flag_relayd_for_destroy(struct consumer_relayd_sock_pair *relayd)
+{
+	assert(relayd);
+
+	/* Set destroy flag for this object */
+	uatomic_set(&relayd->destroy_flag, 1);
+
+	/* Destroy the relayd if refcount is 0 */
+	if (uatomic_read(&relayd->refcount) == 0) {
+		consumer_destroy_relayd(relayd);
+	}
+}
+
 /*
  * Remove a stream from the global list protected by a mutex. This
  * function is also responsible for freeing its data structures.
diff --git a/src/common/consumer.h b/src/common/consumer.h
index da3c4ce5a..fc5d5ef14 100644
--- a/src/common/consumer.h
+++ b/src/common/consumer.h
@@ -384,5 +384,7 @@ int lttng_consumer_on_recv_stream(struct lttng_consumer_stream *stream);
 int consumer_add_relayd_socket(int net_seq_idx, int sock_type,
 		struct lttng_consumer_local_data *ctx, int sock,
 		struct pollfd *consumer_sockpoll, struct lttcomm_sock *relayd_sock);
+void consumer_flag_relayd_for_destroy(
+		struct consumer_relayd_sock_pair *relayd);
 
 #endif /* LIB_CONSUMER_H */
diff --git a/src/common/kernel-consumer/kernel-consumer.c b/src/common/kernel-consumer/kernel-consumer.c
index 86ccddfd0..4a7ba0451 100644
--- a/src/common/kernel-consumer/kernel-consumer.c
+++ b/src/common/kernel-consumer/kernel-consumer.c
@@ -211,26 +211,30 @@ int lttng_kconsumer_recv_cmd(struct lttng_consumer_local_data *ctx,
 	}
 	case LTTNG_CONSUMER_DESTROY_RELAYD:
 	{
+		uint64_t index = msg.u.destroy_relayd.net_seq_idx;
 		struct consumer_relayd_sock_pair *relayd;
 
-		DBG("Kernel consumer destroying relayd %" PRIu64,
-				msg.u.destroy_relayd.net_seq_idx);
+		DBG("Kernel consumer destroying relayd %" PRIu64, index);
 
 		/* Get relayd reference if exists. */
-		relayd = consumer_find_relayd(msg.u.destroy_relayd.net_seq_idx);
+		relayd = consumer_find_relayd(index);
 		if (relayd == NULL) {
-			ERR("Unable to find relayd %" PRIu64,
-					msg.u.destroy_relayd.net_seq_idx);
+			ERR("Unable to find relayd %" PRIu64, index);
 			goto end_nosignal;
 		}
 
-		/* Set destroy flag for this object */
-		uatomic_set(&relayd->destroy_flag, 1);
+		/*
+		 * Each relayd socket pair has a refcount of stream attached to it
+		 * which tells if the relayd is still active or not depending on the
+		 * refcount value.
+		 *
+		 * This will set the destroy flag of the relayd object and destroy it
+		 * if the refcount reaches zero when called.
+		 *
+		 * The destroy can happen either here or when a stream fd hangs up.
+		 */
+		consumer_flag_relayd_for_destroy(relayd);
 
-		/* Destroy the relayd if refcount is 0 else set the destroy flag. */
-		if (uatomic_read(&relayd->refcount) == 0) {
-			consumer_destroy_relayd(relayd);
-		}
 		goto end_nosignal;
 	}
 	default:
diff --git a/src/common/ust-consumer/ust-consumer.c b/src/common/ust-consumer/ust-consumer.c
index a8872aaf3..9cafe398e 100644
--- a/src/common/ust-consumer/ust-consumer.c
+++ b/src/common/ust-consumer/ust-consumer.c
@@ -241,25 +241,30 @@ int lttng_ustconsumer_recv_cmd(struct lttng_consumer_local_data *ctx,
 	}
 	case LTTNG_CONSUMER_DESTROY_RELAYD:
 	{
+		uint64_t index = msg.u.destroy_relayd.net_seq_idx;
 		struct consumer_relayd_sock_pair *relayd;
 
-		DBG("UST consumer destroying relayd %" PRIu64,
-				msg.u.destroy_relayd.net_seq_idx);
+		DBG("UST consumer destroying relayd %" PRIu64, index);
 
 		/* Get relayd reference if exists. */
-		relayd = consumer_find_relayd(msg.u.destroy_relayd.net_seq_idx);
+		relayd = consumer_find_relayd(index);
 		if (relayd == NULL) {
-			ERR("Unable to find relayd %" PRIu64, msg.u.destroy_relayd.net_seq_idx);
+			ERR("Unable to find relayd %" PRIu64, index);
 			goto end_nosignal;
 		}
 
-		/* Set destroy flag for this object */
-		uatomic_set(&relayd->destroy_flag, 1);
+		/*
+		 * Each relayd socket pair has a refcount of stream attached to it
+		 * which tells if the relayd is still active or not depending on the
+		 * refcount value.
+		 *
+		 * This will set the destroy flag of the relayd object and destroy it
+		 * if the refcount reaches zero when called.
+		 *
+		 * The destroy can happen either here or when a stream fd hangs up.
+		 */
+		consumer_flag_relayd_for_destroy(relayd);
 
-		/* Destroy the relayd if refcount is 0 else set the destroy flag. */
-		if (uatomic_read(&relayd->refcount) == 0) {
-			consumer_destroy_relayd(relayd);
-		}
 		goto end_nosignal;
 	}
 	case LTTNG_CONSUMER_UPDATE_STREAM: