From: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Date: Mon, 27 Jan 2014 03:10:34 +0000 (-0500)
Subject: Fix: consumerd: only return readiness when health is ready
X-Git-Tag: v2.5.0-rc1~252
X-Git-Url: https://git.lttng.org/?p=lttng-tools.git;a=commitdiff_plain;h=748b7b07caecdc5f7ac4a73e008a7d0a84d422c4

Fix: consumerd: only return readiness when health is ready

Wait for health check to be ready before returning readiness to session
daemon.

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

diff --git a/src/bin/lttng-consumerd/health-consumerd.c b/src/bin/lttng-consumerd/health-consumerd.c
index 413df9acf..ad2b5245a 100644
--- a/src/bin/lttng-consumerd/health-consumerd.c
+++ b/src/bin/lttng-consumerd/health-consumerd.c
@@ -233,6 +233,10 @@ void *thread_manage_health(void *data)
 		goto error;
 	}
 
+	/* Perform prior memory accesses before decrementing ready */
+	cmm_smp_mb__before_uatomic_dec();
+	uatomic_dec(&lttng_consumer_ready);
+
 	while (1) {
 		DBG("Health check ready");
 
diff --git a/src/bin/lttng-consumerd/lttng-consumerd.c b/src/bin/lttng-consumerd/lttng-consumerd.c
index 2b5528d64..4a9a7a492 100644
--- a/src/bin/lttng-consumerd/lttng-consumerd.c
+++ b/src/bin/lttng-consumerd/lttng-consumerd.c
@@ -79,6 +79,8 @@ struct health_app *health_consumerd;
 
 const char *tracing_group_name = DEFAULT_TRACING_GROUP;
 
+int lttng_consumer_ready = NR_LTTNG_CONSUMER_READY;
+
 enum lttng_consumer_type lttng_consumer_get_type(void)
 {
 	if (!ctx) {
@@ -419,6 +421,15 @@ int main(int argc, char **argv)
 		goto health_error;
 	}
 
+	/*
+	 * Wait for health thread to be initialized before letting the
+	 * sessiond thread reply to the sessiond that we are ready.
+	 */
+	while (uatomic_read(&lttng_consumer_ready)) {
+		sleep(1);
+	}
+	cmm_smp_mb();	/* Read ready before following operations */
+
 	/* Create thread to manage channels */
 	ret = pthread_create(&channel_thread, NULL, consumer_thread_channel_poll,
 			(void *) ctx);
diff --git a/src/bin/lttng-consumerd/lttng-consumerd.h b/src/bin/lttng-consumerd/lttng-consumerd.h
index 5662429ad..6d18fdf88 100644
--- a/src/bin/lttng-consumerd/lttng-consumerd.h
+++ b/src/bin/lttng-consumerd/lttng-consumerd.h
@@ -19,6 +19,10 @@
 #ifndef _LTTNG_CONSUMERD_H
 #define _LTTNG_CONSUMERD_H
 
+
+#define NR_LTTNG_CONSUMER_READY		1
+extern int lttng_consumer_ready;
+
 const char *tracing_group_name;
 
 enum lttng_consumer_type lttng_consumer_get_type(void);