From b0035e5704f912abf6dbdf1aca0e5cdaa56956be Mon Sep 17 00:00:00 2001
From: Julian Oes <julian@oes.ch>
Date: Tue, 3 Sep 2019 16:34:29 +0200
Subject: [PATCH] mavlink: prevent race if shut down immediately

If we do mavlink stop-all right after mavlink start, we do a perf_free
before actually having stopped the threads accessing the perf counters.
---
 src/modules/mavlink/mavlink_main.cpp | 9 +++------
 src/modules/mavlink/mavlink_main.h   | 2 +-
 2 files changed, 4 insertions(+), 7 deletions(-)

diff --git a/src/modules/mavlink/mavlink_main.cpp b/src/modules/mavlink/mavlink_main.cpp
index b40db93711..4813fe20dc 100644
--- a/src/modules/mavlink/mavlink_main.cpp
+++ b/src/modules/mavlink/mavlink_main.cpp
@@ -183,9 +183,6 @@ Mavlink::Mavlink() :
 
 Mavlink::~Mavlink()
 {
-	perf_free(_loop_perf);
-	perf_free(_loop_interval_perf);
-
 	if (_task_running) {
 		/* task wakes up every 10ms or so at the longest */
 		_task_should_exit = true;
@@ -205,6 +202,9 @@ Mavlink::~Mavlink()
 			}
 		} while (_task_running);
 	}
+
+	perf_free(_loop_perf);
+	perf_free(_loop_interval_perf);
 }
 
 void
@@ -2458,9 +2458,6 @@ Mavlink::task_main(int argc, char *argv[])
 		}
 
 		perf_end(_loop_perf);
-
-		/* confirm task running only once fully initialized */
-		_task_running = true;
 	}
 
 	/* first wait for threads to complete before tearing down anything */
diff --git a/src/modules/mavlink/mavlink_main.h b/src/modules/mavlink/mavlink_main.h
index 12d1c07573..a73ec6649e 100644
--- a/src/modules/mavlink/mavlink_main.h
+++ b/src/modules/mavlink/mavlink_main.h
@@ -546,7 +546,7 @@ private:
 
 	uORB::PublicationQueued<telemetry_status_s>	_telem_status_pub{ORB_ID(telemetry_status)};
 
-	bool			_task_running{false};
+	bool			_task_running{true};
 	static bool		_boot_complete;
 	static constexpr int	MAVLINK_MAX_INSTANCES{4};
 	static constexpr int	MAVLINK_MIN_INTERVAL{1500};