From 9e91ca82942a4b639d7079c5f573409e9fcd683b Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Beat=20K=C3=BCng?= <beat-kueng@gmx.net>
Date: Mon, 9 May 2022 16:33:36 +0200
Subject: [PATCH] log_writer_file: protect access to _should_run, use
 px4::atomicbool for _exit_thread

---
 src/modules/logger/log_writer_file.cpp | 12 ++++++++----
 src/modules/logger/log_writer_file.h   |  5 +++--
 2 files changed, 11 insertions(+), 6 deletions(-)

diff --git a/src/modules/logger/log_writer_file.cpp b/src/modules/logger/log_writer_file.cpp
index b32d5ff0ae..e6453a8080 100644
--- a/src/modules/logger/log_writer_file.cpp
+++ b/src/modules/logger/log_writer_file.cpp
@@ -287,7 +287,9 @@ int LogWriterFile::hardfault_store_filename(const char *log_file)
 
 void LogWriterFile::stop_log(LogType type)
 {
+	lock();
 	_buffers[(int)type]._should_run = false;
+	unlock();
 	notify();
 }
 
@@ -312,8 +314,10 @@ int LogWriterFile::thread_start()
 void LogWriterFile::thread_stop()
 {
 	// this will terminate the main loop of the writer thread
-	_exit_thread = true;
+	lock();
+	_exit_thread.store(true);
 	_buffers[0]._should_run = _buffers[1]._should_run = false;
+	unlock();
 
 	notify();
 
@@ -335,10 +339,10 @@ void *LogWriterFile::run_helper(void *context)
 
 void LogWriterFile::run()
 {
-	while (!_exit_thread) {
+	while (!_exit_thread.load()) {
 		// Outer endless loop
 		// Wait for _should_run flag
-		while (!_exit_thread) {
+		while (!_exit_thread.load()) {
 			bool start = false;
 			pthread_mutex_lock(&_mtx);
 			pthread_cond_wait(&_cv, &_mtx);
@@ -350,7 +354,7 @@ void LogWriterFile::run()
 			}
 		}
 
-		if (_exit_thread) {
+		if (_exit_thread.load()) {
 			break;
 		}
 
diff --git a/src/modules/logger/log_writer_file.h b/src/modules/logger/log_writer_file.h
index 01db3bdaaa..b6bfcdcf8b 100644
--- a/src/modules/logger/log_writer_file.h
+++ b/src/modules/logger/log_writer_file.h
@@ -34,6 +34,7 @@
 #pragma once
 
 #include <px4_platform_common/defines.h>
+#include <px4_platform_common/atomic.h>
 #include <stdint.h>
 #include <pthread.h>
 #include <drivers/drv_hrt.h>
@@ -205,8 +206,8 @@ private:
 
 	LogFileBuffer _buffers[(int)LogType::Count];
 
-	bool 		_exit_thread = false;
-	bool		_need_reliable_transfer = false;
+	px4::atomic_bool	_exit_thread{false};
+	bool			_need_reliable_transfer{false};
 	pthread_mutex_t		_mtx;
 	pthread_cond_t		_cv;
 	pthread_t _thread = 0;