clean up file open/close logic

src/modules/logger/log_writer.cpp

@@ -22,11 +22,23 @@ LogWriter::LogWriter(uint8_t *buffer, size_t buffer_size) :
 void LogWriter::start_log(const char *filename)
 {
 	::strncpy(_filename, filename, sizeof(_filename));
+	_fd = ::open(_filename, O_CREAT | O_WRONLY, PX4_O_MODE_666);
+
+	if (_fd < 0) {
+		PX4_WARN("can't open log file %s", _filename);
+		_should_run = false;
+		return;
+
+	} else {
+		PX4_WARN("opened log file: %s", _filename);
+		_should_run = true;
+		_running = true;
+	}
+
 	// Clear buffer and counters
 	_head = 0;
 	_count = 0;
 	_total_written = 0;
-	_should_run = true;
 	notify();
 }
 
@@ -90,21 +102,7 @@ void LogWriter::run()
 	}
 
 	while (!_exit_thread) {
-		// Outer endless loop, start new file each time
-		// _filename must be set before setting _should_run = true
-
-
-		_fd = ::open(_filename, O_CREAT | O_WRONLY, PX4_O_MODE_666);
-
-		if (_fd < 0) {
-			PX4_WARN("can't open log file %s", _filename);
-			_should_run = false;
-			continue;
-		}
-
-		PX4_WARN("started, log file: %s", _filename);
-
-		_should_run = true;
+		// Outer endless loop
 
 		int poll_count = 0;
 		int written = 0;
@@ -164,22 +162,25 @@ void LogWriter::run()
 				_total_written += written;
 			}
 
-			if (!_should_run && written == static_cast<int>(available) && !is_part) {
+			if (_running && !_should_run && written == static_cast<int>(available) && !is_part) {
 				// Stop only when all data written
+				_running = false;
+				_head = 0;
+				_count = 0;
+
+				int res = ::close(_fd);
+
+				if (res) {
+					PX4_WARN("error closing log file");
+
+				} else {
+					PX4_WARN("closed logfile: %s, bytes written: %zu", _filename, _total_written);
+				}
+
 				break;
 			}
 		}
 
-		_head = 0;
-		_count = 0;
-
-		int res = ::close(_fd);
-
-		if (res) {
-			PX4_WARN("error closing log file");
-		}
-
-		PX4_WARN("stopped, bytes written: %zu", _total_written);
 	}
 }