+/*
+ * Copyright (C) 2016 - EfficiOS Inc., Alexandre Montplaisir <alexmonthy@efficios.com>
+ *
+ * This library is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU Lesser General Public License, version 2.1 only,
+ * as published by the Free Software Foundation.
+ *
+ * This library is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public License
+ * for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public License
+ * along with this library; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
+ */
+
+package org.lttng.ust.agent.utils;
+
+/**
+ * Logging infrastructure for the lttng-ust Java agent. It prints log messages
+ * to stderr but only when the environment variable LTTNG_UST_DEBUG is defined.
+ *
+ * @author Alexandre Montplaisir
+ */
+public class LttngUstAgentLogger {
+
+ private static final String ENV_VAR_NAME = "LTTNG_UST_DEBUG";
+ private static final boolean LOGGING_ENABLED = (System.getenv(ENV_VAR_NAME) == null ? false : true);
+
+ /**
+ * Log event. Will be printed to stderr if the environment variable
+ * "LTTNG_UST_DEBUG" is defined.
+ *
+ * @param c
+ * The class logging the message (should normally be called with
+ * {@link #getClass()}).
+ * @param message
+ * The message to print
+ */
+ public static void log(Class<?> c, String message) {
+ if (LOGGING_ENABLED) {
+ System.err.println(c.getSimpleName() + ": " + message);
+ }
+ }
+}