Implement Java agent application context retrieval

[lttng-ust.git] / liblttng-ust-java-agent / java / lttng-ust-agent-common / org / lttng / ust / agent / context / LttngContextApi.java

diff --git a/liblttng-ust-java-agent/java/lttng-ust-agent-common/org/lttng/ust/agent/context/LttngContextApi.java b/liblttng-ust-java-agent/java/lttng-ust-agent-common/org/lttng/ust/agent/context/LttngContextApi.java
new file mode 100644 (file)
index 0000000..15062c9
--- /dev/null
+++ b/liblttng-ust-java-agent/java/lttng-ust-agent-common/org/lttng/ust/agent/context/LttngContextApi.java
@@ -0,0 +1,54 @@
+/*
+ * 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.context;
+
+/**
+ * Virtual class containing the Java side of the LTTng-UST context provider
+ * registering/unregistering methods.
+ *
+ * @author Alexandre Montplaisir
+ */
+final class LttngContextApi {
+
+       private LttngContextApi() {}
+
+       /**
+        * Register a context provider to UST.
+        *
+        * The callbacks are the same for all providers, and are defined in the .c
+        * file. The only needed information is the retriever (which is called
+        * "provider" from UST'S point of view) name.
+        *
+        * @param provider_name
+        *            The name of the provider
+        * @return The pointer to the created provider object. It's useless in the
+        *         Java space, but will be needed for
+        *         {@link #unregisterProvider(long)}.
+        */
+       static native long registerProvider(String provider_name);
+
+       /**
+        * Unregister a previously-registered context provider from UST.
+        *
+        * @param provider_ref
+        *            The pointer to the provider object, obtained from
+        *            {@link #registerProvider}
+        */
+       static native void unregisterProvider(long provider_ref);
+}
+