Add a thread utility class and thread list

[lttng-tools.git] / src / bin / lttng-sessiond / thread.h

diff --git a/src/bin/lttng-sessiond/thread.h b/src/bin/lttng-sessiond/thread.h
new file mode 100644 (file)
index 0000000..3b85d0b
--- /dev/null
+++ b/src/bin/lttng-sessiond/thread.h
@@ -0,0 +1,72 @@
+/*
+ * Copyright (C) 2018 - Jérémie Galarneau <jeremie.galarneau@efficios.com>
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License, version 2 only, as
+ * published by the Free Software Foundation.
+ *
+ * This program 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 General Public License for
+ * more details.
+ *
+ * You should have received a copy of the GNU General Public License along with
+ * this program; if not, write to the Free Software Foundation, Inc., 51
+ * Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
+ */
+
+#include <stdbool.h>
+
+#ifndef THREAD_H
+#define THREAD_H
+
+struct lttng_thread;
+
+/* Main function of the new thread. */
+typedef void *(*lttng_thread_entry_point)(void *);
+
+/* Callback invoked to initiate the shutdown a thread. */
+typedef bool (*lttng_thread_shutdown_cb)(void *);
+
+/*
+ * Callback invoked to clean-up the thread data.
+ * Invoked when the thread is destroyed to ensure there is no
+ * race between a use by the "thread shutdown callback" and
+ * a use by the thread itself.
+ */
+typedef void (*lttng_thread_cleanup_cb)(void *);
+
+/*
+ * Returns a reference to the newly-created thread.
+ * The shutdown and cleanup callbacks are optional.
+ */
+struct lttng_thread *lttng_thread_create(const char *name,
+               lttng_thread_entry_point entry,
+               lttng_thread_shutdown_cb shutdown,
+               lttng_thread_cleanup_cb cleanup,
+               void *thread_data);
+
+bool lttng_thread_get(struct lttng_thread *thread);
+void lttng_thread_put(struct lttng_thread *thread);
+
+const char *lttng_thread_get_name(const struct lttng_thread *thread);
+
+/*
+ * Explicitly shutdown a thread. This function returns once the
+ * thread has returned and been joined.
+ *
+ * It is invalid to call this function more than once on a thread.
+ *
+ * Returns true on success, false on error.
+ */
+bool lttng_thread_shutdown(struct lttng_thread *thread);
+
+/*
+ * Shutdown all orphaned threads (threads to which no external reference
+ * exist).
+ *
+ * Returns once all orphaned threads have been joined.
+ */
+void lttng_thread_list_shutdown_orphans(void);
+
+#endif /* THREAD_H */