common: move utils_create_lock_file to its own file

[lttng-tools.git] / src / common / lockfile.hpp

diff --git a/src/common/lockfile.hpp b/src/common/lockfile.hpp
new file mode 100644 (file)
index 0000000..1f8e01d
--- /dev/null
+++ b/src/common/lockfile.hpp
@@ -0,0 +1,25 @@
+/*
+ * Copyright (C) 2023 Jérémie Galarneau <jeremie.galarneau@efficios.com>
+ *
+ * SPDX-License-Identifier: LGPL-2.1-only
+ *
+ */
+
+#ifndef COMMON_LOCKFILE_H
+#define COMMON_LOCKFILE_H
+
+/*
+ * Create lock file to the given path and filename.
+ * Returns the associated file descriptor, -1 on error.
+ *
+ * Note that on systems that don't support flock, POSIX file locks are used.
+ * As such, the file lock is dropped whenever any of the file descriptors
+ * associated to the file's description is closed.
+ *
+ * For instance, the lock file is dropped if the process forks+exits or
+ * forks+execve as the child process closes a file descriptor referencing
+ * the file description of 'filepath'.
+ */
+int utils_create_lock_file(const char *filepath);
+
+#endif /* COMMON_LOCKFILE_H */