common: compile libcommon as C++

[lttng-tools.git] / src / common / fd-handle.cpp

diff --git a/src/common/fd-handle.cpp b/src/common/fd-handle.cpp
new file mode 100644 (file)
index 0000000..d8b5b78
--- /dev/null
+++ b/src/common/fd-handle.cpp
@@ -0,0 +1,94 @@
+/*
+ * Copyright (C) 2020 Jérémie Galarneau <jeremie.galarneau@efficios.com>
+ *
+ * SPDX-License-Identifier: LGPL-2.1-only
+ *
+ */
+
+#include <unistd.h>
+#include <urcu/ref.h>
+
+#include "fd-handle.h"
+#include <common/error.h>
+
+struct fd_handle {
+       struct urcu_ref ref;
+       int fd;
+};
+
+static void fd_handle_release(struct urcu_ref *ref)
+{
+       int ret;
+       struct fd_handle *handle = container_of(ref, struct fd_handle, ref);
+
+       LTTNG_ASSERT(handle->fd >= 0);
+       ret = close(handle->fd);
+       if (ret == -1) {
+               PERROR("Failed to close file descriptor of fd_handle upon release: fd = %d",
+                               handle->fd);
+       }
+
+       free(handle);
+}
+
+struct fd_handle *fd_handle_create(int fd)
+{
+       struct fd_handle *handle = NULL;
+
+       if (fd < 0) {
+               ERR("Attempted to create an fd_handle from an invalid file descriptor: fd = %d",
+                               fd);
+               goto end;
+       }
+
+       handle = (fd_handle *) zmalloc(sizeof(*handle));
+       if (!handle) {
+               PERROR("Failed to allocate fd_handle");
+               goto end;
+       }
+
+       urcu_ref_init(&handle->ref);
+       handle->fd = fd;
+
+end:
+       return handle;
+}
+
+void fd_handle_get(struct fd_handle *handle)
+{
+       if (!handle) {
+               return;
+       }
+
+       urcu_ref_get(&handle->ref);
+}
+
+void fd_handle_put(struct fd_handle *handle)
+{
+       if (!handle) {
+               return;
+       }
+
+       urcu_ref_put(&handle->ref, fd_handle_release);
+}
+
+int fd_handle_get_fd(struct fd_handle *handle)
+{
+       LTTNG_ASSERT(handle);
+       return handle->fd;
+}
+
+struct fd_handle *fd_handle_copy(const struct fd_handle *handle)
+{
+       struct fd_handle *new_handle = NULL;
+       const int new_fd = dup(handle->fd);
+
+       if (new_fd < 0) {
+               PERROR("Failed to duplicate file descriptor while copying fd_handle: fd = %d", handle->fd);
+               goto end;
+       }
+
+       new_handle = fd_handle_create(new_fd);
+end:
+       return new_handle;
+}