1 files changed, 231 insertions, 0 deletions
diff --git a/src/libudev/libudev-queue.c b/src/libudev/libudev-queue.c
new file mode 100644
index 0000000..0af99e5
--- /dev/null
+++ b/src/libudev/libudev-queue.c
@@ -0,0 +1,231 @@
+/* SPDX-License-Identifier: LGPL-2.1-or-later */
+/***
+  Copyright © 2009 Alan Jenkins <alan-jenkins@tuffmail.co.uk>
+***/
+
+#include <errno.h>
+#include <unistd.h>
+
+#include "libudev.h"
+
+#include "alloc-util.h"
+#include "fd-util.h"
+#include "io-util.h"
+#include "udev-util.h"
+
+/**
+ * SECTION:libudev-queue
+ * @short_description: access to currently active events
+ *
+ * This exports the current state of the udev processing queue.
+ */
+
+/**
+ * udev_queue:
+ *
+ * Opaque object representing the current event queue in the udev daemon.
+ */
+struct udev_queue {
+        struct udev *udev;
+        unsigned n_ref;
+        int fd;
+};
+
+/**
+ * udev_queue_new:
+ * @udev: udev library context
+ *
+ * The initial refcount is 1, and needs to be decremented to
+ * release the resources of the udev queue context.
+ *
+ * Returns: the udev queue context, or #NULL on error.
+ **/
+_public_ struct udev_queue *udev_queue_new(struct udev *udev) {
+        struct udev_queue *udev_queue;
+
+        udev_queue = new(struct udev_queue, 1);
+        if (!udev_queue)
+                return_with_errno(NULL, ENOMEM);
+
+        *udev_queue = (struct udev_queue) {
+                .udev = udev,
+                .n_ref = 1,
+                .fd = -EBADF,
+        };
+
+        return udev_queue;
+}
+
+static struct udev_queue *udev_queue_free(struct udev_queue *udev_queue) {
+        assert(udev_queue);
+
+        safe_close(udev_queue->fd);
+        return mfree(udev_queue);
+}
+
+/**
+ * udev_queue_ref:
+ * @udev_queue: udev queue context
+ *
+ * Take a reference of a udev queue context.
+ *
+ * Returns: the same udev queue context.
+ **/
+
+/**
+ * udev_queue_unref:
+ * @udev_queue: udev queue context
+ *
+ * Drop a reference of a udev queue context. If the refcount reaches zero,
+ * the resources of the queue context will be released.
+ *
+ * Returns: #NULL
+ **/
+DEFINE_PUBLIC_TRIVIAL_REF_UNREF_FUNC(struct udev_queue, udev_queue, udev_queue_free);
+
+/**
+ * udev_queue_get_udev:
+ * @udev_queue: udev queue context
+ *
+ * Retrieve the udev library context the queue context was created with.
+ *
+ * Returns: the udev library context.
+ **/
+_public_ struct udev *udev_queue_get_udev(struct udev_queue *udev_queue) {
+        assert_return_errno(udev_queue, NULL, EINVAL);
+
+        return udev_queue->udev;
+}
+
+/**
+ * udev_queue_get_kernel_seqnum:
+ * @udev_queue: udev queue context
+ *
+ * This function is deprecated.
+ *
+ * Returns: 0.
+ **/
+_public_ unsigned long long int udev_queue_get_kernel_seqnum(struct udev_queue *udev_queue) {
+        return 0;
+}
+
+/**
+ * udev_queue_get_udev_seqnum:
+ * @udev_queue: udev queue context
+ *
+ * This function is deprecated.
+ *
+ * Returns: 0.
+ **/
+_public_ unsigned long long int udev_queue_get_udev_seqnum(struct udev_queue *udev_queue) {
+        return 0;
+}
+
+/**
+ * udev_queue_get_udev_is_active:
+ * @udev_queue: udev queue context
+ *
+ * Check if udev is active on the system.
+ *
+ * Returns: a flag indicating if udev is active.
+ **/
+_public_ int udev_queue_get_udev_is_active(struct udev_queue *udev_queue) {
+        return access("/run/udev/control", F_OK) >= 0;
+}
+
+/**
+ * udev_queue_get_queue_is_empty:
+ * @udev_queue: udev queue context
+ *
+ * Check if udev is currently processing any events.
+ *
+ * Returns: a flag indicating if udev is currently handling events.
+ **/
+_public_ int udev_queue_get_queue_is_empty(struct udev_queue *udev_queue) {
+        return udev_queue_is_empty() > 0;
+}
+
+/**
+ * udev_queue_get_seqnum_sequence_is_finished:
+ * @udev_queue: udev queue context
+ * @start: first event sequence number
+ * @end: last event sequence number
+ *
+ * This function is deprecated, and equivalent to udev_queue_get_queue_is_empty().
+ *
+ * Returns: a flag indicating if udev is currently handling events.
+ **/
+_public_ int udev_queue_get_seqnum_sequence_is_finished(struct udev_queue *udev_queue,
+                                                        unsigned long long int start, unsigned long long int end) {
+        return udev_queue_is_empty() > 0;
+}
+
+/**
+ * udev_queue_get_seqnum_is_finished:
+ * @udev_queue: udev queue context
+ * @seqnum: sequence number
+ *
+ * This function is deprecated, and equivalent to udev_queue_get_queue_is_empty().
+ *
+ * Returns: a flag indicating if udev is currently handling events.
+ **/
+_public_ int udev_queue_get_seqnum_is_finished(struct udev_queue *udev_queue, unsigned long long int seqnum) {
+        return udev_queue_is_empty() > 0;
+}
+
+/**
+ * udev_queue_get_queued_list_entry:
+ * @udev_queue: udev queue context
+ *
+ * This function is deprecated.
+ *
+ * Returns: NULL.
+ **/
+_public_ struct udev_list_entry *udev_queue_get_queued_list_entry(struct udev_queue *udev_queue) {
+        return_with_errno(NULL, ENODATA);
+}
+
+/**
+ * udev_queue_get_fd:
+ * @udev_queue: udev queue context
+ *
+ * Returns: a file descriptor to watch for a queue to become empty.
+ */
+_public_ int udev_queue_get_fd(struct udev_queue *udev_queue) {
+        _cleanup_close_ int fd = -EBADF;
+
+        assert_return(udev_queue, -EINVAL);
+
+        if (udev_queue->fd >= 0)
+                return udev_queue->fd;
+
+        fd = inotify_init1(IN_CLOEXEC);
+        if (fd < 0)
+                return -errno;
+
+        if (inotify_add_watch(fd, "/run/udev" , IN_DELETE) < 0)
+                return -errno;
+
+        return udev_queue->fd = TAKE_FD(fd);
+}
+
+/**
+ * udev_queue_flush:
+ * @udev_queue: udev queue context
+ *
+ * Returns: the result of clearing the watch for queue changes.
+ */
+_public_ int udev_queue_flush(struct udev_queue *udev_queue) {
+        int r;
+
+        assert_return(udev_queue, -EINVAL);
+
+        if (udev_queue->fd < 0)
+                return -EINVAL;
+
+        r = flush_fd(udev_queue->fd);
+        if (r < 0)
+                return r;
+
+        return 0;
+}