runqueue: add a simple task queueing/completion tracking implementation

Signed-off-by: Felix Fietkau <nbd@openwrt.org>

1 files changed, 113 insertions, 0 deletions

diff --git a/runqueue.h b/runqueue.h
new file mode 100644
index 0000000..ad64f3d
--- /dev/null
+++ b/runqueue.h
@@ -0,0 +1,113 @@
+/*
+ * runqueue.c - a simple task queueing/completion tracking helper
+ *
+ * Copyright (C) 2013 Felix Fietkau <nbd@openwrt.org>
+ *
+ * Permission to use, copy, modify, and/or distribute this software for any
+ * purpose with or without fee is hereby granted, provided that the above
+ * copyright notice and this permission notice appear in all copies.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
+ * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
+ * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
+ * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
+ * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
+ * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
+ * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+ */
+
+#ifndef __LIBUBOX_RUNQUEUE_H
+#define __LIBUBOX_RUNQUEUE_H
+
+#include <libubox/list.h>
+#include <libubox/safe_list.h>
+#include <libubox/uloop.h>
+
+struct runqueue;
+struct runqueue_task;
+struct runqueue_task_type;
+
+struct runqueue {
+	struct safe_list tasks_active;
+	struct safe_list tasks_inactive;
+	struct uloop_timeout timeout;
+
+	int running_tasks;
+	int max_running_tasks;
+	bool stopped;
+	bool empty;
+
+	/* called when the runqueue is emptied */
+	void (*empty_cb)(struct runqueue *q);
+};
+
+struct runqueue_task_type {
+	const char *name;
+
+	/*
+	 * called when a task is requested to run
+	 *
+	 * The task is removed from the list before this callback is run. It
+	 * can re-arm itself using runqueue_task_add.
+	 */
+	void (*run)(struct runqueue *q, struct runqueue_task *t);
+
+	/*
+	 * called to request cancelling a task
+	 *
+	 * int type is used as an optional hint for the method to be used when
+	 * cancelling the task, e.g. a signal number for processes. Calls
+	 * runqueue_task_complete when done.
+	 */
+	void (*cancel)(struct runqueue *q, struct runqueue_task *t, int type);
+
+	/*
+	 * called to kill a task. must not make any calls to runqueue_task_complete,
+	 * it has already been removed from the list.
+	 */
+	void (*kill)(struct runqueue *q, struct runqueue_task *t);
+};
+
+struct runqueue_task {
+	struct safe_list list;
+	const struct runqueue_task_type *type;
+	struct runqueue *q;
+
+	struct uloop_timeout timeout;
+	int run_timeout;
+	int cancel_timeout;
+	int cancel_type;
+
+	bool queued;
+	bool running;
+	bool cancelled;
+};
+
+struct runqueue_process {
+	struct runqueue_task task;
+	struct uloop_process proc;
+	void (*complete)(struct runqueue *q, struct runqueue_process *p, int ret);
+};
+
+void runqueue_init(struct runqueue *q);
+void runqueue_cancel(struct runqueue *q);
+void runqueue_cancel_active(struct runqueue *q);
+void runqueue_cancel_pending(struct runqueue *q);
+void runqueue_kill(struct runqueue *q);
+
+void runqueue_stop(struct runqueue *q);
+void runqueue_resume(struct runqueue *q);
+
+void runqueue_task_add(struct runqueue *q, struct runqueue_task *t, bool running);
+void runqueue_task_complete(struct runqueue_task *t);
+
+void runqueue_task_cancel(struct runqueue_task *t, int type);
+void runqueue_task_kill(struct runqueue_task *t);
+
+void runqueue_process_add(struct runqueue *q, struct runqueue_process *p, pid_t pid);
+
+/* to be used only from runqueue_process callbacks */
+void runqueue_process_cancel_cb(struct runqueue *q, struct runqueue_task *t, int type);
+void runqueue_process_kill_cb(struct runqueue *q, struct runqueue_task *t);
+
+#endif