port taskqs to vmd for use in future work on virtio devices

these are backed by pthreads rather than kthreads and mutexes, and
only support creating a taskq serviced by a single worker thread.
task_set, task_add, and task_del all work the same though.

these are not linked into the build yet.

ok mlarkin@

1 files changed, 43 insertions, 0 deletions

diff --git a/usr.sbin/vmd/task.h b/usr.sbin/vmd/task.h
new file mode 100644
index 00000000000..bf97ba1ddb9
--- /dev/null
+++ b/usr.sbin/vmd/task.h
@@ -0,0 +1,43 @@
+/*	$OpenBSD: task.h,v 1.1 2017/09/15 02:39:33 dlg Exp $ */
+
+/*
+ * Copyright (c) 2013 David Gwynne <dlg@openbsd.org>
+ *
+ * Permission to use, copy, modify, and 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 _TASK_H_
+#define _TASK_H_
+
+#include <sys/queue.h>
+
+struct taskq;
+
+struct task {
+	TAILQ_ENTRY(task) t_entry;
+	void		(*t_func)(void *);
+	void		*t_arg;
+	unsigned int	t_flags;
+};
+
+TAILQ_HEAD(task_list, task);
+
+#define TASK_INITIALIZER(_f, _a)  {{ NULL, NULL }, (_f), (_a), 0 }
+
+struct taskq	*taskq_create(const char *);
+
+void		 task_set(struct task *, void (*)(void *), void *);
+int		 task_add(struct taskq *, struct task *);
+int		 task_del(struct taskq *, struct task *);
+
+#endif /* _TASK_H_ */