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authorDavid Gwynne <dlg@cvs.openbsd.org>2017-09-15 02:39:34 +0000
committerDavid Gwynne <dlg@cvs.openbsd.org>2017-09-15 02:39:34 +0000
commitb5e44e8f19222d7e02940ce71b8259e0fe576607 (patch)
treeea12526ded7291c5a027c825adc6599338790a9c /usr.sbin
parentc1c62339eedd38104f0f636ee805da612792320e (diff)
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@
Diffstat (limited to 'usr.sbin')
-rw-r--r--usr.sbin/vmd/task.c156
-rw-r--r--usr.sbin/vmd/task.h43
2 files changed, 199 insertions, 0 deletions
diff --git a/usr.sbin/vmd/task.c b/usr.sbin/vmd/task.c
new file mode 100644
index 00000000000..e76914db590
--- /dev/null
+++ b/usr.sbin/vmd/task.c
@@ -0,0 +1,156 @@
+/* $OpenBSD: task.c,v 1.1 2017/09/15 02:39:33 dlg Exp $ */
+
+/*
+ * Copyright (c) 2017 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.
+ */
+
+#include <errno.h>
+#include <stddef.h>
+#include <stdlib.h>
+#include <pthread.h>
+#include <pthread_np.h>
+
+#include "task.h"
+
+#define ISSET(_v, _m) ((_v) & (_m))
+#define SET(_v, _m) ((_v) |= (_m))
+#define CLR(_v, _m) ((_v) &= ~(_m))
+
+struct taskq {
+ pthread_t thread;
+ struct task_list list;
+ pthread_mutex_t mtx;
+ pthread_cond_t cv;
+};
+
+#define TASK_ONQUEUE (1 << 0)
+
+static void *taskq_run(void *);
+
+struct taskq *
+taskq_create(const char *name)
+{
+ struct taskq *tq;
+ int error;
+
+ tq = malloc(sizeof(*tq));
+ if (tq == NULL)
+ return (NULL);
+
+ TAILQ_INIT(&tq->list);
+
+ error = pthread_mutex_init(&tq->mtx, NULL);
+ if (error != 0)
+ goto free;
+
+ error = pthread_cond_init(&tq->cv, NULL);
+ if (error != 0)
+ goto mtx;
+
+ error = pthread_create(&tq->thread, NULL, taskq_run, tq);
+ if (error != 0)
+ goto cv;
+
+ pthread_set_name_np(tq->thread, name);
+
+ return (tq);
+
+cv:
+ pthread_cond_destroy(&tq->cv);
+mtx:
+ pthread_mutex_destroy(&tq->mtx); /* can this really fail? */
+free:
+ free(tq);
+
+ errno = error;
+ return (NULL);
+}
+
+static void *
+taskq_run(void *tqarg)
+{
+ struct taskq *tq = tqarg;
+ struct task *t;
+
+ void (*t_func)(void *);
+ void *t_arg;
+
+ for (;;) {
+ pthread_mutex_lock(&tq->mtx);
+ while ((t = TAILQ_FIRST(&tq->list)) == NULL)
+ pthread_cond_wait(&tq->cv, &tq->mtx);
+
+ TAILQ_REMOVE(&tq->list, t, t_entry);
+ CLR(t->t_flags, TASK_ONQUEUE);
+
+ t_func = t->t_func;
+ t_arg = t->t_arg;
+
+ pthread_mutex_unlock(&tq->mtx);
+
+ (*t_func)(t_arg);
+ }
+
+ return (NULL);
+}
+
+void
+task_set(struct task *t, void (*fn)(void *), void *arg)
+{
+ t->t_func = fn;
+ t->t_arg = arg;
+ t->t_flags = 0;
+}
+
+int
+task_add(struct taskq *tq, struct task *t)
+{
+ int rv = 1;
+
+ if (ISSET(t->t_flags, TASK_ONQUEUE))
+ return (0);
+
+ pthread_mutex_lock(&tq->mtx);
+ if (ISSET(t->t_flags, TASK_ONQUEUE))
+ rv = 0;
+ else {
+ SET(t->t_flags, TASK_ONQUEUE);
+ TAILQ_INSERT_TAIL(&tq->list, t, t_entry);
+ pthread_cond_signal(&tq->cv);
+ }
+ pthread_mutex_unlock(&tq->mtx);
+
+ return (rv);
+}
+
+int
+task_del(struct taskq *tq, struct task *t)
+{
+ int rv = 1;
+
+ if (!ISSET(t->t_flags, TASK_ONQUEUE))
+ return (0);
+
+ pthread_mutex_lock(&tq->mtx);
+ if (!ISSET(t->t_flags, TASK_ONQUEUE))
+ rv = 0;
+ else {
+ TAILQ_REMOVE(&tq->list, t, t_entry);
+ CLR(t->t_flags, TASK_ONQUEUE);
+ }
+ pthread_mutex_unlock(&tq->mtx);
+
+ return (rv);
+}
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_ */