First preview release.

todo.c

@@ -0,0 +1,175 @@
+/*-
+ * Copyright (c) 2014 Poul-Henning Kamp
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED.  IN NO EVENT SHALL AUTHOR OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+ * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ *
+ * todo-list scheduler
+ * ===================
+ *
+ * This is a simple "TODO-list" scheduler for calling things at certain
+ * times.  Jobs can be one-shot or repeated and repeated jobs can abort.
+ */
+
+#include <stdarg.h>
+#include <stdio.h>
+#include <stdlib.h>
+
+#include "ntimed.h"
+
+struct todo {
+	unsigned		magic;
+#define TODO_MAGIC		0x5279009a
+	TAILQ_ENTRY(todo)	list;
+
+	todo_f			*func;
+	void			*priv;
+	struct timestamp	when;
+	double			repeat;
+
+	char			what[40];
+};
+
+struct todolist {
+	unsigned		magic;
+#define TODOLIST_MAGIC		0x7db66255
+	TAILQ_HEAD(,todo)	todolist;
+};
+
+struct todolist *
+TODO_NewList(void)
+{
+	struct todolist *tdl;
+
+	ALLOC_OBJ(tdl, TODOLIST_MAGIC);
+	AN(tdl);
+	TAILQ_INIT(&tdl->todolist);
+	return (tdl);
+}
+
+static void
+todo_insert(struct todolist *tdl, struct todo *tp)
+{
+	struct todo *tp1;
+
+	TAILQ_FOREACH(tp1, &tdl->todolist, list) {
+		if (TS_Diff(&tp1->when, &tp->when) > 0.0) {
+			TAILQ_INSERT_BEFORE(tp1, tp, list);
+			return;
+		}
+	}
+	TAILQ_INSERT_TAIL(&tdl->todolist, tp, list);
+}
+
+/**********************************************************************
+ * Return a pointer to the todo item, so the API can support cancellation.
+ * (Cancellation will be necessary for NTP-peer removal)
+ *
+ * For ease of debugging, TODO jobs have a name.
+ */
+
+struct todo *
+TODO_ScheduleAbs(struct todolist *tdl, todo_f *func, void *priv,
+    const struct timestamp *when, double repeat, const char *fmt, ...)
+{
+	struct todo *tp;
+	va_list ap;
+
+	CHECK_OBJ_NOTNULL(tdl, TODOLIST_MAGIC);
+	AN(func);
+	CHECK_OBJ_NOTNULL(when, TIMESTAMP_MAGIC);
+	assert(repeat >= 0.0);
+	AN(fmt);
+
+	ALLOC_OBJ(tp, TODO_MAGIC);
+	AN(tp);
+	tp->func = func;
+	tp->priv = priv;
+	tp->when = *when;
+	tp->repeat = repeat;
+	va_start(ap, fmt);
+	(void)vsnprintf(tp->what, sizeof tp->what, fmt, ap);
+	va_end(ap);
+	todo_insert(tdl, tp);
+	return (tp);
+}
+
+struct todo *
+TODO_ScheduleRel(struct todolist *tdl, todo_f *func, void *priv,
+    double when, double repeat, const char *fmt, ...)
+{
+	struct todo *tp;
+	va_list ap;
+
+	CHECK_OBJ_NOTNULL(tdl, TODOLIST_MAGIC);
+	AN(func);
+	assert(when >= 0.0);
+	assert(repeat >= 0.0);
+	AN(fmt);
+
+	ALLOC_OBJ(tp, TODO_MAGIC);
+	AN(tp);
+	tp->func = func;
+	tp->priv = priv;
+	TB_Now(&tp->when);
+	TS_Add(&tp->when, when);
+	tp->repeat = repeat;
+	va_start(ap, fmt);
+	(void)vsnprintf(tp->what, sizeof tp->what, fmt, ap);
+	va_end(ap);
+	todo_insert(tdl, tp);
+	return (tp);
+}
+
+/**********************************************************************
+ * Schedule TODO list until failure or empty
+ */
+
+enum todo_e
+TODO_Run(struct ocx *ocx, struct todolist *tdl)
+{
+	struct todo *tp;
+	enum todo_e ret = TODO_OK;
+	char buf[40];
+
+	CHECK_OBJ_NOTNULL(tdl, TODOLIST_MAGIC);
+	while(!TAILQ_EMPTY(&tdl->todolist)) {
+		tp = TAILQ_FIRST(&tdl->todolist);
+		TS_SleepUntil(&tp->when);
+		TS_Format(buf, sizeof buf, &tp->when);
+		Put(ocx, OCX_TRACE, "Now %s %s\n", buf, tp->what);
+		ret = tp->func(ocx, tdl, tp->priv);
+		if (ret == TODO_FAIL)
+			break;
+		if (ret == TODO_DONE || tp->repeat == 0.0) {
+			TAILQ_REMOVE(&tdl->todolist, tp, list);
+			FREE_OBJ(tp);
+		} else if (ret == TODO_OK) {
+			TS_Add(&tp->when, tp->repeat);
+			TAILQ_REMOVE(&tdl->todolist, tp, list);
+			todo_insert(tdl, tp);
+		} else {
+			WRONG("Invalid Return from todo->func");
+		}
+	}
+	return (ret);
+}