1 /*-
2  * Copyright (c) 2014 Poul-Henning Kamp
3  * All rights reserved.
4  *
5  * Redistribution and use in source and binary forms, with or without
6  * modification, are permitted provided that the following conditions
7  * are met:
8  * 1. Redistributions of source code must retain the above copyright
9  *    notice, this list of conditions and the following disclaimer.
10  * 2. Redistributions in binary form must reproduce the above copyright
11  *    notice, this list of conditions and the following disclaimer in the
12  *    documentation and/or other materials provided with the distribution.
13  *
14  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
15  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
16  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
17  * ARE DISCLAIMED.  IN NO EVENT SHALL AUTHOR OR CONTRIBUTORS BE LIABLE
18  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
19  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
20  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
21  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
22  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
23  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
24  * SUCH DAMAGE.
25  *
26  * todo-list scheduler
27  * ===================
28  *
29  * This is a simple "TODO-list" scheduler for calling things at certain
30  * times.  Jobs can be one-shot or repeated and repeated jobs can abort.
31  *
32  * For ease of debugging, TODO jobs have a name.
33  */
34 
35 #include <stdarg.h>
36 #include <stdio.h>
37 #include <stdlib.h>
38 
39 #include "ntimed.h"
40 
41 struct todo {
42 	unsigned		magic;
43 #define TODO_MAGIC		0x5279009a
44 	TAILQ_ENTRY(todo)	list;
45 
46 	todo_f			*func;
47 	void			*priv;
48 	struct timestamp	when;
49 	double			repeat;
50 
51 	char			what[40];
52 };
53 
54 struct todolist {
55 	unsigned		magic;
56 #define TODOLIST_MAGIC		0x7db66255
57 	TAILQ_HEAD(,todo)	todolist;
58 };
59 
60 struct todolist *
TODO_NewList(void)61 TODO_NewList(void)
62 {
63 	struct todolist *tdl;
64 
65 	ALLOC_OBJ(tdl, TODOLIST_MAGIC);
66 	AN(tdl);
67 	TAILQ_INIT(&tdl->todolist);
68 	return (tdl);
69 }
70 
71 static void
todo_insert(struct todolist * tdl,struct todo * tp)72 todo_insert(struct todolist *tdl, struct todo *tp)
73 {
74 	struct todo *tp1;
75 
76 	TAILQ_FOREACH(tp1, &tdl->todolist, list) {
77 		if (TS_Diff(&tp1->when, &tp->when) > 0.0) {
78 			TAILQ_INSERT_BEFORE(tp1, tp, list);
79 			return;
80 		}
81 	}
82 	TAILQ_INSERT_TAIL(&tdl->todolist, tp, list);
83 }
84 
85 /**********************************************************************
86  */
87 
88 void
TODO_Cancel(struct todolist * tdl,uintptr_t * tp)89 TODO_Cancel(struct todolist *tdl, uintptr_t *tp)
90 {
91 	struct todo *tp2;
92 
93 	CHECK_OBJ_NOTNULL(tdl, TODOLIST_MAGIC);
94 	AN(tp);
95 	AN(*tp);
96 
97 	TAILQ_FOREACH(tp2, &tdl->todolist, list)
98 		if ((uintptr_t)tp2 == *tp)
99 			break;
100 	CHECK_OBJ_NOTNULL(tp2, TODO_MAGIC);
101 	TAILQ_REMOVE(&tdl->todolist, tp2, list);
102 	FREE_OBJ(tp2);
103 	*tp = 0;
104 }
105 
106 /**********************************************************************
107  */
108 
109 uintptr_t
TODO_ScheduleAbs(struct todolist * tdl,todo_f * func,void * priv,const struct timestamp * when,double repeat,const char * fmt,...)110 TODO_ScheduleAbs(struct todolist *tdl, todo_f *func, void *priv,
111     const struct timestamp *when, double repeat, const char *fmt, ...)
112 {
113 	struct todo *tp;
114 	va_list ap;
115 
116 	CHECK_OBJ_NOTNULL(tdl, TODOLIST_MAGIC);
117 	AN(func);
118 	CHECK_OBJ_NOTNULL(when, TIMESTAMP_MAGIC);
119 	assert(repeat >= 0.0);
120 	AN(fmt);
121 
122 	ALLOC_OBJ(tp, TODO_MAGIC);
123 	AN(tp);
124 	tp->func = func;
125 	tp->priv = priv;
126 	tp->when = *when;
127 	tp->repeat = repeat;
128 	va_start(ap, fmt);
129 	(void)vsnprintf(tp->what, sizeof tp->what, fmt, ap);
130 	va_end(ap);
131 	todo_insert(tdl, tp);
132 	return ((uintptr_t)tp);
133 }
134 
135 uintptr_t
TODO_ScheduleRel(struct todolist * tdl,todo_f * func,void * priv,double when,double repeat,const char * fmt,...)136 TODO_ScheduleRel(struct todolist *tdl, todo_f *func, void *priv,
137     double when, double repeat, const char *fmt, ...)
138 {
139 	struct todo *tp;
140 	va_list ap;
141 
142 	CHECK_OBJ_NOTNULL(tdl, TODOLIST_MAGIC);
143 	AN(func);
144 	assert(when >= 0.0);
145 	assert(repeat >= 0.0);
146 	AN(fmt);
147 
148 	ALLOC_OBJ(tp, TODO_MAGIC);
149 	AN(tp);
150 	tp->func = func;
151 	tp->priv = priv;
152 	TB_Now(&tp->when);
153 	TS_Add(&tp->when, when);
154 	tp->repeat = repeat;
155 	va_start(ap, fmt);
156 	(void)vsnprintf(tp->what, sizeof tp->what, fmt, ap);
157 	va_end(ap);
158 	todo_insert(tdl, tp);
159 	return ((uintptr_t)tp);
160 }
161 
162 /**********************************************************************
163  * Schedule TODO list until failure or empty
164  */
165 
166 enum todo_e
TODO_Run(struct ocx * ocx,struct todolist * tdl)167 TODO_Run(struct ocx *ocx, struct todolist *tdl)
168 {
169 	struct todo *tp;
170 	enum todo_e ret = TODO_OK;
171 	char buf[40];
172 	int i;
173 
174 	CHECK_OBJ_NOTNULL(tdl, TODOLIST_MAGIC);
175 	while(!TAILQ_EMPTY(&tdl->todolist)) {
176 		tp = TAILQ_FIRST(&tdl->todolist);
177 		i = TS_SleepUntil(&tp->when);
178 		if (i == 1)
179 			return (TODO_INTR);
180 		AZ(i);
181 		TS_Format(buf, sizeof buf, &tp->when);
182 		Put(ocx, OCX_TRACE, "Now %s %s\n", buf, tp->what);
183 		ret = tp->func(ocx, tdl, tp->priv);
184 		if (ret == TODO_FAIL)
185 			break;
186 		if (ret == TODO_DONE || tp->repeat == 0.0) {
187 			TAILQ_REMOVE(&tdl->todolist, tp, list);
188 			FREE_OBJ(tp);
189 		} else if (ret == TODO_OK) {
190 			TS_Add(&tp->when, tp->repeat);
191 			TAILQ_REMOVE(&tdl->todolist, tp, list);
192 			todo_insert(tdl, tp);
193 		} else {
194 			WRONG("Invalid Return from todo->func");
195 		}
196 	}
197 	return (ret);
198 }
199