xref: /xnu-11215/bsd/net/devtimer.c (revision a3bb9fcc)
1 /*
2  * Copyright (c) 2004,2007-2008 Apple Inc. All rights reserved.
3  *
4  * @APPLE_OSREFERENCE_LICENSE_HEADER_START@
5  *
6  * This file contains Original Code and/or Modifications of Original Code
7  * as defined in and that are subject to the Apple Public Source License
8  * Version 2.0 (the 'License'). You may not use this file except in
9  * compliance with the License. The rights granted to you under the License
10  * may not be used to create, or enable the creation or redistribution of,
11  * unlawful or unlicensed copies of an Apple operating system, or to
12  * circumvent, violate, or enable the circumvention or violation of, any
13  * terms of an Apple operating system software license agreement.
14  *
15  * Please obtain a copy of the License at
16  * http://www.opensource.apple.com/apsl/ and read it before using this file.
17  *
18  * The Original Code and all software distributed under the License are
19  * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
20  * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
21  * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
22  * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
23  * Please see the License for the specific language governing rights and
24  * limitations under the License.
25  *
26  * @APPLE_OSREFERENCE_LICENSE_HEADER_END@
27  */
28 
29 /*
30  * devtimer.c
31  * - timer source based on <kern/thread_call.h>
32  */
33 
34 /*
35  * Modification History:
36  *
37  * June 22, 2004	Dieter Siegmund ([email protected])
38  * - created
39  */
40 #include <sys/param.h>
41 #include <sys/kernel.h>
42 #include <sys/malloc.h>
43 #include <kern/thread_call.h>
44 #include <net/devtimer.h>
45 #include <libkern/OSAtomic.h>
46 
47 #ifdef DEVTIMER_DEBUG
48 #define _devtimer_printf	printf
49 #else /* !DEVTIMER_DEBUG */
50 static __inline__ void
51 _devtimer_printf(__unused const char * fmt, ...)
52 {
53 }
54 #endif /* !DEVTIMER_DEBUG */
55 
56 struct devtimer_s {
57     void *			dt_callout;
58     devtimer_timeout_func	dt_timeout_func;
59     devtimer_process_func	dt_process_func;
60     void *			dt_arg0;
61     void *			dt_arg1;
62     void *			dt_arg2;
63     int				dt_generation;
64     UInt32			dt_retain_count;
65 };
66 
67 #define M_DEVTIMER	M_DEVBUF
68 
69 static __inline__ void
70 timeval_add(struct timeval tv1, struct timeval tv2,
71 	    struct timeval * result)
72 {
73     result->tv_sec = tv1.tv_sec + tv2.tv_sec;
74     result->tv_usec = tv1.tv_usec + tv2.tv_usec;
75     if (result->tv_usec > DEVTIMER_USECS_PER_SEC) {
76 	result->tv_usec -= DEVTIMER_USECS_PER_SEC;
77 	result->tv_sec++;
78     }
79     return;
80 }
81 
82 static __inline__ uint64_t
83 timeval_to_absolutetime(struct timeval tv)
84 {
85     uint64_t	secs;
86     uint64_t	usecs;
87 
88     clock_interval_to_absolutetime_interval(tv.tv_sec, NSEC_PER_SEC,
89 					    &secs);
90     clock_interval_to_absolutetime_interval(tv.tv_usec, NSEC_PER_USEC,
91 					    &usecs);
92     return (secs + usecs);
93 }
94 
95 
96 __private_extern__ int
97 devtimer_valid(devtimer_ref timer)
98 {
99     return (timer->dt_callout != NULL);
100 }
101 
102 __private_extern__ void
103 devtimer_retain(devtimer_ref timer)
104 {
105     OSIncrementAtomic(&timer->dt_retain_count);
106     return;
107 }
108 
109 __private_extern__ void
110 devtimer_invalidate(devtimer_ref timer)
111 {
112     devtimer_cancel(timer);
113     timer->dt_arg0 = NULL;
114     if (timer->dt_callout != NULL) {
115 	thread_call_free(timer->dt_callout);
116 	timer->dt_callout = NULL;
117     }
118     return;
119 }
120 
121 __private_extern__ void
122 devtimer_release(devtimer_ref timer)
123 {
124     UInt32	old_retain_count;
125 
126     old_retain_count = OSDecrementAtomic(&timer->dt_retain_count);
127     switch (old_retain_count) {
128     case 0:
129 	panic("devtimer_release: retain count is 0\n");
130 	break;
131     case 1:
132 	devtimer_invalidate(timer);
133 	FREE(timer, M_DEVTIMER);
134 	_devtimer_printf("devtimer: timer released\n");
135 	break;
136     default:
137 	break;
138     }
139     return;
140 }
141 
142 static void
143 devtimer_process(void * param0, void * param1)
144 {
145     int				generation = *(int*)param1;
146     devtimer_process_func 	process_func;
147     devtimer_timeout_func 	timeout_func;
148     devtimer_ref		timer = (devtimer_ref)param0;
149 
150     process_func = timer->dt_process_func;
151     if (process_func != NULL) {
152 	(*process_func)(timer, devtimer_process_func_event_lock);
153     }
154     timeout_func = timer->dt_timeout_func;
155     if (timeout_func != NULL) {
156 	timer->dt_timeout_func = NULL;
157 	if (timer->dt_generation == generation) {
158 	    (*timeout_func)(timer->dt_arg0, timer->dt_arg1, timer->dt_arg2);
159 	}
160     }
161     devtimer_release(timer);
162     if (process_func != NULL) {
163 	(*process_func)(timer, devtimer_process_func_event_unlock);
164     }
165     return;
166 }
167 
168 __private_extern__ void *
169 devtimer_arg0(devtimer_ref timer)
170 {
171     return (timer->dt_arg0);
172 }
173 
174 __private_extern__ devtimer_ref
175 devtimer_create(devtimer_process_func process_func, void * arg0)
176 {
177     devtimer_ref	timer;
178 
179     timer = _MALLOC(sizeof(*timer), M_DEVTIMER, M_WAITOK);
180     if (timer == NULL) {
181 	return (timer);
182     }
183     bzero(timer, sizeof(*timer));
184     devtimer_retain(timer);
185     timer->dt_callout = thread_call_allocate(devtimer_process, timer);
186     if (timer->dt_callout == NULL) {
187 	_devtimer_printf("devtimer: thread_call_allocate failed\n");
188 	devtimer_release(timer);
189 	timer = NULL;
190     }
191     timer->dt_process_func = process_func;
192     timer->dt_arg0 = arg0;
193     return (timer);
194 }
195 
196 __private_extern__ void
197 devtimer_set_absolute(devtimer_ref timer,
198 		      struct timeval abs_time,
199 		      devtimer_timeout_func timeout_func,
200 		      void * arg1, void * arg2)
201 {
202     if (timer->dt_callout == NULL) {
203 	printf("devtimer_set_absolute: uninitialized/freed timer\n");
204 	return;
205     }
206     devtimer_cancel(timer);
207     if (timeout_func == NULL) {
208 	return;
209     }
210     timer->dt_timeout_func = timeout_func;
211     timer->dt_arg1 = arg1;
212     timer->dt_arg2 = arg2;
213     _devtimer_printf("devtimer: wakeup time is (%d.%d)\n",
214 		     abs_time.tv_sec, abs_time.tv_usec);
215     timer->dt_generation++;
216     devtimer_retain(timer);
217     thread_call_enter1_delayed(timer->dt_callout,
218 			       &timer->dt_generation,
219 			       timeval_to_absolutetime(abs_time));
220     return;
221 }
222 
223 __private_extern__ void
224 devtimer_set_relative(devtimer_ref timer,
225 		      struct timeval rel_time,
226 		      devtimer_timeout_func timeout_func,
227 		      void * arg1, void * arg2)
228 {
229     struct timeval		abs_time;
230     struct timeval		current_time;
231 
232     current_time = devtimer_current_time();
233     timeval_add(current_time, rel_time, &abs_time);
234     devtimer_set_absolute(timer, abs_time, timeout_func, arg1, arg2);
235     return;
236 }
237 
238 __private_extern__ void
239 devtimer_cancel(devtimer_ref timer)
240 {
241     if (timer->dt_timeout_func != NULL) {
242 	timer->dt_timeout_func = NULL;
243 	if (timer->dt_callout != NULL) {
244 	    _devtimer_printf("devtimer: cancelling timer source\n");
245 	    if (thread_call_cancel(timer->dt_callout)) {
246 		devtimer_release(timer);
247 	    }
248 	    else {
249 		_devtimer_printf("devtimer: delayed release\n");
250 	    }
251 	}
252     }
253     return;
254 }
255 
256 __private_extern__ int
257 devtimer_enabled(devtimer_ref timer)
258 {
259     return (timer->dt_timeout_func != NULL);
260 }
261 
262 __private_extern__ int32_t
263 devtimer_current_secs(void)
264 {
265     struct timeval	tv;
266 
267     tv = devtimer_current_time();
268     return (tv.tv_sec);
269 }
270 
271 __private_extern__ struct timeval
272 devtimer_current_time(void)
273 {
274     struct timeval 	tv;
275     clock_sec_t sec;
276     clock_usec_t usec;
277 
278     clock_get_system_microtime(&sec, &usec);
279     tv.tv_sec = sec;
280     tv.tv_usec = usec;
281     return (tv);
282 }
283