Commit | Line | Data |
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c0a31329 TG |
1 | /* |
2 | * include/linux/hrtimer.h | |
3 | * | |
4 | * hrtimers - High-resolution kernel timers | |
5 | * | |
6 | * Copyright(C) 2005, Thomas Gleixner <tglx@linutronix.de> | |
7 | * Copyright(C) 2005, Red Hat, Inc., Ingo Molnar | |
8 | * | |
9 | * data type definitions, declarations, prototypes | |
10 | * | |
11 | * Started by: Thomas Gleixner and Ingo Molnar | |
12 | * | |
13 | * For licencing details see kernel-base/COPYING | |
14 | */ | |
15 | #ifndef _LINUX_HRTIMER_H | |
16 | #define _LINUX_HRTIMER_H | |
17 | ||
18 | #include <linux/rbtree.h> | |
19 | #include <linux/ktime.h> | |
20 | #include <linux/init.h> | |
21 | #include <linux/list.h> | |
22 | #include <linux/wait.h> | |
40b86062 | 23 | #include <linux/percpu.h> |
507e1231 | 24 | #include <linux/timer.h> |
40b86062 | 25 | |
c0a31329 | 26 | |
3c8aa39d TG |
27 | struct hrtimer_clock_base; |
28 | struct hrtimer_cpu_base; | |
29 | ||
c0a31329 TG |
30 | /* |
31 | * Mode arguments of xxx_hrtimer functions: | |
32 | */ | |
33 | enum hrtimer_mode { | |
597d0275 AB |
34 | HRTIMER_MODE_ABS = 0x0, /* Time value is absolute */ |
35 | HRTIMER_MODE_REL = 0x1, /* Time value is relative to now */ | |
36 | HRTIMER_MODE_PINNED = 0x02, /* Timer is bound to CPU */ | |
37 | HRTIMER_MODE_ABS_PINNED = 0x02, | |
38 | HRTIMER_MODE_REL_PINNED = 0x03, | |
c0a31329 TG |
39 | }; |
40 | ||
c9cb2e3d TG |
41 | /* |
42 | * Return values for the callback function | |
43 | */ | |
c0a31329 | 44 | enum hrtimer_restart { |
c9cb2e3d TG |
45 | HRTIMER_NORESTART, /* Timer is not restarted */ |
46 | HRTIMER_RESTART, /* Timer must be restarted */ | |
c0a31329 TG |
47 | }; |
48 | ||
54cdfdb4 TG |
49 | /* |
50 | * Values to track state of the timer | |
303e967f TG |
51 | * |
52 | * Possible states: | |
53 | * | |
54 | * 0x00 inactive | |
55 | * 0x01 enqueued into rbtree | |
56 | * 0x02 callback function running | |
54cdfdb4 | 57 | * |
b00c1a99 | 58 | * Special cases: |
303e967f TG |
59 | * 0x03 callback function running and enqueued |
60 | * (was requeued on another CPU) | |
b00c1a99 | 61 | * 0x09 timer was migrated on CPU hotunplug |
303e967f TG |
62 | * The "callback function running and enqueued" status is only possible on |
63 | * SMP. It happens for example when a posix timer expired and the callback | |
64 | * queued a signal. Between dropping the lock which protects the posix timer | |
65 | * and reacquiring the base lock of the hrtimer, another CPU can deliver the | |
66 | * signal and rearm the timer. We have to preserve the callback running state, | |
67 | * as otherwise the timer could be removed before the softirq code finishes the | |
68 | * the handling of the timer. | |
69 | * | |
3eb05676 | 70 | * The HRTIMER_STATE_ENQUEUED bit is always or'ed to the current state to |
303e967f TG |
71 | * preserve the HRTIMER_STATE_CALLBACK bit in the above scenario. |
72 | * | |
73 | * All state transitions are protected by cpu_base->lock. | |
74 | */ | |
75 | #define HRTIMER_STATE_INACTIVE 0x00 | |
76 | #define HRTIMER_STATE_ENQUEUED 0x01 | |
77 | #define HRTIMER_STATE_CALLBACK 0x02 | |
ca109491 | 78 | #define HRTIMER_STATE_MIGRATE 0x04 |
303e967f | 79 | |
c0a31329 TG |
80 | /** |
81 | * struct hrtimer - the basic hrtimer structure | |
c0a31329 | 82 | * @node: red black tree node for time ordered insertion |
592aa999 | 83 | * @_expires: the absolute expiry time in the hrtimers internal |
c0a31329 | 84 | * representation. The time is related to the clock on |
592aa999 TG |
85 | * which the timer is based. Is setup by adding |
86 | * slack to the _softexpires value. For non range timers | |
87 | * identical to _softexpires. | |
88 | * @_softexpires: the absolute earliest expiry time of the hrtimer. | |
89 | * The time which was given as expiry time when the timer | |
90 | * was armed. | |
c0a31329 | 91 | * @function: timer expiry callback function |
c0a31329 | 92 | * @base: pointer to the timer base (per cpu and per clock) |
303e967f | 93 | * @state: state information (See bit values above) |
54cdfdb4 TG |
94 | * @start_site: timer statistics field to store the site where the timer |
95 | * was started | |
96 | * @start_comm: timer statistics field to store the name of the process which | |
97 | * started the timer | |
98 | * @start_pid: timer statistics field to store the pid of the task which | |
99 | * started the timer | |
c0a31329 | 100 | * |
54cdfdb4 | 101 | * The hrtimer structure must be initialized by hrtimer_init() |
c0a31329 TG |
102 | */ |
103 | struct hrtimer { | |
3c8aa39d | 104 | struct rb_node node; |
799b64de | 105 | ktime_t _expires; |
654c8e0b | 106 | ktime_t _softexpires; |
3c8aa39d TG |
107 | enum hrtimer_restart (*function)(struct hrtimer *); |
108 | struct hrtimer_clock_base *base; | |
303e967f | 109 | unsigned long state; |
82f67cd9 | 110 | #ifdef CONFIG_TIMER_STATS |
1b024690 | 111 | int start_pid; |
82f67cd9 IM |
112 | void *start_site; |
113 | char start_comm[16]; | |
82f67cd9 | 114 | #endif |
c0a31329 TG |
115 | }; |
116 | ||
00362e33 TG |
117 | /** |
118 | * struct hrtimer_sleeper - simple sleeper structure | |
00362e33 TG |
119 | * @timer: embedded timer structure |
120 | * @task: task to wake up | |
121 | * | |
122 | * task is set to NULL, when the timer expires. | |
123 | */ | |
124 | struct hrtimer_sleeper { | |
125 | struct hrtimer timer; | |
126 | struct task_struct *task; | |
127 | }; | |
128 | ||
c0a31329 | 129 | /** |
d1d67174 | 130 | * struct hrtimer_clock_base - the timer base for a specific clock |
05fb6bf0 | 131 | * @cpu_base: per cpu clock base |
3c8aa39d TG |
132 | * @index: clock type index for per_cpu support when moving a |
133 | * timer to a base on another cpu. | |
92127c7a TG |
134 | * @active: red black tree root node for the active timers |
135 | * @first: pointer to the timer node which expires first | |
136 | * @resolution: the resolution of the clock, in nanoseconds | |
137 | * @get_time: function to retrieve the current time of the clock | |
92127c7a | 138 | * @softirq_time: the time when running the hrtimer queue in the softirq |
54cdfdb4 | 139 | * @offset: offset of this clock to the monotonic base |
c0a31329 | 140 | */ |
3c8aa39d TG |
141 | struct hrtimer_clock_base { |
142 | struct hrtimer_cpu_base *cpu_base; | |
c0a31329 | 143 | clockid_t index; |
c0a31329 | 144 | struct rb_root active; |
288867ec | 145 | struct rb_node *first; |
e2787630 | 146 | ktime_t resolution; |
c0a31329 | 147 | ktime_t (*get_time)(void); |
92127c7a | 148 | ktime_t softirq_time; |
54cdfdb4 TG |
149 | #ifdef CONFIG_HIGH_RES_TIMERS |
150 | ktime_t offset; | |
54cdfdb4 | 151 | #endif |
3c8aa39d TG |
152 | }; |
153 | ||
154 | #define HRTIMER_MAX_CLOCK_BASES 2 | |
155 | ||
156 | /* | |
157 | * struct hrtimer_cpu_base - the per cpu clock bases | |
158 | * @lock: lock protecting the base and associated clock bases | |
159 | * and timers | |
3c8aa39d TG |
160 | * @clock_base: array of clock bases for this cpu |
161 | * @curr_timer: the timer which is executing a callback right now | |
54cdfdb4 TG |
162 | * @expires_next: absolute time of the next event which was scheduled |
163 | * via clock_set_next_event() | |
164 | * @hres_active: State of high resolution mode | |
165 | * @check_clocks: Indictator, when set evaluate time source and clock | |
166 | * event devices whether high resolution mode can be | |
167 | * activated. | |
54cdfdb4 | 168 | * @nr_events: Total number of timer interrupt events |
3c8aa39d TG |
169 | */ |
170 | struct hrtimer_cpu_base { | |
171 | spinlock_t lock; | |
3c8aa39d | 172 | struct hrtimer_clock_base clock_base[HRTIMER_MAX_CLOCK_BASES]; |
54cdfdb4 TG |
173 | #ifdef CONFIG_HIGH_RES_TIMERS |
174 | ktime_t expires_next; | |
175 | int hres_active; | |
54cdfdb4 TG |
176 | unsigned long nr_events; |
177 | #endif | |
c0a31329 TG |
178 | }; |
179 | ||
63ca243b AV |
180 | static inline void hrtimer_set_expires(struct hrtimer *timer, ktime_t time) |
181 | { | |
799b64de | 182 | timer->_expires = time; |
654c8e0b | 183 | timer->_softexpires = time; |
63ca243b | 184 | } |
654c8e0b AV |
185 | |
186 | static inline void hrtimer_set_expires_range(struct hrtimer *timer, ktime_t time, ktime_t delta) | |
187 | { | |
188 | timer->_softexpires = time; | |
189 | timer->_expires = ktime_add_safe(time, delta); | |
190 | } | |
191 | ||
192 | static inline void hrtimer_set_expires_range_ns(struct hrtimer *timer, ktime_t time, unsigned long delta) | |
193 | { | |
194 | timer->_softexpires = time; | |
195 | timer->_expires = ktime_add_safe(time, ns_to_ktime(delta)); | |
196 | } | |
197 | ||
63ca243b AV |
198 | static inline void hrtimer_set_expires_tv64(struct hrtimer *timer, s64 tv64) |
199 | { | |
799b64de | 200 | timer->_expires.tv64 = tv64; |
654c8e0b | 201 | timer->_softexpires.tv64 = tv64; |
63ca243b AV |
202 | } |
203 | ||
204 | static inline void hrtimer_add_expires(struct hrtimer *timer, ktime_t time) | |
205 | { | |
799b64de | 206 | timer->_expires = ktime_add_safe(timer->_expires, time); |
654c8e0b | 207 | timer->_softexpires = ktime_add_safe(timer->_softexpires, time); |
63ca243b AV |
208 | } |
209 | ||
7597bc94 | 210 | static inline void hrtimer_add_expires_ns(struct hrtimer *timer, u64 ns) |
63ca243b | 211 | { |
799b64de | 212 | timer->_expires = ktime_add_ns(timer->_expires, ns); |
654c8e0b | 213 | timer->_softexpires = ktime_add_ns(timer->_softexpires, ns); |
63ca243b AV |
214 | } |
215 | ||
216 | static inline ktime_t hrtimer_get_expires(const struct hrtimer *timer) | |
217 | { | |
799b64de | 218 | return timer->_expires; |
63ca243b AV |
219 | } |
220 | ||
654c8e0b AV |
221 | static inline ktime_t hrtimer_get_softexpires(const struct hrtimer *timer) |
222 | { | |
223 | return timer->_softexpires; | |
224 | } | |
225 | ||
63ca243b AV |
226 | static inline s64 hrtimer_get_expires_tv64(const struct hrtimer *timer) |
227 | { | |
799b64de | 228 | return timer->_expires.tv64; |
63ca243b | 229 | } |
654c8e0b AV |
230 | static inline s64 hrtimer_get_softexpires_tv64(const struct hrtimer *timer) |
231 | { | |
232 | return timer->_softexpires.tv64; | |
233 | } | |
63ca243b AV |
234 | |
235 | static inline s64 hrtimer_get_expires_ns(const struct hrtimer *timer) | |
236 | { | |
799b64de | 237 | return ktime_to_ns(timer->_expires); |
63ca243b AV |
238 | } |
239 | ||
240 | static inline ktime_t hrtimer_expires_remaining(const struct hrtimer *timer) | |
241 | { | |
799b64de | 242 | return ktime_sub(timer->_expires, timer->base->get_time()); |
63ca243b AV |
243 | } |
244 | ||
54cdfdb4 TG |
245 | #ifdef CONFIG_HIGH_RES_TIMERS |
246 | struct clock_event_device; | |
247 | ||
248 | extern void clock_was_set(void); | |
995f054f | 249 | extern void hres_timers_resume(void); |
54cdfdb4 TG |
250 | extern void hrtimer_interrupt(struct clock_event_device *dev); |
251 | ||
252 | /* | |
253 | * In high resolution mode the time reference must be read accurate | |
254 | */ | |
255 | static inline ktime_t hrtimer_cb_get_time(struct hrtimer *timer) | |
256 | { | |
257 | return timer->base->get_time(); | |
258 | } | |
259 | ||
8f4d37ec PZ |
260 | static inline int hrtimer_is_hres_active(struct hrtimer *timer) |
261 | { | |
262 | return timer->base->cpu_base->hres_active; | |
263 | } | |
264 | ||
2075eb8d AV |
265 | extern void hrtimer_peek_ahead_timers(void); |
266 | ||
54cdfdb4 TG |
267 | /* |
268 | * The resolution of the clocks. The resolution value is returned in | |
269 | * the clock_getres() system call to give application programmers an | |
270 | * idea of the (in)accuracy of timers. Timer values are rounded up to | |
271 | * this resolution values. | |
272 | */ | |
151db1fc TB |
273 | # define HIGH_RES_NSEC 1 |
274 | # define KTIME_HIGH_RES (ktime_t) { .tv64 = HIGH_RES_NSEC } | |
275 | # define MONOTONIC_RES_NSEC HIGH_RES_NSEC | |
54cdfdb4 TG |
276 | # define KTIME_MONOTONIC_RES KTIME_HIGH_RES |
277 | ||
278 | #else | |
279 | ||
151db1fc | 280 | # define MONOTONIC_RES_NSEC LOW_RES_NSEC |
54cdfdb4 TG |
281 | # define KTIME_MONOTONIC_RES KTIME_LOW_RES |
282 | ||
becf8b5d TG |
283 | /* |
284 | * clock_was_set() is a NOP for non- high-resolution systems. The | |
285 | * time-sorted order guarantees that a timer does not expire early and | |
286 | * is expired in the next softirq when the clock was advanced. | |
287 | */ | |
54cdfdb4 | 288 | static inline void clock_was_set(void) { } |
2075eb8d | 289 | static inline void hrtimer_peek_ahead_timers(void) { } |
54cdfdb4 | 290 | |
995f054f IM |
291 | static inline void hres_timers_resume(void) { } |
292 | ||
54cdfdb4 TG |
293 | /* |
294 | * In non high resolution mode the time reference is taken from | |
295 | * the base softirq time variable. | |
296 | */ | |
297 | static inline ktime_t hrtimer_cb_get_time(struct hrtimer *timer) | |
298 | { | |
299 | return timer->base->softirq_time; | |
300 | } | |
301 | ||
8f4d37ec PZ |
302 | static inline int hrtimer_is_hres_active(struct hrtimer *timer) |
303 | { | |
304 | return 0; | |
305 | } | |
54cdfdb4 TG |
306 | #endif |
307 | ||
d316c57f TG |
308 | extern ktime_t ktime_get(void); |
309 | extern ktime_t ktime_get_real(void); | |
becf8b5d | 310 | |
2e94d1f7 AV |
311 | |
312 | DECLARE_PER_CPU(struct tick_device, tick_cpu_device); | |
2e94d1f7 AV |
313 | |
314 | ||
c0a31329 TG |
315 | /* Exported timer functions: */ |
316 | ||
317 | /* Initialize timers: */ | |
7978672c GA |
318 | extern void hrtimer_init(struct hrtimer *timer, clockid_t which_clock, |
319 | enum hrtimer_mode mode); | |
c0a31329 | 320 | |
237fc6e7 TG |
321 | #ifdef CONFIG_DEBUG_OBJECTS_TIMERS |
322 | extern void hrtimer_init_on_stack(struct hrtimer *timer, clockid_t which_clock, | |
323 | enum hrtimer_mode mode); | |
324 | ||
325 | extern void destroy_hrtimer_on_stack(struct hrtimer *timer); | |
326 | #else | |
327 | static inline void hrtimer_init_on_stack(struct hrtimer *timer, | |
328 | clockid_t which_clock, | |
329 | enum hrtimer_mode mode) | |
330 | { | |
331 | hrtimer_init(timer, which_clock, mode); | |
332 | } | |
333 | static inline void destroy_hrtimer_on_stack(struct hrtimer *timer) { } | |
334 | #endif | |
335 | ||
c0a31329 TG |
336 | /* Basic timer operations: */ |
337 | extern int hrtimer_start(struct hrtimer *timer, ktime_t tim, | |
338 | const enum hrtimer_mode mode); | |
da8f2e17 AV |
339 | extern int hrtimer_start_range_ns(struct hrtimer *timer, ktime_t tim, |
340 | unsigned long range_ns, const enum hrtimer_mode mode); | |
7f1e2ca9 PZ |
341 | extern int |
342 | __hrtimer_start_range_ns(struct hrtimer *timer, ktime_t tim, | |
343 | unsigned long delta_ns, | |
344 | const enum hrtimer_mode mode, int wakeup); | |
345 | ||
c0a31329 TG |
346 | extern int hrtimer_cancel(struct hrtimer *timer); |
347 | extern int hrtimer_try_to_cancel(struct hrtimer *timer); | |
348 | ||
63ca243b AV |
349 | static inline int hrtimer_start_expires(struct hrtimer *timer, |
350 | enum hrtimer_mode mode) | |
351 | { | |
da8f2e17 AV |
352 | unsigned long delta; |
353 | ktime_t soft, hard; | |
354 | soft = hrtimer_get_softexpires(timer); | |
355 | hard = hrtimer_get_expires(timer); | |
356 | delta = ktime_to_ns(ktime_sub(hard, soft)); | |
4ce105d3 | 357 | return hrtimer_start_range_ns(timer, soft, delta, mode); |
63ca243b AV |
358 | } |
359 | ||
c9cb2e3d TG |
360 | static inline int hrtimer_restart(struct hrtimer *timer) |
361 | { | |
654c8e0b | 362 | return hrtimer_start_expires(timer, HRTIMER_MODE_ABS); |
c9cb2e3d | 363 | } |
c0a31329 TG |
364 | |
365 | /* Query timers: */ | |
366 | extern ktime_t hrtimer_get_remaining(const struct hrtimer *timer); | |
367 | extern int hrtimer_get_res(const clockid_t which_clock, struct timespec *tp); | |
368 | ||
69239749 | 369 | extern ktime_t hrtimer_get_next_event(void); |
69239749 | 370 | |
303e967f TG |
371 | /* |
372 | * A timer is active, when it is enqueued into the rbtree or the callback | |
373 | * function is running. | |
374 | */ | |
c0a31329 TG |
375 | static inline int hrtimer_active(const struct hrtimer *timer) |
376 | { | |
303e967f | 377 | return timer->state != HRTIMER_STATE_INACTIVE; |
c0a31329 TG |
378 | } |
379 | ||
54cdfdb4 TG |
380 | /* |
381 | * Helper function to check, whether the timer is on one of the queues | |
382 | */ | |
383 | static inline int hrtimer_is_queued(struct hrtimer *timer) | |
384 | { | |
ca109491 | 385 | return timer->state & HRTIMER_STATE_ENQUEUED; |
54cdfdb4 TG |
386 | } |
387 | ||
4346f654 OH |
388 | /* |
389 | * Helper function to check, whether the timer is running the callback | |
390 | * function | |
391 | */ | |
392 | static inline int hrtimer_callback_running(struct hrtimer *timer) | |
393 | { | |
394 | return timer->state & HRTIMER_STATE_CALLBACK; | |
395 | } | |
396 | ||
c0a31329 | 397 | /* Forward a hrtimer so it expires after now: */ |
4d672e7a | 398 | extern u64 |
44f21475 | 399 | hrtimer_forward(struct hrtimer *timer, ktime_t now, ktime_t interval); |
c0a31329 | 400 | |
5e05ad7d | 401 | /* Forward a hrtimer so it expires after the hrtimer's current now */ |
4d672e7a DL |
402 | static inline u64 hrtimer_forward_now(struct hrtimer *timer, |
403 | ktime_t interval) | |
5e05ad7d DL |
404 | { |
405 | return hrtimer_forward(timer, timer->base->get_time(), interval); | |
406 | } | |
407 | ||
10c94ec1 TG |
408 | /* Precise sleep: */ |
409 | extern long hrtimer_nanosleep(struct timespec *rqtp, | |
080344b9 | 410 | struct timespec __user *rmtp, |
10c94ec1 TG |
411 | const enum hrtimer_mode mode, |
412 | const clockid_t clockid); | |
1711ef38 | 413 | extern long hrtimer_nanosleep_restart(struct restart_block *restart_block); |
10c94ec1 | 414 | |
00362e33 TG |
415 | extern void hrtimer_init_sleeper(struct hrtimer_sleeper *sl, |
416 | struct task_struct *tsk); | |
417 | ||
654c8e0b AV |
418 | extern int schedule_hrtimeout_range(ktime_t *expires, unsigned long delta, |
419 | const enum hrtimer_mode mode); | |
7bb67439 AV |
420 | extern int schedule_hrtimeout(ktime_t *expires, const enum hrtimer_mode mode); |
421 | ||
c0a31329 TG |
422 | /* Soft interrupt function to run the hrtimer queues: */ |
423 | extern void hrtimer_run_queues(void); | |
d3d74453 | 424 | extern void hrtimer_run_pending(void); |
c0a31329 TG |
425 | |
426 | /* Bootup initialization: */ | |
427 | extern void __init hrtimers_init(void); | |
428 | ||
79bf2bb3 | 429 | #if BITS_PER_LONG < 64 |
4d672e7a | 430 | extern u64 ktime_divns(const ktime_t kt, s64 div); |
79bf2bb3 | 431 | #else /* BITS_PER_LONG < 64 */ |
4d672e7a | 432 | # define ktime_divns(kt, div) (u64)((kt).tv64 / (div)) |
79bf2bb3 TG |
433 | #endif |
434 | ||
88ad0bf6 IM |
435 | /* Show pending timers: */ |
436 | extern void sysrq_timer_list_show(void); | |
437 | ||
82f67cd9 IM |
438 | /* |
439 | * Timer-statistics info: | |
440 | */ | |
441 | #ifdef CONFIG_TIMER_STATS | |
442 | ||
443 | extern void timer_stats_update_stats(void *timer, pid_t pid, void *startf, | |
c5c061b8 VP |
444 | void *timerf, char *comm, |
445 | unsigned int timer_flag); | |
82f67cd9 IM |
446 | |
447 | static inline void timer_stats_account_hrtimer(struct hrtimer *timer) | |
448 | { | |
8629ea2e | 449 | if (likely(!timer_stats_active)) |
507e1231 | 450 | return; |
82f67cd9 | 451 | timer_stats_update_stats(timer, timer->start_pid, timer->start_site, |
c5c061b8 | 452 | timer->function, timer->start_comm, 0); |
82f67cd9 IM |
453 | } |
454 | ||
455 | extern void __timer_stats_hrtimer_set_start_info(struct hrtimer *timer, | |
456 | void *addr); | |
457 | ||
458 | static inline void timer_stats_hrtimer_set_start_info(struct hrtimer *timer) | |
459 | { | |
460 | __timer_stats_hrtimer_set_start_info(timer, __builtin_return_address(0)); | |
461 | } | |
462 | ||
463 | static inline void timer_stats_hrtimer_clear_start_info(struct hrtimer *timer) | |
464 | { | |
465 | timer->start_site = NULL; | |
466 | } | |
467 | #else | |
468 | static inline void timer_stats_account_hrtimer(struct hrtimer *timer) | |
469 | { | |
470 | } | |
471 | ||
472 | static inline void timer_stats_hrtimer_set_start_info(struct hrtimer *timer) | |
473 | { | |
474 | } | |
475 | ||
476 | static inline void timer_stats_hrtimer_clear_start_info(struct hrtimer *timer) | |
477 | { | |
478 | } | |
479 | #endif | |
480 | ||
c0a31329 | 481 | #endif |