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source: vbox/trunk/include/iprt/timer.h@ 76585

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1/** @file
2 * IPRT - Timer.
3 */
4
5/*
6 * Copyright (C) 2006-2019 Oracle Corporation
7 *
8 * This file is part of VirtualBox Open Source Edition (OSE), as
9 * available from http://www.virtualbox.org. This file is free software;
10 * you can redistribute it and/or modify it under the terms of the GNU
11 * General Public License (GPL) as published by the Free Software
12 * Foundation, in version 2 as it comes in the "COPYING" file of the
13 * VirtualBox OSE distribution. VirtualBox OSE is distributed in the
14 * hope that it will be useful, but WITHOUT ANY WARRANTY of any kind.
15 *
16 * The contents of this file may alternatively be used under the terms
17 * of the Common Development and Distribution License Version 1.0
18 * (CDDL) only, as it comes in the "COPYING.CDDL" file of the
19 * VirtualBox OSE distribution, in which case the provisions of the
20 * CDDL are applicable instead of those of the GPL.
21 *
22 * You may elect to license modified versions of this file under the
23 * terms and conditions of either the GPL or the CDDL or both.
24 */
25
26#ifndef IPRT_INCLUDED_timer_h
27#define IPRT_INCLUDED_timer_h
28#ifndef RT_WITHOUT_PRAGMA_ONCE
29# pragma once
30#endif
31
32
33#include <iprt/cdefs.h>
34#include <iprt/types.h>
35
36
37RT_C_DECLS_BEGIN
38
39/** @defgroup grp_rt_timer RTTimer - Timer
40 *
41 * The IPRT timer API provides a simple abstraction of recurring and one-shot callback timers.
42 *
43 * Because of the great variation in the native APIs and the quality of
44 * the service delivered by those native APIs, the timers are operated
45 * on at best effort basis.
46 *
47 * All the ring-3 implementations are naturally at the mercy of the scheduler,
48 * which means that the callback rate might vary quite a bit and we might skip
49 * ticks. Many systems have a restriction that a process can only have one
50 * timer. IPRT currently makes no efforts at multiplexing timers in those kind
51 * of situations and will simply fail if you try to create more than one timer.
52 *
53 * Things are generally better in ring-0. The implementations will use interrupt
54 * time callbacks wherever available, and if not, resort to a high priority
55 * kernel thread.
56 *
57 * @ingroup grp_rt
58 * @{
59 */
60
61
62/** Timer handle. */
63typedef struct RTTIMER *PRTTIMER;
64
65/**
66 * Timer callback function.
67 *
68 * The context this call is made in varies with different platforms and
69 * kernel / user mode IPRT.
70 *
71 * In kernel mode a timer callback should not waste time, it shouldn't
72 * waste stack and it should be prepared that some APIs might not work
73 * correctly because of weird OS restrictions in this context that we
74 * haven't discovered and avoided yet. Please fix those APIs so they
75 * at least avoid panics and weird behaviour.
76 *
77 * @param pTimer Timer handle.
78 * @param pvUser User argument.
79 * @param iTick The current timer tick. This is always 1 on the first
80 * callback after the timer was started. For omni timers
81 * this will be 1 when a cpu comes back online.
82 */
83typedef DECLCALLBACK(void) FNRTTIMER(PRTTIMER pTimer, void *pvUser, uint64_t iTick);
84/** Pointer to FNRTTIMER() function. */
85typedef FNRTTIMER *PFNRTTIMER;
86
87
88/**
89 * Create a recurring timer.
90 *
91 * @returns iprt status code.
92 * @param ppTimer Where to store the timer handle.
93 * @param uMilliesInterval Milliseconds between the timer ticks.
94 * This is rounded up to the system granularity.
95 * @param pfnTimer Callback function which shall be scheduled for execution
96 * on every timer tick.
97 * @param pvUser User argument for the callback.
98 * @see RTTimerCreateEx, RTTimerStart, RTTimerStop, RTTimerChangeInterval,
99 * RTTimerDestroy, RTTimerGetSystemGranularity
100 */
101RTDECL(int) RTTimerCreate(PRTTIMER *ppTimer, unsigned uMilliesInterval, PFNRTTIMER pfnTimer, void *pvUser);
102
103/**
104 * Create a suspended timer.
105 *
106 * @returns iprt status code.
107 * @retval VERR_NOT_SUPPORTED if an unsupported flag was specfied.
108 * @retval VERR_CPU_NOT_FOUND if the specified CPU
109 *
110 * @param ppTimer Where to store the timer handle.
111 * @param u64NanoInterval The interval between timer ticks specified in nanoseconds if it's
112 * a recurring timer. This is rounded to the fit the system timer granularity.
113 * For one shot timers, pass 0.
114 * @param fFlags Timer flags.
115 * @param pfnTimer Callback function which shall be scheduled for execution
116 * on every timer tick.
117 * @param pvUser User argument for the callback.
118 * @see RTTimerStart, RTTimerStop, RTTimerChangeInterval, RTTimerDestroy,
119 * RTTimerGetSystemGranularity, RTTimerCanDoHighResolution
120 */
121RTDECL(int) RTTimerCreateEx(PRTTIMER *ppTimer, uint64_t u64NanoInterval, uint32_t fFlags, PFNRTTIMER pfnTimer, void *pvUser);
122
123/** @name RTTimerCreateEx flags
124 * @{ */
125/** Any CPU is fine. (Must be 0.) */
126#define RTTIMER_FLAGS_CPU_ANY UINT32_C(0)
127/** One specific CPU */
128#define RTTIMER_FLAGS_CPU_SPECIFIC RT_BIT(16)
129/** Omni timer, run on all online CPUs.
130 * @remarks The timer callback isn't necessarily running at the time same time on each CPU. */
131#define RTTIMER_FLAGS_CPU_ALL ( RTTIMER_FLAGS_CPU_MASK | RTTIMER_FLAGS_CPU_SPECIFIC )
132/** CPU mask. */
133#define RTTIMER_FLAGS_CPU_MASK UINT32_C(0xffff)
134/** Desire a high resolution timer that works with RTTimerChangeInterval and
135 * isn't subject to RTTimerGetSystemGranularity rounding.
136 * @remarks This is quietly ignored if the feature isn't supported. */
137#define RTTIMER_FLAGS_HIGH_RES RT_BIT(17)
138/** Convert a CPU set index (0-based) to RTTimerCreateEx flags.
139 * This will automatically OR in the RTTIMER_FLAGS_CPU_SPECIFIC flag. */
140#define RTTIMER_FLAGS_CPU(iCpu) ( (iCpu) | RTTIMER_FLAGS_CPU_SPECIFIC )
141/** Macro that validates the flags. */
142#define RTTIMER_FLAGS_ARE_VALID(fFlags) \
143 ( !((fFlags) & ~((fFlags) & RTTIMER_FLAGS_CPU_SPECIFIC ? UINT32_C(0x3ffff) : UINT32_C(0x30000))) )
144/** @} */
145
146/**
147 * Stops and destroys a running timer.
148 *
149 * @returns iprt status code.
150 * @retval VERR_INVALID_CONTEXT if executing at the wrong IRQL (windows), PIL
151 * (solaris), or similar. Portable code does not destroy timers with
152 * preemption (or interrupts) disabled.
153 * @param pTimer Timer to stop and destroy. NULL is ok.
154 */
155RTDECL(int) RTTimerDestroy(PRTTIMER pTimer);
156
157/**
158 * Starts a suspended timer.
159 *
160 * @returns IPRT status code.
161 * @retval VERR_INVALID_HANDLE if pTimer isn't valid.
162 * @retval VERR_TIMER_ACTIVE if the timer isn't suspended.
163 * @retval VERR_CPU_OFFLINE if the CPU the timer was created to run on is not
164 * online (this include the case where it's not present in the
165 * system).
166 *
167 * @param pTimer The timer to activate.
168 * @param u64First The RTTimeSystemNanoTS() for when the timer should start
169 * firing (relative). If 0 is specified, the timer will
170 * fire ASAP.
171 * @remarks When RTTimerCanDoHighResolution returns true, this API is
172 * callable with preemption disabled in ring-0.
173 * @see RTTimerStop
174 */
175RTDECL(int) RTTimerStart(PRTTIMER pTimer, uint64_t u64First);
176
177/**
178 * Stops an active timer.
179 *
180 * @todo May return while the timer callback function is being services on
181 * some platforms (ring-0 Windows, ring-0 linux). This needs to be
182 * addressed at some point...
183 *
184 * @returns IPRT status code.
185 * @retval VERR_INVALID_HANDLE if pTimer isn't valid.
186 * @retval VERR_TIMER_SUSPENDED if the timer isn't active.
187 * @retval VERR_NOT_SUPPORTED if the IPRT implementation doesn't support
188 * stopping a timer.
189 *
190 * @param pTimer The timer to suspend.
191 * @remarks Can be called from the timer callback function to stop it.
192 * @see RTTimerStart
193 */
194RTDECL(int) RTTimerStop(PRTTIMER pTimer);
195
196/**
197 * Changes the interval of a periodic timer.
198 *
199 * If the timer is active, it is implementation dependent whether the change
200 * takes place immediately or after the next tick. To get defined behavior,
201 * stop the timer before calling this API.
202 *
203 * @returns IPRT status code.
204 * @retval VERR_INVALID_HANDLE if pTimer isn't valid.
205 * @retval VERR_NOT_SUPPORTED if not supported.
206 * @retval VERR_INVALID_STATE if not a periodic timer.
207 *
208 * @param pTimer The timer to activate.
209 * @param u64NanoInterval The interval between timer ticks specified in
210 * nanoseconds. This is rounded to the fit the
211 * system timer granularity.
212 * @remarks Callable from the timer callback. Callable with preemption
213 * disabled in ring-0.
214 */
215RTDECL(int) RTTimerChangeInterval(PRTTIMER pTimer, uint64_t u64NanoInterval);
216
217/**
218 * Gets the (current) timer granularity of the system.
219 *
220 * @returns The timer granularity of the system in nanoseconds.
221 * @see RTTimerRequestSystemGranularity
222 */
223RTDECL(uint32_t) RTTimerGetSystemGranularity(void);
224
225/**
226 * Requests a specific system timer granularity.
227 *
228 * Successfull calls to this API must be coupled with the exact same number of
229 * calls to RTTimerReleaseSystemGranularity() in order to undo any changes made.
230 *
231 *
232 * @returns IPRT status code.
233 * @retval VERR_NOT_SUPPORTED if the requested value isn't supported by the host platform
234 * or if the host platform doesn't support modifying the system timer granularity.
235 * @retval VERR_PERMISSION_DENIED if the caller doesn't have the necessary privilege to
236 * modify the system timer granularity.
237 *
238 * @param u32Request The requested system timer granularity in nanoseconds.
239 * @param pu32Granted Where to store the granted system granularity. This is the value
240 * that should be passed to RTTimerReleaseSystemGranularity(). It
241 * is what RTTimerGetSystemGranularity() would return immediately
242 * after the change was made.
243 *
244 * The value differ from the request in two ways; rounding and
245 * scale. Meaning if your request is for 10.000.000 you might
246 * be granted 10.000.055 or 1.000.000.
247 * @see RTTimerReleaseSystemGranularity, RTTimerGetSystemGranularity
248 */
249RTDECL(int) RTTimerRequestSystemGranularity(uint32_t u32Request, uint32_t *pu32Granted);
250
251/**
252 * Releases a system timer granularity grant acquired by RTTimerRequestSystemGranularity().
253 *
254 * @returns IPRT status code.
255 * @retval VERR_NOT_SUPPORTED if the host platform doesn't have any way of modifying
256 * the system timer granularity.
257 * @retval VERR_WRONG_ORDER if nobody call RTTimerRequestSystemGranularity() with the
258 * given grant value.
259 * @param u32Granted The granted system granularity.
260 * @see RTTimerRequestSystemGranularity
261 */
262RTDECL(int) RTTimerReleaseSystemGranularity(uint32_t u32Granted);
263
264/**
265 * Checks if the system support high resolution timers.
266 *
267 * The kind of support we are checking for is the kind of dynamically
268 * reprogrammable timers employed by recent Solaris and Linux kernels. It also
269 * implies that we can specify microsecond (or even better maybe) intervals
270 * without getting into trouble.
271 *
272 * @returns true if supported, false it not.
273 *
274 * @remarks Returning true also means RTTimerChangeInterval must be implemented
275 * and RTTimerStart be callable with preemption disabled.
276 */
277RTDECL(bool) RTTimerCanDoHighResolution(void);
278
279
280/**
281 * Timer callback function for low res timers.
282 *
283 * This is identical to FNRTTIMER except for the first parameter, so
284 * see FNRTTIMER for details.
285 *
286 * @param hTimerLR The low resolution timer handle.
287 * @param pvUser User argument.
288 * @param iTick The current timer tick. This is always 1 on the first
289 * callback after the timer was started. Will jump if we've
290 * skipped ticks when lagging behind.
291 */
292typedef DECLCALLBACK(void) FNRTTIMERLR(RTTIMERLR hTimerLR, void *pvUser, uint64_t iTick);
293/** Pointer to FNRTTIMER() function. */
294typedef FNRTTIMERLR *PFNRTTIMERLR;
295
296
297/**
298 * Create a recurring low resolution timer.
299 *
300 * @returns iprt status code.
301 * @param phTimerLR Where to store the timer handle.
302 * @param uMilliesInterval Milliseconds between the timer ticks, at least 100 ms.
303 * If higher resolution is required use the other API.
304 * @param pfnTimer Callback function which shall be scheduled for execution
305 * on every timer tick.
306 * @param pvUser User argument for the callback.
307 * @see RTTimerLRCreateEx, RTTimerLRDestroy, RTTimerLRStop
308 */
309RTDECL(int) RTTimerLRCreate(PRTTIMERLR phTimerLR, uint32_t uMilliesInterval, PFNRTTIMERLR pfnTimer, void *pvUser);
310
311/**
312 * Create a suspended low resolution timer.
313 *
314 * @returns iprt status code.
315 * @retval VERR_NOT_SUPPORTED if an unsupported flag was specfied.
316 *
317 * @param phTimerLR Where to store the timer handle.
318 * @param u64NanoInterval The interval between timer ticks specified in nanoseconds if it's
319 * a recurring timer, the minimum for is 100000000 ns.
320 * For one shot timers, pass 0.
321 * @param fFlags Timer flags. Same as RTTimerCreateEx.
322 * @param pfnTimer Callback function which shall be scheduled for execution
323 * on every timer tick.
324 * @param pvUser User argument for the callback.
325 * @see RTTimerLRStart, RTTimerLRStop, RTTimerLRDestroy
326 */
327RTDECL(int) RTTimerLRCreateEx(PRTTIMERLR phTimerLR, uint64_t u64NanoInterval, uint32_t fFlags, PFNRTTIMERLR pfnTimer, void *pvUser);
328
329/**
330 * Stops and destroys a running low resolution timer.
331 *
332 * @returns iprt status code.
333 * @param hTimerLR The low resolution timer to stop and destroy.
334 * NIL_RTTIMERLR is accepted.
335 */
336RTDECL(int) RTTimerLRDestroy(RTTIMERLR hTimerLR);
337
338/**
339 * Starts a low resolution timer.
340 *
341 * @returns IPRT status code.
342 * @retval VERR_INVALID_HANDLE if pTimer isn't valid.
343 * @retval VERR_TIMER_ACTIVE if the timer isn't suspended.
344 *
345 * @param hTimerLR The low resolution timer to activate.
346 * @param u64First The RTTimeSystemNanoTS() for when the timer should start
347 * firing (relative), the minimum is 100000000 ns.
348 * If 0 is specified, the timer will fire ASAP.
349 *
350 * @see RTTimerLRStop
351 */
352RTDECL(int) RTTimerLRStart(RTTIMERLR hTimerLR, uint64_t u64First);
353
354/**
355 * Stops an active low resolution timer.
356 *
357 * @returns IPRT status code.
358 * @retval VERR_INVALID_HANDLE if pTimer isn't valid.
359 * @retval VERR_TIMER_SUSPENDED if the timer isn't active.
360 * @retval VERR_NOT_SUPPORTED if the IPRT implementation doesn't support stopping a timer.
361 *
362 * @param hTimerLR The low resolution timer to suspend.
363 *
364 * @see RTTimerLRStart
365 */
366RTDECL(int) RTTimerLRStop(RTTIMERLR hTimerLR);
367
368/**
369 * Changes the interval of a low resolution timer.
370 *
371 * If the timer is active, the next tick will occure immediately just like with
372 * RTTimerLRStart() when u64First parameter is zero.
373 *
374 * @returns IPRT status code.
375 * @retval VERR_INVALID_HANDLE if pTimer isn't valid.
376 * @retval VERR_NOT_SUPPORTED if not supported.
377 *
378 * @param hTimerLR The low resolution timer to update.
379 * @param u64NanoInterval The interval between timer ticks specified in
380 * nanoseconds. This is rounded to the fit the
381 * system timer granularity.
382 * @remarks Callable from the timer callback.
383 */
384RTDECL(int) RTTimerLRChangeInterval(RTTIMERLR hTimerLR, uint64_t u64NanoInterval);
385
386/** @} */
387
388RT_C_DECLS_END
389
390#endif /* !IPRT_INCLUDED_timer_h */
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