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source: vbox/trunk/include/iprt/timer.h@ 103224

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1/** @file
2 * IPRT - Timer.
3 */
4
5/*
6 * Copyright (C) 2006-2023 Oracle and/or its affiliates.
7 *
8 * This file is part of VirtualBox base platform packages, as
9 * available from https://www.virtualbox.org.
10 *
11 * This program is free software; you can redistribute it and/or
12 * modify it under the terms of the GNU General Public License
13 * as published by the Free Software Foundation, in version 3 of the
14 * License.
15 *
16 * This program is distributed in the hope that it will be useful, but
17 * WITHOUT ANY WARRANTY; without even the implied warranty of
18 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
19 * General Public License for more details.
20 *
21 * You should have received a copy of the GNU General Public License
22 * along with this program; if not, see <https://www.gnu.org/licenses>.
23 *
24 * The contents of this file may alternatively be used under the terms
25 * of the Common Development and Distribution License Version 1.0
26 * (CDDL), a copy of it is provided in the "COPYING.CDDL" file included
27 * in the VirtualBox distribution, in which case the provisions of the
28 * CDDL are applicable instead of those of the GPL.
29 *
30 * You may elect to license modified versions of this file under the
31 * terms and conditions of either the GPL or the CDDL or both.
32 *
33 * SPDX-License-Identifier: GPL-3.0-only OR CDDL-1.0
34 */
35
36#ifndef IPRT_INCLUDED_timer_h
37#define IPRT_INCLUDED_timer_h
38#ifndef RT_WITHOUT_PRAGMA_ONCE
39# pragma once
40#endif
41
42
43#include <iprt/cdefs.h>
44#include <iprt/types.h>
45
46
47RT_C_DECLS_BEGIN
48
49/** @defgroup grp_rt_timer RTTimer - Timer
50 *
51 * The IPRT timer API provides a simple abstraction of recurring and one-shot callback timers.
52 *
53 * Because of the great variation in the native APIs and the quality of
54 * the service delivered by those native APIs, the timers are operated
55 * on at best effort basis.
56 *
57 * All the ring-3 implementations are naturally at the mercy of the scheduler,
58 * which means that the callback rate might vary quite a bit and we might skip
59 * ticks. Many systems have a restriction that a process can only have one
60 * timer. IPRT currently makes no efforts at multiplexing timers in those kind
61 * of situations and will simply fail if you try to create more than one timer.
62 *
63 * Things are generally better in ring-0. The implementations will use interrupt
64 * time callbacks wherever available, and if not, resort to a high priority
65 * kernel thread.
66 *
67 * @ingroup grp_rt
68 * @{
69 */
70
71
72/** Timer handle. */
73typedef struct RTTIMER *PRTTIMER;
74
75/**
76 * Timer callback function.
77 *
78 * The context this call is made in varies with different platforms and
79 * kernel / user mode IPRT.
80 *
81 * In kernel mode a timer callback should not waste time, it shouldn't
82 * waste stack and it should be prepared that some APIs might not work
83 * correctly because of weird OS restrictions in this context that we
84 * haven't discovered and avoided yet. Please fix those APIs so they
85 * at least avoid panics and weird behaviour.
86 *
87 * @param pTimer Timer handle.
88 * @param pvUser User argument.
89 * @param iTick The current timer tick. This is always 1 on the first
90 * callback after the timer was started. For omni timers
91 * this will be 1 when a cpu comes back online.
92 */
93typedef DECLCALLBACKTYPE(void, FNRTTIMER,(PRTTIMER pTimer, void *pvUser, uint64_t iTick));
94/** Pointer to FNRTTIMER() function. */
95typedef FNRTTIMER *PFNRTTIMER;
96
97
98/**
99 * Create a recurring timer.
100 *
101 * @returns iprt status code.
102 * @param ppTimer Where to store the timer handle.
103 * @param uMilliesInterval Milliseconds between the timer ticks.
104 * This is rounded up to the system granularity.
105 * @param pfnTimer Callback function which shall be scheduled for execution
106 * on every timer tick.
107 * @param pvUser User argument for the callback.
108 * @see RTTimerCreateEx, RTTimerStart, RTTimerStop, RTTimerChangeInterval,
109 * RTTimerDestroy, RTTimerGetSystemGranularity
110 */
111RTDECL(int) RTTimerCreate(PRTTIMER *ppTimer, unsigned uMilliesInterval, PFNRTTIMER pfnTimer, void *pvUser);
112
113/**
114 * Create a suspended timer.
115 *
116 * @returns iprt status code.
117 * @retval VERR_NOT_SUPPORTED if an unsupported flag was specfied.
118 * @retval VERR_CPU_NOT_FOUND if the specified CPU
119 *
120 * @param ppTimer Where to store the timer handle.
121 * @param u64NanoInterval The interval between timer ticks specified in nanoseconds if it's
122 * a recurring timer. This is rounded to the fit the system timer granularity.
123 * For one shot timers, pass 0.
124 * @param fFlags Timer flags.
125 * @param pfnTimer Callback function which shall be scheduled for execution
126 * on every timer tick.
127 * @param pvUser User argument for the callback.
128 * @see RTTimerStart, RTTimerStop, RTTimerChangeInterval, RTTimerDestroy,
129 * RTTimerGetSystemGranularity, RTTimerCanDoHighResolution
130 */
131RTDECL(int) RTTimerCreateEx(PRTTIMER *ppTimer, uint64_t u64NanoInterval, uint32_t fFlags, PFNRTTIMER pfnTimer, void *pvUser);
132
133/** @name RTTimerCreateEx flags
134 * @{ */
135/** Any CPU is fine. (Must be 0.) */
136#define RTTIMER_FLAGS_CPU_ANY UINT32_C(0)
137/** One specific CPU */
138#define RTTIMER_FLAGS_CPU_SPECIFIC RT_BIT(16)
139/** Omni timer, run on all online CPUs.
140 * @remarks The timer callback isn't necessarily running at the time same time on each CPU. */
141#define RTTIMER_FLAGS_CPU_ALL ( RTTIMER_FLAGS_CPU_MASK | RTTIMER_FLAGS_CPU_SPECIFIC )
142/** CPU mask. */
143#define RTTIMER_FLAGS_CPU_MASK UINT32_C(0xffff)
144/** Desire a high resolution timer that works with RTTimerChangeInterval and
145 * isn't subject to RTTimerGetSystemGranularity rounding.
146 * @remarks This is quietly ignored if the feature isn't supported. */
147#define RTTIMER_FLAGS_HIGH_RES RT_BIT(17)
148/** Convert a CPU set index (0-based) to RTTimerCreateEx flags.
149 * This will automatically OR in the RTTIMER_FLAGS_CPU_SPECIFIC flag. */
150#define RTTIMER_FLAGS_CPU(iCpu) ( (iCpu) | RTTIMER_FLAGS_CPU_SPECIFIC )
151/** Macro that validates the flags. */
152#define RTTIMER_FLAGS_ARE_VALID(fFlags) \
153 ( !((fFlags) & ((fFlags) & RTTIMER_FLAGS_CPU_SPECIFIC ? ~UINT32_C(0x3ffff) : ~UINT32_C(0x30000))) )
154/** @} */
155
156/**
157 * Stops and destroys a running timer.
158 *
159 * @returns iprt status code.
160 * @retval VERR_INVALID_CONTEXT if executing at the wrong IRQL (windows), PIL
161 * (solaris), or similar. Portable code does not destroy timers with
162 * preemption (or interrupts) disabled.
163 * @param pTimer Timer to stop and destroy. NULL is ok.
164 */
165RTDECL(int) RTTimerDestroy(PRTTIMER pTimer);
166
167/**
168 * Starts a suspended timer.
169 *
170 * @returns IPRT status code.
171 * @retval VERR_INVALID_HANDLE if pTimer isn't valid.
172 * @retval VERR_TIMER_ACTIVE if the timer isn't suspended.
173 * @retval VERR_CPU_OFFLINE if the CPU the timer was created to run on is not
174 * online (this include the case where it's not present in the
175 * system).
176 *
177 * @param pTimer The timer to activate.
178 * @param u64First The RTTimeSystemNanoTS() for when the timer should start
179 * firing (relative). If 0 is specified, the timer will
180 * fire ASAP.
181 * @remarks When RTTimerCanDoHighResolution returns true, this API is
182 * callable with preemption disabled in ring-0.
183 * @see RTTimerStop
184 */
185RTDECL(int) RTTimerStart(PRTTIMER pTimer, uint64_t u64First);
186
187/**
188 * Stops an active timer.
189 *
190 * @todo May return while the timer callback function is being services on
191 * some platforms (ring-0 Windows, ring-0 linux). This needs to be
192 * addressed at some point...
193 *
194 * @returns IPRT status code.
195 * @retval VERR_INVALID_HANDLE if pTimer isn't valid.
196 * @retval VERR_TIMER_SUSPENDED if the timer isn't active.
197 * @retval VERR_NOT_SUPPORTED if the IPRT implementation doesn't support
198 * stopping a timer.
199 *
200 * @param pTimer The timer to suspend.
201 * @remarks Can be called from the timer callback function to stop it.
202 * @see RTTimerStart
203 */
204RTDECL(int) RTTimerStop(PRTTIMER pTimer);
205
206/**
207 * Changes the interval of a periodic timer.
208 *
209 * If the timer is active, it is implementation dependent whether the change
210 * takes place immediately or after the next tick. To get defined behavior,
211 * stop the timer before calling this API.
212 *
213 * @returns IPRT status code.
214 * @retval VERR_INVALID_HANDLE if pTimer isn't valid.
215 * @retval VERR_NOT_SUPPORTED if not supported.
216 * @retval VERR_INVALID_STATE if not a periodic timer.
217 *
218 * @param pTimer The timer to activate.
219 * @param u64NanoInterval The interval between timer ticks specified in
220 * nanoseconds. This is rounded to the fit the
221 * system timer granularity.
222 * @remarks Callable from the timer callback. Callable with preemption
223 * disabled in ring-0.
224 */
225RTDECL(int) RTTimerChangeInterval(PRTTIMER pTimer, uint64_t u64NanoInterval);
226
227/**
228 * Gets the (current) timer granularity of the system.
229 *
230 * @returns The timer granularity of the system in nanoseconds.
231 * @see RTTimerRequestSystemGranularity
232 */
233RTDECL(uint32_t) RTTimerGetSystemGranularity(void);
234
235/**
236 * Requests a specific system timer granularity.
237 *
238 * Successfull calls to this API must be coupled with the exact same number of
239 * calls to RTTimerReleaseSystemGranularity() in order to undo any changes made.
240 *
241 *
242 * @returns IPRT status code.
243 * @retval VERR_NOT_SUPPORTED if the requested value isn't supported by the host platform
244 * or if the host platform doesn't support modifying the system timer granularity.
245 * @retval VERR_PERMISSION_DENIED if the caller doesn't have the necessary privilege to
246 * modify the system timer granularity.
247 *
248 * @param u32Request The requested system timer granularity in nanoseconds.
249 * @param pu32Granted Where to store the granted system granularity. This is the value
250 * that should be passed to RTTimerReleaseSystemGranularity(). It
251 * is what RTTimerGetSystemGranularity() would return immediately
252 * after the change was made.
253 *
254 * The value differ from the request in two ways; rounding and
255 * scale. Meaning if your request is for 10.000.000 you might
256 * be granted 10.000.055 or 1.000.000.
257 * @see RTTimerReleaseSystemGranularity, RTTimerGetSystemGranularity
258 */
259RTDECL(int) RTTimerRequestSystemGranularity(uint32_t u32Request, uint32_t *pu32Granted);
260
261/**
262 * Releases a system timer granularity grant acquired by RTTimerRequestSystemGranularity().
263 *
264 * @returns IPRT status code.
265 * @retval VERR_NOT_SUPPORTED if the host platform doesn't have any way of modifying
266 * the system timer granularity.
267 * @retval VERR_WRONG_ORDER if nobody call RTTimerRequestSystemGranularity() with the
268 * given grant value.
269 * @param u32Granted The granted system granularity.
270 * @see RTTimerRequestSystemGranularity
271 */
272RTDECL(int) RTTimerReleaseSystemGranularity(uint32_t u32Granted);
273
274/**
275 * Checks if the system support high resolution timers.
276 *
277 * The kind of support we are checking for is the kind of dynamically
278 * reprogrammable timers employed by recent Solaris and Linux kernels. It also
279 * implies that we can specify microsecond (or even better maybe) intervals
280 * without getting into trouble.
281 *
282 * @returns true if supported, false it not.
283 *
284 * @remarks Returning true also means RTTimerChangeInterval must be implemented
285 * and RTTimerStart be callable with preemption disabled.
286 */
287RTDECL(bool) RTTimerCanDoHighResolution(void);
288
289
290/**
291 * Timer callback function for low res timers.
292 *
293 * This is identical to FNRTTIMER except for the first parameter, so
294 * see FNRTTIMER for details.
295 *
296 * @param hTimerLR The low resolution timer handle.
297 * @param pvUser User argument.
298 * @param iTick The current timer tick. This is always 1 on the first
299 * callback after the timer was started. Will jump if we've
300 * skipped ticks when lagging behind.
301 */
302typedef DECLCALLBACKTYPE(void, FNRTTIMERLR,(RTTIMERLR hTimerLR, void *pvUser, uint64_t iTick));
303/** Pointer to FNRTTIMER() function. */
304typedef FNRTTIMERLR *PFNRTTIMERLR;
305
306
307/**
308 * Create a recurring low resolution timer.
309 *
310 * @returns iprt status code.
311 * @param phTimerLR Where to store the timer handle.
312 * @param uMilliesInterval Milliseconds between the timer ticks, at least 100 ms.
313 * If higher resolution is required use the other API.
314 * @param pfnTimer Callback function which shall be scheduled for execution
315 * on every timer tick.
316 * @param pvUser User argument for the callback.
317 * @see RTTimerLRCreateEx, RTTimerLRDestroy, RTTimerLRStop
318 */
319RTDECL(int) RTTimerLRCreate(PRTTIMERLR phTimerLR, uint32_t uMilliesInterval, PFNRTTIMERLR pfnTimer, void *pvUser);
320
321/**
322 * Create a suspended low resolution timer.
323 *
324 * @returns iprt status code.
325 * @retval VERR_NOT_SUPPORTED if an unsupported flag was specfied.
326 *
327 * @param phTimerLR Where to store the timer handle.
328 * @param u64NanoInterval The interval between timer ticks specified in nanoseconds if it's
329 * a recurring timer, the minimum for is 100000000 ns.
330 * For one shot timers, pass 0.
331 * @param fFlags Timer flags. Same as RTTimerCreateEx.
332 * @param pfnTimer Callback function which shall be scheduled for execution
333 * on every timer tick.
334 * @param pvUser User argument for the callback.
335 * @see RTTimerLRStart, RTTimerLRStop, RTTimerLRDestroy
336 */
337RTDECL(int) RTTimerLRCreateEx(PRTTIMERLR phTimerLR, uint64_t u64NanoInterval, uint32_t fFlags, PFNRTTIMERLR pfnTimer, void *pvUser);
338
339/**
340 * Stops and destroys a running low resolution timer.
341 *
342 * @returns iprt status code.
343 * @param hTimerLR The low resolution timer to stop and destroy.
344 * NIL_RTTIMERLR is accepted.
345 */
346RTDECL(int) RTTimerLRDestroy(RTTIMERLR hTimerLR);
347
348/**
349 * Starts a low resolution timer.
350 *
351 * @returns IPRT status code.
352 * @retval VERR_INVALID_HANDLE if pTimer isn't valid.
353 * @retval VERR_TIMER_ACTIVE if the timer isn't suspended.
354 *
355 * @param hTimerLR The low resolution timer to activate.
356 * @param u64First The RTTimeSystemNanoTS() for when the timer should start
357 * firing (relative), the minimum is 100000000 ns.
358 * If 0 is specified, the timer will fire ASAP.
359 *
360 * @see RTTimerLRStop
361 */
362RTDECL(int) RTTimerLRStart(RTTIMERLR hTimerLR, uint64_t u64First);
363
364/**
365 * Stops an active low resolution timer.
366 *
367 * @returns IPRT status code.
368 * @retval VERR_INVALID_HANDLE if pTimer isn't valid.
369 * @retval VERR_TIMER_SUSPENDED if the timer isn't active.
370 * @retval VERR_NOT_SUPPORTED if the IPRT implementation doesn't support stopping a timer.
371 *
372 * @param hTimerLR The low resolution timer to suspend.
373 *
374 * @see RTTimerLRStart
375 */
376RTDECL(int) RTTimerLRStop(RTTIMERLR hTimerLR);
377
378/**
379 * Changes the interval of a low resolution timer.
380 *
381 * If the timer is active, the next tick will occure immediately just like with
382 * RTTimerLRStart() when u64First parameter is zero.
383 *
384 * @returns IPRT status code.
385 * @retval VERR_INVALID_HANDLE if pTimer isn't valid.
386 * @retval VERR_NOT_SUPPORTED if not supported.
387 *
388 * @param hTimerLR The low resolution timer to update.
389 * @param u64NanoInterval The interval between timer ticks specified in
390 * nanoseconds. This is rounded to the fit the
391 * system timer granularity.
392 * @remarks Callable from the timer callback.
393 */
394RTDECL(int) RTTimerLRChangeInterval(RTTIMERLR hTimerLR, uint64_t u64NanoInterval);
395
396/** @} */
397
398RT_C_DECLS_END
399
400#endif /* !IPRT_INCLUDED_timer_h */
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