VirtualBox

source: vbox/trunk/src/VBox/Runtime/generic/timer-generic.cpp@ 14398

Last change on this file since 14398 was 14298, checked in by vboxsync, 16 years ago

Corrected a couple of grammos.
  • Property svn:eol-style set to native
  • Property svn:keywords set to Id
File size: 9.6 KB
Line 
1/** $Id: timer-generic.cpp 14298 2008-11-18 12:47:26Z vboxsync $ */
2/** @file
3 * IPRT - Timers, Generic.
4 */
5
6/*
7 * Copyright (C) 2006-2007 Sun Microsystems, Inc.
8 *
9 * This file is part of VirtualBox Open Source Edition (OSE), as
10 * available from http://www.virtualbox.org. This file is free software;
11 * you can redistribute it and/or modify it under the terms of the GNU
12 * General Public License (GPL) as published by the Free Software
13 * Foundation, in version 2 as it comes in the "COPYING" file of the
14 * VirtualBox OSE distribution. VirtualBox OSE is distributed in the
15 * hope that it will be useful, but WITHOUT ANY WARRANTY of any kind.
16 *
17 * The contents of this file may alternatively be used under the terms
18 * of the Common Development and Distribution License Version 1.0
19 * (CDDL) only, as it comes in the "COPYING.CDDL" file of the
20 * VirtualBox OSE distribution, in which case the provisions of the
21 * CDDL are applicable instead of those of the GPL.
22 *
23 * You may elect to license modified versions of this file under the
24 * terms and conditions of either the GPL or the CDDL or both.
25 *
26 * Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa
27 * Clara, CA 95054 USA or visit http://www.sun.com if you need
28 * additional information or have any questions.
29 */
30
31
32/*******************************************************************************
33* Header Files *
34*******************************************************************************/
35#include <iprt/timer.h>
36#include <iprt/thread.h>
37#include <iprt/err.h>
38#include <iprt/assert.h>
39#include <iprt/alloc.h>
40#include <iprt/asm.h>
41#include <iprt/semaphore.h>
42#include <iprt/time.h>
43#include <iprt/log.h>
44#include "internal/magics.h"
45
46
47
48/*******************************************************************************
49* Structures and Typedefs *
50*******************************************************************************/
51/**
52 * The internal representation of a timer handle.
53 */
54typedef struct RTTIMER
55{
56 /** Magic.
57 * This is RTTIMER_MAGIC, but changes to something else before the timer
58 * is destroyed to indicate clearly that thread should exit. */
59 uint32_t volatile u32Magic;
60 /** Flag indicating the timer is suspended. */
61 uint8_t volatile fSuspended;
62 /** Flag indicating that the timer has been destroyed. */
63 uint8_t volatile fDestroyed;
64 /** Callback. */
65 PFNRTTIMER pfnTimer;
66 /** User argument. */
67 void *pvUser;
68 /** The timer thread. */
69 RTTHREAD Thread;
70 /** Event semaphore on which the thread is blocked. */
71 RTSEMEVENT Event;
72 /** The timer interval. 0 if one-shot. */
73 uint64_t u64NanoInterval;
74 /** The start of the current run (ns).
75 * This is used to calculate when the timer ought to fire the next time. */
76 uint64_t volatile u64StartTS;
77 /** The start of the current run (ns).
78 * This is used to calculate when the timer ought to fire the next time. */
79 uint64_t volatile u64NextTS;
80 /** The current tick number (since u64StartTS). */
81 uint64_t volatile iTick;
82} RTTIMER;
83
84
85/*******************************************************************************
86* Internal Functions *
87*******************************************************************************/
88static DECLCALLBACK(int) rtTimerThread(RTTHREAD Thread, void *pvUser);
89
90
91RTDECL(int) RTTimerCreateEx(PRTTIMER *ppTimer, uint64_t u64NanoInterval, unsigned fFlags, PFNRTTIMER pfnTimer, void *pvUser)
92{
93 *ppTimer = NULL;
94
95 /*
96 * We don't support the fancy MP features.
97 */
98 if (fFlags & RTTIMER_FLAGS_CPU_SPECIFIC)
99 return VERR_NOT_SUPPORTED;
100
101 /*
102 * Allocate and initialize the timer handle.
103 */
104 PRTTIMER pTimer = (PRTTIMER)RTMemAlloc(sizeof(*pTimer));
105 if (!pTimer)
106 return VERR_NO_MEMORY;
107
108 pTimer->u32Magic = RTTIMER_MAGIC;
109 pTimer->fSuspended = true;
110 pTimer->fDestroyed = false;
111 pTimer->pfnTimer = pfnTimer;
112 pTimer->pvUser = pvUser;
113 pTimer->Thread = NIL_RTTHREAD;
114 pTimer->Event = NIL_RTSEMEVENT;
115 pTimer->u64NanoInterval = u64NanoInterval;
116 pTimer->u64StartTS = 0;
117
118 int rc = RTSemEventCreate(&pTimer->Event);
119 if (RT_SUCCESS(rc))
120 {
121 rc = RTThreadCreate(&pTimer->Thread, rtTimerThread, pTimer, 0, RTTHREADTYPE_TIMER, RTTHREADFLAGS_WAITABLE, "TIMER");
122 if (RT_SUCCESS(rc))
123 {
124 *ppTimer = pTimer;
125 return VINF_SUCCESS;
126 }
127
128 pTimer->u32Magic = 0;
129 RTSemEventDestroy(pTimer->Event);
130 pTimer->Event = NIL_RTSEMEVENT;
131 }
132 RTMemFree(pTimer);
133
134 return rc;
135}
136
137
138/**
139 * Validates the timer handle.
140 *
141 * @returns true if valid, false if invalid.
142 * @param pTimer The handle.
143 */
144DECLINLINE(bool) rtTimerIsValid(PRTTIMER pTimer)
145{
146 AssertReturn(VALID_PTR(pTimer), false);
147 AssertReturn(pTimer->u32Magic == RTTIMER_MAGIC, false);
148 AssertReturn(!pTimer->fDestroyed, false);
149 return true;
150}
151
152
153RTDECL(int) RTTimerDestroy(PRTTIMER pTimer)
154{
155 /* It's ok to pass NULL pointer. */
156 if (pTimer == /*NIL_RTTIMER*/ NULL)
157 return VINF_SUCCESS;
158 if (!rtTimerIsValid(pTimer))
159 return VERR_INVALID_HANDLE;
160
161 /*
162 * If the timer is active, we just flag it to self destruct on the next tick.
163 * If it's suspended we can safely set the destroy flag and signal it.
164 */
165 RTTHREAD Thread = pTimer->Thread;
166 if (!pTimer->fSuspended)
167 {
168 ASMAtomicXchgU8(&pTimer->fSuspended, true);
169 ASMAtomicXchgU8(&pTimer->fDestroyed, true);
170 }
171 else
172 {
173 ASMAtomicXchgU8(&pTimer->fDestroyed, true);
174 int rc = RTSemEventSignal(pTimer->Event);
175 if (rc == VERR_ALREADY_POSTED)
176 rc = VINF_SUCCESS;
177 AssertRC(rc);
178 }
179
180 RTThreadWait(Thread, 250, NULL);
181 return VINF_SUCCESS;
182}
183
184
185RTDECL(int) RTTimerStart(PRTTIMER pTimer, uint64_t u64First)
186{
187 if (!rtTimerIsValid(pTimer))
188 return VERR_INVALID_HANDLE;
189 if (!pTimer->fSuspended)
190 return VERR_TIMER_ACTIVE;
191
192 /*
193 * Calc when it should start fireing and give the thread a kick so it get going.
194 */
195 u64First += RTTimeNanoTS();
196 ASMAtomicXchgU64(&pTimer->iTick, 0);
197 ASMAtomicXchgU64(&pTimer->u64StartTS, u64First);
198 ASMAtomicXchgU64(&pTimer->u64NextTS, u64First);
199 ASMAtomicXchgU8(&pTimer->fSuspended, false);
200 int rc = RTSemEventSignal(pTimer->Event);
201 if (rc == VERR_ALREADY_POSTED)
202 rc = VINF_SUCCESS;
203 AssertRC(rc);
204 return rc;
205}
206
207
208RTDECL(int) RTTimerStop(PRTTIMER pTimer)
209{
210 if (!rtTimerIsValid(pTimer))
211 return VERR_INVALID_HANDLE;
212 if (pTimer->fSuspended)
213 return VERR_TIMER_SUSPENDED;
214
215 /*
216 * Mark it as suspended and kick the thread.
217 */
218 ASMAtomicXchgU8(&pTimer->fSuspended, true);
219 int rc = RTSemEventSignal(pTimer->Event);
220 if (rc == VERR_ALREADY_POSTED)
221 rc = VINF_SUCCESS;
222 AssertRC(rc);
223 return rc;
224}
225
226
227static DECLCALLBACK(int) rtTimerThread(RTTHREAD Thread, void *pvUser)
228{
229 PRTTIMER pTimer = (PRTTIMER)pvUser;
230
231 /*
232 * The loop.
233 */
234 while (!pTimer->fDestroyed)
235 {
236 if (pTimer->fSuspended)
237 {
238 int rc = RTSemEventWait(pTimer->Event, RT_INDEFINITE_WAIT);
239 if (RT_FAILURE(rc) && rc != VERR_INTERRUPTED)
240 {
241 AssertRC(rc);
242 RTThreadSleep(1000); /* Don't cause trouble! */
243 }
244 }
245 else
246 {
247 const uint64_t u64NanoTS = RTTimeNanoTS();
248 if (u64NanoTS >= pTimer->u64NextTS)
249 {
250 pTimer->iTick++;
251 pTimer->pfnTimer(pTimer, pTimer->pvUser, pTimer->iTick);
252
253 /* status changed? */
254 if (pTimer->fSuspended || pTimer->fDestroyed)
255 continue;
256
257 /* one shot? */
258 if (!pTimer->u64NanoInterval)
259 {
260 ASMAtomicXchgU8(&pTimer->fSuspended, true);
261 continue;
262 }
263
264 /* calc the next time we should fire. */
265 pTimer->u64NextTS = pTimer->u64StartTS + pTimer->iTick * pTimer->u64NanoInterval;
266 if (pTimer->u64NextTS < u64NanoTS)
267#ifdef IN_RING3 /* In ring-3 we'll catch up lost ticks immediately. */
268 pTimer->u64NextTS = u64NanoTS + 1;
269#else
270 pTimer->u64NextTS = u64NanoTS + RTTimerGetSystemGranularity() / 2;
271#endif
272 }
273
274 /* block. */
275 uint64_t cNanoSeconds = pTimer->u64NextTS - u64NanoTS;
276#ifdef IN_RING3 /* In ring-3 we'll catch up lost ticks immediately. */
277 if (cNanoSeconds > 10)
278#endif
279 {
280 int rc = RTSemEventWait(pTimer->Event, cNanoSeconds < 1000000 ? 1 : cNanoSeconds / 1000000);
281 if (RT_FAILURE(rc) && rc != VERR_INTERRUPTED && rc != VERR_TIMEOUT)
282 {
283 AssertRC(rc);
284 RTThreadSleep(1000); /* Don't cause trouble! */
285 }
286 }
287 }
288 }
289
290 /*
291 * Release the timer resources.
292 */
293 ASMAtomicIncU32(&pTimer->u32Magic); /* make the handle invalid. */
294 int rc = RTSemEventDestroy(pTimer->Event); AssertRC(rc);
295 pTimer->Event = NIL_RTSEMEVENT;
296 pTimer->Thread = NIL_RTTHREAD;
297 RTMemFree(pTimer);
298
299 return VINF_SUCCESS;
300}
301
302
303
304
305RTDECL(uint32_t) RTTimerGetSystemGranularity(void)
306{
307 return 10000000; /* 10ms */
308}
309
310
311RTDECL(int) RTTimerRequestSystemGranularity(uint32_t u32Request, uint32_t *pu32Granted)
312{
313 return VERR_NOT_SUPPORTED;
314}
315
316
317RTDECL(int) RTTimerReleaseSystemGranularity(uint32_t u32Granted)
318{
319 return VERR_NOT_SUPPORTED;
320}
321
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