semeventwait-r0drv-solaris.h@ 34296

Last change on this file since 34296 was 33736, checked in by vboxsync, 14 years ago
semeventwait-r0drv-solaris.h: Disabled deadlocking fallback code.
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1	/* $Id: semeventwait-r0drv-solaris.h 33736 2010-11-03 16:30:23Z vboxsync $ */
2	/** @file
3	* IPRT - Solaris Ring-0 Driver Helpers for Event Semaphore Waits.
4	*/
5
6	/*
7	* Copyright (C) 2006-2010 Oracle Corporation
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
27
28	#ifndef ___r0drv_solaris_semeventwait_r0drv_solaris_h
29	#define ___r0drv_solaris_semeventwait_r0drv_solaris_h
30
31	#include "the-solaris-kernel.h"
32
33	#include <iprt/err.h>
34	#include <iprt/string.h>
35	#include <iprt/time.h>
36
37
38	/** The resolution (nanoseconds) specified when using timeout_generic. */
39	#define RTR0SEMSOLWAIT_RESOLUTION 50000
40
41
42	/**
43	* Solaris semaphore wait structure.
44	*/
45	typedef struct RTR0SEMSOLWAIT
46	{
47	/** The absolute timeout given as nanoseconds since the start of the
48	* monotonic clock. */
49	uint64_t uNsAbsTimeout;
50	/** The timeout in nanoseconds relative to the start of the wait. */
51	uint64_t cNsRelTimeout;
52	/** The native timeout value. */
53	union
54	{
55	/** The timeout (abs lbolt) when fHighRes is false. */
56	clock_t lTimeout;
57	} u;
58	/** Set if we use high resolution timeouts. */
59	bool fHighRes;
60	/** Set if it's an indefinite wait. */
61	bool fIndefinite;
62	/** Set if we've already timed out.
63	* Set by rtR0SemSolWaitDoIt or rtR0SemSolWaitHighResTimeout, read by
64	* rtR0SemSolWaitHasTimedOut. */
65	bool volatile fTimedOut;
66	/** Whether the wait was interrupted. */
67	bool fInterrupted;
68	/** Interruptible or uninterruptible wait. */
69	bool fInterruptible;
70	/** The thread to wake up. */
71	kthread_t *pThread;
72	#if 0 /* @bugref{5342} */
73	/** Cylic timer ID (used by the timeout callback). */
74	cyclic_id_t idCy;
75	#endif
76	/** The mutex associated with the condition variable wait. */
77	void volatile *pvMtx;
78	} RTR0SEMSOLWAIT;
79	/** Pointer to a solaris semaphore wait structure. */
80	typedef RTR0SEMSOLWAIT *PRTR0SEMSOLWAIT;
81
82
83	/**
84	* Initializes a wait.
85	*
86	* The caller MUST check the wait condition BEFORE calling this function or the
87	* timeout logic will be flawed.
88	*
89	* @returns VINF_SUCCESS or VERR_TIMEOUT.
90	* @param pWait The wait structure.
91	* @param fFlags The wait flags.
92	* @param uTimeout The timeout.
93	* @param pWaitQueue The wait queue head.
94	*/
95	DECLINLINE(int) rtR0SemSolWaitInit(PRTR0SEMSOLWAIT pWait, uint32_t fFlags, uint64_t uTimeout)
96	{
97	/*
98	* Process the flags and timeout.
99	*/
100	if (!(fFlags & RTSEMWAIT_FLAGS_INDEFINITE))
101	{
102	if (fFlags & RTSEMWAIT_FLAGS_MILLISECS)
103	uTimeout = uTimeout < UINT64_MAX / UINT32_C(1000000) * UINT32_C(1000000)
104	? uTimeout * UINT32_C(1000000)
105	: UINT64_MAX;
106	if (uTimeout == UINT64_MAX)
107	fFlags \|= RTSEMWAIT_FLAGS_INDEFINITE;
108	else
109	{
110	uint64_t u64Now;
111	if (fFlags & RTSEMWAIT_FLAGS_RELATIVE)
112	{
113	if (uTimeout == 0)
114	return VERR_TIMEOUT;
115
116	u64Now = RTTimeSystemNanoTS();
117	pWait->cNsRelTimeout = uTimeout;
118	pWait->uNsAbsTimeout = u64Now + uTimeout;
119	if (pWait->uNsAbsTimeout < u64Now) /* overflow */
120	fFlags \|= RTSEMWAIT_FLAGS_INDEFINITE;
121	}
122	else
123	{
124	u64Now = RTTimeSystemNanoTS();
125	if (u64Now >= uTimeout)
126	return VERR_TIMEOUT;
127
128	pWait->cNsRelTimeout = uTimeout - u64Now;
129	pWait->uNsAbsTimeout = uTimeout;
130	}
131	}
132	}
133
134	if (!(fFlags & RTSEMWAIT_FLAGS_INDEFINITE))
135	{
136	pWait->fIndefinite = false;
137	if ( ( (fFlags & (RTSEMWAIT_FLAGS_NANOSECS \| RTSEMWAIT_FLAGS_ABSOLUTE))
138	\|\| pWait->cNsRelTimeout < UINT32_C(1000000000) / 100 /Hz/ * 4)
139	&& g_pfnrtR0Sol_timeout_generic != NULL /* See @bugref{5342} */)
140	pWait->fHighRes = true;
141	else
142	{
143	uint64_t cTicks = NSEC_TO_TICK_ROUNDUP(uTimeout);
144	if (cTicks >= LONG_MAX)
145	fFlags \|= RTSEMWAIT_FLAGS_INDEFINITE;
146	else
147	{
148	pWait->u.lTimeout = ddi_get_lbolt() + cTicks;
149	pWait->fHighRes = false;
150	}
151	}
152	}
153
154	if (fFlags & RTSEMWAIT_FLAGS_INDEFINITE)
155	{
156	pWait->fIndefinite = true;
157	pWait->fHighRes = false;
158	pWait->uNsAbsTimeout = UINT64_MAX;
159	pWait->cNsRelTimeout = UINT64_MAX;
160	pWait->u.lTimeout = LONG_MAX;
161	}
162
163	pWait->fTimedOut = false;
164	pWait->fInterrupted = false;
165	pWait->fInterruptible = !!(fFlags & RTSEMWAIT_FLAGS_INTERRUPTIBLE);
166	pWait->pThread = curthread;
167	pWait->pvMtx = NULL;
168	#if 0 /* @bugref{5342} */
169	pWait->idCy = CYCLIC_NONE;
170	#endif
171
172	return VINF_SUCCESS;
173	}
174
175
176	#if 0 /* @bugref{5342} */
177	/**
178	* Cyclic timeout callback that sets the timeout indicator and wakes up the
179	* waiting thread.
180	*
181	* @param pvUser The wait structure.
182	*/
183	static void rtR0SemSolWaitHighResTimeout(void *pvUser)
184	{
185	PRTR0SEMSOLWAIT pWait = (PRTR0SEMSOLWAIT)pvUser;
186	kthread_t *pThread = pWait->pThread;
187	kmutex_t pMtx = (kmutex_t )ASMAtomicReadPtr(&pWait->pvMtx);
188	if (VALID_PTR(pMtx))
189	{
190	/* Enter the mutex here to make sure the thread has gone to sleep
191	before we wake it up.
192	Note: Trying to take the cpu_lock here doesn't work. */
193	/** @todo LOCK ORDER INVERSION (pMtx & cpu_lock when arming the timer, here it's inverted).
194	* Possible fix: Use the thread lock for sleep/wakeup race prevention
195	* instead of the mutex associated with the cv/event. */
196	mutex_enter(pMtx);
197	if (mutex_owner(&cpu_lock) == curthread)
198	{
199	cyclic_remove(pWait->idCy);
200	pWait->idCy = CYCLIC_NONE;
201	}
202	ASMAtomicWriteBool(&pWait->fTimedOut, true);
203	mutex_exit(pMtx);
204	setrun(pThread);
205	}
206	}
207	#endif
208
209
210	/**
211	* Timeout callback that sets the timeout indicator and wakes up the waiting
212	* thread.
213	*
214	* @param pvUser The wait structure.
215	*/
216	static void rtR0SemSolWaitTimeout(void *pvUser)
217	{
218	PRTR0SEMSOLWAIT pWait = (PRTR0SEMSOLWAIT)pvUser;
219	kthread_t *pThread = pWait->pThread;
220	kmutex_t pMtx = (kmutex_t )ASMAtomicReadPtr(&pWait->pvMtx);
221	if (VALID_PTR(pMtx))
222	{
223	/* Enter the mutex here to make sure the thread has gone to sleep
224	before we wake it up. */
225	mutex_enter(pMtx);
226	ASMAtomicWriteBool(&pWait->fTimedOut, true);
227	mutex_exit(pMtx);
228	setrun(pThread);
229	}
230	}
231
232
233	/**
234	* Do the actual wait.
235	*
236	* @param pWait The wait structure.
237	* @param pCnd The condition variable to wait on.
238	* @param pMtx The mutex related to the condition variable.
239	* The caller has entered this.
240	*/
241	DECLINLINE(void) rtR0SemSolWaitDoIt(PRTR0SEMSOLWAIT pWait, kcondvar_t pCnd, kmutex_t pMtx)
242	{
243	union
244	{
245	callout_id_t idCo;
246	timeout_id_t idTom;
247	} u;
248
249	/*
250	* Arm the timeout callback.
251	*/
252	bool const fHasTimeout = !pWait->fIndefinite;
253	if (fHasTimeout)
254	{
255	ASMAtomicWritePtr(&pWait->pvMtx, pMtx); /* atomic is paranoia */
256
257	if (pWait->fHighRes)
258	{
259	#if 0 /* @bugref{5342} */
260	if (g_pfnrtR0Sol_timeout_generic != NULL)
261	#endif
262	{
263	/*
264	* High resolution timeout - arm a high resolution timeout callback
265	* for waking up the thread at the desired time.
266	*/
267	u.idCo = g_pfnrtR0Sol_timeout_generic(CALLOUT_REALTIME, rtR0SemSolWaitTimeout, pWait,
268	pWait->uNsAbsTimeout, RTR0SEMSOLWAIT_RESOLUTION,
269	CALLOUT_FLAG_ABSOLUTE);
270	}
271	#if 0 /* @bugref{5342} */
272	else
273	{
274	/*
275	* High resolution timeout - arm a one-shot cyclic for waking up
276	* the thread at the desired time.
277	*/
278	cyc_handler_t Cyh;
279	Cyh.cyh_arg = pWait;
280	Cyh.cyh_func = rtR0SemSolWaitHighResTimeout;
281	Cyh.cyh_level = CY_LOW_LEVEL; /// @todo try CY_LOCK_LEVEL and CY_HIGH_LEVEL?
282
283	cyc_time_t Cyt;
284	Cyt.cyt_when = pWait->uNsAbsTimeout;
285	Cyt.cyt_interval = UINT64_C(1000000000) * 60;
286
287	mutex_enter(&cpu_lock);
288	pWait->idCy = cyclic_add(&Cyh, &Cyt);
289	mutex_exit(&cpu_lock);
290	}
291	#endif
292	}
293	else
294	{
295	/*
296	* Normal timeout.
297	* We're better off with our own callback like on the timeout man page,
298	* than calling cv_timedwait[_sig]().
299	*/
300	u.idTom = realtime_timeout(rtR0SemSolWaitTimeout, pWait, pWait->u.lTimeout);
301	}
302	}
303
304	/*
305	* Do the waiting.
306	* (rc > 0 - normal wake-up; rc == 0 - interruption; rc == -1 - timeout)
307	*/
308	if (pWait->fInterruptible)
309	{
310	int rc = cv_wait_sig(pCnd, pMtx);
311	if (RT_UNLIKELY(rc <= 0))
312	{
313	if (RT_LIKELY(rc == 0))
314	pWait->fInterrupted = true;
315	else
316	AssertMsgFailed(("rc=%d\n", rc)); /* no timeouts, see above! */
317	}
318	}
319	else
320	cv_wait(pCnd, pMtx);
321
322	/*
323	* Remove the timeout callback. Drop the lock while we're doing that
324	* to reduce lock contention / deadlocks. (Too bad we are stuck with the
325	* cv_* API here, it's doing a little bit too much.)
326	*/
327	if (fHasTimeout)
328	{
329	ASMAtomicWritePtr(&pWait->pvMtx, NULL);
330	mutex_exit(pMtx);
331
332	if (pWait->fHighRes)
333	{
334	#if 0 /* @bugref{5342} */
335	if (g_pfnrtR0Sol_timeout_generic != NULL)
336	#endif
337	g_pfnrtR0Sol_untimeout_generic(u.idCo, 0 /nowait/);
338	#if 0 /* @bugref{5342} */
339	else
340	{
341	mutex_enter(&cpu_lock);
342	if (pWait->idCy != CYCLIC_NONE)
343	{
344	cyclic_remove(pWait->idCy);
345	pWait->idCy = CYCLIC_NONE;
346	}
347	mutex_exit(&cpu_lock);
348	}
349	#endif
350	}
351	else
352	untimeout(u.idTom);
353
354	mutex_enter(pMtx);
355	}
356	}
357
358
359	/**
360	* Checks if a solaris wait was interrupted.
361	*
362	* @returns true / false
363	* @param pWait The wait structure.
364	* @remarks This shall be called before the first rtR0SemSolWaitDoIt().
365	*/
366	DECLINLINE(bool) rtR0SemSolWaitWasInterrupted(PRTR0SEMSOLWAIT pWait)
367	{
368	return pWait->fInterrupted;
369	}
370
371
372	/**
373	* Checks if a solaris wait has timed out.
374	*
375	* @returns true / false
376	* @param pWait The wait structure.
377	*/
378	DECLINLINE(bool) rtR0SemSolWaitHasTimedOut(PRTR0SEMSOLWAIT pWait)
379	{
380	return pWait->fTimedOut;
381	}
382
383
384	/**
385	* Deletes a solaris wait.
386	*
387	* @param pWait The wait structure.
388	*/
389	DECLINLINE(void) rtR0SemSolWaitDelete(PRTR0SEMSOLWAIT pWait)
390	{
391	pWait->pThread = NULL;
392	}
393
394
395	/**
396	* Enters the mutex, unpinning the underlying current thread if contended and
397	* we're on an interrupt thread.
398	*
399	* The unpinning is done to prevent a deadlock, see s this could lead to a
400	* deadlock (see #4259 for the full explanation)
401	*
402	* @param pMtx The mutex to enter.
403	*/
404	DECLINLINE(void) rtR0SemSolWaitEnterMutexWithUnpinningHack(kmutex_t *pMtx)
405	{
406	int fAcquired = mutex_tryenter(pMtx);
407	if (!fAcquired)
408	{
409	/*
410	* Note! This assumes nobody is using the RTThreadPreemptDisable in an
411	* interrupt context and expects it to work right. The swtch will
412	* result in a voluntary preemption. To fix this, we would have to
413	* do our own counting in RTThreadPreemptDisable/Restore like we do
414	* on systems which doesn't do preemption (OS/2, linux, ...) and
415	* check whether preemption was disabled via RTThreadPreemptDisable
416	* or not and only call swtch if RTThreadPreemptDisable wasn't called.
417	*/
418	if (curthread->t_intr && getpil() < DISP_LEVEL)
419	{
420	RTTHREADPREEMPTSTATE PreemptState = RTTHREADPREEMPTSTATE_INITIALIZER;
421	RTThreadPreemptDisable(&PreemptState);
422	preempt();
423	RTThreadPreemptRestore(&PreemptState);
424	}
425	mutex_enter(pMtx);
426	}
427	}
428
429
430	/**
431	* Gets the max resolution of the timeout machinery.
432	*
433	* @returns Resolution specified in nanoseconds.
434	*/
435	DECLINLINE(uint32_t) rtR0SemSolWaitGetResolution(void)
436	{
437	return g_pfnrtR0Sol_timeout_generic != NULL
438	? RTR0SEMSOLWAIT_RESOLUTION
439	: cyclic_getres();
440	}
441
442	#endif

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source: vbox/trunk/src/VBox/Runtime/r0drv/solaris/semeventwait-r0drv-solaris.h@ 34296

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