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source: vbox/trunk/src/VBox/Runtime/r0drv/linux/semeventmulti-r0drv-linux.c@ 58591

Last change on this file since 58591 was 57358, checked in by vboxsync, 9 years ago

*: scm cleanup run.
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File size: 11.4 KB
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1/* $Id: semeventmulti-r0drv-linux.c 57358 2015-08-14 15:16:38Z vboxsync $ */
2/** @file
3 * IPRT - Multiple Release Event Semaphores, Ring-0 Driver, Linux.
4 */
5
6/*
7 * Copyright (C) 2006-2015 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/*********************************************************************************************************************************
29* Header Files *
30*********************************************************************************************************************************/
31#define RTSEMEVENTMULTI_WITHOUT_REMAPPING
32#include "the-linux-kernel.h"
33#include "internal/iprt.h"
34#include <iprt/semaphore.h>
35
36#include <iprt/assert.h>
37#include <iprt/asm.h>
38#include <iprt/err.h>
39#include <iprt/mem.h>
40#include <iprt/lockvalidator.h>
41
42#include "waitqueue-r0drv-linux.h"
43#include "internal/magics.h"
44
45
46/*********************************************************************************************************************************
47* Defined Constants And Macros *
48*********************************************************************************************************************************/
49/** @name fStateAndGen values
50 * @{ */
51/** The state bit number. */
52#define RTSEMEVENTMULTILNX_STATE_BIT 0
53/** The state mask. */
54#define RTSEMEVENTMULTILNX_STATE_MASK RT_BIT_32(RTSEMEVENTMULTILNX_STATE_BIT)
55/** The generation mask. */
56#define RTSEMEVENTMULTILNX_GEN_MASK ~RTSEMEVENTMULTILNX_STATE_MASK
57/** The generation shift. */
58#define RTSEMEVENTMULTILNX_GEN_SHIFT 1
59/** The initial variable value. */
60#define RTSEMEVENTMULTILNX_STATE_GEN_INIT UINT32_C(0xfffffffc)
61/** @} */
62
63
64/*********************************************************************************************************************************
65* Structures and Typedefs *
66*********************************************************************************************************************************/
67/**
68 * Linux event semaphore.
69 */
70typedef struct RTSEMEVENTMULTIINTERNAL
71{
72 /** Magic value (RTSEMEVENTMULTI_MAGIC). */
73 uint32_t volatile u32Magic;
74 /** The object state bit and generation counter.
75 * The generation counter is incremented every time the object is
76 * signalled. */
77 uint32_t volatile fStateAndGen;
78 /** Reference counter. */
79 uint32_t volatile cRefs;
80 /** The wait queue. */
81 wait_queue_head_t Head;
82} RTSEMEVENTMULTIINTERNAL, *PRTSEMEVENTMULTIINTERNAL;
83
84
85
86
87
88RTDECL(int) RTSemEventMultiCreate(PRTSEMEVENTMULTI phEventMultiSem)
89{
90 return RTSemEventMultiCreateEx(phEventMultiSem, 0 /*fFlags*/, NIL_RTLOCKVALCLASS, NULL);
91}
92
93
94RTDECL(int) RTSemEventMultiCreateEx(PRTSEMEVENTMULTI phEventMultiSem, uint32_t fFlags, RTLOCKVALCLASS hClass,
95 const char *pszNameFmt, ...)
96{
97 PRTSEMEVENTMULTIINTERNAL pThis;
98 IPRT_LINUX_SAVE_EFL_AC();
99
100 AssertReturn(!(fFlags & ~RTSEMEVENTMULTI_FLAGS_NO_LOCK_VAL), VERR_INVALID_PARAMETER);
101 pThis = (PRTSEMEVENTMULTIINTERNAL)RTMemAlloc(sizeof(*pThis));
102 if (pThis)
103 {
104 pThis->u32Magic = RTSEMEVENTMULTI_MAGIC;
105 pThis->fStateAndGen = RTSEMEVENTMULTILNX_STATE_GEN_INIT;
106 pThis->cRefs = 1;
107 init_waitqueue_head(&pThis->Head);
108
109 *phEventMultiSem = pThis;
110 IPRT_LINUX_RESTORE_EFL_AC();
111 return VINF_SUCCESS;
112 }
113 IPRT_LINUX_RESTORE_EFL_AC();
114 return VERR_NO_MEMORY;
115}
116RT_EXPORT_SYMBOL(RTSemEventMultiCreate);
117
118
119/**
120 * Retain a reference to the semaphore.
121 *
122 * @param pThis The semaphore.
123 */
124DECLINLINE(void) rtR0SemEventMultiLnxRetain(PRTSEMEVENTMULTIINTERNAL pThis)
125{
126 uint32_t cRefs = ASMAtomicIncU32(&pThis->cRefs);
127 NOREF(cRefs);
128 Assert(cRefs && cRefs < 100000);
129}
130
131
132/**
133 * Release a reference, destroy the thing if necessary.
134 *
135 * @param pThis The semaphore.
136 */
137DECLINLINE(void) rtR0SemEventMultiLnxRelease(PRTSEMEVENTMULTIINTERNAL pThis)
138{
139 if (RT_UNLIKELY(ASMAtomicDecU32(&pThis->cRefs) == 0))
140 {
141 Assert(pThis->u32Magic != RTSEMEVENTMULTI_MAGIC);
142 RTMemFree(pThis);
143 }
144}
145
146
147RTDECL(int) RTSemEventMultiDestroy(RTSEMEVENTMULTI hEventMultiSem)
148{
149 IPRT_LINUX_SAVE_EFL_AC();
150
151 /*
152 * Validate input.
153 */
154 PRTSEMEVENTMULTIINTERNAL pThis = (PRTSEMEVENTMULTIINTERNAL)hEventMultiSem;
155 if (pThis == NIL_RTSEMEVENTMULTI)
156 return VINF_SUCCESS;
157 AssertPtrReturn(pThis, VERR_INVALID_PARAMETER);
158 AssertMsgReturn(pThis->u32Magic == RTSEMEVENTMULTI_MAGIC, ("%p u32Magic=%RX32\n", pThis, pThis->u32Magic), VERR_INVALID_PARAMETER);
159 Assert(pThis->cRefs > 0);
160
161 /*
162 * Invalidate it and signal the object just in case.
163 */
164 ASMAtomicWriteU32(&pThis->u32Magic, ~RTSEMEVENTMULTI_MAGIC);
165 ASMAtomicAndU32(&pThis->fStateAndGen, RTSEMEVENTMULTILNX_GEN_MASK);
166 Assert(!waitqueue_active(&pThis->Head));
167 wake_up_all(&pThis->Head);
168 rtR0SemEventMultiLnxRelease(pThis);
169
170 IPRT_LINUX_RESTORE_EFL_AC();
171 return VINF_SUCCESS;
172}
173RT_EXPORT_SYMBOL(RTSemEventMultiDestroy);
174
175
176RTDECL(int) RTSemEventMultiSignal(RTSEMEVENTMULTI hEventMultiSem)
177{
178 IPRT_LINUX_SAVE_EFL_AC();
179 uint32_t fNew;
180 uint32_t fOld;
181
182 /*
183 * Validate input.
184 */
185 PRTSEMEVENTMULTIINTERNAL pThis = (PRTSEMEVENTMULTIINTERNAL)hEventMultiSem;
186 if (!pThis)
187 return VERR_INVALID_PARAMETER;
188 AssertPtrReturn(pThis, VERR_INVALID_PARAMETER);
189 AssertMsgReturn(pThis->u32Magic == RTSEMEVENTMULTI_MAGIC, ("%p u32Magic=%RX32\n", pThis, pThis->u32Magic), VERR_INVALID_PARAMETER);
190 rtR0SemEventMultiLnxRetain(pThis);
191
192 /*
193 * Signal the event object. The cause of the paranoia here is racing to try
194 * deal with racing RTSemEventMultiSignal calls (should probably be
195 * forbidden, but it's relatively easy to handle).
196 */
197 do
198 {
199 fNew = fOld = ASMAtomicUoReadU32(&pThis->fStateAndGen);
200 fNew += 1 << RTSEMEVENTMULTILNX_GEN_SHIFT;
201 fNew |= RTSEMEVENTMULTILNX_STATE_MASK;
202 }
203 while (!ASMAtomicCmpXchgU32(&pThis->fStateAndGen, fNew, fOld));
204
205 wake_up_all(&pThis->Head);
206
207 rtR0SemEventMultiLnxRelease(pThis);
208 IPRT_LINUX_RESTORE_EFL_AC();
209 return VINF_SUCCESS;
210}
211RT_EXPORT_SYMBOL(RTSemEventMultiSignal);
212
213
214RTDECL(int) RTSemEventMultiReset(RTSEMEVENTMULTI hEventMultiSem)
215{
216 /*
217 * Validate input.
218 */
219 PRTSEMEVENTMULTIINTERNAL pThis = (PRTSEMEVENTMULTIINTERNAL)hEventMultiSem;
220 if (!pThis)
221 return VERR_INVALID_PARAMETER;
222 AssertPtrReturn(pThis, VERR_INVALID_PARAMETER);
223 AssertMsgReturn(pThis->u32Magic == RTSEMEVENTMULTI_MAGIC, ("%p u32Magic=%RX32\n", pThis, pThis->u32Magic), VERR_INVALID_PARAMETER);
224 rtR0SemEventMultiLnxRetain(pThis);
225
226 /*
227 * Reset it.
228 */
229 ASMAtomicAndU32(&pThis->fStateAndGen, ~RTSEMEVENTMULTILNX_STATE_MASK);
230
231 rtR0SemEventMultiLnxRelease(pThis);
232 return VINF_SUCCESS;
233}
234RT_EXPORT_SYMBOL(RTSemEventMultiReset);
235
236
237/**
238 * Worker for RTSemEventMultiWaitEx and RTSemEventMultiWaitExDebug.
239 *
240 * @returns VBox status code.
241 * @param pThis The event semaphore.
242 * @param fFlags See RTSemEventMultiWaitEx.
243 * @param uTimeout See RTSemEventMultiWaitEx.
244 * @param pSrcPos The source code position of the wait.
245 */
246static int rtR0SemEventMultiLnxWait(PRTSEMEVENTMULTIINTERNAL pThis, uint32_t fFlags, uint64_t uTimeout,
247 PCRTLOCKVALSRCPOS pSrcPos)
248{
249 uint32_t fOrgStateAndGen;
250 int rc;
251
252 /*
253 * Validate the input.
254 */
255 AssertPtrReturn(pThis, VERR_INVALID_PARAMETER);
256 AssertMsgReturn(pThis->u32Magic == RTSEMEVENTMULTI_MAGIC, ("%p u32Magic=%RX32\n", pThis, pThis->u32Magic), VERR_INVALID_PARAMETER);
257 AssertReturn(RTSEMWAIT_FLAGS_ARE_VALID(fFlags), VERR_INVALID_PARAMETER);
258 rtR0SemEventMultiLnxRetain(pThis);
259
260 /*
261 * Is the event already signalled or do we have to wait?
262 */
263 fOrgStateAndGen = ASMAtomicUoReadU32(&pThis->fStateAndGen);
264 if (fOrgStateAndGen & RTSEMEVENTMULTILNX_STATE_MASK)
265 rc = VINF_SUCCESS;
266 else
267 {
268 /*
269 * We have to wait.
270 */
271 RTR0SEMLNXWAIT Wait;
272 IPRT_LINUX_SAVE_EFL_AC();
273 rc = rtR0SemLnxWaitInit(&Wait, fFlags, uTimeout, &pThis->Head);
274 if (RT_SUCCESS(rc))
275 {
276 IPRT_DEBUG_SEMS_STATE(pThis, 'E');
277 for (;;)
278 {
279 /* The destruction test. */
280 if (RT_UNLIKELY(pThis->u32Magic != RTSEMEVENTMULTI_MAGIC))
281 rc = VERR_SEM_DESTROYED;
282 else
283 {
284 rtR0SemLnxWaitPrepare(&Wait);
285
286 /* Check the exit conditions. */
287 if (RT_UNLIKELY(pThis->u32Magic != RTSEMEVENTMULTI_MAGIC))
288 rc = VERR_SEM_DESTROYED;
289 else if (ASMAtomicUoReadU32(&pThis->fStateAndGen) != fOrgStateAndGen)
290 rc = VINF_SUCCESS;
291 else if (rtR0SemLnxWaitHasTimedOut(&Wait))
292 rc = VERR_TIMEOUT;
293 else if (rtR0SemLnxWaitWasInterrupted(&Wait))
294 rc = VERR_INTERRUPTED;
295 else
296 {
297 /* Do the wait and then recheck the conditions. */
298 rtR0SemLnxWaitDoIt(&Wait);
299 continue;
300 }
301 }
302 break;
303 }
304
305 rtR0SemLnxWaitDelete(&Wait);
306 IPRT_DEBUG_SEMS_STATE_RC(pThis, 'E', rc);
307 }
308 IPRT_LINUX_RESTORE_EFL_AC();
309 }
310
311 rtR0SemEventMultiLnxRelease(pThis);
312 return rc;
313}
314
315
316RTDECL(int) RTSemEventMultiWaitEx(RTSEMEVENTMULTI hEventMultiSem, uint32_t fFlags, uint64_t uTimeout)
317{
318#ifndef RTSEMEVENT_STRICT
319 return rtR0SemEventMultiLnxWait(hEventMultiSem, fFlags, uTimeout, NULL);
320#else
321 RTLOCKVALSRCPOS SrcPos = RTLOCKVALSRCPOS_INIT_NORMAL_API();
322 return rtR0SemEventMultiLnxWait(hEventMultiSem, fFlags, uTimeout, &SrcPos);
323#endif
324}
325RT_EXPORT_SYMBOL(RTSemEventMultiWaitEx);
326
327
328RTDECL(int) RTSemEventMultiWaitExDebug(RTSEMEVENTMULTI hEventMultiSem, uint32_t fFlags, uint64_t uTimeout,
329 RTHCUINTPTR uId, RT_SRC_POS_DECL)
330{
331 RTLOCKVALSRCPOS SrcPos = RTLOCKVALSRCPOS_INIT_DEBUG_API();
332 return rtR0SemEventMultiLnxWait(hEventMultiSem, fFlags, uTimeout, &SrcPos);
333}
334RT_EXPORT_SYMBOL(RTSemEventMultiWaitExDebug);
335
336
337RTDECL(uint32_t) RTSemEventMultiGetResolution(void)
338{
339 return rtR0SemLnxWaitGetResolution();
340}
341RT_EXPORT_SYMBOL(RTSemEventMultiGetResolution);
342
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