VirtualBox

source: vbox/trunk/src/VBox/Runtime/r0drv/linux/semevent-r0drv-linux.c@ 13040

Last change on this file since 13040 was 8245, checked in by vboxsync, 17 years ago

rebranding: IPRT files again.

  • Property svn:eol-style set to native
  • Property svn:keywords set to Id
File size: 6.8 KB
Line 
1/* $Id: semevent-r0drv-linux.c 8245 2008-04-21 17:24:28Z vboxsync $ */
2/** @file
3 * IPRT - Single Release Event Semaphores, Ring-0 Driver, Linux.
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 "the-linux-kernel.h"
36#include <iprt/semaphore.h>
37#include <iprt/alloc.h>
38#include <iprt/assert.h>
39#include <iprt/asm.h>
40#include <iprt/err.h>
41
42#include "internal/magics.h"
43
44
45/*******************************************************************************
46* Structures and Typedefs *
47*******************************************************************************/
48/**
49 * Linux event semaphore.
50 */
51typedef struct RTSEMEVENTINTERNAL
52{
53 /** Magic value (RTSEMEVENT_MAGIC). */
54 uint32_t volatile u32Magic;
55 /** The object status - !0 when signaled and 0 when reset. */
56 uint32_t volatile fState;
57 /** The wait queue. */
58 wait_queue_head_t Head;
59} RTSEMEVENTINTERNAL, *PRTSEMEVENTINTERNAL;
60
61
62
63RTDECL(int) RTSemEventCreate(PRTSEMEVENT pEventSem)
64{
65 PRTSEMEVENTINTERNAL pEventInt = (PRTSEMEVENTINTERNAL)RTMemAlloc(sizeof(*pEventInt));
66 if (pEventInt)
67 {
68 pEventInt->u32Magic = RTSEMEVENT_MAGIC;
69 init_waitqueue_head(&pEventInt->Head);
70 *pEventSem = pEventInt;
71 return VINF_SUCCESS;
72 }
73 return VERR_NO_MEMORY;
74}
75
76
77RTDECL(int) RTSemEventDestroy(RTSEMEVENT EventSem)
78{
79 /*
80 * Validate input.
81 */
82 PRTSEMEVENTINTERNAL pEventInt = (PRTSEMEVENTINTERNAL)EventSem;
83 if (!pEventInt)
84 return VERR_INVALID_PARAMETER;
85 if (pEventInt->u32Magic != RTSEMEVENT_MAGIC)
86 {
87 AssertMsgFailed(("pEventInt->u32Magic=%RX32 pEventInt=%p\n", pEventInt->u32Magic, pEventInt));
88 return VERR_INVALID_PARAMETER;
89 }
90
91 /*
92 * Invalidate it and signal the object just in case.
93 */
94 ASMAtomicIncU32(&pEventInt->u32Magic);
95 ASMAtomicXchgU32(&pEventInt->fState, 0);
96 Assert(!waitqueue_active(&pEventInt->Head));
97 wake_up_all(&pEventInt->Head);
98 RTMemFree(pEventInt);
99 return VINF_SUCCESS;
100}
101
102
103RTDECL(int) RTSemEventSignal(RTSEMEVENT EventSem)
104{
105 /*
106 * Validate input.
107 */
108 PRTSEMEVENTINTERNAL pEventInt = (PRTSEMEVENTINTERNAL)EventSem;
109 if (!pEventInt)
110 return VERR_INVALID_PARAMETER;
111 if ( !pEventInt
112 || pEventInt->u32Magic != RTSEMEVENT_MAGIC)
113 {
114 AssertMsgFailed(("pEventInt->u32Magic=%RX32 pEventInt=%p\n", pEventInt ? pEventInt->u32Magic : 0, pEventInt));
115 return VERR_INVALID_PARAMETER;
116 }
117
118 /*
119 * Signal the event object.
120 */
121 ASMAtomicXchgU32(&pEventInt->fState, 1);
122 wake_up(&pEventInt->Head);
123
124 return VINF_SUCCESS;
125}
126
127
128/**
129 * Worker for RTSemEvent and RTSemEventNoResume.
130 *
131 * @returns VBox status code.
132 * @param pEventInt The event semaphore.
133 * @param cMillies The number of milliseconds to wait.
134 * @param fInterruptible Whether it's an interruptible wait or not.
135 */
136static int rtSemEventWait(PRTSEMEVENTINTERNAL pEventInt, unsigned cMillies, bool fInterruptible)
137{
138 /*
139 * Ok wait for it.
140 */
141 DEFINE_WAIT(Wait);
142 int rc = VINF_SUCCESS;
143 long lTimeout = cMillies == RT_INDEFINITE_WAIT ? MAX_SCHEDULE_TIMEOUT : msecs_to_jiffies(cMillies);
144#ifdef IPRT_DEBUG_SEMS
145 snprintf(current->comm, TASK_COMM_LEN, "e%lx", IPRT_DEBUG_SEMS_ADDRESS(pEventInt));
146#endif
147 for (;;)
148 {
149 /* make everything thru schedule() atomic scheduling wise. */
150 prepare_to_wait(&pEventInt->Head, &Wait, fInterruptible ? TASK_INTERRUPTIBLE : TASK_UNINTERRUPTIBLE);
151
152 /* check the condition. */
153 if (ASMAtomicCmpXchgU32(&pEventInt->fState, 0, 1))
154 break;
155
156 /* check for pending signals. */
157 if (fInterruptible && signal_pending(current))
158 {
159 rc = VERR_INTERRUPTED;
160 break;
161 }
162
163 /* wait */
164 lTimeout = schedule_timeout(lTimeout);
165
166 /* Check if someone destroyed the semaphore while we were waiting. */
167 if (pEventInt->u32Magic != RTSEMEVENT_MAGIC)
168 {
169 rc = VERR_SEM_DESTROYED;
170 break;
171 }
172
173 /* check for timeout. */
174 if (!lTimeout)
175 {
176 rc = VERR_TIMEOUT;
177 break;
178 }
179 }
180
181 finish_wait(&pEventInt->Head, &Wait);
182#ifdef IPRT_DEBUG_SEMS
183 snprintf(current->comm, TASK_COMM_LEN, "e%lx:%d", IPRT_DEBUG_SEMS_ADDRESS(pEventInt), rc);
184#endif
185 return rc;
186}
187
188
189RTDECL(int) RTSemEventWait(RTSEMEVENT EventSem, unsigned cMillies)
190{
191 PRTSEMEVENTINTERNAL pEventInt = (PRTSEMEVENTINTERNAL)EventSem;
192 if (!pEventInt)
193 return VERR_INVALID_PARAMETER;
194 if ( !pEventInt
195 || pEventInt->u32Magic != RTSEMEVENT_MAGIC)
196 {
197 AssertMsgFailed(("pEventInt->u32Magic=%RX32 pEventInt=%p\n", pEventInt ? pEventInt->u32Magic : 0, pEventInt));
198 return VERR_INVALID_PARAMETER;
199 }
200
201 if (ASMAtomicCmpXchgU32(&pEventInt->fState, 0, 1))
202 return VINF_SUCCESS;
203 return rtSemEventWait(pEventInt, cMillies, false /* fInterruptible */);
204}
205
206
207RTDECL(int) RTSemEventWaitNoResume(RTSEMEVENT EventSem, unsigned cMillies)
208{
209 PRTSEMEVENTINTERNAL pEventInt = (PRTSEMEVENTINTERNAL)EventSem;
210 if (!pEventInt)
211 return VERR_INVALID_PARAMETER;
212 if ( !pEventInt
213 || pEventInt->u32Magic != RTSEMEVENT_MAGIC)
214 {
215 AssertMsgFailed(("pEventInt->u32Magic=%RX32 pEventInt=%p\n", pEventInt ? pEventInt->u32Magic : 0, pEventInt));
216 return VERR_INVALID_PARAMETER;
217 }
218
219 if (ASMAtomicCmpXchgU32(&pEventInt->fState, 0, 1))
220 return VINF_SUCCESS;
221 return rtSemEventWait(pEventInt, cMillies, true /* fInterruptible */);
222}
223
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