handletablesimple.cpp@ 27802

Last change on this file since 27802 was 25000, checked in by vboxsync, 15 years ago
IPRT: Fixed -Wshadow warnings, found two bugs in error paths.
Property svn:eol-style set to `native` Property svn:keywords set to `Author Date Id Revision`
File size: 10.3 KB

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1	/* $Id: handletablesimple.cpp 25000 2009-11-26 14:22:44Z vboxsync $ */
2	/** @file
3	* IPRT - Handle Tables.
4	*/
5
6	/*
7	* Copyright (C) 2008 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/handletable.h>
36	#include "internal/iprt.h"
37
38	#include <iprt/mem.h>
39	#include <iprt/spinlock.h>
40	#include <iprt/err.h>
41	#include <iprt/assert.h>
42	#include <iprt/param.h>
43	#include <iprt/string.h>
44	#include <iprt/asm.h>
45	#include "internal/magics.h"
46	#include "handletable.h"
47
48
49	RTDECL(int) RTHandleTableAlloc(RTHANDLETABLE hHandleTable, void pvObj, uint32_t ph)
50	{
51	/* validate the input */
52	PRTHANDLETABLEINT pThis = (PRTHANDLETABLEINT)hHandleTable;
53	AssertPtrReturn(pThis, VERR_INVALID_HANDLE);
54	AssertReturn(pThis->u32Magic == RTHANDLETABLE_MAGIC, VERR_INVALID_HANDLE);
55	AssertReturn(!(pThis->fFlags & RTHANDLETABLE_FLAGS_CONTEXT), VERR_INVALID_FUNCTION);
56	AssertReturn(!RTHT_IS_FREE(pvObj), VERR_INVALID_PARAMETER);
57	AssertPtrReturn(ph, VERR_INVALID_POINTER);
58	*ph = pThis->uBase - 1;
59
60	/*
61	* Allocation loop.
62	*/
63	RTSPINLOCKTMP Tmp /= no init /;
64	rtHandleTableLock(pThis, &Tmp);
65
66	int rc;
67	do
68	{
69	/*
70	* Try grab a free entry from the head of the free list.
71	*/
72	uint32_t i = pThis->iFreeHead;
73	if (i != NIL_RTHT_INDEX)
74	{
75	PRTHTENTRYFREE pFree = (PRTHTENTRYFREE)rtHandleTableLookupSimpleIdx(pThis, i);
76	Assert(pFree);
77	if (i == pThis->iFreeTail)
78	pThis->iFreeTail = pThis->iFreeHead = NIL_RTHT_INDEX;
79	else
80	pThis->iFreeHead = RTHT_GET_FREE_IDX(pFree);
81	pThis->cCurAllocated++;
82	Assert(pThis->cCurAllocated <= pThis->cCur);
83
84	/*
85	* Setup the entry and return.
86	*/
87	PRTHTENTRY pEntry = (PRTHTENTRY)pFree;
88	pEntry->pvObj = pvObj;
89	*ph = i + pThis->uBase;
90	rc = VINF_SUCCESS;
91	}
92	/*
93	* Must expand the handle table, unless it's full.
94	*/
95	else if (pThis->cCur >= pThis->cMax)
96	{
97	rc = VERR_NO_MORE_HANDLES;
98	Assert(pThis->cCur == pThis->cCurAllocated);
99	}
100	else
101	{
102	/*
103	* Do we have to expand the 1st level table too?
104	*/
105	uint32_t const iLevel1 = pThis->cCur / RTHT_LEVEL2_ENTRIES;
106	uint32_t cLevel1 = iLevel1 >= pThis->cLevel1
107	? pThis->cLevel1 + PAGE_SIZE / sizeof(void *)
108	: 0;
109	if (cLevel1 > pThis->cMax / RTHT_LEVEL2_ENTRIES)
110	cLevel1 = pThis->cMax / RTHT_LEVEL2_ENTRIES;
111	Assert(!cLevel1 \|\| pThis->cMax / RTHT_LEVEL2_ENTRIES >= RTHT_LEVEL1_DYN_ALLOC_THRESHOLD);
112
113	/* leave the lock (never do fancy stuff from behind a spinlock). */
114	rtHandleTableUnlock(pThis, &Tmp);
115
116	/*
117	* Do the allocation(s).
118	*/
119	rc = VERR_TRY_AGAIN;
120	void **papvLevel1 = NULL;
121	if (cLevel1)
122	{
123	papvLevel1 = (void *)RTMemAlloc(sizeof(void ) * cLevel1);
124	if (!papvLevel1)
125	return VERR_NO_MEMORY;
126	}
127
128	PRTHTENTRY paTable = (PRTHTENTRY)RTMemAlloc(sizeof(paTable) RTHT_LEVEL2_ENTRIES);
129	if (!paTable)
130	{
131	RTMemFree(papvLevel1);
132	return VERR_NO_MEMORY;
133	}
134
135	/* re-enter the lock. */
136	rtHandleTableLock(pThis, &Tmp);
137
138	/*
139	* Insert the new bits, but be a bit careful as someone might have
140	* raced us expanding the table.
141	*/
142	/* deal with the 1st level lookup expansion first */
143	if (cLevel1)
144	{
145	Assert(papvLevel1);
146	if (cLevel1 > pThis->cLevel1)
147	{
148	/* Replace the 1st level table. */
149	memcpy(papvLevel1, pThis->papvLevel1, sizeof(void ) pThis->cLevel1);
150	memset(&papvLevel1[pThis->cLevel1], 0, sizeof(void ) (cLevel1 - pThis->cLevel1));
151	pThis->cLevel1 = cLevel1;
152	void **papvTmp = pThis->papvLevel1;
153	pThis->papvLevel1 = papvLevel1;
154	papvLevel1 = papvTmp;
155	}
156
157	/* free the obsolete one (outside the lock of course) */
158	rtHandleTableUnlock(pThis, &Tmp);
159	RTMemFree(papvLevel1);
160	rtHandleTableLock(pThis, &Tmp);
161	}
162
163	/* insert the table we allocated. */
164	uint32_t iLevel1New = pThis->cCur / RTHT_LEVEL2_ENTRIES;
165	if ( iLevel1New < pThis->cLevel1
166	&& pThis->cCur < pThis->cMax)
167	{
168	pThis->papvLevel1[iLevel1New] = paTable;
169
170	/* link all entries into a free list. */
171	Assert(!(pThis->cCur % RTHT_LEVEL2_ENTRIES));
172	for (i = 0; i < RTHT_LEVEL2_ENTRIES - 1; i++)
173	RTHT_SET_FREE_IDX((PRTHTENTRYFREE)&paTable[i], i + 1 + pThis->cCur);
174	RTHT_SET_FREE_IDX((PRTHTENTRYFREE)&paTable[RTHT_LEVEL2_ENTRIES - 1], NIL_RTHT_INDEX);
175
176	/* join the free list with the other. */
177	if (pThis->iFreeTail == NIL_RTHT_INDEX)
178	pThis->iFreeHead = pThis->cCur;
179	else
180	{
181	PRTHTENTRYFREE pPrev = (PRTHTENTRYFREE)rtHandleTableLookupSimpleIdx(pThis, pThis->iFreeTail);
182	Assert(pPrev);
183	RTHT_SET_FREE_IDX(pPrev, pThis->cCur);
184	}
185	pThis->iFreeTail = pThis->cCur + RTHT_LEVEL2_ENTRIES - 1;
186
187	pThis->cCur += RTHT_LEVEL2_ENTRIES;
188	}
189	else
190	{
191	/* free the table (raced someone, and we lost). */
192	rtHandleTableUnlock(pThis, &Tmp);
193	RTMemFree(paTable);
194	rtHandleTableLock(pThis, &Tmp);
195	}
196
197	rc = VERR_TRY_AGAIN;
198	}
199	} while (rc == VERR_TRY_AGAIN);
200
201	rtHandleTableUnlock(pThis, &Tmp);
202
203	return rc;
204	}
205	RT_EXPORT_SYMBOL(RTHandleTableAlloc);
206
207
208	RTDECL(void *) RTHandleTableLookup(RTHANDLETABLE hHandleTable, uint32_t h)
209	{
210	/* validate the input */
211	PRTHANDLETABLEINT pThis = (PRTHANDLETABLEINT)hHandleTable;
212	AssertPtrReturn(pThis, NULL);
213	AssertReturn(pThis->u32Magic == RTHANDLETABLE_MAGIC, NULL);
214	AssertReturn(!(pThis->fFlags & RTHANDLETABLE_FLAGS_CONTEXT), NULL);
215
216	void *pvObj = NULL;
217
218	/* acquire the lock */
219	RTSPINLOCKTMP Tmp /= no init /;
220	rtHandleTableLock(pThis, &Tmp);
221
222	/*
223	* Perform the lookup and retaining.
224	*/
225	PRTHTENTRY pEntry = rtHandleTableLookupSimple(pThis, h);
226	if (pEntry)
227	{
228	pvObj = pEntry->pvObj;
229	if (!RTHT_IS_FREE(pvObj))
230	{
231	if (pThis->pfnRetain)
232	{
233	int rc = pThis->pfnRetain(hHandleTable, pEntry->pvObj, NULL, pThis->pvRetainUser);
234	if (RT_FAILURE(rc))
235	pvObj = NULL;
236	}
237	}
238	else
239	pvObj = NULL;
240	}
241
242	/* release the lock */
243	rtHandleTableUnlock(pThis, &Tmp);
244	return pvObj;
245	}
246	RT_EXPORT_SYMBOL(RTHandleTableLookup);
247
248
249	RTDECL(void *) RTHandleTableFree(RTHANDLETABLE hHandleTable, uint32_t h)
250	{
251	/* validate the input */
252	PRTHANDLETABLEINT pThis = (PRTHANDLETABLEINT)hHandleTable;
253	AssertPtrReturn(pThis, NULL);
254	AssertReturn(pThis->u32Magic == RTHANDLETABLE_MAGIC, NULL);
255	AssertReturn(!(pThis->fFlags & RTHANDLETABLE_FLAGS_CONTEXT), NULL);
256
257	void *pvObj = NULL;
258
259	/* acquire the lock */
260	RTSPINLOCKTMP Tmp /= no init /;
261	rtHandleTableLock(pThis, &Tmp);
262
263	/*
264	* Perform the lookup and retaining.
265	*/
266	PRTHTENTRY pEntry = rtHandleTableLookupSimple(pThis, h);
267	if (pEntry)
268	{
269	pvObj = pEntry->pvObj;
270	if (!RTHT_IS_FREE(pvObj))
271	{
272	if (pThis->pfnRetain)
273	{
274	int rc = pThis->pfnRetain(hHandleTable, pEntry->pvObj, NULL, pThis->pvRetainUser);
275	if (RT_FAILURE(rc))
276	pvObj = NULL;
277	}
278
279	/*
280	* Link it into the free list.
281	*/
282	if (pvObj)
283	{
284	PRTHTENTRYFREE pFree = (PRTHTENTRYFREE)pEntry;
285	RTHT_SET_FREE_IDX(pFree, NIL_RTHT_INDEX);
286
287	uint32_t const i = h - pThis->uBase;
288	if (pThis->iFreeTail == NIL_RTHT_INDEX)
289	pThis->iFreeHead = pThis->iFreeTail = i;
290	else
291	{
292	PRTHTENTRYFREE pPrev = (PRTHTENTRYFREE)rtHandleTableLookupSimpleIdx(pThis, pThis->iFreeTail);
293	Assert(pPrev);
294	RTHT_SET_FREE_IDX(pPrev, i);
295	pThis->iFreeTail = i;
296	}
297
298	Assert(pThis->cCurAllocated > 0);
299	pThis->cCurAllocated--;
300	}
301	}
302	else
303	pvObj = NULL;
304	}
305
306	/* release the lock */
307	rtHandleTableUnlock(pThis, &Tmp);
308	return pvObj;
309	}
310	RT_EXPORT_SYMBOL(RTHandleTableFree);
311

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source: vbox/trunk/src/VBox/Runtime/common/misc/handletablesimple.cpp@ 27802

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