handletablesimple.cpp@ 10789

Last change on this file since 10789 was 10789, checked in by vboxsync, 17 years ago
IPRT: Implemented the simple handle table variant too.
Property svn:eol-style set to `native` Property svn:keywords set to `Author Date Id Revision`
File size: 10.1 KB

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1	/* $Id: handletablesimple.cpp 10789 2008-07-21 17:22:32Z 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.215389.xyz. 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	* Header Files *
33	*******************************************************************************/
34	#include <iprt/handletable.h>
35	#include <iprt/mem.h>
36	#include <iprt/spinlock.h>
37	#include <iprt/err.h>
38	#include <iprt/assert.h>
39	#include <iprt/param.h>
40	#include <iprt/string.h>
41	#include <iprt/asm.h>
42	#include "internal/magics.h"
43	#include "handletable.h"
44
45
46	RTDECL(int) RTHandleTableAlloc(RTHANDLETABLE hHandleTable, void pvObj, uint32_t ph)
47	{
48	/* validate the input */
49	PRTHANDLETABLEINT pThis = (PRTHANDLETABLEINT)hHandleTable;
50	AssertPtrReturn(pThis, VERR_INVALID_HANDLE);
51	AssertReturn(pThis->u32Magic == RTHANDLETABLE_MAGIC, VERR_INVALID_HANDLE);
52	AssertReturn(!(pThis->fFlags & RTHANDLETABLE_FLAGS_CONTEXT), VERR_INVALID_FUNCTION);
53	AssertReturn(!RTHT_IS_FREE(pvObj), VERR_INVALID_PARAMETER);
54	AssertPtrReturn(ph, VERR_INVALID_POINTER);
55	*ph = pThis->uBase - 1;
56
57	/*
58	* Allocation loop.
59	*/
60	RTSPINLOCKTMP Tmp;
61	rtHandleTableLock(pThis, &Tmp);
62
63	int rc;
64	do
65	{
66	/*
67	* Try grab a free entry from the head of the free list.
68	*/
69	uint32_t i = pThis->iFreeHead;
70	if (i != NIL_RTHT_INDEX)
71	{
72	PRTHTENTRYFREE pFree = (PRTHTENTRYFREE)rtHandleTableLookupSimpleIdx(pThis, i);
73	Assert(pFree);
74	if (i == pThis->iFreeTail)
75	pThis->iFreeTail = pThis->iFreeHead = NIL_RTHT_INDEX;
76	else
77	pThis->iFreeHead = RTHT_GET_FREE_IDX(pFree);
78	pThis->cCurAllocated++;
79	Assert(pThis->cCurAllocated <= pThis->cCur);
80
81	/*
82	* Setup the entry and return.
83	*/
84	PRTHTENTRY pEntry = (PRTHTENTRY)pFree;
85	pEntry->pvObj = pvObj;
86	*ph = i + pThis->uBase;
87	rc = VINF_SUCCESS;
88	}
89	/*
90	* Must expand the handle table, unless it's full.
91	*/
92	else if (pThis->cCur >= pThis->cMax)
93	{
94	rc = VERR_NO_MORE_HANDLES;
95	Assert(pThis->cCur == pThis->cCurAllocated);
96	}
97	else
98	{
99	/*
100	* Do we have to expand the 1st level table too?
101	*/
102	uint32_t const iLevel1 = pThis->cCur / RTHT_LEVEL2_ENTRIES;
103	uint32_t cLevel1 = iLevel1 >= pThis->cLevel1
104	? pThis->cLevel1 + PAGE_SIZE / sizeof(void *)
105	: 0;
106	if (cLevel1 > pThis->cMax / RTHT_LEVEL2_ENTRIES)
107	cLevel1 = pThis->cMax / RTHT_LEVEL2_ENTRIES;
108	Assert(!cLevel1 \|\| pThis->cMax / RTHT_LEVEL2_ENTRIES >= RTHT_LEVEL1_DYN_ALLOC_THRESHOLD);
109
110	/* leave the lock (never do fancy stuff from behind a spinlock). */
111	rtHandleTableUnlock(pThis, &Tmp);
112
113	/*
114	* Do the allocation(s).
115	*/
116	rc = VERR_TRY_AGAIN;
117	void **papvLevel1 = NULL;
118	if (cLevel1)
119	{
120	papvLevel1 = (void *)RTMemAlloc(sizeof(void ) * cLevel1);
121	if (!papvLevel1)
122	return VERR_NO_MEMORY;
123	}
124
125	PRTHTENTRY paTable = (PRTHTENTRY)RTMemAlloc(sizeof(paTable) RTHT_LEVEL2_ENTRIES);
126	if (!paTable)
127	{
128	RTMemFree(papvLevel1);
129	return VERR_NO_MEMORY;
130	}
131
132	/* re-enter the lock. */
133	rtHandleTableLock(pThis, &Tmp);
134
135	/*
136	* Insert the new bits, but be a bit careful as someone might have
137	* raced us expanding the table.
138	*/
139	/* deal with the 1st level lookup expansion first */
140	if (cLevel1)
141	{
142	Assert(papvLevel1);
143	if (cLevel1 > pThis->cLevel1)
144	{
145	/* Replace the 1st level table. */
146	memcpy(papvLevel1, pThis->papvLevel1, sizeof(void ) pThis->cLevel1);
147	memset(&papvLevel1[pThis->cLevel1], 0, sizeof(void ) (cLevel1 - pThis->cLevel1));
148	pThis->cLevel1 = cLevel1;
149	void **papvTmp = pThis->papvLevel1;
150	pThis->papvLevel1 = papvLevel1;
151	papvLevel1 = papvTmp;
152	}
153
154	/* free the obsolete one (outside the lock of course) */
155	rtHandleTableUnlock(pThis, &Tmp);
156	RTMemFree(papvLevel1);
157	rtHandleTableLock(pThis, &Tmp);
158	}
159
160	/* insert the table we allocated */
161	if (pThis->cCur < pThis->cMax)
162	{
163	uint32_t iLevel1New = pThis->cCur / RTHT_LEVEL2_ENTRIES;
164	pThis->papvLevel1[iLevel1New] = paTable;
165
166	/* link all entries into a free list. */
167	Assert(!(pThis->cCur % RTHT_LEVEL2_ENTRIES));
168	for (uint32_t i = 0; i < RTHT_LEVEL2_ENTRIES - 1; i++)
169	RTHT_SET_FREE_IDX((PRTHTENTRYFREE)&paTable[i], i + 1 + pThis->cCur);
170	RTHT_SET_FREE_IDX((PRTHTENTRYFREE)&paTable[RTHT_LEVEL2_ENTRIES - 1], NIL_RTHT_INDEX);
171
172	/* join the free list with the other. */
173	if (pThis->iFreeTail == NIL_RTHT_INDEX)
174	pThis->iFreeHead = pThis->cCur;
175	else
176	{
177	PRTHTENTRYFREE pPrev = (PRTHTENTRYFREE)rtHandleTableLookupSimpleIdx(pThis, pThis->iFreeTail);
178	Assert(pPrev);
179	RTHT_SET_FREE_IDX(pPrev, pThis->cCur);
180	}
181	pThis->iFreeTail = pThis->cCur + RTHT_LEVEL2_ENTRIES - 1;
182
183	pThis->cCur += RTHT_LEVEL2_ENTRIES;
184	}
185	else
186	{
187	/* free the table (raced someone, and we lost). */
188	rtHandleTableUnlock(pThis, &Tmp);
189	RTMemFree(paTable);
190	rtHandleTableLock(pThis, &Tmp);
191	}
192
193	rc = VERR_TRY_AGAIN;
194	}
195	} while (rc == VERR_TRY_AGAIN);
196
197	rtHandleTableUnlock(pThis, &Tmp);
198
199	return rc;
200	}
201
202
203	RTDECL(void *) RTHandleTableLookup(RTHANDLETABLE hHandleTable, uint32_t h)
204	{
205	/* validate the input */
206	PRTHANDLETABLEINT pThis = (PRTHANDLETABLEINT)hHandleTable;
207	AssertPtrReturn(pThis, NULL);
208	AssertReturn(pThis->u32Magic == RTHANDLETABLE_MAGIC, NULL);
209	AssertReturn(!(pThis->fFlags & RTHANDLETABLE_FLAGS_CONTEXT), NULL);
210
211	void *pvObj = NULL;
212
213	/* acquire the lock */
214	RTSPINLOCKTMP Tmp;
215	rtHandleTableLock(pThis, &Tmp);
216
217	/*
218	* Perform the lookup and retaining.
219	*/
220	PRTHTENTRY pEntry = rtHandleTableLookupSimple(pThis, h);
221	if (pEntry)
222	{
223	pvObj = pEntry->pvObj;
224	if (!RTHT_IS_FREE(pvObj))
225	{
226	if (pThis->pfnRetain)
227	{
228	int rc = pThis->pfnRetain(hHandleTable, pEntry->pvObj, NULL, pThis->pvRetainUser);
229	if (RT_FAILURE(rc))
230	pvObj = NULL;
231	}
232	}
233	else
234	pvObj = NULL;
235	}
236
237	/* release the lock */
238	rtHandleTableUnlock(pThis, &Tmp);
239	return pvObj;
240	}
241
242
243	RTDECL(void *) RTHandleTableFree(RTHANDLETABLE hHandleTable, uint32_t h)
244	{
245	/* validate the input */
246	PRTHANDLETABLEINT pThis = (PRTHANDLETABLEINT)hHandleTable;
247	AssertPtrReturn(pThis, NULL);
248	AssertReturn(pThis->u32Magic == RTHANDLETABLE_MAGIC, NULL);
249	AssertReturn(!(pThis->fFlags & RTHANDLETABLE_FLAGS_CONTEXT), NULL);
250
251	void *pvObj = NULL;
252
253	/* acquire the lock */
254	RTSPINLOCKTMP Tmp;
255	rtHandleTableLock(pThis, &Tmp);
256
257	/*
258	* Perform the lookup and retaining.
259	*/
260	PRTHTENTRY pEntry = rtHandleTableLookupSimple(pThis, h);
261	if (pEntry)
262	{
263	pvObj = pEntry->pvObj;
264	if (!RTHT_IS_FREE(pvObj))
265	{
266	if (pThis->pfnRetain)
267	{
268	int rc = pThis->pfnRetain(hHandleTable, pEntry->pvObj, NULL, pThis->pvRetainUser);
269	if (RT_FAILURE(rc))
270	pvObj = NULL;
271	}
272
273	/*
274	* Link it into the free list.
275	*/
276	if (pvObj)
277	{
278	PRTHTENTRYFREE pFree = (PRTHTENTRYFREE)pEntry;
279	RTHT_SET_FREE_IDX(pFree, NIL_RTHT_INDEX);
280
281	uint32_t const i = h - pThis->uBase;
282	if (pThis->iFreeTail == NIL_RTHT_INDEX)
283	pThis->iFreeHead = pThis->iFreeTail = i;
284	else
285	{
286	PRTHTENTRYFREE pPrev = (PRTHTENTRYFREE)rtHandleTableLookupSimpleIdx(pThis, pThis->iFreeTail);
287	Assert(pPrev);
288	RTHT_SET_FREE_IDX(pPrev, i);
289	pThis->iFreeTail = i;
290	}
291
292	Assert(pThis->cCurAllocated > 0);
293	pThis->cCurAllocated--;
294	}
295	}
296	else
297	pvObj = NULL;
298	}
299
300	/* release the lock */
301	rtHandleTableUnlock(pThis, &Tmp);
302	return pvObj;
303	}
304

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source: vbox/trunk/src/VBox/Runtime/common/misc/handletablesimple.cpp@ 10789

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