handletablectx.cpp@ 10789

Last change on this file since 10789 was 10789, checked in by vboxsync, 16 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: 10.5 KB

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1	/* $Id: handletablectx.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.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	* 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) RTHandleTableAllocWithCtx(RTHANDLETABLE hHandleTable, void pvObj, void pvCtx, 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)rtHandleTableLookupWithCtxIdx(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	PRTHTENTRYCTX pEntry = (PRTHTENTRYCTX)pFree;
85	pEntry->pvObj = pvObj;
86	pEntry->pvCtx = pvCtx;
87	*ph = i + pThis->uBase;
88	rc = VINF_SUCCESS;
89	}
90	/*
91	* Must expand the handle table, unless it's full.
92	*/
93	else if (pThis->cCur >= pThis->cMax)
94	{
95	rc = VERR_NO_MORE_HANDLES;
96	Assert(pThis->cCur == pThis->cCurAllocated);
97	}
98	else
99	{
100	/*
101	* Do we have to expand the 1st level table too?
102	*/
103	uint32_t const iLevel1 = pThis->cCur / RTHT_LEVEL2_ENTRIES;
104	uint32_t cLevel1 = iLevel1 >= pThis->cLevel1
105	? pThis->cLevel1 + PAGE_SIZE / sizeof(void *)
106	: 0;
107	if (cLevel1 > pThis->cMax / RTHT_LEVEL2_ENTRIES)
108	cLevel1 = pThis->cMax / RTHT_LEVEL2_ENTRIES;
109	Assert(!cLevel1 \|\| pThis->cMax / RTHT_LEVEL2_ENTRIES >= RTHT_LEVEL1_DYN_ALLOC_THRESHOLD);
110
111	/* leave the lock (never do fancy stuff from behind a spinlock). */
112	rtHandleTableUnlock(pThis, &Tmp);
113
114	/*
115	* Do the allocation(s).
116	*/
117	rc = VERR_TRY_AGAIN;
118	void **papvLevel1 = NULL;
119	if (cLevel1)
120	{
121	papvLevel1 = (void *)RTMemAlloc(sizeof(void ) * cLevel1);
122	if (!papvLevel1)
123	return VERR_NO_MEMORY;
124	}
125
126	PRTHTENTRYCTX paTable = (PRTHTENTRYCTX)RTMemAlloc(sizeof(paTable) RTHT_LEVEL2_ENTRIES);
127	if (!paTable)
128	{
129	RTMemFree(papvLevel1);
130	return VERR_NO_MEMORY;
131	}
132
133	/* re-enter the lock. */
134	rtHandleTableLock(pThis, &Tmp);
135
136	/*
137	* Insert the new bits, but be a bit careful as someone might have
138	* raced us expanding the table.
139	*/
140	/* deal with the 1st level lookup expansion first */
141	if (cLevel1)
142	{
143	Assert(papvLevel1);
144	if (cLevel1 > pThis->cLevel1)
145	{
146	/* Replace the 1st level table. */
147	memcpy(papvLevel1, pThis->papvLevel1, sizeof(void ) pThis->cLevel1);
148	memset(&papvLevel1[pThis->cLevel1], 0, sizeof(void ) (cLevel1 - pThis->cLevel1));
149	pThis->cLevel1 = cLevel1;
150	void **papvTmp = pThis->papvLevel1;
151	pThis->papvLevel1 = papvLevel1;
152	papvLevel1 = papvTmp;
153	}
154
155	/* free the obsolete one (outside the lock of course) */
156	rtHandleTableUnlock(pThis, &Tmp);
157	RTMemFree(papvLevel1);
158	rtHandleTableLock(pThis, &Tmp);
159	}
160
161	/* insert the table we allocated */
162	if (pThis->cCur < pThis->cMax)
163	{
164	uint32_t iLevel1New = pThis->cCur / RTHT_LEVEL2_ENTRIES;
165	pThis->papvLevel1[iLevel1New] = paTable;
166
167	/* link all entries into a free list. */
168	Assert(!(pThis->cCur % RTHT_LEVEL2_ENTRIES));
169	for (uint32_t i = 0; i < RTHT_LEVEL2_ENTRIES - 1; i++)
170	{
171	RTHT_SET_FREE_IDX((PRTHTENTRYFREE)&paTable[i], i + 1 + pThis->cCur);
172	paTable[i].pvCtx = (void *)~(uintptr_t)7;
173	}
174	RTHT_SET_FREE_IDX((PRTHTENTRYFREE)&paTable[RTHT_LEVEL2_ENTRIES - 1], NIL_RTHT_INDEX);
175	paTable[RTHT_LEVEL2_ENTRIES - 1].pvCtx = (void *)~(uintptr_t)7;
176
177	/* join the free list with the other. */
178	if (pThis->iFreeTail == NIL_RTHT_INDEX)
179	pThis->iFreeHead = pThis->cCur;
180	else
181	{
182	PRTHTENTRYFREE pPrev = (PRTHTENTRYFREE)rtHandleTableLookupWithCtxIdx(pThis, pThis->iFreeTail);
183	Assert(pPrev);
184	RTHT_SET_FREE_IDX(pPrev, pThis->cCur);
185	}
186	pThis->iFreeTail = pThis->cCur + RTHT_LEVEL2_ENTRIES - 1;
187
188	pThis->cCur += RTHT_LEVEL2_ENTRIES;
189	}
190	else
191	{
192	/* free the table (raced someone, and we lost). */
193	rtHandleTableUnlock(pThis, &Tmp);
194	RTMemFree(paTable);
195	rtHandleTableLock(pThis, &Tmp);
196	}
197
198	rc = VERR_TRY_AGAIN;
199	}
200	} while (rc == VERR_TRY_AGAIN);
201
202	rtHandleTableUnlock(pThis, &Tmp);
203
204	return rc;
205	}
206
207
208	RTDECL(void ) RTHandleTableLookupWithCtx(RTHANDLETABLE hHandleTable, uint32_t h, void pvCtx)
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;
220	rtHandleTableLock(pThis, &Tmp);
221
222	/*
223	* Perform the lookup and retaining.
224	*/
225	PRTHTENTRYCTX pEntry = rtHandleTableLookupWithCtx(pThis, h);
226	if (pEntry && pEntry->pvCtx == pvCtx)
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, pvCtx, 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
247
248	RTDECL(void ) RTHandleTableFreeWithCtx(RTHANDLETABLE hHandleTable, uint32_t h, void pvCtx)
249	{
250	/* validate the input */
251	PRTHANDLETABLEINT pThis = (PRTHANDLETABLEINT)hHandleTable;
252	AssertPtrReturn(pThis, NULL);
253	AssertReturn(pThis->u32Magic == RTHANDLETABLE_MAGIC, NULL);
254	AssertReturn(pThis->fFlags & RTHANDLETABLE_FLAGS_CONTEXT, NULL);
255
256	void *pvObj = NULL;
257
258	/* acquire the lock */
259	RTSPINLOCKTMP Tmp;
260	rtHandleTableLock(pThis, &Tmp);
261
262	/*
263	* Perform the lookup and retaining.
264	*/
265	PRTHTENTRYCTX pEntry = rtHandleTableLookupWithCtx(pThis, h);
266	if (pEntry && pEntry->pvCtx == pvCtx)
267	{
268	pvObj = pEntry->pvObj;
269	if (!RTHT_IS_FREE(pvObj))
270	{
271	if (pThis->pfnRetain)
272	{
273	int rc = pThis->pfnRetain(hHandleTable, pEntry->pvObj, pvCtx, pThis->pvRetainUser);
274	if (RT_FAILURE(rc))
275	pvObj = NULL;
276	}
277
278	/*
279	* Link it into the free list.
280	*/
281	if (pvObj)
282	{
283	pEntry->pvCtx = (void *)~(uintptr_t)7;
284
285	PRTHTENTRYFREE pFree = (PRTHTENTRYFREE)pEntry;
286	RTHT_SET_FREE_IDX(pFree, NIL_RTHT_INDEX);
287
288	uint32_t const i = h - pThis->uBase;
289	if (pThis->iFreeTail == NIL_RTHT_INDEX)
290	pThis->iFreeHead = pThis->iFreeTail = i;
291	else
292	{
293	PRTHTENTRYFREE pPrev = (PRTHTENTRYFREE)rtHandleTableLookupWithCtxIdx(pThis, pThis->iFreeTail);
294	Assert(pPrev);
295	RTHT_SET_FREE_IDX(pPrev, i);
296	pThis->iFreeTail = i;
297	}
298
299	Assert(pThis->cCurAllocated > 0);
300	pThis->cCurAllocated--;
301	}
302	}
303	else
304	pvObj = NULL;
305	}
306
307	/* release the lock */
308	rtHandleTableUnlock(pThis, &Tmp);
309	return pvObj;
310	}
311

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

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