handletablectx.cpp@ 69111

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1	/* $Id: handletablectx.cpp 69111 2017-10-17 14:26:02Z vboxsync $ */
2	/** @file
3	* IPRT - Handle Tables.
4	*/
5
6	/*
7	* Copyright (C) 2008-2017 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	#include <iprt/handletable.h>
32	#include "internal/iprt.h"
33
34	#include <iprt/mem.h>
35	#include <iprt/spinlock.h>
36	#include <iprt/err.h>
37	#include <iprt/assert.h>
38	#include <iprt/param.h>
39	#include <iprt/string.h>
40	#include <iprt/asm.h>
41	#include "internal/magics.h"
42	#include "handletable.h"
43
44
45	RTDECL(int) RTHandleTableAllocWithCtx(RTHANDLETABLE hHandleTable, void pvObj, void pvCtx, uint32_t *ph)
46	{
47	PRTHANDLETABLEINT pThis;
48	int rc;
49
50	/* validate the input */
51	pThis = (PRTHANDLETABLEINT)hHandleTable;
52	AssertPtrReturn(pThis, VERR_INVALID_HANDLE);
53	AssertReturn(pThis->u32Magic == RTHANDLETABLE_MAGIC, VERR_INVALID_HANDLE);
54	AssertReturn(pThis->fFlags & RTHANDLETABLE_FLAGS_CONTEXT, VERR_INVALID_FUNCTION);
55	AssertReturn(!RTHT_IS_FREE(pvObj), VERR_INVALID_PARAMETER);
56	AssertPtrReturn(ph, VERR_INVALID_POINTER);
57	*ph = pThis->uBase - 1;
58
59	/*
60	* Allocation loop.
61	*/
62	rtHandleTableLock(pThis);
63
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	PRTHTENTRYCTX pEntry;
73	PRTHTENTRYFREE pFree = (PRTHTENTRYFREE)rtHandleTableLookupWithCtxIdx(pThis, i);
74	Assert(pFree);
75	if (i == pThis->iFreeTail)
76	pThis->iFreeTail = pThis->iFreeHead = NIL_RTHT_INDEX;
77	else
78	pThis->iFreeHead = RTHT_GET_FREE_IDX(pFree);
79	pThis->cCurAllocated++;
80	Assert(pThis->cCurAllocated <= pThis->cCur);
81
82	/*
83	* Setup the entry and return.
84	*/
85	pEntry = (PRTHTENTRYCTX)pFree;
86	pEntry->pvObj = pvObj;
87	pEntry->pvCtx = pvCtx;
88	*ph = i + pThis->uBase;
89	rc = VINF_SUCCESS;
90	}
91	/*
92	* Must expand the handle table, unless it's full.
93	*/
94	else if (pThis->cCur >= pThis->cMax)
95	{
96	rc = VERR_NO_MORE_HANDLES;
97	Assert(pThis->cCur == pThis->cCurAllocated);
98	}
99	else
100	{
101	void **papvLevel1;
102	uint32_t iLevel1New;
103	PRTHTENTRYCTX paTable;
104
105	/*
106	* Do we have to expand the 1st level table too?
107	*/
108	uint32_t const iLevel1 = pThis->cCur / RTHT_LEVEL2_ENTRIES;
109	uint32_t cLevel1 = iLevel1 >= pThis->cLevel1
110	? pThis->cLevel1 + PAGE_SIZE / sizeof(void *)
111	: 0;
112	if (cLevel1 > pThis->cMax / RTHT_LEVEL2_ENTRIES)
113	cLevel1 = pThis->cMax / RTHT_LEVEL2_ENTRIES;
114	Assert(!cLevel1 \|\| pThis->cMax / RTHT_LEVEL2_ENTRIES >= RTHT_LEVEL1_DYN_ALLOC_THRESHOLD);
115
116	/* leave the lock (never do fancy stuff from behind a spinlock). */
117	rtHandleTableUnlock(pThis);
118
119	/*
120	* Do the allocation(s).
121	*/
122	rc = VERR_TRY_AGAIN;
123	papvLevel1 = NULL;
124	if (cLevel1)
125	{
126	papvLevel1 = (void *)RTMemAlloc(sizeof(void ) * cLevel1);
127	if (!papvLevel1)
128	return VERR_NO_MEMORY;
129	}
130
131	paTable = (PRTHTENTRYCTX)RTMemAlloc(sizeof(paTable) RTHT_LEVEL2_ENTRIES);
132	if (!paTable)
133	{
134	RTMemFree(papvLevel1);
135	return VERR_NO_MEMORY;
136	}
137
138	/* re-enter the lock. */
139	rtHandleTableLock(pThis);
140
141	/*
142	* Insert the new bits, but be a bit careful as someone might have
143	* raced us expanding the table.
144	*/
145	/* deal with the 1st level lookup expansion first */
146	if (cLevel1)
147	{
148	Assert(papvLevel1);
149	if (cLevel1 > pThis->cLevel1)
150	{
151	void **papvTmp;
152
153	/* Replace the 1st level table. */
154	memcpy(papvLevel1, pThis->papvLevel1, sizeof(void ) pThis->cLevel1);
155	memset(&papvLevel1[pThis->cLevel1], 0, sizeof(void ) (cLevel1 - pThis->cLevel1));
156	pThis->cLevel1 = cLevel1;
157	papvTmp = pThis->papvLevel1;
158	pThis->papvLevel1 = papvLevel1;
159	papvLevel1 = papvTmp;
160	}
161
162	/* free the obsolete one (outside the lock of course) */
163	rtHandleTableUnlock(pThis);
164	RTMemFree(papvLevel1);
165	rtHandleTableLock(pThis);
166	}
167
168	/* insert the table we allocated. */
169	iLevel1New = pThis->cCur / RTHT_LEVEL2_ENTRIES;
170	if ( iLevel1New < pThis->cLevel1
171	&& pThis->cCur < pThis->cMax)
172	{
173	pThis->papvLevel1[iLevel1New] = paTable;
174
175	/* link all entries into a free list. */
176	Assert(!(pThis->cCur % RTHT_LEVEL2_ENTRIES));
177	for (i = 0; i < RTHT_LEVEL2_ENTRIES - 1; i++)
178	{
179	RTHT_SET_FREE_IDX((PRTHTENTRYFREE)&paTable[i], i + 1 + pThis->cCur);
180	paTable[i].pvCtx = (void *)~(uintptr_t)7;
181	}
182	RTHT_SET_FREE_IDX((PRTHTENTRYFREE)&paTable[RTHT_LEVEL2_ENTRIES - 1], NIL_RTHT_INDEX);
183	paTable[RTHT_LEVEL2_ENTRIES - 1].pvCtx = (void *)~(uintptr_t)7;
184
185	/* join the free list with the other. */
186	if (pThis->iFreeTail == NIL_RTHT_INDEX)
187	pThis->iFreeHead = pThis->cCur;
188	else
189	{
190	PRTHTENTRYFREE pPrev = (PRTHTENTRYFREE)rtHandleTableLookupWithCtxIdx(pThis, pThis->iFreeTail);
191	Assert(pPrev);
192	RTHT_SET_FREE_IDX(pPrev, pThis->cCur);
193	}
194	pThis->iFreeTail = pThis->cCur + RTHT_LEVEL2_ENTRIES - 1;
195
196	pThis->cCur += RTHT_LEVEL2_ENTRIES;
197	}
198	else
199	{
200	/* free the table (raced someone, and we lost). */
201	rtHandleTableUnlock(pThis);
202	RTMemFree(paTable);
203	rtHandleTableLock(pThis);
204	}
205
206	rc = VERR_TRY_AGAIN;
207	}
208	} while (rc == VERR_TRY_AGAIN);
209
210	rtHandleTableUnlock(pThis);
211
212	return rc;
213	}
214	RT_EXPORT_SYMBOL(RTHandleTableAllocWithCtx);
215
216
217	RTDECL(void ) RTHandleTableLookupWithCtx(RTHANDLETABLE hHandleTable, uint32_t h, void pvCtx)
218	{
219	void *pvObj = NULL;
220	PRTHTENTRYCTX pEntry;
221	PRTHANDLETABLEINT pThis;
222
223	/* validate the input */
224	pThis = (PRTHANDLETABLEINT)hHandleTable;
225	AssertPtrReturn(pThis, NULL);
226	AssertReturn(pThis->u32Magic == RTHANDLETABLE_MAGIC, NULL);
227	AssertReturn(pThis->fFlags & RTHANDLETABLE_FLAGS_CONTEXT, NULL);
228
229
230	/* acquire the lock */
231	rtHandleTableLock(pThis);
232
233	/*
234	* Perform the lookup and retaining.
235	*/
236	pEntry = rtHandleTableLookupWithCtx(pThis, h);
237	if (pEntry && pEntry->pvCtx == pvCtx)
238	{
239	pvObj = pEntry->pvObj;
240	if (!RTHT_IS_FREE(pvObj))
241	{
242	if (pThis->pfnRetain)
243	{
244	int rc = pThis->pfnRetain(hHandleTable, pEntry->pvObj, pvCtx, pThis->pvRetainUser);
245	if (RT_FAILURE(rc))
246	pvObj = NULL;
247	}
248	}
249	else
250	pvObj = NULL;
251	}
252
253	/* release the lock */
254	rtHandleTableUnlock(pThis);
255	return pvObj;
256	}
257	RT_EXPORT_SYMBOL(RTHandleTableLookupWithCtx);
258
259
260	RTDECL(void ) RTHandleTableFreeWithCtx(RTHANDLETABLE hHandleTable, uint32_t h, void pvCtx)
261	{
262	void *pvObj = NULL;
263	PRTHTENTRYCTX pEntry;
264	PRTHANDLETABLEINT pThis;
265
266	/* validate the input */
267	pThis = (PRTHANDLETABLEINT)hHandleTable;
268	AssertPtrReturn(pThis, NULL);
269	AssertReturn(pThis->u32Magic == RTHANDLETABLE_MAGIC, NULL);
270	AssertReturn(pThis->fFlags & RTHANDLETABLE_FLAGS_CONTEXT, NULL);
271
272
273	/* acquire the lock */
274	rtHandleTableLock(pThis);
275
276	/*
277	* Perform the lookup and retaining.
278	*/
279	pEntry = rtHandleTableLookupWithCtx(pThis, h);
280	if (pEntry && pEntry->pvCtx == pvCtx)
281	{
282	pvObj = pEntry->pvObj;
283	if (!RTHT_IS_FREE(pvObj))
284	{
285	if (pThis->pfnRetain)
286	{
287	int rc = pThis->pfnRetain(hHandleTable, pEntry->pvObj, pvCtx, pThis->pvRetainUser);
288	if (RT_FAILURE(rc))
289	pvObj = NULL;
290	}
291
292	/*
293	* Link it into the free list.
294	*/
295	if (pvObj)
296	{
297	PRTHTENTRYFREE pFree;
298	uint32_t i;
299
300	pEntry->pvCtx = (void *)~(uintptr_t)7;
301
302	pFree = (PRTHTENTRYFREE)pEntry;
303	RTHT_SET_FREE_IDX(pFree, NIL_RTHT_INDEX);
304
305	i = h - pThis->uBase;
306	if (pThis->iFreeTail == NIL_RTHT_INDEX)
307	pThis->iFreeHead = pThis->iFreeTail = i;
308	else
309	{
310	PRTHTENTRYFREE pPrev = (PRTHTENTRYFREE)rtHandleTableLookupWithCtxIdx(pThis, pThis->iFreeTail);
311	Assert(pPrev);
312	RTHT_SET_FREE_IDX(pPrev, i);
313	pThis->iFreeTail = i;
314	}
315
316	Assert(pThis->cCurAllocated > 0);
317	pThis->cCurAllocated--;
318	}
319	}
320	else
321	pvObj = NULL;
322	}
323
324	/* release the lock */
325	rtHandleTableUnlock(pThis);
326	return pvObj;
327	}
328	RT_EXPORT_SYMBOL(RTHandleTableFreeWithCtx);
329

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source: vbox/trunk/src/VBox/Runtime/common/misc/handletablectx.cpp@ 69111

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