Adding upstream version 6.0.4-dfsg.upstream/6.0.4-dfsgupstream

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 249 insertions, 0 deletions

diff --git a/include/iprt/handletable.h b/include/iprt/handletable.h
new file mode 100644
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+++ b/include/iprt/handletable.h
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+/** @file
+ * IPRT - Handle Tables.
+ */
+
+/*
+ * Copyright (C) 2008-2019 Oracle Corporation
+ *
+ * This file is part of VirtualBox Open Source Edition (OSE), as
+ * available from http://www.virtualbox.org. This file is free software;
+ * you can redistribute it and/or modify it under the terms of the GNU
+ * General Public License (GPL) as published by the Free Software
+ * Foundation, in version 2 as it comes in the "COPYING" file of the
+ * VirtualBox OSE distribution. VirtualBox OSE is distributed in the
+ * hope that it will be useful, but WITHOUT ANY WARRANTY of any kind.
+ *
+ * The contents of this file may alternatively be used under the terms
+ * of the Common Development and Distribution License Version 1.0
+ * (CDDL) only, as it comes in the "COPYING.CDDL" file of the
+ * VirtualBox OSE distribution, in which case the provisions of the
+ * CDDL are applicable instead of those of the GPL.
+ *
+ * You may elect to license modified versions of this file under the
+ * terms and conditions of either the GPL or the CDDL or both.
+ */
+
+#ifndef IPRT_INCLUDED_handletable_h
+#define IPRT_INCLUDED_handletable_h
+#ifndef RT_WITHOUT_PRAGMA_ONCE
+# pragma once
+#endif
+
+#include <iprt/cdefs.h>
+#include <iprt/types.h>
+
+RT_C_DECLS_BEGIN
+
+/** @defgroup grp_rt_handletable    RTHandleTable - Handle Tables
+ * @ingroup grp_rt
+ * @{
+ */
+
+/**
+ * Callback for retaining an object during the lookup and free calls.
+ *
+ * This callback is executed when a handle is being looked up in one
+ * way or another from behind the handle table lock. This allows you
+ * to increase the reference (or some equivalent thing) during the
+ * handle lookup and thereby eliminate any race with anyone trying
+ * to free the handle.
+ *
+ * Note that there is no counterpart to this callback, so if you make
+ * use of this you'll have to release the object manually of course.
+ *
+ * Another use of this callback is to do some extra access checking.
+ * Use the return code to indicate whether the lookup should fail
+ * or not (no object is returned on faliure, naturally).
+ *
+ * @returns IPRT status code for the lookup (the caller won't see this).
+ *
+ * @param   hHandleTable    The handle table handle.
+ * @param   pvObj           The object which has been looked up.
+ * @param   pvCtx           The context argument if the handle table was created with the
+ *                          RTHANDLETABLE_FLAGS_CONTEXT set. Otherwise NULL.
+ * @param   pvUser          The user context argument specified when creating the table.
+ */
+typedef DECLCALLBACK(int) FNRTHANDLETABLERETAIN(RTHANDLETABLE hHandleTable, void *pvObj, void *pvCtx, void *pvUser);
+/** Pointer to a FNHANDLETABLERETAIN. */
+typedef FNRTHANDLETABLERETAIN *PFNRTHANDLETABLERETAIN;
+
+/**
+ * Callback for deleting a left over object during RTHandleTableDestroy.
+ *
+ * @param   hHandleTable    The handle table handle.
+ * @param   h               The handle.
+ * @param   pvObj           The object.
+ * @param   pvCtx           The context argument if the handle table was created with the
+ *                          RTHANDLETABLE_FLAGS_CONTEXT set. Otherwise NULL.
+ * @param   pvUser          The user context argument specified when creating the table.
+ *
+ */
+typedef DECLCALLBACK(void) FNRTHANDLETABLEDELETE(RTHANDLETABLE hHandleTable, uint32_t h, void *pvObj, void *pvCtx, void *pvUser);
+/** Pointer to a FNRTHANDLETABLEDELETE. */
+typedef FNRTHANDLETABLEDELETE *PFNRTHANDLETABLEDELETE;
+
+
+/** @name RTHandleTableCreateEx flags
+ * @{ */
+/** Whether the handle table entries takes a context or not.
+ *
+ * This can be useful for associating a handle with for instance a process or
+ * similar in order to prevent anyone but the owner from using the handle.
+ *
+ * Setting this means you will have to use the WithCtx functions to do the
+ * handle management. */
+#define RTHANDLETABLE_FLAGS_CONTEXT         RT_BIT_32(0)
+/** Whether the handle table should take care of the serialization (IRQ unsafe).
+ * If not specified the caller will have to take care of that. */
+#define RTHANDLETABLE_FLAGS_LOCKED          RT_BIT_32(1)
+/** Like RTHANDLETABLE_FLAGS_LOCKED, except it's IRQ safe.
+ * A side-effect is that callbacks may be called with IRQs disabled.  */
+#define RTHANDLETABLE_FLAGS_LOCKED_IRQ_SAFE RT_BIT_32(2)
+/** The mask of valid flags. */
+#define RTHANDLETABLE_FLAGS_MASK            UINT32_C(0x00000007)
+/** @} */
+
+
+/**
+ * Creates a handle table.
+ *
+ * The handle table translates a 32-bit handle into an object pointer,
+ * optionally calling you back so you can retain the object without
+ * racing RTHandleTableFree.
+ *
+ * @returns IPRT status code and on success a handle table handle will be stored at the
+ *          location phHandleTable points at.
+ *
+ * @param   phHandleTable   Where to store the handle table handle on success.
+ * @param   fFlags          Flags, see RTHANDLETABLE_FLAGS_*.
+ * @param   uBase           The handle base value. This is the value of the
+ *                          first handle to be returned.
+ * @param   cMax            The max number of handles. When exceeded the RTHandleTableAlloc
+ *                          or RTHandleTableAllocWithCtx calls will fail. Note that this
+ *                          number will be rounded up to a multiple of the sub-table size,
+ *                          or if it's too close to UINT32_MAX it will be rounded down.
+ * @param   pfnRetain       Optional retain callback that will be called from behind the
+ *                          lock (if any) during lookup.
+ * @param   pvUser          The user argument to the retain callback.
+ */
+RTDECL(int)     RTHandleTableCreateEx(PRTHANDLETABLE phHandleTable, uint32_t fFlags, uint32_t uBase, uint32_t cMax,
+                                      PFNRTHANDLETABLERETAIN pfnRetain, void *pvUser);
+
+/**
+ * A simplified version of the RTHandleTableCreateEx API.
+ *
+ * It assumes a max of about 64K handles with 1 being the base. The table
+ * access will serialized (RTHANDLETABLE_FLAGS_LOCKED).
+ *
+ * @returns IPRT status code and *phHandleTable.
+ *
+ * @param   phHandleTable   Where to store the handle table handle on success.
+ */
+RTDECL(int)     RTHandleTableCreate(PRTHANDLETABLE phHandleTable);
+
+/**
+ * Destroys a handle table.
+ *
+ * If any entries are still in used the pfnDelete callback will be invoked
+ * on each of them (if specfied) to allow to you clean things up.
+ *
+ * @returns IPRT status code
+ *
+ * @param   hHandleTable    The handle to the handle table.
+ * @param   pfnDelete       Function to be called back on each handle still in use. Optional.
+ * @param   pvUser          The user argument to pfnDelete.
+ */
+RTDECL(int)     RTHandleTableDestroy(RTHANDLETABLE hHandleTable, PFNRTHANDLETABLEDELETE pfnDelete, void *pvUser);
+
+/**
+ * Allocates a handle from the handle table.
+ *
+ * @returns IPRT status code, almost any.
+ * @retval  VINF_SUCCESS on success.
+ * @retval  VERR_NO_MEMORY if we failed to extend the handle table.
+ * @retval  VERR_NO_MORE_HANDLES if we're out of handles.
+ *
+ * @param   hHandleTable    The handle to the handle table.
+ * @param   pvObj           The object to associate with the new handle.
+ *                          This must be aligned on a 4 byte boundary.
+ * @param   ph              Where to return the handle on success.
+ *
+ * @remarks Do not call this if RTHANDLETABLE_FLAGS_CONTEXT was used during creation.
+ */
+RTDECL(int)     RTHandleTableAlloc(RTHANDLETABLE hHandleTable, void *pvObj, uint32_t *ph);
+
+/**
+ * Looks up a handle.
+ *
+ * @returns The object pointer on success. NULL on failure.
+ *
+ * @param   hHandleTable    The handle to the handle table.
+ * @param   h               The handle to lookup.
+ *
+ * @remarks Do not call this if RTHANDLETABLE_FLAGS_CONTEXT was used during creation.
+ */
+RTDECL(void *)  RTHandleTableLookup(RTHANDLETABLE hHandleTable, uint32_t h);
+
+/**
+ * Looks up and frees a handle.
+ *
+ * @returns The object pointer on success. NULL on failure.
+ *
+ * @param   hHandleTable    The handle to the handle table.
+ * @param   h               The handle to lookup.
+ *
+ * @remarks Do not call this if RTHANDLETABLE_FLAGS_CONTEXT was used during creation.
+ */
+RTDECL(void *)  RTHandleTableFree(RTHANDLETABLE hHandleTable, uint32_t h);
+
+/**
+ * Allocates a handle from the handle table.
+ *
+ * @returns IPRT status code, almost any.
+ * @retval  VINF_SUCCESS on success.
+ * @retval  VERR_NO_MEMORY if we failed to extend the handle table.
+ * @retval  VERR_NO_MORE_HANDLES if we're out of handles.
+ *
+ * @param   hHandleTable    The handle to the handle table.
+ * @param   pvObj           The object to associate with the new handle.
+ *                          This must be aligned on a 4 byte boundary.
+ * @param   pvCtx           The context to associate with the new handle.
+ * @param   ph              Where to return the handle on success.
+ *
+ * @remarks Call this if RTHANDLETABLE_FLAGS_CONTEXT was used during creation.
+ */
+RTDECL(int)     RTHandleTableAllocWithCtx(RTHANDLETABLE hHandleTable, void *pvObj, void *pvCtx, uint32_t *ph);
+
+/**
+ * Looks up a handle.
+ *
+ * @returns The object pointer on success. NULL on failure.
+ *
+ * @param   hHandleTable    The handle to the handle table.
+ * @param   h               The handle to lookup.
+ * @param   pvCtx           The handle context, this must match what was given on allocation.
+ *
+ * @remarks Call this if RTHANDLETABLE_FLAGS_CONTEXT was used during creation.
+ */
+RTDECL(void *)  RTHandleTableLookupWithCtx(RTHANDLETABLE hHandleTable, uint32_t h, void *pvCtx);
+
+/**
+ * Looks up and frees a handle.
+ *
+ * @returns The object pointer on success. NULL on failure.
+ *
+ * @param   hHandleTable    The handle to the handle table.
+ * @param   h               The handle to lookup.
+ * @param   pvCtx           The handle context, this must match what was given on allocation.
+ *
+ * @remarks Call this if RTHANDLETABLE_FLAGS_CONTEXT was used during creation.
+ */
+RTDECL(void *)  RTHandleTableFreeWithCtx(RTHANDLETABLE hHandleTable, uint32_t h, void *pvCtx);
+
+/** @} */
+
+RT_C_DECLS_END
+
+
+#endif /* !IPRT_INCLUDED_handletable_h */
+