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, 160 insertions, 0 deletions

diff --git a/include/iprt/shmem.h b/include/iprt/shmem.h
new file mode 100644
index 00000000..74877903
--- /dev/null
+++ b/include/iprt/shmem.h
@@ -0,0 +1,160 @@
+/** @file
+ * IPRT - Named shared memory.
+ */
+
+/*
+ * Copyright (C) 2018-2019 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_shmem_h
+#define IPRT_INCLUDED_shmem_h
+#ifndef RT_WITHOUT_PRAGMA_ONCE
+# pragma once
+#endif
+
+#include <iprt/types.h>
+
+RT_C_DECLS_BEGIN
+
+/** @defgroup grp_rt_shmem RTShMem - Shared memory.
+ * @ingroup grp_rt
+ */
+
+/** @name Open flags for RTShMemOpen().
+ * @{
+ */
+/** Creates a new shared memory object or opens an already existing one. */
+#define RTSHMEM_O_F_CREATE            RT_BIT_32(0)
+/** Creates a new shared memory object failing if one with the same name exists already. */
+#define RTSHMEM_O_F_CREATE_EXCL       (RTSHMEM_O_F_CREATE | RT_BIT_32(1))
+/** Opens the shared memory object for read access. */
+#define RTSHMEM_O_F_READ              RT_BIT_32(2)
+/** Opens the shared memory object for write access. */
+#define RTSHMEM_O_F_WRITE             RT_BIT_32(3)
+/** Opens the shared memory object for read and write access. */
+#define RTSHMEM_O_F_READWRITE         (RTSHMEM_O_F_READ | RTSHMEM_O_F_WRITE)
+/** Truncates the shared memory object to 0 bytes on open. */
+#define RTSHMEM_O_F_TRUNCATE          RT_BIT_32(4)
+/** Mappings may be created with executable access right (required to be known on Windows beforehand). */
+#define RTSHMEM_O_F_MAYBE_EXEC        RT_BIT_32(5)
+/** Mask of all valid flags. */
+#define RTSHMEM_O_F_VALID_MASK        UINT32_C(0x0000003f)
+/** @} */
+
+/**
+ * Creates or opens a new shared memory object with the given name.
+ *
+ * @returns IPRT status code.
+ * @retval VERR_OUT_OF_RANGE if the mapping hint count is too big.
+ * @param   phShMem         Where to store the handle to the shared memory object on success.
+ * @param   pszName         Name of the shared memory object to open or create.
+ * @param   fFlags          Combination of RTSHMEM_O_F_* flags.
+ * @param   cbMax           Maximum number of bytes to reserve for the shared memory object.
+ *                          On some platforms this can be 0 and set to another value using RTShMemSetSize() afterwards.
+ *                          Giving 0 on Windows results in an error as shared memory objects there do not support
+ *                          changing the size afterwards.
+ * @param   cMappingsHint   Hint about the possible number of mappings created later on, set to 0 for a default value.
+ */
+RTDECL(int) RTShMemOpen(PRTSHMEM phShMem, const char *pszName, uint32_t fFlags, size_t cbMax, uint32_t cMappingsHint);
+
+/**
+ * Closes the given shared memory object.
+ *
+ * @returns IPRT status code.
+ * @retval  VERR_INVALID_STATE if there is still a mapping active for the given shared memory object.
+ * @param   hShMem          The shared memory object handle.
+ *
+ * @note The shared memory object will be deleted if the creator closes it.
+ */
+RTDECL(int) RTShMemClose(RTSHMEM hShMem);
+
+/**
+ * Returns the number of references (i.e. mappings) held for the given shared memory object.
+ *
+ * @returns Reference count or 0 on invalid handle.
+ * @param   hShMem          The shared memory object handle.
+ */
+RTDECL(uint32_t) RTShMemRefCount(RTSHMEM hShMem);
+
+/**
+ * Sets the size of the given shared memory object.
+ *
+ * @returns IPRT status code.
+ * @retval  VERR_INVALID_STATE if there are mappings active for the given shared memory object.
+ * @retval  VERR_NOT_SUPPORTED on some hosts which do not support changing the size after creation.
+ * @param   hShMem          The shared memory object handle.
+ * @param   cbMem           Size of the memory object handle in bytes.
+ */
+RTDECL(int) RTShMemSetSize(RTSHMEM hShMem, size_t cbMem);
+
+/**
+ * Queries the current size of the shared memory object.
+ *
+ * @returns IPRT status code.
+ * @param   hShMem          The shared memory object handle.
+ * @param   pcbMem          Where to store the size of the shared memory object on success.
+ */
+RTDECL(int) RTShMemQuerySize(RTSHMEM hShMem, size_t *pcbMem);
+
+/** @name Region mapping flags for RTShMemMapRegion().
+ * @{
+ */
+/** Read access. */
+#define RTSHMEM_MAP_F_READ            RT_BIT_32(0)
+/** Write access. */
+#define RTSHMEM_MAP_F_WRITE           RT_BIT_32(1)
+/** Execute access. */
+#define RTSHMEM_MAP_F_EXEC            RT_BIT_32(2)
+/** Copy on write, any write creates a new page private to the callers address space and changes
+ * in that area are not shared with other processes using the hsared memory object. */
+#define RTSHMEM_MAP_F_COW             RT_BIT_32(3)
+/** Mask of all valid flags. */
+#define RTSHMEM_MAP_F_VALID_MASK      UINT32_C(0x0000000f)
+/** @} */
+
+/**
+ * Maps a region of the given shared memory object into the callers address space.
+ *
+ * @returns IPRT status code.
+ * @retval  VERR_SHMEM_MAXIMUM_MAPPINGS_REACHED if the maximum number of mappings was reached (host dependent).
+ * @retval  VERR_ACCESS_DENIED if the requested memory access rights do not line up with the flags given when opening
+ *          the memory object (requesting write access for a readonly shared memory object for example).
+ * @param   hShMem          The shared memory object handle.
+ * @param   offRegion       Offset into the shared memory object to start mapping at.
+ * @param   cbRegion        Size of the region to map.
+ * @param   fFlags          Desired properties of the mapped region, combination of RTSHMEM_MAP_F_* defines.
+ * @param   ppv             Where to store the start address of the mapped region on success.
+ */
+RTDECL(int) RTShMemMapRegion(RTSHMEM hShMem, size_t offRegion, size_t cbRegion, uint32_t fFlags, void **ppv);
+
+/**
+ * Unmaps the given region of the shared memory object.
+ *
+ * @returns IPRT status code.
+ * @param   hShMem          The shared memory object handle.
+ * @param   pv              Pointer to the mapped region obtained with RTShMemMapRegion() earlier on.
+ */
+RTDECL(int) RTShMemUnmapRegion(RTSHMEM hShMem, void *pv);
+
+/** @} */
+RT_C_DECLS_END
+
+#endif /* !IPRT_INCLUDED_shmem_h */
+