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, 155 insertions, 0 deletions

diff --git a/include/iprt/circbuf.h b/include/iprt/circbuf.h
new file mode 100644
index 00000000..17d01451
--- /dev/null
+++ b/include/iprt/circbuf.h
@@ -0,0 +1,155 @@
+/** @file
+ * IPRT - Lock Free Circular Buffer
+ */
+
+/*
+ * Copyright (C) 2010-2019 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_circbuf_h
+#define IPRT_INCLUDED_circbuf_h
+#ifndef RT_WITHOUT_PRAGMA_ONCE
+# pragma once
+#endif
+
+#include <iprt/types.h>
+
+/** @defgroup grp_rt_circbuf    RTCircBuf - Lock Free Circular Buffer
+ * @ingroup grp_rt
+ *
+ * Implementation of a lock free circular buffer which could be used in a multi
+ * threaded environment. Note that only the acquire, release and getter
+ * functions are threading aware. So don't use reset if the circular buffer is
+ * still in use.
+ *
+ * @{
+ */
+
+RT_C_DECLS_BEGIN
+
+/** Pointer to a circular buffer (abstract). */
+typedef struct RTCIRCBUF *PRTCIRCBUF;
+
+/**
+ * Create a circular buffer.
+ *
+ * @returns IPRT status code.
+ *
+ * @param   ppBuf          Where to store the buffer.
+ * @param   cbSize         The size of the new buffer.
+ */
+RTDECL(int) RTCircBufCreate(PRTCIRCBUF *ppBuf, size_t cbSize);
+
+/**
+ * Destroy the circular buffer.
+ *
+ * @param   pBuf           The buffer to destroy.  NULL is ignored.
+ */
+RTDECL(void) RTCircBufDestroy(PRTCIRCBUF pBuf);
+
+/**
+ * Reset all position information in the circular buffer.
+ *
+ * @note This function is not multi threading aware.
+ *
+ * @param   pBuf           The buffer to reset.
+ */
+RTDECL(void) RTCircBufReset(PRTCIRCBUF pBuf);
+
+/**
+ * Returns the current free space of the buffer.
+ *
+ * @param   pBuf           The buffer to query.
+ */
+RTDECL(size_t) RTCircBufFree(PRTCIRCBUF pBuf);
+
+/**
+ * Returns the current used space of the buffer.
+ *
+ * @param   pBuf           The buffer to query.
+ */
+RTDECL(size_t) RTCircBufUsed(PRTCIRCBUF pBuf);
+
+/**
+ * Returns the size of the buffer.
+ *
+ * @param   pBuf           The buffer to query.
+ */
+RTDECL(size_t) RTCircBufSize(PRTCIRCBUF pBuf);
+
+RTDECL(bool) RTCircBufIsReading(PRTCIRCBUF pBuf);
+RTDECL(bool) RTCircBufIsWriting(PRTCIRCBUF pBuf);
+
+/**
+ * Returns the current read offset (in bytes) within the buffer.
+ *
+ * @param   pBuf           The buffer to query.
+ */
+RTDECL(size_t) RTCircBufOffsetRead(PRTCIRCBUF pBuf);
+
+/**
+ * Returns the current write offset (in bytes) within the buffer.
+ *
+ * @param   pBuf           The buffer to query.
+ */
+RTDECL(size_t) RTCircBufOffsetWrite(PRTCIRCBUF pBuf);
+
+/**
+ * Acquire a block of the circular buffer for reading.
+ *
+ * @param   pBuf           The buffer to acquire from.
+ * @param   cbReqSize      The requested size of the block.
+ * @param   ppvStart       The resulting memory pointer.
+ * @param   pcbSize        The resulting size of the memory pointer.
+ */
+RTDECL(void) RTCircBufAcquireReadBlock(PRTCIRCBUF pBuf, size_t cbReqSize, void **ppvStart, size_t *pcbSize);
+
+/**
+ * Release a block which was acquired by RTCircBufAcquireReadBlock.
+ *
+ * @param   pBuf           The buffer to acquire from.
+ * @param   cbSize         The size of the block.
+ */
+RTDECL(void) RTCircBufReleaseReadBlock(PRTCIRCBUF pBuf, size_t cbSize);
+
+/**
+ * Acquire a block of the circular buffer for writing.
+ *
+ * @param   pBuf           The buffer to acquire from.
+ * @param   cbReqSize      The requested size of the block.
+ * @param   ppvStart       The resulting memory pointer.
+ * @param   pcbSize        The resulting size of the memory pointer.
+ */
+RTDECL(void) RTCircBufAcquireWriteBlock(PRTCIRCBUF pBuf, size_t cbReqSize, void **ppvStart, size_t *pcbSize);
+
+/**
+ * Release a block which was acquired by RTCircBufAcquireWriteBlock.
+ *
+ * @param   pBuf           The buffer to acquire from.
+ * @param   cbSize         The size of the block.
+ */
+RTDECL(void) RTCircBufReleaseWriteBlock(PRTCIRCBUF pBuf, size_t cbSize);
+
+RT_C_DECLS_END
+
+/** @} */
+
+#endif /* !IPRT_INCLUDED_circbuf_h */
+