pipe-posix.cpp revision 4efd24e631e5312d1fb78ae7ccaf9de912ff0e9f
4efd24e631e5312d1fb78ae7ccaf9de912ff0e9fvboxsync * IPRT - Anonymous Pipes, POSIX Implementation.
637712559132d2b3617aea0103fb0385978da14evboxsync * Copyright (C) 2010 Sun Microsystems, Inc.
637712559132d2b3617aea0103fb0385978da14evboxsync * This file is part of VirtualBox Open Source Edition (OSE), as
637712559132d2b3617aea0103fb0385978da14evboxsync * available from http://www.virtualbox.org. This file is free software;
637712559132d2b3617aea0103fb0385978da14evboxsync * you can redistribute it and/or modify it under the terms of the GNU
637712559132d2b3617aea0103fb0385978da14evboxsync * General Public License (GPL) as published by the Free Software
637712559132d2b3617aea0103fb0385978da14evboxsync * Foundation, in version 2 as it comes in the "COPYING" file of the
637712559132d2b3617aea0103fb0385978da14evboxsync * VirtualBox OSE distribution. VirtualBox OSE is distributed in the
637712559132d2b3617aea0103fb0385978da14evboxsync * hope that it will be useful, but WITHOUT ANY WARRANTY of any kind.
637712559132d2b3617aea0103fb0385978da14evboxsync * The contents of this file may alternatively be used under the terms
637712559132d2b3617aea0103fb0385978da14evboxsync * of the Common Development and Distribution License Version 1.0
637712559132d2b3617aea0103fb0385978da14evboxsync * (CDDL) only, as it comes in the "COPYING.CDDL" file of the
637712559132d2b3617aea0103fb0385978da14evboxsync * VirtualBox OSE distribution, in which case the provisions of the
637712559132d2b3617aea0103fb0385978da14evboxsync * CDDL are applicable instead of those of the GPL.
637712559132d2b3617aea0103fb0385978da14evboxsync * You may elect to license modified versions of this file under the
637712559132d2b3617aea0103fb0385978da14evboxsync * terms and conditions of either the GPL or the CDDL or both.
637712559132d2b3617aea0103fb0385978da14evboxsync * Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa
637712559132d2b3617aea0103fb0385978da14evboxsync * Clara, CA 95054 USA or visit http://www.sun.com if you need
637712559132d2b3617aea0103fb0385978da14evboxsync * additional information or have any questions.
637712559132d2b3617aea0103fb0385978da14evboxsync/*******************************************************************************
637712559132d2b3617aea0103fb0385978da14evboxsync* Header Files *
637712559132d2b3617aea0103fb0385978da14evboxsync*******************************************************************************/
b41f65ee355ae1d4b24473c6d6d70c653497429avboxsync/*******************************************************************************
b41f65ee355ae1d4b24473c6d6d70c653497429avboxsync* Structures and Typedefs *
b41f65ee355ae1d4b24473c6d6d70c653497429avboxsync*******************************************************************************/
b41f65ee355ae1d4b24473c6d6d70c653497429avboxsync /** Magic value (RTPIPE_MAGIC). */
b41f65ee355ae1d4b24473c6d6d70c653497429avboxsync /** The file descriptor. */
b41f65ee355ae1d4b24473c6d6d70c653497429avboxsync /** Set if this is the read end, clear if it's the write end. */
b41f65ee355ae1d4b24473c6d6d70c653497429avboxsync /** Atomically operated state variable.
b41f65ee355ae1d4b24473c6d6d70c653497429avboxsync * - Bits 0 thru 29 - Users of the new mode.
b41f65ee355ae1d4b24473c6d6d70c653497429avboxsync * - Bit 30 - The pipe mode, set indicates blocking.
b41f65ee355ae1d4b24473c6d6d70c653497429avboxsync * - Bit 31 - Set when we're switching the mode.
b41f65ee355ae1d4b24473c6d6d70c653497429avboxsync/*******************************************************************************
b41f65ee355ae1d4b24473c6d6d70c653497429avboxsync* Defined Constants And Macros *
b41f65ee355ae1d4b24473c6d6d70c653497429avboxsync*******************************************************************************/
b41f65ee355ae1d4b24473c6d6d70c653497429avboxsync/** @name RTPIPEINTERNAL::u32State defines
b41f65ee355ae1d4b24473c6d6d70c653497429avboxsync#define RTPIPE_POSIX_USERS_MASK UINT32_C(0x3fffffff)
637712559132d2b3617aea0103fb0385978da14evboxsyncRTDECL(int) RTPipeCreate(PRTPIPE phPipeRead, PRTPIPE phPipeWrite, uint32_t fFlags)
b41f65ee355ae1d4b24473c6d6d70c653497429avboxsync AssertPtrReturn(phPipeWrite, VERR_INVALID_POINTER);
b41f65ee355ae1d4b24473c6d6d70c653497429avboxsync AssertReturn(!(fFlags & ~RTPIPE_C_VALID_MASK), VERR_INVALID_PARAMETER);
b41f65ee355ae1d4b24473c6d6d70c653497429avboxsync * Create the pipe and set the close-on-exec flag if requested.
b41f65ee355ae1d4b24473c6d6d70c653497429avboxsync * Create the two handles.
b41f65ee355ae1d4b24473c6d6d70c653497429avboxsync RTPIPEINTERNAL *pThisR = (RTPIPEINTERNAL *)RTMemAlloc(sizeof(RTPIPEINTERNAL));
b41f65ee355ae1d4b24473c6d6d70c653497429avboxsync RTPIPEINTERNAL *pThisW = (RTPIPEINTERNAL *)RTMemAlloc(sizeof(RTPIPEINTERNAL));
b41f65ee355ae1d4b24473c6d6d70c653497429avboxsync * Before we leave, make sure to shut up SIGPIPE.
b41f65ee355ae1d4b24473c6d6d70c653497429avboxsync AssertReturn(pThis->u32Magic == RTPIPE_MAGIC, VERR_INVALID_HANDLE);
b41f65ee355ae1d4b24473c6d6d70c653497429avboxsync * Do the cleanup.
b41f65ee355ae1d4b24473c6d6d70c653497429avboxsync AssertReturn(ASMAtomicCmpXchgU32(&pThis->u32Magic, ~RTPIPE_MAGIC, RTPIPE_MAGIC), VERR_INVALID_HANDLE);
b41f65ee355ae1d4b24473c6d6d70c653497429avboxsync if (ASMAtomicReadU32(&pThis->u32State) & RTPIPE_POSIX_USERS_MASK)
b41f65ee355ae1d4b24473c6d6d70c653497429avboxsync AssertPtrReturn(pThis, (RTHCINTPTR)(unsigned int)-1);
b41f65ee355ae1d4b24473c6d6d70c653497429avboxsync AssertReturn(pThis->u32Magic == RTPIPE_MAGIC, (RTHCINTPTR)(unsigned int)-1);
b41f65ee355ae1d4b24473c6d6d70c653497429avboxsync * Prepare blocking mode.
b41f65ee355ae1d4b24473c6d6d70c653497429avboxsync * @returns VINF_SUCCESS
b41f65ee355ae1d4b24473c6d6d70c653497429avboxsync * @retval VERR_WRONG_ORDER
b41f65ee355ae1d4b24473c6d6d70c653497429avboxsync * @retval VERR_INTERNAL_ERROR_4
b41f65ee355ae1d4b24473c6d6d70c653497429avboxsync * @param pThis The pipe handle.
b41f65ee355ae1d4b24473c6d6d70c653497429avboxsync * Update the state.
b41f65ee355ae1d4b24473c6d6d70c653497429avboxsync uint32_t u32State = ASMAtomicReadU32(&pThis->u32State);
b41f65ee355ae1d4b24473c6d6d70c653497429avboxsync uint32_t const cUsers = (u32State & RTPIPE_POSIX_USERS_MASK);
b41f65ee355ae1d4b24473c6d6d70c653497429avboxsync AssertReturn(cUsers < RTPIPE_POSIX_USERS_MASK / 2, VERR_INTERNAL_ERROR_4);
b41f65ee355ae1d4b24473c6d6d70c653497429avboxsync if (ASMAtomicCmpXchgU32(&pThis->u32State, u32State, u32StateOld))
b41f65ee355ae1d4b24473c6d6d70c653497429avboxsync else if (cUsers == 0)
b41f65ee355ae1d4b24473c6d6d70c653497429avboxsync u32State = 1 | RTPIPE_POSIX_SWITCHING | RTPIPE_POSIX_BLOCKING;
b41f65ee355ae1d4b24473c6d6d70c653497429avboxsync if (ASMAtomicCmpXchgU32(&pThis->u32State, u32State, u32StateOld))
b41f65ee355ae1d4b24473c6d6d70c653497429avboxsync * Do the switching.
b41f65ee355ae1d4b24473c6d6d70c653497429avboxsync || fcntl(pThis->fd, F_SETFL, fFlags & ~O_NONBLOCK) != -1)
b41f65ee355ae1d4b24473c6d6d70c653497429avboxsync ASMAtomicBitClear(&pThis->u32State, RTPIPE_POSIX_SWITCHING_BIT);
b41f65ee355ae1d4b24473c6d6d70c653497429avboxsync * Prepare non-blocking mode.
b41f65ee355ae1d4b24473c6d6d70c653497429avboxsync * @returns VINF_SUCCESS
b41f65ee355ae1d4b24473c6d6d70c653497429avboxsync * @retval VERR_WRONG_ORDER
b41f65ee355ae1d4b24473c6d6d70c653497429avboxsync * @retval VERR_INTERNAL_ERROR_4
b41f65ee355ae1d4b24473c6d6d70c653497429avboxsync * @param pThis The pipe handle.
b41f65ee355ae1d4b24473c6d6d70c653497429avboxsyncstatic int rtPipeTryNonBlocking(RTPIPEINTERNAL *pThis)
b41f65ee355ae1d4b24473c6d6d70c653497429avboxsync * Update the state.
b41f65ee355ae1d4b24473c6d6d70c653497429avboxsync uint32_t u32State = ASMAtomicReadU32(&pThis->u32State);
b41f65ee355ae1d4b24473c6d6d70c653497429avboxsync uint32_t const cUsers = (u32State & RTPIPE_POSIX_USERS_MASK);
b41f65ee355ae1d4b24473c6d6d70c653497429avboxsync AssertReturn(cUsers < RTPIPE_POSIX_USERS_MASK / 2, VERR_INTERNAL_ERROR_4);
b41f65ee355ae1d4b24473c6d6d70c653497429avboxsync if (ASMAtomicCmpXchgU32(&pThis->u32State, u32State, u32StateOld))
b41f65ee355ae1d4b24473c6d6d70c653497429avboxsync else if (cUsers == 0)
b41f65ee355ae1d4b24473c6d6d70c653497429avboxsync if (ASMAtomicCmpXchgU32(&pThis->u32State, u32State, u32StateOld))
b41f65ee355ae1d4b24473c6d6d70c653497429avboxsync * Do the switching.
b41f65ee355ae1d4b24473c6d6d70c653497429avboxsync || fcntl(pThis->fd, F_SETFL, fFlags | O_NONBLOCK) != -1)
b41f65ee355ae1d4b24473c6d6d70c653497429avboxsync ASMAtomicBitClear(&pThis->u32State, RTPIPE_POSIX_SWITCHING_BIT);
b41f65ee355ae1d4b24473c6d6d70c653497429avboxsync * Checks if the read pipe has a HUP condition.
b41f65ee355ae1d4b24473c6d6d70c653497429avboxsync * @returns true if HUP, false if no.
b41f65ee355ae1d4b24473c6d6d70c653497429avboxsync * @param pThis The pipe handle (read).
b41f65ee355ae1d4b24473c6d6d70c653497429avboxsyncstatic bool rtPipePosixHasHup(RTPIPEINTERNAL *pThis)
637712559132d2b3617aea0103fb0385978da14evboxsyncRTDECL(int) RTPipeRead(RTPIPE hPipe, void *pvBuf, size_t cbToRead, size_t *pcbRead)
b41f65ee355ae1d4b24473c6d6d70c653497429avboxsync AssertReturn(pThis->u32Magic == RTPIPE_MAGIC, VERR_INVALID_HANDLE);
b41f65ee355ae1d4b24473c6d6d70c653497429avboxsync ssize_t cbRead = read(pThis->fd, pvBuf, RT_MIN(cbToRead, SSIZE_MAX));
b41f65ee355ae1d4b24473c6d6d70c653497429avboxsync if (cbRead || !cbToRead || !rtPipePosixHasHup(pThis))
637712559132d2b3617aea0103fb0385978da14evboxsyncRTDECL(int) RTPipeReadBlocking(RTPIPE hPipe, void *pvBuf, size_t cbToRead)
b41f65ee355ae1d4b24473c6d6d70c653497429avboxsync AssertReturn(pThis->u32Magic == RTPIPE_MAGIC, VERR_INVALID_HANDLE);
b41f65ee355ae1d4b24473c6d6d70c653497429avboxsync ssize_t cbRead = read(pThis->fd, pvBuf, RT_MIN(cbToRead, SSIZE_MAX));
b41f65ee355ae1d4b24473c6d6d70c653497429avboxsync if (!cbRead && cbToRead > 0 && rtPipePosixHasHup(pThis))
b41f65ee355ae1d4b24473c6d6d70c653497429avboxsync /* advance */
637712559132d2b3617aea0103fb0385978da14evboxsyncRTDECL(int) RTPipeWrite(RTPIPE hPipe, const void *pvBuf, size_t cbToWrite, size_t *pcbWritten)
b41f65ee355ae1d4b24473c6d6d70c653497429avboxsync AssertReturn(pThis->u32Magic == RTPIPE_MAGIC, VERR_INVALID_HANDLE);
45c4c3d2db1a166b7b1e92960adb823960821386vboxsync ssize_t cbWritten = write(pThis->fd, pvBuf, RT_MIN(cbToWrite, SSIZE_MAX));
637712559132d2b3617aea0103fb0385978da14evboxsyncRTDECL(int) RTPipeWriteBlocking(RTPIPE hPipe, const void *pvBuf, size_t cbToWrite)
b41f65ee355ae1d4b24473c6d6d70c653497429avboxsync AssertReturn(pThis->u32Magic == RTPIPE_MAGIC, VERR_INVALID_HANDLE);
b41f65ee355ae1d4b24473c6d6d70c653497429avboxsync ssize_t cbWritten = write(pThis->fd, pvBuf, RT_MIN(cbToWrite, SSIZE_MAX));
b41f65ee355ae1d4b24473c6d6d70c653497429avboxsync /* advance */
b41f65ee355ae1d4b24473c6d6d70c653497429avboxsync } while (cbToWrite > 0);
b41f65ee355ae1d4b24473c6d6d70c653497429avboxsync AssertReturn(pThis->u32Magic == RTPIPE_MAGIC, VERR_INVALID_HANDLE);
637712559132d2b3617aea0103fb0385978da14evboxsyncRTDECL(int) RTPipeSelectOne(RTPIPE hPipe, RTMSINTERVAL cMillies)