/** @file * IPRT - Polling I/O Handles. */ /* * Copyright (C) 2010-2020 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_poll_h #define IPRT_INCLUDED_poll_h #ifndef RT_WITHOUT_PRAGMA_ONCE # pragma once #endif #include #include RT_C_DECLS_BEGIN /** @defgroup grp_rt_poll RTPoll - Polling I/O Handles * @ingroup grp_rt * @{ */ /** @name Poll events * @{ */ /** Readable without blocking. */ #define RTPOLL_EVT_READ RT_BIT_32(0) /** Writable without blocking. */ #define RTPOLL_EVT_WRITE RT_BIT_32(1) /** Error condition, hangup, exception or similar. */ #define RTPOLL_EVT_ERROR RT_BIT_32(2) /** Mask of the valid bits. */ #define RTPOLL_EVT_VALID_MASK UINT32_C(0x00000007) /** @} */ /** * Polls on the specified poll set until an event occurs on one of the handles * or the timeout expires. * * @returns IPRT status code. * @retval VINF_SUCCESS if an event occurred on a handle. Note that these * @retval VERR_INVALID_HANDLE if @a hPollSet is invalid. * @retval VERR_CONCURRENT_ACCESS if another thread is already accessing the set. The * user is responsible for ensuring single threaded access. * @retval VERR_TIMEOUT if @a cMillies ellapsed without any events. * @retval VERR_DEADLOCK if @a cMillies is set to RT_INDEFINITE_WAIT and there * are no valid handles in the set. * * @param hPollSet The set to poll on. * @param cMillies Number of milliseconds to wait. Use * RT_INDEFINITE_WAIT to wait for ever. * @param pfEvents Where to return details about the events that * occurred. Optional. * @param pid Where to return the ID associated with the * handle when calling RTPollSetAdd. Optional. * * @sa RTPollNoResume * * @remarks The caller is responsible for ensuring */ RTDECL(int) RTPoll(RTPOLLSET hPollSet, RTMSINTERVAL cMillies, uint32_t *pfEvents, uint32_t *pid); /** * Same as RTPoll except that it will return when interrupted. * * @returns IPRT status code. * @retval VINF_SUCCESS if an event occurred on a handle. Note that these * @retval VERR_INVALID_HANDLE if @a hPollSet is invalid. * @retval VERR_CONCURRENT_ACCESS if another thread is already accessing the set. The * user is responsible for ensuring single threaded access. * @retval VERR_TIMEOUT if @a cMillies ellapsed without any events. * @retval VERR_DEADLOCK if @a cMillies is set to RT_INDEFINITE_WAIT and there * are no valid handles in the set. * @retval VERR_INTERRUPTED if a signal or other asynchronous event interrupted * the polling. * * @param hPollSet The set to poll on. * @param cMillies Number of milliseconds to wait. Use * RT_INDEFINITE_WAIT to wait for ever. * @param pfEvents Where to return details about the events that * occurred. Optional. * @param pid Where to return the ID associated with the * handle when calling RTPollSetAdd. Optional. */ RTDECL(int) RTPollNoResume(RTPOLLSET hPollSet, RTMSINTERVAL cMillies, uint32_t *pfEvents, uint32_t *pid); /** * Creates a poll set with no members. * * @returns IPRT status code. * @param phPollSet Where to return the poll set handle. */ RTDECL(int) RTPollSetCreate(PRTPOLLSET phPollSet); /** * Destroys a poll set. * * @returns IPRT status code. * @param hPollSet The poll set to destroy. NIL_POLLSET is quietly * ignored (VINF_SUCCESS). */ RTDECL(int) RTPollSetDestroy(RTPOLLSET hPollSet); /** * Adds a generic handle to the poll set. * * If a handle is entered more than once, it is recommended to add the one with * RTPOLL_EVT_ERROR first to ensure that you get the right ID back when an error * actually occurs. On some hosts it is possible that polling for * RTPOLL_EVT_READ on a socket may cause it to return error conditions because * the two cannot so easily be distinguished. * * Also note that RTPOLL_EVT_ERROR may be returned by RTPoll even if not asked * for. * * @returns IPRT status code * @retval VERR_CONCURRENT_ACCESS if another thread is already accessing the set. The * user is responsible for ensuring single threaded access. * @retval VERR_POLL_HANDLE_NOT_POLLABLE if the specified handle is not * pollable. * @retval VERR_POLL_HANDLE_ID_EXISTS if the handle ID is already in use in the * set. * * @param hPollSet The poll set to modify. * @param pHandle The handle to add. NIL handles are quietly * ignored. * @param fEvents Which events to poll for. * @param id The handle ID. */ RTDECL(int) RTPollSetAdd(RTPOLLSET hPollSet, PCRTHANDLE pHandle, uint32_t fEvents, uint32_t id); /** * Removes a generic handle from the poll set. * * @returns IPRT status code * @retval VERR_INVALID_HANDLE if @a hPollSet not valid. * @retval VERR_CONCURRENT_ACCESS if another thread is already accessing the set. The * user is responsible for ensuring single threaded access. * @retval VERR_POLL_HANDLE_ID_NOT_FOUND if @a id doesn't resolve to a valid * handle. * * @param hPollSet The poll set to modify. * @param id The handle ID of the handle that should be * removed. */ RTDECL(int) RTPollSetRemove(RTPOLLSET hPollSet, uint32_t id); /** * Query a handle in the poll set by it's ID. * * @returns IPRT status code * @retval VINF_SUCCESS if the handle was found. @a *pHandle is set. * @retval VERR_INVALID_HANDLE if @a hPollSet is invalid. * @retval VERR_CONCURRENT_ACCESS if another thread is already accessing the set. The * user is responsible for ensuring single threaded access. * @retval VERR_POLL_HANDLE_ID_NOT_FOUND if there is no handle with that ID. * * @param hPollSet The poll set to query. * @param id The ID of the handle. * @param pHandle Where to return the handle details. Optional. */ RTDECL(int) RTPollSetQueryHandle(RTPOLLSET hPollSet, uint32_t id, PRTHANDLE pHandle); /** * Gets the number of handles in the set. * * @retval The handle count. * @retval UINT32_MAX if @a hPollSet is invalid or there is concurrent access. * * @param hPollSet The poll set. */ RTDECL(uint32_t) RTPollSetGetCount(RTPOLLSET hPollSet); /** * Modifies the events to poll for for the given id. * * @returns IPRT status code. * @retval VERR_INVALID_HANDLE if @a hPollSet not valid. * @retval VERR_CONCURRENT_ACCESS if another thread is already accessing the set. The * user is responsible for ensuring single threaded access. * @retval VERR_POLL_HANDLE_ID_NOT_FOUND if @a id doesn't resolve to a valid * handle. * * @param hPollSet The poll set to modify. * @param id The handle ID to change the events for. * @param fEvents Which events to poll for. */ RTDECL(int) RTPollSetEventsChange(RTPOLLSET hPollSet, uint32_t id, uint32_t fEvents); /** * Adds a pipe handle to the set. * * @returns See RTPollSetAdd. * * @param hPollSet The poll set. * @param hPipe The pipe handle. * @param fEvents Which events to poll for. * @param id The handle ID. * * @todo Maybe we could figure out what to poll for depending on the kind of * pipe we're dealing with. */ DECLINLINE(int) RTPollSetAddPipe(RTPOLLSET hPollSet, RTPIPE hPipe, uint32_t fEvents, uint32_t id) { RTHANDLE Handle; Handle.enmType = RTHANDLETYPE_PIPE; Handle.u.uInt = 0; Handle.u.hPipe = hPipe; return RTPollSetAdd(hPollSet, &Handle, fEvents, id); } /** * Adds a socket handle to the set. * * @returns See RTPollSetAdd. * * @param hPollSet The poll set. * @param hSocket The socket handle. * @param fEvents Which events to poll for. * @param id The handle ID. */ DECLINLINE(int) RTPollSetAddSocket(RTPOLLSET hPollSet, RTSOCKET hSocket, uint32_t fEvents, uint32_t id) { RTHANDLE Handle; Handle.enmType = RTHANDLETYPE_SOCKET; Handle.u.uInt = 0; Handle.u.hSocket = hSocket; return RTPollSetAdd(hPollSet, &Handle, fEvents, id); } /** @} */ RT_C_DECLS_END #endif /* !IPRT_INCLUDED_poll_h */