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Diffstat (limited to 'include/iprt/poll.h')
| -rw-r--r-- | include/iprt/poll.h | 255 |
1 files changed, 255 insertions, 0 deletions
diff --git a/include/iprt/poll.h b/include/iprt/poll.h new file mode 100644 index 00000000..c22ea9cd --- /dev/null +++ b/include/iprt/poll.h @@ -0,0 +1,255 @@ +/** @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 <iprt/cdefs.h> +#include <iprt/types.h> + +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 */ + |