/** @file * IPRT - Request Queue & Pool. */ /* * Copyright (C) 2006-2022 Oracle and/or its affiliates. * * This file is part of VirtualBox base platform packages, as * available from https://www.virtualbox.org. * * This program is free software; you can redistribute it and/or * modify it under the terms of the GNU General Public License * as published by the Free Software Foundation, in version 3 of the * License. * * This program is distributed in the hope that it will be useful, but * WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU * General Public License for more details. * * You should have received a copy of the GNU General Public License * along with this program; if not, see . * * The contents of this file may alternatively be used under the terms * of the Common Development and Distribution License Version 1.0 * (CDDL), a copy of it is provided in the "COPYING.CDDL" file included * in the VirtualBox 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. * * SPDX-License-Identifier: GPL-3.0-only OR CDDL-1.0 */ #ifndef IPRT_INCLUDED_req_h #define IPRT_INCLUDED_req_h #ifndef RT_WITHOUT_PRAGMA_ONCE # pragma once #endif #include #include #include RT_C_DECLS_BEGIN /** @defgroup grp_rt_req RTReq - Request Queue & Pool. * @ingroup grp_rt * @{ */ /** Request queue handle. */ typedef struct RTREQQUEUEINT *RTREQQUEUE; /** Pointer to a request queue handle. */ typedef RTREQQUEUE *PRTREQQUEUE; /** NIL request queue handle. */ #define NIL_RTREQQUEUE ((RTREQQUEUE)0) /** Request thread pool handle. */ typedef struct RTREQPOOLINT *RTREQPOOL; /** Poiner to a request thread pool handle. */ typedef RTREQPOOL *PRTREQPOOL; /** NIL request pool handle. */ #define NIL_RTREQPOOL ((RTREQPOOL)0) /** * Request type. */ typedef enum RTREQTYPE { /** Invalid request. */ RTREQTYPE_INVALID = 0, /** RT: Internal. */ RTREQTYPE_INTERNAL, /** Maximum request type (exclusive). Used for validation. */ RTREQTYPE_MAX } RTREQTYPE; /** * Request flags. */ typedef enum RTREQFLAGS { /** The request returns a IPRT status code. */ RTREQFLAGS_IPRT_STATUS = 0, /** The request is a void request and have no status code. */ RTREQFLAGS_VOID = 1, /** Return type mask. */ RTREQFLAGS_RETURN_MASK = 1, /** Caller does not wait on the packet. */ RTREQFLAGS_NO_WAIT = 2 } RTREQFLAGS; /** A request packet. */ typedef struct RTREQ RTREQ; /** Pointer to an RT request packet. */ typedef RTREQ *PRTREQ; /** Nil request handle. */ #define NIL_RTREQ ((PRTREQ)0) #ifdef IN_RING3 /** * Create a request packet queue * * @returns IPRT status code. * @param phQueue Where to store the request queue handle. */ RTDECL(int) RTReqQueueCreate(PRTREQQUEUE phQueue); /** * Destroy a request packet queue * * @returns IPRT status code. * @param hQueue The request queue. */ RTDECL(int) RTReqQueueDestroy(RTREQQUEUE hQueue); /** * Process one or more request packets * * @returns IPRT status code. Any non-VINF_SUCCESS returns from request * processing is immediately propagated to the caller. * @retval VERR_TIMEOUT if @a cMillies was reached without the packet being * added. * @retval VERR_INVALID_HANDLE if @a hQueue not a valid queue handle. * * @param hQueue The request queue. * @param cMillies Max number of milliseconds to wait for a pending * request. This is not adjusted down before another * wait, so the function may end up waiting for much * longer than the given amount if there are requests * trickling in at a rate slightly higher than the * timeout. * * Use RT_INDEFINITE_WAIT to process requests until a * non-VINF_SUCCESS return code is encountered. * * @remarks The function may repeatedly try wait for @a cMillies on new * requests if requests arrive before it times out. */ RTDECL(int) RTReqQueueProcess(RTREQQUEUE hQueue, RTMSINTERVAL cMillies); /** * Allocate and queue a call request. * * If it's desired to poll on the completion of the request set cMillies * to 0 and use RTReqWait() to check for completion. In the other case * use RT_INDEFINITE_WAIT. * The returned request packet must be freed using RTReqRelease(). * * @returns iprt statuscode. * Will not return VERR_INTERRUPTED. * @returns VERR_TIMEOUT if cMillies was reached without the packet being completed. * * @param hQueue The request queue. * @param ppReq Where to store the pointer to the request. * This will be NULL or a valid request pointer no matter what happens. * @param cMillies Number of milliseconds to wait for the request to * be completed. Use RT_INDEFINITE_WAIT to only * wait till it's completed. * @param pfnFunction Pointer to the function to call. * @param cArgs Number of arguments following in the ellipsis. * @param ... Function arguments. * * @remarks See remarks on RTReqQueueCallV. */ RTDECL(int) RTReqQueueCall(RTREQQUEUE hQueue, PRTREQ *ppReq, RTMSINTERVAL cMillies, PFNRT pfnFunction, unsigned cArgs, ...); /** * Allocate and queue a call request to a void function. * * If it's desired to poll on the completion of the request set cMillies * to 0 and use RTReqWait() to check for completion. In the other case * use RT_INDEFINITE_WAIT. * The returned request packet must be freed using RTReqRelease(). * * @returns IPRT status code. * Will not return VERR_INTERRUPTED. * @returns VERR_TIMEOUT if cMillies was reached without the packet being completed. * * @param hQueue The request queue. * @param ppReq Where to store the pointer to the request. * This will be NULL or a valid request pointer no matter what happens. * @param cMillies Number of milliseconds to wait for the request to * be completed. Use RT_INDEFINITE_WAIT to only * wait till it's completed. * @param pfnFunction Pointer to the function to call. * @param cArgs Number of arguments following in the ellipsis. * @param ... Function arguments. * * @remarks See remarks on RTReqQueueCallV. */ RTDECL(int) RTReqQueueCallVoid(RTREQQUEUE hQueue, PRTREQ *ppReq, RTMSINTERVAL cMillies, PFNRT pfnFunction, unsigned cArgs, ...); /** * Allocate and queue a call request to a void function. * * If it's desired to poll on the completion of the request set cMillies * to 0 and use RTReqWait() to check for completion. In the other case * use RT_INDEFINITE_WAIT. * The returned request packet must be freed using RTReqRelease(). * * @returns IPRT status code. * Will not return VERR_INTERRUPTED. * @returns VERR_TIMEOUT if cMillies was reached without the packet being completed. * * @param hQueue The request queue. * @param ppReq Where to store the pointer to the request. Optional * when RTREQFLAGS_NO_WAIT is used. * This variable will be set to NIL or a valid request * handle no matter what happens. * @param cMillies Number of milliseconds to wait for the request to * be completed. Use RT_INDEFINITE_WAIT to only * wait till it's completed. * @param fFlags A combination of the RTREQFLAGS values. * @param pfnFunction Pointer to the function to call. * @param cArgs Number of arguments following in the ellipsis. * @param ... Function arguments. * * @remarks See remarks on RTReqQueueCallV. */ RTDECL(int) RTReqQueueCallEx(RTREQQUEUE hQueue, PRTREQ *ppReq, RTMSINTERVAL cMillies, unsigned fFlags, PFNRT pfnFunction, unsigned cArgs, ...); /** * Allocate and queue a call request. * * If it's desired to poll on the completion of the request set cMillies * to 0 and use RTReqWait() to check for completion. In the other case * use RT_INDEFINITE_WAIT. * The returned request packet must be freed using RTReqRelease(). * * @returns IPRT status code. * Will not return VERR_INTERRUPTED. * @returns VERR_TIMEOUT if cMillies was reached without the packet being completed. * * @param hQueue The request queue. * @param ppReq Where to store the pointer to the request. Optional * when RTREQFLAGS_NO_WAIT is used. * This variable will be set to NIL or a valid request * handle no matter what happens. * @param cMillies Number of milliseconds to wait for the request to * be completed. Use RT_INDEFINITE_WAIT to only * wait till it's completed. * @param fFlags A combination of the RTREQFLAGS values. * @param pfnFunction Pointer to the function to call. * @param cArgs Number of arguments following in the ellipsis. * @param Args Variable argument vector. * * @remarks Caveats: * - Do not pass anything which is larger than an uintptr_t. * - 64-bit integers are larger than uintptr_t on 32-bit hosts. * Pass integers > 32-bit by reference (pointers). * - Don't use NULL since it should be the integer 0 in C++ and may * therefore end up with garbage in the bits 63:32 on 64-bit * hosts because 'int' is 32-bit. * Use (void *)NULL or (uintptr_t)0 instead of NULL. */ RTDECL(int) RTReqQueueCallV(RTREQQUEUE hQueue, PRTREQ *ppReq, RTMSINTERVAL cMillies, unsigned fFlags, PFNRT pfnFunction, unsigned cArgs, va_list Args); /** * Checks if the queue is busy or not. * * The caller is responsible for dealing with any concurrent submitts. * * @returns true if busy, false if idle. * @param hQueue The queue. */ RTDECL(bool) RTReqQueueIsBusy(RTREQQUEUE hQueue); /** * Allocates a request packet. * * The caller allocates a request packet, fills in the request data * union and queues the request. * * @returns IPRT status code. * * @param hQueue The request queue. * @param enmType Package type. * @param phReq Where to store the handle to the new request. */ RTDECL(int) RTReqQueueAlloc(RTREQQUEUE hQueue, RTREQTYPE enmType, PRTREQ *phReq); /** * Creates a request thread pool. * * The core configuration is given as parameters, finer pool tuning can be * achieved via RTReqPoolSetCfgVar. * * @returns IPRT status code. * @param cMaxThreads The maximum number of worker threads. * UINT32_MAX is an alias for the highest * allowed thread count. * @param cMsMinIdle The number of milliseconds a worker * thread needs to be idle before it is * considered for shutdown. The value * RT_INDEFINITE_WAIT disables automatic * idle thread shutdown. * @param cThreadsPushBackThreshold At which worker thread count the push * back should kick in. * @param cMsMaxPushBack The max number of milliseconds to push * back a submitter. UINT32_MAX is an * alias for the highest allowed push back. * @param pszName The pool name. Keep it short as it is * used for naming worker threads. * @param phPool Where to return the pool handle. */ RTDECL(int) RTReqPoolCreate(uint32_t cMaxThreads, RTMSINTERVAL cMsMinIdle, uint32_t cThreadsPushBackThreshold, uint32_t cMsMaxPushBack, const char *pszName, PRTREQPOOL phPool); /** * Retains a reference to a request thread pool. * * @returns The new reference count, UINT32_MAX on invalid handle (asserted). * @param hPool The request thread pool handle. */ RTDECL(uint32_t) RTReqPoolRetain(RTREQPOOL hPool); /** * Releases a reference to the request thread pool. * * When the reference count reaches zero, the request will be pooled for reuse. * * @returns The new reference count, UINT32_MAX on invalid handle (asserted). * @param hPool The request thread pool handle. */ RTDECL(uint32_t) RTReqPoolRelease(RTREQPOOL hPool); /** * Request thread pool configuration variable. */ typedef enum RTREQPOOLCFGVAR { /** Invalid zero value. */ RTREQPOOLCFGVAR_INVALID = 0, /** The desired RTTHREADTYPE of the worker threads. */ RTREQPOOLCFGVAR_THREAD_TYPE, /** The RTTHREADFLAGS mask for the worker threads (not waitable). */ RTREQPOOLCFGVAR_THREAD_FLAGS, /** The minimum number of threads to keep handy once spawned. */ RTREQPOOLCFGVAR_MIN_THREADS, /** The maximum number of thread to start. */ RTREQPOOLCFGVAR_MAX_THREADS, /** The minimum number of milliseconds a worker thread needs to be idle * before we consider shutting it down. The other shutdown criteria * being set by RTREQPOOLCFGVAR_MIN_THREADS. The value * RT_INDEFINITE_WAIT can be used to disable shutting down idle threads. */ RTREQPOOLCFGVAR_MS_MIN_IDLE, /** The sleep period, in milliseoncds, to employ when idling. The value * RT_INDEFINITE_WAIT can be used to disable shutting down idle threads. */ RTREQPOOLCFGVAR_MS_IDLE_SLEEP, /** The number of threads at which to start pushing back. The value * UINT64_MAX is an alias for the current upper thread count limit, i.e. * disabling push back. The value 0 (zero) is an alias for the current * lower thread count, a good value to start pushing back at. The value * must otherwise be within */ RTREQPOOLCFGVAR_PUSH_BACK_THRESHOLD, /** The minimum push back time in milliseconds. */ RTREQPOOLCFGVAR_PUSH_BACK_MIN_MS, /** The maximum push back time in milliseconds. */ RTREQPOOLCFGVAR_PUSH_BACK_MAX_MS, /** The maximum number of free requests to keep handy for recycling. */ RTREQPOOLCFGVAR_MAX_FREE_REQUESTS, /** The end of the range of valid config variables. */ RTREQPOOLCFGVAR_END, /** Blow the type up to 32-bits. */ RTREQPOOLCFGVAR_32BIT_HACK = 0x7fffffff } RTREQPOOLCFGVAR; /** * Sets a config variable for a request thread pool. * * @returns IPRT status code. * @param hPool The pool handle. * @param enmVar The variable to set. * @param uValue The new value. */ RTDECL(int) RTReqPoolSetCfgVar(RTREQPOOL hPool, RTREQPOOLCFGVAR enmVar, uint64_t uValue); /** * Gets a config variable for a request thread pool. * * @returns The value, UINT64_MAX on invalid parameters. * @param hPool The pool handle. * @param enmVar The variable to query. */ RTDECL(uint64_t) RTReqPoolGetCfgVar(RTREQPOOL hPool, RTREQPOOLCFGVAR enmVar); /** * Request thread pool statistics value names. */ typedef enum RTREQPOOLSTAT { /** The invalid zero value, as per tradition. */ RTREQPOOLSTAT_INVALID = 0, /** The current number of worker threads. */ RTREQPOOLSTAT_THREADS, /** The number of threads that have been created. */ RTREQPOOLSTAT_THREADS_CREATED, /** The total number of requests that have been processed. */ RTREQPOOLSTAT_REQUESTS_PROCESSED, /** The total number of requests that have been submitted. */ RTREQPOOLSTAT_REQUESTS_SUBMITTED, /** The total number of requests that have been cancelled. */ RTREQPOOLSTAT_REQUESTS_CANCELLED, /** the current number of pending (waiting) requests. */ RTREQPOOLSTAT_REQUESTS_PENDING, /** The current number of active (executing) requests. */ RTREQPOOLSTAT_REQUESTS_ACTIVE, /** The current number of free (recycled) requests. */ RTREQPOOLSTAT_REQUESTS_FREE, /** Total time the requests took to process. */ RTREQPOOLSTAT_NS_TOTAL_REQ_PROCESSING, /** Total time the requests had to wait in the queue before being * scheduled. */ RTREQPOOLSTAT_NS_TOTAL_REQ_QUEUED, /** Average time the requests took to process. */ RTREQPOOLSTAT_NS_AVERAGE_REQ_PROCESSING, /** Average time the requests had to wait in the queue before being * scheduled. */ RTREQPOOLSTAT_NS_AVERAGE_REQ_QUEUED, /** The end of the valid statistics value names. */ RTREQPOOLSTAT_END, /** Blow the type up to 32-bit. */ RTREQPOOLSTAT_32BIT_HACK = 0x7fffffff } RTREQPOOLSTAT; /** * Reads a statistics value from the request thread pool. * * @returns The value, UINT64_MAX if an invalid parameter was given. * @param hPool The request thread pool handle. * @param enmStat The statistics value to get. */ RTDECL(uint64_t) RTReqPoolGetStat(RTREQPOOL hPool, RTREQPOOLSTAT enmStat); /** * Allocates a request packet. * * This is mostly for internal use, please use the convenience methods. * * @returns IPRT status code. * * @param hPool The request thread pool handle. * @param enmType Package type. * @param phReq Where to store the handle to the new request. */ RTDECL(int) RTReqPoolAlloc(RTREQPOOL hPool, RTREQTYPE enmType, PRTREQ *phReq); /** * Calls a function on a worker thread. * * @returns IPRT status code. * @param hPool The request thread pool handle. * @param cMillies The number of milliseconds to wait for the request * to be processed. * @param phReq Where to store the pointer to the request. Optional * when RTREQFLAGS_NO_WAIT is used. * This variable will be set to NIL or a valid request * handle no matter what happens. * @param fFlags A combination of RTREQFLAGS values. * @param pfnFunction The function to be called. Must be declared by a * DECL macro because of calling conventions. * @param cArgs The number of arguments in the ellipsis. * @param ... Arguments. * * @remarks The function better avoid taking uint64_t and structs as part of the * arguments (use pointers to these instead). In general anything * that's larger than an uintptr_t is problematic. */ RTDECL(int) RTReqPoolCallEx(RTREQPOOL hPool, RTMSINTERVAL cMillies, PRTREQ *phReq, uint32_t fFlags, PFNRT pfnFunction, unsigned cArgs, ...); /** * Calls a function on a worker thread. * * @returns IPRT status code. * @param hPool The request thread pool handle. * @param cMillies The number of milliseconds to wait for the request * to be processed. * @param phReq Where to store the pointer to the request. Optional * when RTREQFLAGS_NO_WAIT is used. * This variable will be set to NIL or a valid request * handle no matter what happens. * @param fFlags A combination of RTREQFLAGS values. * @param pfnFunction The function to be called. Must be declared by a * DECL macro because of calling conventions. * @param cArgs The number of arguments in the variable argument * list. * @param va Arguments. * @remarks See remarks on RTReqPoolCallEx. */ RTDECL(int) RTReqPoolCallExV(RTREQPOOL hPool, RTMSINTERVAL cMillies, PRTREQ *phReq, uint32_t fFlags, PFNRT pfnFunction, unsigned cArgs, va_list va); /** * Calls a function on a worker thread, wait for it to return. * * @returns IPRT status code returned by @a pfnFunction or request pool error. * @param hPool The request thread pool handle. * @param pfnFunction The function to be called. Must be declared by a * DECL macro because of calling conventions. The * function must return an int value compatible with * the IPRT status code convention. * @param cArgs The number of arguments in the elipsis. * @param ... Arguments. * @remarks See remarks on RTReqPoolCallEx. */ RTDECL(int) RTReqPoolCallWait(RTREQPOOL hPool, PFNRT pfnFunction, unsigned cArgs, ...); /** * Calls a function on a worker thread, don't wait for it to return. * * @returns IPRT status code. * @param hPool The request thread pool handle. * @param pfnFunction The function to be called. Must be declared by a * DECL macro because of calling conventions. The * function should return an int value compatible with * the IPRT status code convention, thought it's not * all that important as it's thrown away. * @param cArgs The number of arguments in the elipsis. * @param ... Arguments. * @remarks See remarks on RTReqPoolCallEx. */ RTDECL(int) RTReqPoolCallNoWait(RTREQPOOL hPool, PFNRT pfnFunction, unsigned cArgs, ...); /** * Calls a void function on a worker thread. * * @returns IPRT status code. * @param hPool The request thread pool handle. * @param pfnFunction The function to be called. Must be declared by a * DECL macro because of calling conventions. The * function is taken to return void. * @param cArgs The number of arguments in the elipsis. * @param ... Arguments. * @remarks See remarks on RTReqPoolCallEx. */ RTDECL(int) RTReqPoolCallVoidWait(RTREQPOOL hPool, PFNRT pfnFunction, unsigned cArgs, ...); /** * Call a void function on a worker thread, don't wait for it to return. * * @returns IPRT status code. * @param hPool The request thread pool handle. * @param pfnFunction The function to be called. Must be declared by a * DECL macro because of calling conventions. The * function is taken to return void. * @param cArgs The number of arguments in the elipsis. * @param ... Arguments. * @remarks See remarks on RTReqPoolCallEx. */ RTDECL(int) RTReqPoolCallVoidNoWait(RTREQPOOL hPool, PFNRT pfnFunction, unsigned cArgs, ...); /** * Retains a reference to a request. * * @returns The new reference count, UINT32_MAX on invalid handle (asserted). * @param hReq The request handle. */ RTDECL(uint32_t) RTReqRetain(PRTREQ hReq); /** * Releases a reference to the request. * * When the reference count reaches zero, the request will be pooled for reuse. * * @returns The new reference count, UINT32_MAX on invalid handle (asserted). * @param hReq Package to release. */ RTDECL(uint32_t) RTReqRelease(PRTREQ hReq); /** * Queues a request. * * The request must be allocated using RTReqQueueAlloc() or RTReqPoolAlloc() and * contain all the required data. * * If it's desired to poll on the completion of the request set cMillies * to 0 and use RTReqWait() to check for completion. In the other case * use RT_INDEFINITE_WAIT. * * @returns IPRT status code. * Will not return VERR_INTERRUPTED. * @returns VERR_TIMEOUT if cMillies was reached without the packet being completed. * * @param pReq The request to queue. * @param cMillies Number of milliseconds to wait for the request to * be completed. Use RT_INDEFINITE_WAIT to only * wait till it's completed. */ RTDECL(int) RTReqSubmit(PRTREQ pReq, RTMSINTERVAL cMillies); /** * Cancels a pending request. * * @returns IPRT status code. * @retval VERR_RT_REQUEST_STATE if the request is not cancellable. * * @param hReq The request to cancel. */ RTDECL(int) RTReqCancel(PRTREQ hReq); /** * Waits for a request to be completed. * * @returns IPRT status code. * Will not return VERR_INTERRUPTED. * @returns VERR_TIMEOUT if cMillies was reached without the packet being completed. * * @param pReq The request to wait for. * @param cMillies Number of milliseconds to wait. * Use RT_INDEFINITE_WAIT to only wait till it's completed. */ RTDECL(int) RTReqWait(PRTREQ pReq, RTMSINTERVAL cMillies); /** * Gets the status of the request. * * @returns IPRT status code. * * @param pReq The request to get the status for. */ RTDECL(int) RTReqGetStatus(PRTREQ pReq); #endif /* IN_RING3 */ /** @} */ RT_C_DECLS_END #endif /* !IPRT_INCLUDED_req_h */