req.h revision f5edc444546b57af847ae33f2bd1e10442496e47
/** @file
* IPRT - Request Queue & Pool.
*/
/*
* Copyright (C) 2006-2011 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_req_h
#define ___iprt_req_h
#include <iprt/cdefs.h>
#include <iprt/types.h>
#include <iprt/stdarg.h>
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, Queue process thread will free it. */
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.
* @returns VERR_TIMEOUT if cMillies was reached without the packet being added.
*
* @param hQueue The request queue.
* @param cMillies Number of milliseconds to wait for a pending request.
* Use RT_INDEFINITE_WAIT to only wait till one is added.
*/
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 not 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 not 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.
* This will be NULL or a valid request pointer not matter what happens, unless fFlags
* contains RTREQFLAGS_NO_WAIT when it will be optional and always NULL.
* @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.
* This will be NULL or a valid request pointer not matter what happens, unless fFlags
* contains RTREQFLAGS_NO_WAIT when it will be optional and always NULL.
* @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);
/**
* Retainsa 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 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 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;
/**
* Read 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);
RTDECL(int) RTReqPoolCallEx( RTREQPOOL hPool, RTMSINTERVAL cMillies, PRTREQ *phReq, uint32_t fFlags, PFNRT pfnFunction, unsigned cArgs, ...);
RTDECL(int) RTReqPoolCallExV(RTREQPOOL hPool, RTMSINTERVAL cMillies, PRTREQ *phReq, uint32_t fFlags, PFNRT pfnFunction, unsigned cArgs, va_list va);
RTDECL(int) RTReqPoolCallWait(RTREQPOOL hPool, PFNRT pfnFunction, unsigned cArgs, ...);
RTDECL(int) RTReqPoolCallNoWait(RTREQPOOL hPool, PFNRT pfnFunction, unsigned cArgs, ...);
RTDECL(int) RTReqPoolCallVoidWait(RTREQPOOL hPool, PFNRT pfnFunction, unsigned cArgs, ...);
RTDECL(int) RTReqPoolCallVoidNoWait(RTREQPOOL hPool, PFNRT pfnFunction, unsigned cArgs, ...);
/**
* Retainsa 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);
/**
* Queue a request.
*
* The quest 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);
/**
* Wait 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);
/**
* Get the status of the request.
*
* @returns Status code in the IPRT tradition.
*
* @param pReq The request.
*/
RTDECL(int) RTReqGetStatus(PRTREQ pReq);
#endif /* IN_RING3 */
/** @} */
RT_C_DECLS_END
#endif