windows-nt/Source/XPSP1/NT/public/internal/drivers/inc/rt.h
2020-09-26 16:20:57 +08:00

368 lines
13 KiB
C

/*++
Copyright (c) Microsoft Corporation. All rights reserved.
Module Name:
rt.h
Abstract:
This is the public include file for realtime executive (rt.sys) clients.
Author:
Joseph Ballantyne
Environment:
Kernel Mode
Revision History:
--*/
#ifdef __cplusplus
extern "C" {
#endif
// The following values can be ORed together and the result passed as the Flags argument
// to the RtCreateThread and RtAdjustCpuLoad routines.
#define CPUCYCLES 0x10000
#define INSTRUCTIONS 0x20000
#define USESFLOAT 0x00001
#define USESMMX 0x00002
// These should be used when calculating the desired period and duration to be
// passed to RtCreateThread and RtAdjustCpuLoad.
#define WEEK 604800000000000000I64
#define DAY 86400000000000000I64
#define HOUR 3600000000000000I64
#define MIN 60000000000000I64
#define SEC 1000000000000I64
#define MSEC 1000000000I64
#define USEC 1000000I64
#define NSEC 1000I64
#define PSEC 1I64
#define X86 1
#define INTEL 1
#define AMD 2
typedef struct {
ULONG ProcessorCount; // Number of CPUs in the system.
ULONG CpuArchitecture; // Architecture of CPU, currently always X86==1
ULONG CpuManufacturer; // Manufacturer ID, Intel==1, AMD==2
ULONG CpuFamily; // CPU Family as reported by cpuid instruction. 0x0-0xf
ULONG CpuModel; // CPU Model as reported by cpuid instruction. 0x0-0xf
ULONG CpuStepping; // CPU Stepping as reported by cpuid instruction. 0x0-0xf
ULONGLONG CpuFeatures; // CPU features as reported by cpuid instruction.
ULONGLONG CpuExtendedFeatures; // AMD extended features. (Not implemented.) Always 0.
ULONGLONG ProcessorID[2]; // Processor Unique ID. If enabled.
ULONG CpuCyclesPerMsec; // Number of cpu cycles per MSEC.
ULONG SystemBusCyclesPerMsec; // Number of system bus cycles per MSEC.
ULONG ReservedCpuPerMsec; // Total cpu time reserved per ms by existing rt threads. (in picoseconds)
ULONG UsedCpuPerMsec; // Estimate of cpu time used per ms by existing rt threads. (in picoseconds)
ULONG AvailableCpuPerMsec; // Cpu time available per ms for allocation to new rt threads. (in picoseconds)
} SystemInfo;
// The following realtime thread statistics are updated just before control is
// passed by the realtime executive to the realtime thread. Everytime a realtime
// thread is being switched in, these statistics are updated before control is transfered.
// This means the statistics will change over time, but not while a realtime
// thread is running between thread switches.
#pragma pack(push,2)
typedef struct threadstats {
ULONGLONG Period; // Period as passed to RtCreateThread or latest RtAdjustCpuLoad call.
ULONGLONG Duration; // Duration from RtCreateThread or latest RtAdjustCpuLoad call.
ULONG Flags; // Flags from RtCreateThread or latest RtAdjustCpuLoad call.
ULONG StackSize; // StackSize from RtCreateThread call.
ULONGLONG PeriodIndex; // Number of periods since start of thread.
ULONGLONG TimesliceIndex; // Number of times thread has been switched to.
ULONGLONG TimesliceIndexThisPeriod; // Number of times thread switch to this period.
ULONGLONG ThisPeriodStartTime; // Starting time for current period.
ULONGLONG ThisTimesliceStartTime; // Starting time for current timeslice.
ULONGLONG DurationRunThisPeriod; // Total time run so far this period.
ULONGLONG DurationRunLastPeriod; // Total time run in the last period.
} ThreadStats;
#pragma pack(pop)
typedef VOID (*RTTHREADPROC)(PVOID Context, ThreadStats *Statistics);
NTSTATUS
RtVersion (
OUT PULONG Version
);
// RtVersion will return the version number of the currently running
// realtime executive.
// If the realtime executive is running, this function returns
// STATUS_SUCCESS. If for some reason the realtime executive
// cannot run on the current machine then STATUS_NOT_SUPPORTED
// is returned.
// Currently the realtime executive will only run on PII class or newer
// machines.
// If the pointer to the version number is non NULL, then the
// version information for the currently loaded realtime executive
// is returned. The version information will be returned regardless
// of the NTSTATUS code returned by the function.
// The version number returned is in the format xx.xx.xx.xx where each
// xx is 1 byte of the ULONG and the ordering left to right is high
// order byte - > low order byte. ie: 0x01020304 is version 1.2.3.4
// It IS acceptable to pass in a NULL version pointer. In that case
// no version information is returned.
// If this function is called from a real time thread, then the version
// pointer MUST either be NULL, or it MUST point to a local variable on
// that real time thread's stack. Otherwise this function will return
// STATUS_INVALID_PARAMETER.
// If this function is called from Windows, then the pointer must be
// valid for writing. Otherwise it will return STATUS_INVALID_PARAMETER.
// This function may be called from any thread. Windows or realtime.
BOOLEAN
RtThread (
VOID
);
// RtThread returns TRUE if called from within a realtime thread. Otherwise
// it returns FALSE.
NTSTATUS
RtSystemInfo (
ULONG Processor,
SystemInfo *pSystemInfo
);
// RtSystemInfo copies the pertinant processor and system information into the memory
// pointed to by pSystemInfo. If pSystemInfo is null or invalid, then RtSystemInfo
// returns STATUS_INVALID_PARAMETER_2. Otherwise RtSystemInfo will return STATUS_SUCCESS.
// For uniprocessor systems, the Processor number should be zero. For N processor
// systems, the processor numbers range from 0 to N-1. An invalid processor number
// will cause a STATUS_INVALID_PARAMETER_1 to be returned.
NTSTATUS
RtCreateThread (
ULONGLONG Period,
ULONGLONG Duration,
ULONG Flags,
ULONG StackSize,
RTTHREADPROC RtThread,
IN PVOID pRtThreadContext,
OUT PHANDLE pRtThreadHandle
);
// RtCreateThread is used to create a realtime thread.
// Period is the used to determine the frequency at which the realtime thread must be
// run. The current minimum period that can be specified is 1ms.
// Duration is the amount of time within the period that the realtime thread will
// need to run. Percentage CPU load can be calculated as 100*(Duration/Period) as long
// as Duration and Period are both specified in units of time.
// Flags
// This parameter is used to indicate specific requirements of the realtime thread
// being created. Currently supported values for Flags are USESFLOAT and USESMMX.
// A realtime thread that can use floating point instructions must specify the
// USESFLOAT flag. A realtime thread that can use MMX instructions must specify the
// USESMMX flag.
// StackSize is the size of the stack required by the realtime thread in 4k blocks.
// Currently StackSize must be between 1 and 8 inclusive. RtCreateThread will fail
// with STATUS_UNSUCCESSFUL for any other values of StackSize.
// pRtThreadContext is a pointer to the context that should be passed to the thread.
// It may be NULL. It is passed to the realtime thread as the Context parameter.
// pRtThreadHandle is a pointer to an RtThreadHandle that can be output from
// RtCreateThread. pRtThreadHandle can be NULL, in which case no RtThreadHandle is
// returned. Storage for the HANDLE RtThreadHandle must be allocated by the code
// that calls RtCreateThread.
// RtCreateThread may only be called from within a standard windows thread. It MUST NOT
// be called from within a realtime thread.
NTSTATUS
RtDestroyThread (
HANDLE RtThreadHandle
);
// RtDestroyThread removes the realtime thread identified by RtThreadHandle from the
// list of running realtime threads, and releases all resources that were allocated when
// the thread was created. RtThreadHandle must be a handle returned from RtCreateThread.
// RtDestroyThread may only be called from within a standard windows thread. It MUST NOT
// be called from within a realtime thread.
NTSTATUS
RtAdjustCpuLoad (
ULONGLONG Period,
ULONGLONG Duration,
ULONGLONG Phase,
ULONG Flags
);
// This function allows a realtime thread to adjust the amount of CPU that is allocated
// to it. The Flags parameter must currently match that passed in at thread creation
// time, however, the Period and Duration may be different from the Period and Duration
// passed at thread create time. If there is sufficient CPU to meet the new request,
// the function will return STATUS_SUCCESS and the Period and Duration in the thread's
// statistics will be updated to match the values passed in to this function. If
// there is not enough CPU available to meet the request, this function will leave
// the Period and Duration recorded in Statistics unchanged and will return
// STATUS_INSUFFICIENT_RESOURCES.
// This function MUST be called from within a realtime thread. A realtime thread can
// only change its OWN allocation. It cannot change the allocation of any other
// realtime thread.
VOID
RtYield (
ULONGLONG Mark,
ULONGLONG Delta
);
// RtYield will yield execution to other realtime threads in the system.
// It should be called whenever a realtime thread does not require further CPU resources.
// Parameters:
// Mark
// This is the reference time which will be subtracted from the current
// realtime executive scheduler time. Note that this time is ALWAYS
// considered by the scheduler to be in the past. Do NOT pass a time
// which occurs in the future to this parameter.
// Delta
// This is the time that will be compared to the difference between the current
// scheduler time and the mark. The thread will yield execution until
// the difference between the current scheduler time and the mark is greater
// than delta.
// After a thread has called RtYield it will only be run when the following
// code evaluates TRUE. ( (RtTime() - Mark) >= Delta ) Until that occurs
// the thread will NOT run. Unless it is holding a spinlock required by
// some other realtime thread - in which case it will run until it releases
// the spinlock at which point it will again yield.
PVOID
RtAddLogEntry (
ULONG Size
);
// RtAddLogEntry reserves space for a new entry in the realtime logging buffer.
// It returns a pointer to the reserved space. Note that if an unsupported Size
// is specified, or if there is no realtime logging buffer available on the
// system, this routine will return NULL.
// Parameters:
// Size
// This is the size in bytes of the chunk to reserve in the log. It MUST be
// an integral multiple of 16.
// The following standard WDM functions are also safe to call from within a real time
// thread: KeAcquireSpinLock and KeReleaseSpinLock.
// They have been modified to support realtime threads in the following ways:
// KeAcquireSpinLock
// KeAcquireSpinLock will now always attempt to take the spinlock regardless of whether it
// is running on a multiproc or uniproc machine. If the spinlock is already acquired,
// then KeAcquireSpinLock will spin in a loop that calls RtYield(THISTIMESLICE) until
// the spinlock is released.
// It will then claim the spinlock. This means that realtime threads that attempt to
// acquire a held spinlock will BLOCK until the spinlock is free. If you don't HAVE to use
// spinlocks in your realtime threads, DON'T.
// Note that other realtime threads will continue to run as scheduled, but the thread
// waiting for the spinlock will continue yielding all its timeslices until the spinlock
// is released.
// If KeAcquireSpinLock is called from a realtime thread, then it will NOT attempt to
// change any irql levels. This is important, since the current Windows IRQL level may
// be at higher than DISPATCH_LEVEL when this function is called. Furthermore, the OldIrql
// returned by this function when it is called from a realtime thread is always 0xff -
// which is an INVALID irql level.
// If you call KeAcquireSpinLock from a realtime thread you MUST call KeReleaseSpinLock
// for that spinlock from a realtime thread.
// Evenutally, KeAcquireSpinLock will be modified to do an RtDirectedYield to the realtime
// thread that is holding the spinlock.
// KeAcquireSpinLock may be called from within any thread. Realtime or windows.
// KeReleaseSpinLock
// KeReleaseSpinLock now always attempts to release a held spinlock regardless of whether
// it is running on a multiproc or uniproc machine.
// If KeReleaseSpinLock is called from a realtime thread, then it will NOT change any irql
// levels. It will also validate that it has been called with a new irql level of 0xff
// as would have been returned by the KeAcquireSpinLock call in the realtime thread to
// acquire the spinlock.
// At some point KeReleaseSpinLock may do an RtDirectedYield back to the realtime thread
// that yielded when it attempted to acquire the spinlock.
// KeReleaseSpinLock may be called from within any thread. Realtime or windows.
#ifdef __cplusplus
}
#endif