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InterruptService routine

The InterruptService routine (ISR) quickly services a device interrupt and schedules post-interrupt processing of received data, if necessary.

Syntax


KSERVICE_ROUTINE InterruptService;

BOOLEAN InterruptService(
  _In_  struct _KINTERRUPT *Interrupt,
  _In_  PVOID ServiceContext
)
{ ... }

Parameters

Interrupt [in]

Caller-supplied pointer to the KINTERRUPT structure for the interrupt.

ServiceContext [in]

Caller-supplied pointer to context information, specified in a previous call to IoConnectInterrupt or IoConnectInterruptEx.

Return value

If the routine determines that the interrupt did not come from one of the driver's devices, it must return FALSE. Otherwise, the routine must service the interrupt and return TRUE.

Remarks

To register an ISR for a specific interrupt vector and processor affinity, a driver must call IoConnectInterrupt or IoConnectInterruptEx.

A driver's InterruptService routine (ISR) executes in an interrupt context, at some system-assigned DIRQL, as specified by the SynchronizeIrql parameter to IoConnectInterrupt. (Other devices, with higher DIRQL values, can interrupt the ISR.)

Before the system calls an ISR, it acquires the interrupt's spin lock (the SpinLock parameter to IoConnectInterrupt), so the ISR cannot simultaneously execute on another processor. After the ISR returns, the system releases the spin lock.

An ISR must first determine if the interrupt came from one of the driver's devices, by examining context information supplied by Context. If the interrupt is not from one of the driver's devices, the routine must immediately return FALSE so the I/O manager can call other drivers that have registered ISRs for the same processor and interrupt vector.

For more information about implementing ISRs, see Interrupt Service Routines.

Examples

To define an InterruptService callback routine, you must first provide a function declaration that identifies the type of callback routine you're defining. Windows provides a set of callback function types for drivers. Declaring a function using the callback function types helps Code Analysis for Drivers, Static Driver Verifier (SDV), and other verification tools find errors, and it's a requirement for writing drivers for the Windows operating system.

For example, to define an InterruptService callback routine that is named MyInterruptService, use the KSERVICE_ROUTINE type as shown in this code example:


KSERVICE_ROUTINE MyInterruptService;

Then, implement your callback routine as follows:


_Use_decl_annotations_
BOOLEAN
  MyInterruptService(
    struct _KINTERRUPT  *Interrupt,
    PVOID  ServiceContext
    )
  {
      // Function body
  }

The KSERVICE_ROUTINE function type is defined in the Wdm.h header file. To more accurately identify errors when you run the code analysis tools, be sure to add the _Use_decl_annotations_ annotation to your function definition. The _Use_decl_annotations_ annotation ensures that the annotations that are applied to the KSERVICE_ROUTINE function type in the header file are used. For more information about the requirements for function declarations, see Declaring Functions by Using Function Role Types for WDM Drivers. For information about _Use_decl_annotations_, see Annotating Function Behavior.

Requirements

Header

Wdm.h (include Wdm.h, Ntddk.h, or Ntifs.h)

IRQL

Called at DIRQL (see Remarks section).

 

 

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