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ExAcquireSpinLockSharedAtDpcLevel function (wdm.h)

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The ExAcquireSpinLockSharedAtDpcLevel routine acquires a spin lock for shared access by a caller that is already running at IRQL >= DISPATCH_LEVEL.

Syntax

void ExAcquireSpinLockSharedAtDpcLevel(
  PEX_SPIN_LOCK SpinLock
);

Parameters

SpinLock

[in, out] A pointer to the spin lock to acquire for shared access. The caller must not already own this spin lock.

Return value

None

Remarks

On entry to this routine, the caller must be running at IRQL >= DISPATCH_LEVEL. This routine does not change the IRQL.

To release the spin lock, the driver calls the ExReleaseSpinLockSharedFromDpcLevel routine.

A spin lock is a 32-bit variable of type EX_SPIN_LOCK. The driver must allocate the storage for the spin lock and initialize the spin lock to zero. This storage must be located in nonpaged system-space memory.

The caller should hold the spin lock only briefly before releasing it. For more information, see Introduction to Spin Locks.

Recursive acquisition of a spin lock causes deadlock and is not allowed.

Requirements

Requirement Value
Minimum supported client Windows Vista SP1
Header wdm.h
IRQL IRQL >= DISPATCH_LEVEL

See also

ExReleaseSpinLockSharedFromDpcLevel