Export (0) Print
Expand All

Thread.VolatileRead Method (UIntPtr%)

Updated: May 2011

Reads the value of a field. The value is the latest written by any processor in a computer, regardless of the number of processors or the state of processor cache.

This API is not CLS-compliant. 

Namespace:  System.Threading
Assembly:  mscorlib (in mscorlib.dll)

[CLSCompliantAttribute(false)]
public static UIntPtr VolatileRead(
	ref UIntPtr address
)

Parameters

address
Type: System.UIntPtr%

The field to be read.

Return Value

Type: System.UIntPtr
The latest value written to the field by any processor.

VolatileRead and VolatileWrite are for special cases of synchronization. Under normal circumstances, the C# lock statement, the Visual Basic SyncLock statement, and the Monitor class provide easier alternatives.

On a multiprocessor system, VolatileRead obtains the very latest value written to a memory location by any processor. This might require flushing processor caches.

Even on a uniprocessor system, VolatileRead and VolatileWrite ensure that a value is read or written to memory, and not cached (for example, in a processor register). Thus, you can use them to synchronize access to a field that can be updated by another thread, or by hardware.

Calling this method affects only a single memory access. To provide effective synchronization for a field, all access to the field must use VolatileRead or VolatileWrite.

Windows 7, Windows Vista, Windows XP SP2, Windows XP Media Center Edition, Windows XP Professional x64 Edition, Windows XP Starter Edition, Windows Server 2008 R2, Windows Server 2008, Windows Server 2003, Windows Server 2000 SP4, Windows Millennium Edition, Windows 98

The .NET Framework and .NET Compact Framework do not support all versions of every platform. For a list of the supported versions, see .NET Framework System Requirements.

.NET Framework

Supported in: 3.5, 3.0, 2.0, 1.1

Date

History

Reason

May 2011

Removed erroneous statement about C#.

Content bug fix.

Community Additions

ADD
Show:
© 2014 Microsoft