/// <summary>
/// Tries to create a new instance of the <see cref="RIOBufferPool" />.
/// </summary>
/// <param name="rioHandle">The object that provides work with Winsock registered I/O extensions.</param>
/// <param name="segmentLength">The length of the segment.</param>
/// <param name="segmentsCount">The count of the segments.</param>
/// <returns>
/// An instance of <see cref="TryResult{T}" /> which encapsulates result of the operation.
/// <see cref="TryResult{T}.Success" /> contains <c>true</c> if operation was successful, <c>false</c> otherwise.
/// <see cref="TryResult{T}.Result" /> contains valid object if operation was successful, <c>null</c> otherwise.
/// </returns>
/// <remarks>
/// The multiplication of <paramref name="segmentLength" /> and <paramref name="segmentsCount" /> must produce value that is aligned to Memory Allocation Granularity.
/// </remarks>
public static unsafe TryResult<RIOBufferPool> TryCreate(RIOHandle rioHandle, UInt32 segmentLength, UInt32 segmentsCount)
{
// calculate size of the memory buffer to allocate
var bufferLength = segmentLength * segmentsCount;
void* memoryPointer;
IntPtr buffer;
IntPtr bufferId;
// 1 try allocate memory block
{
// try reserve and commit memory block
memoryPointer = KernelInterop.VirtualAlloc(null, bufferLength, KernelInterop.MEM_COMMIT | KernelInterop.MEM_RESERVE, KernelInterop.PAGE_READWRITE);
// check if allocation has failed
if (memoryPointer == null)
{
// get kernel error code
var kernelErrorCode = (KernelErrorCode) KernelInterop.GetLastError();
// return result
return TryResult<RIOBufferPool>.CreateFail(kernelErrorCode);
}
// set buffer
buffer = (IntPtr) memoryPointer;
}
// 2 try register buffer with Registered I/O extensions
{
bufferId = rioHandle.RegisterBuffer(buffer, bufferLength);
if (bufferId == WinsockInterop.RIO_INVALID_BUFFERID)
{
// get winsock error code
var winsockErrorCode = (WinsockErrorCode) WinsockInterop.WSAGetLastError();
// free allocated memory
var freeResult = KernelInterop.VirtualFree(memoryPointer, 0, KernelInterop.MEM_RELEASE);
// set kernel error code
if (freeResult)
{
// return result
return TryResult<RIOBufferPool>.CreateFail(winsockErrorCode);
}
// get kernel error code
var kernelErrorCode = (KernelErrorCode) KernelInterop.GetLastError();
// return result
return TryResult<RIOBufferPool>.CreateFail(kernelErrorCode, winsockErrorCode);
}
}
// 3 success
var result = new RIOBufferPool(buffer, bufferLength, bufferId, segmentLength, segmentsCount);
// return result
return TryResult<RIOBufferPool>.CreateSuccess(result);
}
/// <summary>
/// Tries to create a new instance of the <see cref="RIOBufferPool" />.
/// </summary>
/// <param name="rioHandle">The object that provides work with Winsock registered I/O extensions.</param>
/// <param name="segmentLength">The length of the segment.</param>
/// <param name="segmentsCount">The count of the segments.</param>
/// <returns>
/// An instance of <see cref="TryResult{T}" /> which encapsulates result of the operation.
/// <see cref="TryResult{T}.Success" /> contains <c>true</c> if operation was successful, <c>false</c> otherwise.
/// <see cref="TryResult{T}.Result" /> contains valid object if operation was successful, <c>null</c> otherwise.
/// </returns>
/// <remarks>
/// The multiplication of <paramref name="segmentLength" /> and <paramref name="segmentsCount" /> must produce value that is aligned to Memory Allocation Granularity.
/// </remarks>
public static unsafe TryResult <RIOBufferPool> TryCreate(RIOHandle rioHandle, UInt32 segmentLength, UInt32 segmentsCount)
{
// calculate size of the memory buffer to allocate
var bufferLength = segmentLength * segmentsCount;
void *memoryPointer;
IntPtr buffer;
IntPtr bufferId;
// 1 try allocate memory block
{
// try reserve and commit memory block
memoryPointer = KernelInterop.VirtualAlloc(null, bufferLength, KernelInterop.MEM_COMMIT | KernelInterop.MEM_RESERVE, KernelInterop.PAGE_READWRITE);
// check if allocation has failed
if (memoryPointer == null)
{
// get kernel error code
var kernelErrorCode = (KernelErrorCode)KernelInterop.GetLastError();
// return result
return(TryResult <RIOBufferPool> .CreateFail(kernelErrorCode));
}
// set buffer
buffer = (IntPtr)memoryPointer;
}
// 2 try register buffer with Registered I/O extensions
{
bufferId = rioHandle.RegisterBuffer(buffer, bufferLength);
if (bufferId == WinsockInterop.RIO_INVALID_BUFFERID)
{
// get winsock error code
var winsockErrorCode = (WinsockErrorCode)WinsockInterop.WSAGetLastError();
// free allocated memory
var freeResult = KernelInterop.VirtualFree(memoryPointer, 0, KernelInterop.MEM_RELEASE);
// set kernel error code
if (freeResult)
{
// return result
return(TryResult <RIOBufferPool> .CreateFail(winsockErrorCode));
}
// get kernel error code
var kernelErrorCode = (KernelErrorCode)KernelInterop.GetLastError();
// return result
return(TryResult <RIOBufferPool> .CreateFail(kernelErrorCode, winsockErrorCode));
}
}
// 3 success
var result = new RIOBufferPool(buffer, bufferLength, bufferId, segmentLength, segmentsCount);
// return result
return(TryResult <RIOBufferPool> .CreateSuccess(result));
}
