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Fixes for ReadReport timeouts and lost reports after wait timeouts (#80)
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1. Fixed the issue with Read timing out even when Read time out is set to 0.   This boils down to using an incorrect value for WAIT_INFINITE
2. Fixed the issue with ReadReport failing after being blocked initially on a read.  The Wait after readreport is also now conditional, based on whether or not the ReadReport succeeded.  There is also an additional call to get overlapped result to retrieve data after a Wait
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@ananth-racherla @mikeobrien
ananth-racherla authored and mikeobrien committed Feb 22, 2017
1 parent 0b1fa07 commit 574bc60
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Showing 2 changed files with 38 additions and 22 deletions.
53 changes: 33 additions & 20 deletions src/HidLibrary/HidDevice.cs
View file
Original file line number Diff line number Diff line change
Expand Up @@ -587,12 +587,14 @@ protected HidDeviceData ReadData(int timeout)
{
var buffer = new byte[] { };
var status = HidDeviceData.ReadStatus.NoDataRead;
IntPtr nonManagedBuffer;

if (_deviceCapabilities.InputReportByteLength > 0)
{
uint bytesRead = 0;

buffer = CreateInputBuffer();
nonManagedBuffer = Marshal.AllocHGlobal(buffer.Length);

if (_deviceReadMode == DeviceMode.Overlapped)
{
Expand All @@ -610,40 +612,51 @@ protected HidDeviceData ReadData(int timeout)

try
{
NativeMethods.ReadFile(Handle, buffer, (uint)buffer.Length, out bytesRead, ref overlapped);

var result = NativeMethods.WaitForSingleObject(overlapped.EventHandle, overlapTimeout);

switch (result)
{
case NativeMethods.WAIT_OBJECT_0: status = HidDeviceData.ReadStatus.Success; break;
case NativeMethods.WAIT_TIMEOUT:
status = HidDeviceData.ReadStatus.WaitTimedOut;
buffer = new byte[] { };
break;
var success = NativeMethods.ReadFile(Handle, nonManagedBuffer, (uint)buffer.Length, out bytesRead, ref overlapped);

if (!success) {
var result = NativeMethods.WaitForSingleObject(overlapped.EventHandle, overlapTimeout);

switch (result)
{
case NativeMethods.WAIT_OBJECT_0:
status = HidDeviceData.ReadStatus.Success;
NativeMethods.GetOverlappedResult(Handle, ref overlapped, out bytesRead, false);
break;
case NativeMethods.WAIT_TIMEOUT:
status = HidDeviceData.ReadStatus.WaitTimedOut;
buffer = new byte[] { };
break;
case NativeMethods.WAIT_FAILED:
status = HidDeviceData.ReadStatus.WaitFail;
buffer = new byte[] { };
break;
default:
status = HidDeviceData.ReadStatus.NoDataRead;
buffer = new byte[] { };
break;
status = HidDeviceData.ReadStatus.WaitFail;
buffer = new byte[] { };
break;
default:
status = HidDeviceData.ReadStatus.NoDataRead;
buffer = new byte[] { };
break;
}
}
Marshal.Copy(nonManagedBuffer, buffer, 0, (int)bytesRead);
}
catch { status = HidDeviceData.ReadStatus.ReadError; }
finally { CloseDeviceIO(overlapped.EventHandle); }
finally {
CloseDeviceIO(overlapped.EventHandle);
Marshal.FreeHGlobal(nonManagedBuffer);
}
}
else
{
try
{
var overlapped = new NativeOverlapped();

NativeMethods.ReadFile(Handle, buffer, (uint)buffer.Length, out bytesRead, ref overlapped);
NativeMethods.ReadFile(Handle, nonManagedBuffer, (uint)buffer.Length, out bytesRead, ref overlapped);
status = HidDeviceData.ReadStatus.Success;
Marshal.Copy(nonManagedBuffer, buffer, 0, (int)bytesRead);
}
catch { status = HidDeviceData.ReadStatus.ReadError; }
finally { Marshal.FreeHGlobal(nonManagedBuffer); }
}
}
return new HidDeviceData(buffer, status);
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7 changes: 5 additions & 2 deletions src/HidLibrary/NativeMethods.cs
View file
Original file line number Diff line number Diff line change
Expand Up @@ -17,7 +17,7 @@ internal static class NativeMethods
internal const uint WAIT_OBJECT_0 = 0;
internal const uint WAIT_FAILED = 0xffffffff;

internal const int WAIT_INFINITE = 0xffff;
internal const int WAIT_INFINITE = -1;
[StructLayout(LayoutKind.Sequential)]
internal struct OVERLAPPED
{
Expand Down Expand Up @@ -55,10 +55,13 @@ internal struct SECURITY_ATTRIBUTES
static internal extern IntPtr CreateFile(string lpFileName, uint dwDesiredAccess, int dwShareMode, ref SECURITY_ATTRIBUTES lpSecurityAttributes, int dwCreationDisposition, int dwFlagsAndAttributes, int hTemplateFile);

[DllImport("kernel32.dll", SetLastError = true)]
static internal extern bool ReadFile(IntPtr hFile, [Out] byte[] lpBuffer, uint nNumberOfBytesToRead, out uint lpNumberOfBytesRead, [In] ref System.Threading.NativeOverlapped lpOverlapped);
static internal extern bool ReadFile(IntPtr hFile, IntPtr lpBuffer, uint nNumberOfBytesToRead, out uint lpNumberOfBytesRead, [In] ref System.Threading.NativeOverlapped lpOverlapped);

[DllImport("kernel32.dll")]
static internal extern uint WaitForSingleObject(IntPtr hHandle, int dwMilliseconds);

[DllImport("kernel32.dll", SetLastError = true)]
static internal extern bool GetOverlappedResult(IntPtr hFile, [In] ref System.Threading.NativeOverlapped lpOverlapped, out uint lpNumberOfBytesTransferred, bool bWait);

[DllImport("kernel32.dll")]
static internal extern bool WriteFile(IntPtr hFile, byte[] lpBuffer, uint nNumberOfBytesToWrite, out uint lpNumberOfBytesWritten, [In] ref System.Threading.NativeOverlapped lpOverlapped);
Expand Down

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TeamCity Hid Library :: Deploy Build 3.2.41.0 outcome was SUCCESS
Summary: Running Build time: 00:00:32

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