kernel.c File Reference

#include "precomp.h"

Include dependency graph for kernel.c:

Go to the source code of this file.

Functions
MMRESULT	OpenKernelSoundDeviceByName (IN PWSTR DevicePath, IN BOOLEAN ReadOnly, OUT PHANDLE Handle)
MMRESULT	CloseKernelSoundDevice (IN HANDLE Handle)
MMRESULT	SyncOverlappedDeviceIoControl (IN HANDLE Handle, IN DWORD IoControlCode, IN LPVOID InBuffer, IN DWORD InBufferSize, OUT LPVOID OutBuffer, IN DWORD OutBufferSize, OUT LPDWORD BytesTransferred OPTIONAL)

Function Documentation

CloseKernelSoundDevice()

MMRESULT CloseKernelSoundDevice

(

IN HANDLE

Handle

)

Definition at line 58 of file kernel.c.

{
    VALIDATE_MMSYS_PARAMETER( Handle );
 
    CloseHandle(Handle);
 
    return MMSYSERR_NOERROR;
}

Referenced by CloseNt4SoundDevice(), GetNt4SoundDeviceCapabilities(), and QueryNt4WaveDeviceFormatSupport().

OpenKernelSoundDeviceByName()

MMRESULT OpenKernelSoundDeviceByName	(	IN PWSTR	DevicePath,
		IN BOOLEAN	ReadOnly,
		OUT PHANDLE	Handle
	)

Definition at line 23 of file kernel.c.

{
    DWORD AccessRights;
 
    VALIDATE_MMSYS_PARAMETER( DevicePath );
    VALIDATE_MMSYS_PARAMETER( Handle );
 
    AccessRights = ReadOnly ? GENERIC_READ : GENERIC_READ | GENERIC_WRITE;
 
    SND_TRACE(L"OpenKernelSoundDeviceByName: %wS\n", DevicePath);
    *Handle = CreateFile(DevicePath,
                         AccessRights,
                         FILE_SHARE_WRITE,  /* FIXME? Should be read also? */
                         NULL,
                         OPEN_EXISTING,
                         ReadOnly ? 0 : FILE_FLAG_OVERLAPPED,
                         NULL);
 
    if ( *Handle == INVALID_HANDLE_VALUE )
    {
        SND_ERR(L"CreateFile filed - winerror %d\n", GetLastError());
        return Win32ErrorToMmResult(GetLastError());
    }
 
    return MMSYSERR_NOERROR;
}

Referenced by DetectNt4SoundDevices(), and OpenNt4KernelSoundDevice().

SyncOverlappedDeviceIoControl()

MMRESULT SyncOverlappedDeviceIoControl	(	IN HANDLE	Handle,
		IN DWORD	IoControlCode,
		IN LPVOID	InBuffer,
		IN DWORD	InBufferSize,
		OUT LPVOID	OutBuffer,
		IN DWORD	OutBufferSize,
		OUT LPDWORD BytesTransferred	OPTIONAL
	)

Definition at line 74 of file kernel.c.

{
    OVERLAPPED Overlapped;
    BOOLEAN IoResult;
    DWORD Transferred;
 
    /* Overlapped I/O is done here - this is used for waiting for completion */
    ZeroMemory(&Overlapped, sizeof(OVERLAPPED));
    Overlapped.hEvent = CreateEvent(NULL, FALSE, FALSE, NULL);
 
    if ( ! Overlapped.hEvent )
        return Win32ErrorToMmResult(GetLastError());
 
    /* Talk to the device */
    IoResult = DeviceIoControl(Handle,
                               IoControlCode,
                               InBuffer,
                               InBufferSize,
                               OutBuffer,
                               OutBufferSize,
                               NULL,
                               &Overlapped);
 
    /* If failure occurs, make sure it's not just due to the overlapped I/O */
    if ( ! IoResult )
    {
        if ( GetLastError() != ERROR_IO_PENDING )
        {
            CloseHandle(Overlapped.hEvent);
            return Win32ErrorToMmResult(GetLastError());
        }
    }
 
    /* Wait for the I/O to complete */
    IoResult = GetOverlappedResult(Handle,
                                   &Overlapped,
                                   &Transferred,
                                   TRUE);
 
    /* Don't need this any more */
    CloseHandle(Overlapped.hEvent);
 
    if ( ! IoResult )
        return Win32ErrorToMmResult(GetLastError());
 
    SND_TRACE(L"Transferred %d bytes in Sync overlapped I/O\n", Transferred);
 
    if ( BytesTransferred )
        *BytesTransferred = Transferred;
 
    return MMSYSERR_NOERROR;
}