Function Documentation

◆ FreeCircularBuffer()

NTSTATUS FreeCircularBuffer ( IN PCIRCULAR_BUFFER pBuffer )

Definition at line 30 of file circularbuffer.c.

{
    TRACE_(SERIAL, "FreeCircularBuffer(pBuffer %p)\n", pBuffer);
    ASSERT(pBuffer);
    if (pBuffer->Buffer != NULL)
        ExFreePoolWithTag(pBuffer->Buffer, SERIAL_TAG);
    return STATUS_SUCCESS;
}

Referenced by SerialAddDeviceInternal().

◆ GetNumberOfElementsInCircularBuffer()

ULONG GetNumberOfElementsInCircularBuffer ( IN PCIRCULAR_BUFFER pBuffer )

Definition at line 50 of file circularbuffer.c.

{
    TRACE_(SERIAL, "GetNumberOfElementsInCircularBuffer(pBuffer %p)\n", pBuffer);
    ASSERT(pBuffer);
    return (pBuffer->WritePosition + pBuffer->Length - pBuffer->ReadPosition) % pBuffer->Length;
}

Referenced by SerialInterruptService().

◆ IncreaseCircularBufferSize()

NTSTATUS IncreaseCircularBufferSize	(	IN PCIRCULAR_BUFFER	pBuffer,
		IN ULONG	NewBufferSize
	)

Definition at line 91 of file circularbuffer.c.

{
    PUCHAR NewBuffer;
 
    TRACE_(SERIAL, "IncreaseCircularBufferSize(pBuffer %p, NewBufferSize %lu)\n", pBuffer, NewBufferSize);
    ASSERT(pBuffer);
    ASSERT(pBuffer->Length);
    if (pBuffer->Length > NewBufferSize)
        return STATUS_INVALID_PARAMETER;
    else if (pBuffer->Length == NewBufferSize)
        return STATUS_SUCCESS;
 
    NewBuffer = (PUCHAR)ExAllocatePoolWithTag(NonPagedPool, NewBufferSize * sizeof(UCHAR), SERIAL_TAG);
    if (!NewBuffer)
        return STATUS_INSUFFICIENT_RESOURCES;
    RtlCopyMemory(NewBuffer, pBuffer->Buffer, pBuffer->Length * sizeof(UCHAR));
    ExFreePoolWithTag(pBuffer->Buffer, SERIAL_TAG);
    pBuffer->Buffer = NewBuffer;
    pBuffer->Length = NewBufferSize;
    return STATUS_SUCCESS;
}

Referenced by SerialDeviceControl().

◆ InitializeCircularBuffer()

NTSTATUS InitializeCircularBuffer	(	IN PCIRCULAR_BUFFER	pBuffer,
		IN ULONG	BufferSize
	)

Definition at line 15 of file circularbuffer.c.

{
    TRACE_(SERIAL, "InitializeCircularBuffer(pBuffer %p, BufferSize %lu)\n", pBuffer, BufferSize);
    ASSERT(pBuffer);
    pBuffer->Buffer = (PUCHAR)ExAllocatePoolWithTag(NonPagedPool, BufferSize * sizeof(UCHAR), SERIAL_TAG);
    if (!pBuffer->Buffer)
        return STATUS_INSUFFICIENT_RESOURCES;
    pBuffer->Length = BufferSize;
    pBuffer->ReadPosition = pBuffer->WritePosition = 0;
    return STATUS_SUCCESS;
}

Referenced by SerialAddDeviceInternal().

◆ IsCircularBufferEmpty()

BOOLEAN IsCircularBufferEmpty ( IN PCIRCULAR_BUFFER pBuffer )

Definition at line 41 of file circularbuffer.c.

{
    TRACE_(SERIAL, "IsCircularBufferEmpty(pBuffer %p)\n", pBuffer);
    ASSERT(pBuffer);
    return (pBuffer->ReadPosition == pBuffer->WritePosition);
}

Referenced by PopCircularBufferEntry(), ReadBytes(), and SerialSendByte().

◆ PopCircularBufferEntry()

NTSTATUS PopCircularBufferEntry	(	IN PCIRCULAR_BUFFER	pBuffer,
		OUT PUCHAR	Entry
	)

Definition at line 76 of file circularbuffer.c.

{
    TRACE_(SERIAL, "PopCircularBufferEntry(pBuffer %p)\n", pBuffer);
    ASSERT(pBuffer);
    ASSERT(pBuffer->Length);
    if (IsCircularBufferEmpty(pBuffer))
        return STATUS_ARRAY_BOUNDS_EXCEEDED;
    *Entry = pBuffer->Buffer[pBuffer->ReadPosition];
    pBuffer->ReadPosition = (pBuffer->ReadPosition + 1) % pBuffer->Length;
    return STATUS_SUCCESS;
}

Referenced by ReadBytes(), and SerialSendByte().

◆ PushCircularBufferEntry()

NTSTATUS PushCircularBufferEntry	(	IN PCIRCULAR_BUFFER	pBuffer,
		IN UCHAR	Entry
	)

Definition at line 59 of file circularbuffer.c.

{
    ULONG NextPosition;
    TRACE_(SERIAL, "PushCircularBufferEntry(pBuffer %p, Entry 0x%x)\n", pBuffer, Entry);
    ASSERT(pBuffer);
    ASSERT(pBuffer->Length);
    NextPosition = (pBuffer->WritePosition + 1) % pBuffer->Length;
    if (NextPosition == pBuffer->ReadPosition)
        return STATUS_BUFFER_TOO_SMALL;
    pBuffer->Buffer[pBuffer->WritePosition] = Entry;
    pBuffer->WritePosition = NextPosition;
    return STATUS_SUCCESS;
}

Referenced by SerialReceiveByte(), and SerialWrite().

Functions
NTSTATUS	InitializeCircularBuffer (IN PCIRCULAR_BUFFER pBuffer, IN ULONG BufferSize)

NTSTATUS	FreeCircularBuffer (IN PCIRCULAR_BUFFER pBuffer)

BOOLEAN	IsCircularBufferEmpty (IN PCIRCULAR_BUFFER pBuffer)

ULONG	GetNumberOfElementsInCircularBuffer (IN PCIRCULAR_BUFFER pBuffer)

NTSTATUS	PushCircularBufferEntry (IN PCIRCULAR_BUFFER pBuffer, IN UCHAR Entry)

NTSTATUS	PopCircularBufferEntry (IN PCIRCULAR_BUFFER pBuffer, OUT PUCHAR Entry)

NTSTATUS	IncreaseCircularBufferSize (IN PCIRCULAR_BUFFER pBuffer, IN ULONG NewBufferSize)

Functions