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- Fix calculation of WriteQuotaAvailable and WritePtr when moving memory.

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- Due to the new implementation, Quota is not charged for partial message retrievals. Therefore reset Quota Available to MaxDataLength when last message is read from buffer and check that Quota is greater than 0 before waking the write thread.

svn path=/trunk/; revision=38899
This commit is contained in:
Michael Martin 2009-01-18 16:31:45 +00:00
parent 6e2699957c
commit bd30763563
1 changed files with 13 additions and 10 deletions
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23
reactos/drivers/filesystems/npfs/rw.c
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@ -537,10 +537,10 @@ NpfsRead(IN PDEVICE_OBJECT DeviceObject,
/* Check if buffer is full and the read pointer is not at the start of the buffer */
if ((Ccb->WriteQuotaAvailable == 0) && (Ccb->ReadPtr > Ccb->Data))
{
Ccb->WriteQuotaAvailable += (ULONG_PTR)Ccb->ReadPtr - (ULONG_PTR)Ccb->Data;
memcpy(Ccb->Data, Ccb->ReadPtr, (ULONG_PTR)Ccb->WritePtr - (ULONG_PTR)Ccb->ReadPtr);
Ccb->WritePtr = (PVOID)((ULONG_PTR)Ccb->WritePtr - ((ULONG_PTR)Ccb->WritePtr - (ULONG_PTR)Ccb->ReadPtr));
Ccb->WritePtr = (PVOID)((ULONG_PTR)Ccb->WritePtr - ((ULONG_PTR)Ccb->ReadPtr - (ULONG_PTR)Ccb->Data));
Ccb->ReadPtr = Ccb->Data;
Ccb->WriteQuotaAvailable += (ULONG_PTR)Ccb->WritePtr - (ULONG_PTR)Ccb->ReadPtr;
}
/* For Message mode, the Message length is stored in the buffer preceeding the Message. */
@ -560,7 +560,8 @@ NpfsRead(IN PDEVICE_OBJECT DeviceObject,
/* Use the smaller value */
CopyLength = min(NextMessageLength, Length);
ASSERT(CopyLength > 0);
ASSERT(CopyLength <= Ccb->ReadDataAvailable);
/* retrieve the message from the buffer */
memcpy(Buffer, (PVOID)((ULONG_PTR)Ccb->ReadPtr + sizeof(NextMessageLength)), CopyLength);
@ -571,6 +572,7 @@ NpfsRead(IN PDEVICE_OBJECT DeviceObject,
{
/* Calculate the remaining message new size */
ULONG NewMessageSize = NextMessageLength-CopyLength;
/* Update ReadPtr to point to new Message size location */
Ccb->ReadPtr = (PVOID)((ULONG_PTR)Ccb->ReadPtr + CopyLength);
@ -586,16 +588,16 @@ NpfsRead(IN PDEVICE_OBJECT DeviceObject,
}
else
{
/* This was the last Message, so just zero this messages for safety sake */
/* This was the last Message, so just zero start of buffer for safety sake */
memset(Ccb->Data, 0, NextMessageLength + sizeof(NextMessageLength));
/* Reset to MaxDataLength as partial message retrievals dont
give the length back to Quota */
Ccb->WriteQuotaAvailable = Ccb->MaxDataLength;
/* reset read and write pointer to beginning of buffer */
Ccb->WritePtr = Ccb->Data;
Ccb->ReadPtr = Ccb->Data;
/* Add both the message length and the header to the WriteQuotaAvailable
as they both were removed */
Ccb->WriteQuotaAvailable += (CopyLength + sizeof(CopyLength));
}
#ifndef NDEBUG
DPRINT("Length %d Buffer %x\n",CopyLength,Buffer);
@ -619,7 +621,8 @@ NpfsRead(IN PDEVICE_OBJECT DeviceObject,
else
{
KeResetEvent(&Ccb->ReadEvent);
if (Ccb->PipeState == FILE_PIPE_CONNECTED_STATE)
if ((Ccb->PipeState == FILE_PIPE_CONNECTED_STATE) && (Ccb->WriteQuotaAvailable > 0))
{
KeSetEvent(&Ccb->OtherSide->WriteEvent, IO_NO_INCREMENT, FALSE);
}
@ -870,7 +873,7 @@ NpfsWrite(PDEVICE_OBJECT DeviceObject,
if (CopyLength > ReaderCcb->WriteQuotaAvailable)
{
DPRINT1("Writing %lu byte to pipe would overflow as only %lu bytes are available\n",
CopyLength, ReaderCcb->ReadDataAvailable);
CopyLength, ReaderCcb->WriteQuotaAvailable);
ASSERT(FALSE);
}