From 25f6bd52a7f25f63ef0b2ccc6c98c15a85a3ed13 Mon Sep 17 00:00:00 2001
From: Bill Zissimopoulos <billziss@navimatics.com>
Date: Tue, 24 Nov 2015 15:59:43 -0800
Subject: [PATCH] sys: FspTransactThread

---
 build/VStudio/winfsp.vcxproj         |  1 +
 build/VStudio/winfsp.vcxproj.filters |  3 +
 src/sys/driver.h                     | 12 ++++
 src/sys/ioq.c                        |  7 ++-
 src/sys/transact.c                   | 82 ++++++++++++++++++++++++++++
 5 files changed, 104 insertions(+), 1 deletion(-)
 create mode 100644 src/sys/transact.c

diff --git a/build/VStudio/winfsp.vcxproj b/build/VStudio/winfsp.vcxproj
index f7d94004..4b118dde 100644
--- a/build/VStudio/winfsp.vcxproj
+++ b/build/VStudio/winfsp.vcxproj
@@ -149,6 +149,7 @@
     <ClCompile Include="..\..\src\sys\resource.c" />
     <ClCompile Include="..\..\src\sys\security.c" />
     <ClCompile Include="..\..\src\sys\shutdown.c" />
+    <ClCompile Include="..\..\src\sys\transact.c" />
     <ClCompile Include="..\..\src\sys\volinfo.c" />
     <ClCompile Include="..\..\src\sys\write.c" />
   </ItemGroup>
diff --git a/build/VStudio/winfsp.vcxproj.filters b/build/VStudio/winfsp.vcxproj.filters
index eb72665c..fba2a105 100644
--- a/build/VStudio/winfsp.vcxproj.filters
+++ b/build/VStudio/winfsp.vcxproj.filters
@@ -77,6 +77,9 @@
     <ClCompile Include="..\..\src\sys\ioq.c">
       <Filter>Source</Filter>
     </ClCompile>
+    <ClCompile Include="..\..\src\sys\transact.c">
+      <Filter>Source</Filter>
+    </ClCompile>
   </ItemGroup>
   <ItemGroup>
     <ClInclude Include="..\..\src\sys\driver.h">
diff --git a/src/sys/driver.h b/src/sys/driver.h
index a897b3c5..8783c066 100644
--- a/src/sys/driver.h
+++ b/src/sys/driver.h
@@ -155,12 +155,24 @@ typedef struct
 } FSP_IOQ;
 VOID FspIoqInitialize(FSP_IOQ *Ioq);
 VOID FspIoqEnable(FSP_IOQ *Ioq, int Delta);
+PKEVENT FspIoqPendingIrpEvent(FSP_IOQ *Ioq);
 BOOLEAN FspIoqPostIrp(FSP_IOQ *Ioq, PIRP Irp);
 PIRP FspIoqNextPendingIrp(FSP_IOQ *Ioq, ULONG millis);
 BOOLEAN FspIoqStartProcessingIrp(FSP_IOQ *Ioq, PIRP Irp);
 PIRP FspIoqEndProcessingIrp(FSP_IOQ *Ioq, UINT_PTR IrpHint);
 VOID FspIoqCancelAll(FSP_IOQ *Ioq);
 
+/* transact thread */
+typedef struct
+{
+    PKTHREAD Thread;
+    KEVENT Event;
+    FSP_IOQ *TransactIoq, *Ioq;
+} FSP_TRANSACT_THREAD;
+NTSTATUS FspTransactThreadStart(FSP_TRANSACT_THREAD *TransactThread,
+    FSP_IOQ *TransactIoq, FSP_IOQ *Ioq);
+VOID FspTransactThreadStop(FSP_TRANSACT_THREAD *TransactThread);
+
 /* device extensions */
 enum
 {
diff --git a/src/sys/ioq.c b/src/sys/ioq.c
index 384d9ec4..8a7f9e10 100644
--- a/src/sys/ioq.c
+++ b/src/sys/ioq.c
@@ -174,6 +174,11 @@ VOID FspIoqEnable(FSP_IOQ *Ioq, int Delta)
     KeReleaseSpinLock(&Ioq->SpinLock, Irql);
 }
 
+PKEVENT FspIoqPendingIrpEvent(FSP_IOQ *Ioq)
+{
+    return &Ioq->PendingIrpEvent;
+}
+
 BOOLEAN FspIoqPostIrp(FSP_IOQ *Ioq, PIRP Irp)
 {
     NTSTATUS Result;
@@ -190,7 +195,7 @@ PIRP FspIoqNextPendingIrp(FSP_IOQ *Ioq, ULONG millis)
         Timeout.QuadPart = (LONGLONG)millis * 10000;
         Result = KeWaitForSingleObject(&Ioq->PendingIrpEvent, Executive, KernelMode, FALSE,
             -1 == millis ? 0 : &Timeout);
-        if (!NT_SUCCESS(Result))
+        if (STATUS_SUCCESS != Result)
             return 0;
     }
     return IoCsqRemoveNextIrp(&Ioq->PendingIoCsq, (PVOID)1);
diff --git a/src/sys/transact.c b/src/sys/transact.c
new file mode 100644
index 00000000..e9dcff6f
--- /dev/null
+++ b/src/sys/transact.c
@@ -0,0 +1,82 @@
+/**
+ * @file sys/transact.c
+ *
+ * @copyright 2015 Bill Zissimopoulos
+ */
+
+#include <sys/driver.h>
+
+static KSTART_ROUTINE FspTransactThread;
+NTSTATUS FspTransactThreadStart(FSP_TRANSACT_THREAD *TransactThread,
+    FSP_IOQ *TransactIoq, FSP_IOQ *Ioq);
+VOID FspTransactThreadStop(FSP_TRANSACT_THREAD *TransactThread);
+
+#ifdef ALLOC_PRAGMA
+#pragma alloc_text(PAGE, FspTransactThread)
+#pragma alloc_text(PAGE, FspTransactThreadStart)
+#pragma alloc_text(PAGE, FspTransactThreadStop)
+#endif
+
+static VOID FspTransactThread(PVOID StartContext)
+{
+    PAGED_CODE();
+
+    FSP_TRANSACT_THREAD *TransactThread = StartContext;
+    PVOID WaitObjects[2];
+    WaitObjects[0] = &TransactThread->Event;
+    WaitObjects[1] = FspIoqPendingIrpEvent(TransactThread->TransactIoq);
+    for (;;)
+    {
+        NTSTATUS Result;
+        PIRP Irp;
+
+        Result = KeWaitForMultipleObjects(2, WaitObjects, WaitAny, Executive, KernelMode, FALSE, 0, 0);
+        if (STATUS_WAIT_0 == Result)
+            break; /* stop thread */
+        else if (STATUS_WAIT_1 != Result)
+            continue; /* retry */
+
+        Irp = FspIoqNextPendingIrp(&TransactThread->TransactIoq, 0);
+        if (0 == Irp)
+            continue; /* retry */
+    }
+
+    PsTerminateSystemThread(STATUS_SUCCESS);
+}
+
+NTSTATUS FspTransactThreadStart(FSP_TRANSACT_THREAD *TransactThread,
+    FSP_IOQ *TransactIoq, FSP_IOQ *Ioq)
+{
+    PAGED_CODE();
+
+    NTSTATUS Result;
+    OBJECT_ATTRIBUTES ObjectAttributes;
+    HANDLE ThreadHandle;
+
+    RtlZeroMemory(TransactThread, sizeof *TransactThread);
+    KeInitializeEvent(&TransactThread->Event, NotificationEvent, FALSE);
+    TransactThread->TransactIoq = TransactIoq;
+    TransactThread->Ioq = Ioq;
+
+    InitializeObjectAttributes(&ObjectAttributes, 0, OBJ_KERNEL_HANDLE, 0, 0);
+    Result = PsCreateSystemThread(&ThreadHandle, THREAD_ALL_ACCESS, &ObjectAttributes, 0, 0,
+        FspTransactThread, TransactThread);
+    if (!NT_SUCCESS(Result))
+        return Result;
+
+    Result = ObReferenceObjectByHandle(ThreadHandle, THREAD_ALL_ACCESS, *PsThreadType, KernelMode,
+        &TransactThread->Thread, 0);
+    ASSERT(NT_SUCCESS(Result));
+
+    ZwClose(ThreadHandle);
+
+    return STATUS_SUCCESS;
+}
+
+VOID FspTransactThreadStop(FSP_TRANSACT_THREAD *TransactThread)
+{
+    PAGED_CODE();
+
+    KeSetEvent(&TransactThread->Event, 1, TRUE);
+    KeWaitForSingleObject(&TransactThread->Thread, Executive, KernelMode, FALSE, 0);
+}