From db1dc6fc91110593231a2c44ecc24b3b11d21b2a Mon Sep 17 00:00:00 2001
From: Bill Zissimopoulos <billziss@navimatics.com>
Date: Wed, 23 Dec 2015 23:04:20 -0800
Subject: [PATCH] sys: util: FSP_SYNCHRONOUS_WORK_ITEM

---
 src/sys/driver.h | 12 ++++++++++++
 src/sys/util.c   | 37 +++++++++++++++++++++++++++++++++++++
 2 files changed, 49 insertions(+)

diff --git a/src/sys/driver.h b/src/sys/driver.h
index bbab1c82..8a856967 100644
--- a/src/sys/driver.h
+++ b/src/sys/driver.h
@@ -274,6 +274,18 @@ VOID FspFreeExternal(PVOID Pointer)
 /* utility: GUIDs */
 NTSTATUS FspCreateGuid(GUID *Guid);
 
+/* utility: synchronous work queue */
+typedef struct
+{
+    KEVENT Event;
+    PWORKER_THREAD_ROUTINE Routine;
+    PVOID Context;
+    WORK_QUEUE_ITEM WorkQueueItem;
+} FSP_SYNCHRONOUS_WORK_ITEM;
+VOID FspInitializeSynchronousWorkItem(FSP_SYNCHRONOUS_WORK_ITEM *SynchronousWorkItem,
+    PWORKER_THREAD_ROUTINE Routine, PVOID Context);
+VOID FspExecuteSynchronousWorkItem(FSP_SYNCHRONOUS_WORK_ITEM *SynchronousWorkItem);
+
 /* utility: delayed work queue */
 typedef struct
 {
diff --git a/src/sys/util.c b/src/sys/util.c
index 624ab755..5054c244 100644
--- a/src/sys/util.c
+++ b/src/sys/util.c
@@ -7,6 +7,10 @@
 #include <sys/driver.h>
 
 NTSTATUS FspCreateGuid(GUID *Guid);
+VOID FspInitializeSynchronousWorkItem(FSP_SYNCHRONOUS_WORK_ITEM *SynchronousWorkItem,
+    PWORKER_THREAD_ROUTINE Routine, PVOID Context);
+VOID FspExecuteSynchronousWorkItem(FSP_SYNCHRONOUS_WORK_ITEM *SynchronousWorkItem);
+static WORKER_THREAD_ROUTINE FspExecuteSynchronousWorkItemRoutine;
 VOID FspInitializeDelayedWorkItem(FSP_DELAYED_WORK_ITEM *DelayedWorkItem,
     PWORKER_THREAD_ROUTINE Routine, PVOID Context);
 VOID FspQueueDelayedWorkItem(FSP_DELAYED_WORK_ITEM *DelayedWorkItem, LARGE_INTEGER Delay);
@@ -14,6 +18,9 @@ static KDEFERRED_ROUTINE FspQueueDelayedWorkItemDPC;
 
 #ifdef ALLOC_PRAGMA
 #pragma alloc_text(PAGE, FspCreateGuid)
+#pragma alloc_text(PAGE, FspInitializeSynchronousWorkItem)
+#pragma alloc_text(PAGE, FspExecuteSynchronousWorkItem)
+#pragma alloc_text(PAGE, FspExecuteSynchronousWorkItemRoutine)
 #pragma alloc_text(PAGE, FspInitializeDelayedWorkItem)
 #pragma alloc_text(PAGE, FspQueueDelayedWorkItem)
 #endif
@@ -33,6 +40,36 @@ NTSTATUS FspCreateGuid(GUID *Guid)
     return Result;
 }
 
+VOID FspInitializeSynchronousWorkItem(FSP_SYNCHRONOUS_WORK_ITEM *SynchronousWorkItem,
+    PWORKER_THREAD_ROUTINE Routine, PVOID Context)
+{
+    PAGED_CODE();
+
+    KeInitializeEvent(&SynchronousWorkItem->Event, NotificationEvent, FALSE);
+    SynchronousWorkItem->Routine = Routine;
+    SynchronousWorkItem->Context = Context;
+    ExInitializeWorkItem(&SynchronousWorkItem->WorkQueueItem,
+        FspExecuteSynchronousWorkItemRoutine, SynchronousWorkItem);
+}
+VOID FspExecuteSynchronousWorkItem(FSP_SYNCHRONOUS_WORK_ITEM *SynchronousWorkItem)
+{
+    PAGED_CODE();
+
+    ExQueueWorkItem(&SynchronousWorkItem->WorkQueueItem, DelayedWorkQueue);
+
+    NTSTATUS Result;
+    Result = KeWaitForSingleObject(&SynchronousWorkItem->Event, Executive, KernelMode, FALSE, 0);
+    ASSERT(STATUS_SUCCESS == Result);
+}
+static VOID FspExecuteSynchronousWorkItemRoutine(PVOID Context)
+{
+    PAGED_CODE();
+
+    FSP_SYNCHRONOUS_WORK_ITEM *SynchronousWorkItem = Context;
+    SynchronousWorkItem->Routine(SynchronousWorkItem->Context);
+    KeSetEvent(&SynchronousWorkItem->Event, 1, FALSE);
+}
+
 VOID FspInitializeDelayedWorkItem(FSP_DELAYED_WORK_ITEM *DelayedWorkItem,
     PWORKER_THREAD_ROUTINE Routine, PVOID Context)
 {