From ff81e5e1b064a8f248cc881a85e2fede9d8a0440 Mon Sep 17 00:00:00 2001
From: David Welch <welch@cwcom.net>
Date: Sun, 7 Mar 2004 04:38:41 +0000
Subject: [PATCH] - Use an event rather than a semaphore to wake up the thread
 that writes debug output to disk. Avoids bugchecking if the number of debug
 prints before the thread wakes up exceeds the semaphore limit.

svn path=/trunk/; revision=8559
---
 reactos/ntoskrnl/kd/dlog.c | 19 +++++++++++--------
 1 file changed, 11 insertions(+), 8 deletions(-)

diff --git a/reactos/ntoskrnl/kd/dlog.c b/reactos/ntoskrnl/kd/dlog.c
index 25885006691..b4bab1637ac 100644
--- a/reactos/ntoskrnl/kd/dlog.c
+++ b/reactos/ntoskrnl/kd/dlog.c
@@ -1,4 +1,4 @@
-/* $Id: dlog.c,v 1.11 2004/01/05 14:28:20 weiden Exp $
+/* $Id: dlog.c,v 1.12 2004/03/07 04:38:41 dwelch Exp $
  *
  * COPYRIGHT:       See COPYING in the top level directory
  * PROJECT:         ReactOS kernel
@@ -31,7 +31,7 @@ static ULONG DebugLogOverflow;
 static HANDLE DebugLogThreadHandle;
 static CLIENT_ID DebugLogThreadCid;
 static HANDLE DebugLogFile;
-static KSEMAPHORE DebugLogSem;
+static KEVENT DebugLogEvent;
 
 /* FUNCTIONS *****************************************************************/
 
@@ -43,7 +43,7 @@ DebugLogInit(VOID)
   DebugLogEnd = 0;
   DebugLogOverflow = 0;
   DebugLogCount = 0;
-  KeInitializeSemaphore(&DebugLogSem, 0, 255);
+  KeInitializeEvent(&DebugLogEvent, NotificationEvent, FALSE);
 }
 
 VOID STDCALL
@@ -56,11 +56,13 @@ DebugLogThreadMain(PVOID Context)
 
   for (;;)
     {
-      KeWaitForSingleObject(&DebugLogSem,
+      LARGE_INTEGER TimeOut;
+      TimeOut.QuadPart = -5000000; /* Half a second. */
+      KeWaitForSingleObject(&DebugLogEvent,
 			    0,
 			    KernelMode,
 			    FALSE,
-			    NULL);
+			    &TimeOut);
       KeAcquireSpinLock(&DebugLogLock, &oldIrql);
       while (DebugLogCount > 0)
 	{
@@ -103,6 +105,7 @@ DebugLogThreadMain(PVOID Context)
 	    }
 	  KeAcquireSpinLock(&DebugLogLock, &oldIrql);
 	}
+      KeResetEvent(&DebugLogEvent);
       KeReleaseSpinLock(&DebugLogLock, oldIrql);
     }
 }
@@ -167,7 +170,7 @@ DebugLogWrite(PCH String)
       KeReleaseSpinLock(&DebugLogLock, oldIrql);
       if (oldIrql < DISPATCH_LEVEL)
  	{
-   	KeReleaseSemaphore(&DebugLogSem, IO_NO_INCREMENT, 1, FALSE);
+	  KeSetEvent(&DebugLogEvent, IO_NO_INCREMENT, FALSE);
  	}
       	return;
     }
@@ -184,7 +187,7 @@ DebugLogWrite(PCH String)
  	  KeReleaseSpinLock(&DebugLogLock, oldIrql);
  	  if (oldIrql < DISPATCH_LEVEL)
  	    {
- 	      KeReleaseSemaphore(&DebugLogSem, IO_NO_INCREMENT, 1, FALSE);
+	      KeSetEvent(&DebugLogEvent, IO_NO_INCREMENT, FALSE);
  	    }
  	  return;
  	}
@@ -195,7 +198,7 @@ DebugLogWrite(PCH String)
 
     if (oldIrql < DISPATCH_LEVEL)
     {
-      KeReleaseSemaphore(&DebugLogSem, IO_NO_INCREMENT, 1, FALSE);
+      KeSetEvent(&DebugLogEvent, IO_NO_INCREMENT, FALSE);
     }
 }