From: qwang12 <qwang12@6f19259b-4bc3-4df7-8a09-765794883524>
Date: Fri, 22 Feb 2008 09:43:59 +0000 (+0000)
Subject: Fix a bug reported by EDK940 "The main thread has not LeaveCriticalSection when be... 
X-Git-Tag: edk2-stable201903~21450
X-Git-Url: https://git.proxmox.com/?p=mirror_edk2.git;a=commitdiff_plain;h=1710eeb85ea79ae91c9e23abc448bee553226f59

Fix a bug reported by EDK940 "The main thread has not LeaveCriticalSection when be Suspended, and the child thread will try to EnterCriticalSection, there is the confliction".

git-svn-id: https://edk2.svn.sourceforge.net/svnroot/edk2/trunk/edk2@4745 6f19259b-4bc3-4df7-8a09-765794883524
---

diff --git a/Nt32Pkg/TimerDxe/Timer.c b/Nt32Pkg/TimerDxe/Timer.c
index 97ea73345b..d9944414cf 100644
--- a/Nt32Pkg/TimerDxe/Timer.c
+++ b/Nt32Pkg/TimerDxe/Timer.c
@@ -115,9 +115,12 @@ Returns:
   if (!mCancelTimerThread) {
   
     //
-    //  Suspend the main thread until we are done
+    // Suspend the main thread until we are done.
+    // Enter the critical section before suspending
+    // and leave the critical section after resuming
+    // to avoid deadlock between main and timer thread.
     //
-
+    gWinNt->EnterCriticalSection (&mNtCriticalSection);
     gWinNt->SuspendThread (mNtMainThreadHandle);
 
     //
@@ -127,6 +130,7 @@ Returns:
     //
     if (mCancelTimerThread) {
       gWinNt->ResumeThread (mNtMainThreadHandle);
+      gWinNt->LeaveCriticalSection (&mNtCriticalSection);
       gWinNt->timeKillEvent (wTimerID);
       mMMTimerThreadID = 0;
       return ;
@@ -138,6 +142,7 @@ Returns:
       //  Resume the main thread
       //
       gWinNt->ResumeThread (mNtMainThreadHandle);
+      gWinNt->LeaveCriticalSection (&mNtCriticalSection);
 
       //
       //  Wait for interrupts to be enabled.
@@ -151,6 +156,7 @@ Returns:
       //
       //  Suspend the main thread until we are done
       //
+      gWinNt->EnterCriticalSection (&mNtCriticalSection);
       gWinNt->SuspendThread (mNtMainThreadHandle);
       mCpu->GetInterruptState (mCpu, &InterruptState);
     }
@@ -174,9 +180,7 @@ Returns:
       //  expired since the last call is 10,000 times the number
       //  of ms.  (or 100ns units)
       //
-      gWinNt->EnterCriticalSection (&mNtCriticalSection);
       CallbackFunction = mTimerNotifyFunction;
-      gWinNt->LeaveCriticalSection (&mNtCriticalSection);
 
       //
       // Only invoke the callback function if a Non-NULL handler has been
@@ -194,6 +198,7 @@ Returns:
     //  Resume the main thread
     //
     gWinNt->ResumeThread (mNtMainThreadHandle);
+    gWinNt->LeaveCriticalSection (&mNtCriticalSection);
   } else {
     gWinNt->timeKillEvent (wTimerID);
     mMMTimerThreadID = 0;