Moved standard syslevel APIs declaration to winbase.h.
Use exported syslevel function wherever possible.
Moved SEGPTR declaration to windef16.h.

loader/module.c

diff --git a/loader/module.c b/loader/module.c
index ae2d298..d2c0fb8 100644
--- a/loader/module.c
+++ b/loader/module.c
@@ -17,7 +17,6 @@
 #include "heap.h"
 #include "neexe.h"
 #include "process.h"
-#include "syslevel.h"
 #include "selectors.h"
 #include "debugtools.h"
 #include "callback.h"
@@ -798,9 +797,10 @@
 
     if (ret == 21)  /* 32-bit module */
     {
-        SYSLEVEL_ReleaseWin16Lock();
+        DWORD count;
+        ReleaseThunkLock( &count );
         ret = WinExec( lpCmdLine, nCmdShow );
-        SYSLEVEL_RestoreWin16Lock();
+        RestoreThunkLock( count );
     }
     return ret;
 }
@@ -1452,11 +1452,11 @@
 HMODULE WINAPI LoadLibrary32_16( LPCSTR libname )
 {
     HMODULE hModule;
+    DWORD count;
 
-    SYSLEVEL_ReleaseWin16Lock();
+    ReleaseThunkLock( &count );
     hModule = LoadLibraryA( libname );
-    SYSLEVEL_RestoreWin16Lock();
-
+    RestoreThunkLock( count );
     return hModule;
 }
 

loader/ne/module.c

diff --git a/loader/ne/module.c b/loader/ne/module.c
index fa2cd39..4111aa8 100644
--- a/loader/ne/module.c
+++ b/loader/ne/module.c
@@ -22,7 +22,6 @@
 #include "global.h"
 #include "process.h"
 #include "snoop.h"
-#include "syslevel.h"
 #include "builtin16.h"
 #include "stackframe.h"
 #include "debugtools.h"
@@ -1120,7 +1119,7 @@
     SEGTABLEENTRY *pSegTable = NE_SEG_TABLE( pModule );
     WORD sp;
 
-    SYSLEVEL_EnterWin16Lock();
+    _EnterWin16Lock();
 
     if ( pModule->count > 0 )
     {
@@ -1197,7 +1196,7 @@
         ExitThread( LOWORD(context.Eax) );
     }
 
-    SYSLEVEL_LeaveWin16Lock();
+    _LeaveWin16Lock();
     ExitThread( hInstance );
 }
 

loader/task.c

diff --git a/loader/task.c b/loader/task.c
index 4d3bf8d..7491088 100644
--- a/loader/task.c
+++ b/loader/task.c
@@ -27,8 +27,8 @@
 #include "thread.h"
 #include "toolhelp.h"
 #include "winnt.h"
-#include "winsock.h"
 #include "syslevel.h"
+#include "winsock.h"
 #include "debugtools.h"
 #include "services.h"
 #include "server.h"
@@ -336,9 +336,9 @@
 
     /* Add the task to the linked list */
 
-    SYSLEVEL_EnterWin16Lock();
+    _EnterWin16Lock();
     TASK_LinkTask( hTask );
-    SYSLEVEL_LeaveWin16Lock();
+    _LeaveWin16Lock();
 
     return TRUE;
 }
@@ -384,12 +384,12 @@
     DWORD lockCount;
 
     /* Enter the Win16Lock to protect global data structures */
-    SYSLEVEL_EnterWin16Lock();
+    _EnterWin16Lock();
 
     pTask = (TDB *)GlobalLock16( GetCurrentTask() );
     if ( !pTask ) 
     {
-        SYSLEVEL_LeaveWin16Lock();
+        _LeaveWin16Lock();
         return;
     }
 
@@ -486,7 +486,7 @@
     enum { MODE_YIELD, MODE_SLEEP, MODE_WAKEUP } mode;
     DWORD lockCount;
 
-    SYSLEVEL_EnterWin16Lock();
+    _EnterWin16Lock();
 
     /* Check what we need to do */
     hOldTask = GetCurrentTask();
@@ -521,7 +521,7 @@
         else
         {
             /* nothing to do */
-            SYSLEVEL_LeaveWin16Lock();
+            _LeaveWin16Lock();
             return;
         }
     }
@@ -555,7 +555,7 @@
     if ( mode == MODE_YIELD && hNewTask && hNewTask == hCurrentTask )
     {
         TRACE("returning to the current task (%04x)\n", hCurrentTask );
-        SYSLEVEL_LeaveWin16Lock();
+        _LeaveWin16Lock();
 
         /* Allow Win32 threads to thunk down even while a Win16 task is
            in a tight PeekMessage() or Yield() loop ... */
@@ -600,7 +600,7 @@
         RestoreThunkLock( lockCount );
     }
 
-    SYSLEVEL_LeaveWin16Lock();
+    _LeaveWin16Lock();
 }
 
 /***********************************************************************