fpc/rtl/win/systhrd.inc

696 lines
23 KiB
PHP

{
This file is part of the Free Pascal run time library.
Copyright (c) 2002 by Peter Vreman,
member of the Free Pascal development team.
Linux (pthreads) threading support implementation
See the file COPYING.FPC, included in this distribution,
for details about the copyright.
This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
**********************************************************************}
{*****************************************************************************
Local WINApi imports
*****************************************************************************}
const
{ LocalAlloc flags }
LMEM_FIXED = 0;
LMEM_ZEROINIT = 64;
{$ifndef WINCE}
function TlsAlloc : DWord;
stdcall;external KernelDLL name 'TlsAlloc';
function TlsFree(dwTlsIndex : DWord) : LongBool;
stdcall;external KernelDLL name 'TlsFree';
{$endif WINCE}
function TlsGetValue(dwTlsIndex : DWord) : pointer;
{$ifdef wince}cdecl{$else}stdcall{$endif};external KernelDLL name 'TlsGetValue';
function TlsSetValue(dwTlsIndex : DWord;lpTlsValue : pointer) : LongBool;
{$ifdef wince}cdecl{$else}stdcall{$endif};external KernelDLL name 'TlsSetValue';
function CreateThread(lpThreadAttributes : pointer;
dwStackSize : SIZE_T; lpStartAddress : pointer;lpParameter : pointer;
dwCreationFlags : DWord;var lpThreadId : DWord) : THandle;
{$ifdef wince}cdecl{$else}stdcall{$endif};external KernelDLL name 'CreateThread';
procedure ExitThread(dwExitCode : DWord);
{$ifdef wince}cdecl{$else}stdcall{$endif};external KernelDLL name 'ExitThread';
function LocalAlloc(uFlags:DWord; dwBytes:SIZE_T):Pointer;
{$ifdef wince}cdecl{$else}stdcall{$endif};external KernelDLL name 'LocalAlloc';
function LocalFree(hMem : Pointer):Pointer; {$ifdef wince}cdecl{$else}stdcall{$endif};external KernelDLL name 'LocalFree';
procedure Sleep(dwMilliseconds: DWord); {$ifdef wince}cdecl{$else}stdcall{$endif};external KernelDLL name 'Sleep';
function WinSuspendThread (threadHandle : THandle) : dword; {$ifdef wince}cdecl{$else}stdcall{$endif};external KernelDLL name 'SuspendThread';
function WinResumeThread (threadHandle : THandle) : dword; {$ifdef wince}cdecl{$else}stdcall{$endif};external KernelDLL name 'ResumeThread';
function WinCloseHandle (threadHandle : THandle) : dword; {$ifdef wince}cdecl{$else}stdcall{$endif};external KernelDLL name 'CloseHandle';
function TerminateThread (threadHandle : THandle; var exitCode : dword) : boolean; {$ifdef wince}cdecl{$else}stdcall{$endif};external KernelDLL name 'TerminateThread';
function WaitForSingleObject (hHandle : THandle;Milliseconds: dword): dword; {$ifdef wince}cdecl{$else}stdcall{$endif};external KernelDLL name 'WaitForSingleObject';
function WinThreadSetPriority (threadHandle : THandle; Prio: longint): boolean; {$ifdef wince}cdecl{$else}stdcall{$endif};external KernelDLL name 'SetThreadPriority';
function WinThreadGetPriority (threadHandle : THandle): LongInt; {$ifdef wince}cdecl{$else}stdcall{$endif};external KernelDLL name 'GetThreadPriority';
{$ifndef WINCE}
function WinGetCurrentThread: THandle; stdcall; external KernelDLL name 'GetCurrentThread';
function WinOpenThread(dwDesiredAccess: DWord; bInheritHandle: Boolean; dwThreadId: DWord): THandle; stdcall; external KernelDLL name 'OpenThread';
function WinIsDebuggerPresent: Boolean; stdcall; external KernelDLL name 'IsDebuggerPresent';
type
TSetThreadDescription = function(threadHandle: THandle; lpThreadDescription: PWideChar): HResult; stdcall;
var
WinSetThreadDescription: TSetThreadDescription;
function CreateEvent(lpEventAttributes:pointer;bManualReset:longbool;bInitialState:longbool;lpName:PAnsiChar): THandle; stdcall; external KernelDLL name 'CreateEventA';
function ResetEvent(hEvent:THandle):LONGBOOL; stdcall; external KernelDLL name 'ResetEvent';
function SetEvent(hEvent:THandle):LONGBOOL; stdcall; external KernelDLL name 'SetEvent';
{$endif WINCE}
procedure WinInitCriticalSection(var cs : TRTLCriticalSection);
{$ifdef wince}cdecl{$else}stdcall{$endif};external KernelDLL name 'InitializeCriticalSection';
procedure WinDoneCriticalSection(var cs : TRTLCriticalSection);
{$ifdef wince}cdecl{$else}stdcall{$endif};external KernelDLL name 'DeleteCriticalSection';
procedure WinEnterCriticalSection(var cs : TRTLCriticalSection);
{$ifdef wince}cdecl{$else}stdcall{$endif};external KernelDLL name 'EnterCriticalSection';
procedure WinLeaveCriticalSection(var cs : TRTLCriticalSection);
{$ifdef wince}cdecl{$else}stdcall{$endif};external KernelDLL name 'LeaveCriticalSection';
CONST
WAIT_OBJECT_0 = 0;
WAIT_ABANDONED_0 = $80;
WAIT_TIMEOUT = $102;
WAIT_IO_COMPLETION = $c0;
WAIT_ABANDONED = $80;
WAIT_FAILED = $ffffffff;
{$ifndef SUPPORT_WIN95}
function WinTryEnterCriticalSection(var cs : TRTLCriticalSection):longint;
{$ifdef wince}cdecl{$else}stdcall{$endif};external KernelDLL name 'TryEnterCriticalSection';
{$else SUPPORT_WIN95}
type
TTryEnterCriticalSection = function(var cs : TRTLCriticalSection):longint; stdcall;
var
WinTryEnterCriticalSection : TTryEnterCriticalSection;
{$endif SUPPORT_WIN95}
{*****************************************************************************
Threadvar support
*****************************************************************************}
var
// public names are used by heaptrc unit
threadvarblocksize : dword; public name '_FPC_TlsSize';
{$ifdef FPC_HAS_INDIRECT_ENTRY_INFORMATION}
TLSKey : PDword = nil; public name '_FPC_TlsKey';
{$else FPC_HAS_INDIRECT_ENTRY_INFORMATION}
TLSKeyVar : DWord = $ffffffff;
TLSKey : PDWord = @TLSKeyVar; public name '_FPC_TlsKey';
{$endif FPC_HAS_INDIRECT_ENTRY_INFORMATION}
var
MainThreadIdWin32 : DWORD;
procedure SysInitThreadvar(var offset : dword;size : dword);
begin
offset:=threadvarblocksize;
{$ifdef CPUARM}
// Data must be allocated at 4 bytes boundary for ARM
size:=(size + 3) and not dword(3);
{$endif CPUARM}
inc(threadvarblocksize,size);
end;
procedure SysAllocateThreadVars; public name '_FPC_SysAllocateThreadVars';
var
dataindex : pointer;
errorsave : dword;
begin
{ we've to allocate the memory from system }
{ because the FPC heap management uses }
{ exceptions which use threadvars but }
{ these aren't allocated yet ... }
{ allocate room on the heap for the thread vars }
errorsave:=GetLastError;
if tlskey^=$ffffffff then
RunError(226);
dataindex:=TlsGetValue(tlskey^);
if dataindex=nil then
begin
dataindex:=pointer(LocalAlloc(LMEM_FIXED or LMEM_ZEROINIT,threadvarblocksize));
if dataindex=nil then
RunError(226);
TlsSetValue(tlskey^,dataindex);
end;
SetLastError(errorsave);
end;
function SysRelocateThreadvar(offset : dword) : pointer; forward;
procedure SysInitTLS;
begin
{ do not check IsMultiThread, as program could have altered it, out of Delphi habit }
{ the thread attach/detach code uses locks to avoid multiple calls of this }
if TLSKey^=$ffffffff then
begin
{ We're still running in single thread mode, setup the TLS }
TLSKey^:=TlsAlloc;
InitThreadVars(@SysRelocateThreadvar);
end;
end;
procedure SysFiniMultithreading;
begin
if TLSKey^<>$ffffffff then
TlsFree(TLSKey^);
TLSKey^:=$ffffffff;
end;
function SysRelocateThreadvar(offset : dword) : pointer;
var
dataindex : pointer;
errorsave : dword;
begin
errorsave:=GetLastError;
dataindex:=TlsGetValue(tlskey^);
if dataindex=nil then
begin
SysAllocateThreadVars;
dataindex:=TlsGetValue(tlskey^);
InitThread($1000000);
end;
SetLastError(errorsave);
SysRelocateThreadvar:=DataIndex+Offset;
end;
procedure SysReleaseThreadVars;
var
p: pointer;
begin
if TLSKey^<>$ffffffff then
begin
p:=TlsGetValue(tlskey^);
if Assigned(p) then
LocalFree(p);
TlsSetValue(tlskey^, nil);
end;
end;
{*****************************************************************************
Thread starting
*****************************************************************************}
type
pthreadinfo = ^tthreadinfo;
tthreadinfo = record
f : tthreadfunc;
p : pointer;
stklen : ptruint;
end;
function ThreadMain(param : pointer) : Longint; {$ifdef wince}cdecl{$else}stdcall{$endif};
var
ti : tthreadinfo;
begin
{ Copy parameter to local data }
ti:=pthreadinfo(param)^;
{ Handle all possible threadvar models:
- dynamic threadvars: initialized either in DllMain,
or upon accessing the threadvar ThreadID;
- static threadvars+TLS callback: initialized in TLS callback;
- static threadvars, no callback: ThreadID remains 0 and
initialization happens here. }
if ThreadID=TThreadID(0) then
InitThread(ti.stklen);
dispose(pthreadinfo(param));
{ Start thread function }
{$ifdef DEBUG_MT}
writeln('Jumping to thread function of thread ',Win32GetCurrentThreadId);
{$endif DEBUG_MT}
{$if defined(FPC_USE_WIN64_SEH) or defined(FPC_USE_WIN32_SEH)}
{ use special 'top-level' exception handler around the thread function }
ThreadMain:=main_wrapper(ti.p,pointer(ti.f));
{$else FPC_USE_WIN64_SEH}
ThreadMain:=ti.f(ti.p);
{$endif FPC_USE_WIN64_SEH or FPC_USE_WIN32_SEH}
end;
function SysBeginThread(sa : Pointer;stacksize : ptruint;
ThreadFunction : tthreadfunc;p : pointer;
creationFlags : dword;var ThreadId : TThreadID) : TThreadID;
var
ti : pthreadinfo;
_threadid : dword;
begin
{$ifdef DEBUG_MT}
writeln('Creating new thread');
{$endif DEBUG_MT}
{ Initialize multithreading if not done }
SysInitTLS;
if not IsMultiThread then
begin
{ lazy initialize thread support }
LazyInitThreading;
IsMultiThread:=true;
end;
{ the only way to pass data to the newly created thread
in a MT safe way, is to use the heap }
new(ti);
ti^.f:=ThreadFunction;
ti^.p:=p;
ti^.stklen:=stacksize;
{$ifdef DEBUG_MT}
writeln('Starting new thread');
{$endif DEBUG_MT}
_threadid:=0;
SysBeginThread:=CreateThread(sa,stacksize,@ThreadMain,ti,creationflags,_threadid);
{ creation failed? if yes, we dispose the parameter record }
if SysBeginThread=0 then
begin
{$ifdef DEBUG_MT}
writeln('Thread creation failed');
{$endif DEBUG_MT}
dispose(ti);
end;
ThreadID:=_threadid;
end;
procedure SysEndThread(ExitCode : DWord);
begin
DoneThread;
ExitThread(ExitCode);
end;
procedure SysThreadSwitch;
begin
Sleep(0);
end;
function SysSuspendThread (threadHandle : TThreadID) : dword;
begin
SysSuspendThread:=WinSuspendThread(threadHandle);
end;
function SysResumeThread (threadHandle : TThreadID) : dword;
begin
SysResumeThread:=WinResumeThread(threadHandle);
end;
function SysKillThread (threadHandle : TThreadID) : dword;
var exitCode : dword;
begin
if not TerminateThread (threadHandle, exitCode) then
SysKillThread := GetLastError
else
SysKillThread := 0;
end;
function SysCloseThread (threadHandle : TThreadID) : dword;
begin
SysCloseThread:=winCloseHandle(threadHandle);
end;
function SysWaitForThreadTerminate (threadHandle : TThreadID; TimeoutMs : longint) : dword;
begin
// shouldn't this be a msgwait in case the thread creates "Windows" See comment in waitforsingle?
if timeoutMs = 0 then dec (timeoutMs); // $ffffffff is INFINITE
// does waiting on thread require cowait too ?
SysWaitForThreadTerminate := WaitForSingleObject(threadHandle, TimeoutMs);
end;
function SysThreadSetPriority (threadHandle : TThreadID; Prio: longint): boolean; {-15..+15, 0=normal}
begin
SysThreadSetPriority:=WinThreadSetPriority(threadHandle,Prio);
end;
function SysThreadGetPriority (threadHandle : TThreadID): longint;
begin
SysThreadGetPriority:=WinThreadGetPriority(threadHandle);
end;
function SysGetCurrentThreadId : TThreadID;
begin
SysGetCurrentThreadId:=Win32GetCurrentThreadId;
end;
{$ifndef WINCE}
{ following method is supported on older Windows versions AND currently only supported method by GDB }
procedure RaiseMSVCExceptionMethod(threadHandle: TThreadID; const ThreadName: AnsiString);
const
MS_VC_EXCEPTION: DWord = $406D1388;
type
THREADNAME_INFO = record
dwType: DWord; // Must be 0x1000.
szName: PAnsiChar; // Pointer to name (in user addr space).
dwThreadID: DWord; // Thread ID (-1=caller thread).
dwFlags: DWord; // Reserved for future use, must be zero.
end;
var
thrdinfo: THREADNAME_INFO;
begin
thrdinfo.dwType:=$1000;
thrdinfo.szName:=@ThreadName[1];
thrdinfo.dwThreadID:=threadHandle;
thrdinfo.dwFlags:=0;
try
RaiseException(MS_VC_EXCEPTION, 0, SizeOf(thrdinfo) div SizeOf(DWord), @thrdinfo);
except
{do nothing}
end;
end;
{ following method needs at least Windows 10 version 1607 or Windows Server 2016 }
procedure SetThreadDescriptionMethod(threadHandle: TThreadID; const ThreadName: UnicodeString);
var
thrdhandle: THandle;
ClosingNeeded: Boolean;
begin
if threadHandle=TThreadID(-1) then
begin
thrdhandle:=WinGetCurrentThread;
ClosingNeeded:=False;
end
else
begin
thrdhandle:=WinOpenThread($0400, False, threadHandle);
ClosingNeeded:=True;
end;
WinSetThreadDescription(thrdhandle, @ThreadName[1]);
if ClosingNeeded then
begin
CloseHandle(thrdhandle);
end;
end;
{$endif WINCE}
procedure SysSetThreadDebugNameA(threadHandle: TThreadID; const ThreadName: AnsiString);
begin
{$ifndef WINCE}
if ThreadName = '' then
Exit;
if WinIsDebuggerPresent then
begin
RaiseMSVCExceptionMethod(threadHandle, ThreadName);
end;
if Assigned(WinSetThreadDescription) then
begin
SetThreadDescriptionMethod(threadHandle, UnicodeString(ThreadName));
end;
{$else WINCE}
{$Warning SetThreadDebugNameA needs to be implemented}
{$endif WINCE}
end;
procedure SysSetThreadDebugNameU(threadHandle: TThreadID; const ThreadName: UnicodeString);
begin
{$ifndef WINCE}
if ThreadName = '' then
Exit;
if WinIsDebuggerPresent then
begin
RaiseMSVCExceptionMethod(threadHandle, AnsiString(ThreadName));
end;
if Assigned(WinSetThreadDescription) then
begin
SetThreadDescriptionMethod(threadHandle, ThreadName);
end;
{$else WINCE}
{$Warning SetThreadDebugNameU needs to be implemented}
{$endif WINCE}
end;
{*****************************************************************************
Delphi/Win32 compatibility
*****************************************************************************}
procedure SySInitCriticalSection(var cs);
begin
WinInitCriticalSection(PRTLCriticalSection(@cs)^);
end;
procedure SysDoneCriticalSection(var cs);
begin
WinDoneCriticalSection(PRTLCriticalSection(@cs)^);
end;
procedure SysEnterCriticalSection(var cs);
begin
WinEnterCriticalSection(PRTLCriticalSection(@cs)^);
end;
{$ifdef SUPPORT_WIN95}
function Win95TryEnterCriticalSection(var cs : TRTLCriticalSection):longint;stdcall;
var
MyThreadID : DWORD;
begin
MyThreadId:=GetCurrentThreadId();
if InterlockedIncrement(cs.LockCount)=0 then
begin
cs.OwningThread:=MyThreadId;
cs.RecursionCount:=1;
result:=1;
end
else
begin
if cs.OwningThread=MyThreadId then
begin
InterlockedDecrement(cs.LockCount);
InterlockedIncrement(cs.RecursionCount);
result:=1;
end
else
begin
InterlockedDecrement(cs.LockCount);
result:=0;
end;
end;
end;
{$endif SUPPORT_WIN95}
function SysTryEnterCriticalSection(var cs):longint;
begin
result:=WinTryEnterCriticalSection(PRTLCriticalSection(@cs)^);
end;
procedure SySLeaveCriticalSection(var cs);
begin
WinLeaveCriticalSection(PRTLCriticalSection(@cs)^);
end;
Const
wrSignaled = 0;
wrTimeout = 1;
wrAbandoned= 2;
wrError = 3;
function intBasicEventCreate(EventAttributes : Pointer;
AManualReset,InitialState : Boolean;const Name : ansistring):pEventState;
var
n : PAnsiChar;
begin
if Length(Name) = 0 then
n := Nil
else
n := PAnsiChar(Name);
Result := PEventState(CreateEvent(EventAttributes, AManualReset, InitialState,n));
end;
procedure intbasiceventdestroy(state:peventstate);
begin
closehandle(THandle(state));
end;
procedure intbasiceventResetEvent(state:peventstate);
begin
ResetEvent(THandle(state))
end;
procedure intbasiceventSetEvent(state:peventstate);
begin
SetEvent(THandle(state));
end;
function FirstCoWaitForMultipleHandles(dwFlags, dwTimeout: DWORD; cHandles: uint32; pHandles: PWOHandleArray; out lpdwindex: DWORD): HRESULT; stdcall; forward;
var
Ole32Dll: THandle = 0; { Unloaded at win32 & win64 system_exit. }
CoWaitForMultipleHandlesImpl: function(dwFlags, dwTimeout: DWORD; cHandles: uint32; pHandles: PWOHandleArray; out lpdwindex: DWORD): HRESULT; stdcall;
= @FirstCoWaitForMultipleHandles;
function FirstCoWaitForMultipleHandles(dwFlags, dwTimeout: DWORD; cHandles: uint32; pHandles: PWOHandleArray; out lpdwindex: DWORD): HRESULT; stdcall;
var
LocalOle32Dll: THandle;
begin
if Ole32Dll = 0 then
begin
LocalOle32Dll := WinLoadLibraryW('ole32.dll');
if InterlockedCompareExchange(Pointer(Ole32Dll), Pointer(LocalOle32Dll), nil) <> nil then
WinFreeLibrary(LocalOle32Dll);
end;
CodePointer(CoWaitForMultipleHandlesImpl) := WinGetProcAddress(Ole32Dll, 'CoWaitForMultipleHandles');
Result := CoWaitForMultipleHandlesImpl(dwFlags, dwTimeout, cHandles, pHandles, lpdwindex);
end;
function CoWaitForMultipleHandles(dwFlags, dwTimeout: DWORD; cHandles: uint32; pHandles: PWOHandleArray; out lpdwindex: DWORD): HRESULT;
begin
Result := CoWaitForMultipleHandlesImpl(dwFlags, dwTimeout, cHandles, pHandles, lpdwindex);
end;
function intbasiceventWaitFor(Timeout : Cardinal;state:peventstate;UseCOMWait: Boolean = False) : longint;
const COWAIT_DEFAULT = 0;
RPC_S_CALLPENDING = HRESULT($80010115);
var SignaledIndex : DWORD;
begin
if UseComWait Then
case CoWaitForMultipleHandles(COWAIT_DEFAULT, Timeout, 1, PWOHandleArray(@state), SignaledIndex) of
S_OK: Result := wrSignaled;
RPC_S_CALLPENDING: Result := wrTimeout;
else Result := wrError;
end
else
case WaitForSingleObject(THandle(state), Timeout) of
WAIT_OBJECT_0: Result := wrSignaled;
WAIT_TIMEOUT: Result := wrTimeout;
else result := wrError; { WAIT_FAILED or any other value. Note that only mutex waits can return WAIT_ABANDONED. }
end;
end;
function intRTLEventCreate: PRTLEvent;
begin
Result := PRTLEVENT(CreateEvent(nil, false, false, nil));
end;
procedure intRTLEventDestroy(AEvent: PRTLEvent);
begin
CloseHandle(THANDLE(AEvent));
end;
procedure intRTLEventSetEvent(AEvent: PRTLEvent);
begin
SetEvent(THANDLE(AEvent));
end;
procedure intRTLEventResetEvent(AEvent: PRTLEvent);
begin
ResetEvent(THANDLE(AEvent));
end;
procedure intRTLEventWaitFor(AEvent: PRTLEvent);
const
INFINITE=dword(-1);
begin
WaitForSingleObject(THANDLE(AEvent), INFINITE);
end;
procedure intRTLEventWaitForTimeout(AEvent: PRTLEvent;timeout : longint);
begin
WaitForSingleObject(THANDLE(AEvent), timeout);
end;
Var
WinThreadManager : TThreadManager;
Procedure InitSystemThreads;public name '_FPC_InitSystemThreads';
{$ifndef WINCE}
var
KernelHandle : THandle;
{$endif}
begin
With WinThreadManager do
begin
InitManager :=Nil;
DoneManager :=Nil;
BeginThread :=@SysBeginThread;
EndThread :=@SysEndThread;
SuspendThread :=@SysSuspendThread;
ResumeThread :=@SysResumeThread;
KillThread :=@SysKillThread;
ThreadSwitch :=@SysThreadSwitch;
CloseThread :=@SysCloseThread;
WaitForThreadTerminate :=@SysWaitForThreadTerminate;
ThreadSetPriority :=@SysThreadSetPriority;
ThreadGetPriority :=@SysThreadGetPriority;
GetCurrentThreadId :=@SysGetCurrentThreadId;
SetThreadDebugNameA :=@SysSetThreadDebugNameA;
SetThreadDebugNameU :=@SysSetThreadDebugNameU;
InitCriticalSection :=@SysInitCriticalSection;
DoneCriticalSection :=@SysDoneCriticalSection;
EnterCriticalSection :=@SysEnterCriticalSection;
TryEnterCriticalSection:=@SysTryEnterCriticalSection;
LeaveCriticalSection :=@SysLeaveCriticalSection;
InitThreadVar :=@SysInitThreadVar;
RelocateThreadVar :=@SysRelocateThreadVar;
AllocateThreadVars :=@SysAllocateThreadVars;
ReleaseThreadVars :=@SysReleaseThreadVars;
BasicEventCreate :=@intBasicEventCreate;
BasicEventDestroy :=@intBasicEventDestroy;
BasicEventResetEvent :=@intBasicEventResetEvent;
BasicEventSetEvent :=@intBasicEventSetEvent;
BasiceventWaitFor :=@intBasiceventWaitFor;
RTLEventCreate :=@intRTLEventCreate;
RTLEventDestroy :=@intRTLEventDestroy;
RTLEventSetEvent :=@intRTLEventSetEvent;
RTLEventResetEvent :=@intRTLEventResetEvent;
RTLEventWaitFor :=@intRTLEventWaitFor;
RTLEventWaitForTimeout :=@intRTLEventWaitForTimeout;
end;
SetThreadManager(WinThreadManager);
ThreadID := GetCurrentThreadID;
{$ifndef FPC_USE_TLS_DIRECTORY}
if IsLibrary then
{$endif}
SysInitTLS;
{$ifndef WINCE}
KernelHandle:=GetModuleHandle(KernelDLL);
{$endif}
{$IFDEF SUPPORT_WIN95}
{ Try to find TryEnterCriticalSection function }
if KernelHandle<>0 then
WinTryEnterCriticalSection:=TTryEnterCriticalSection(WinGetProcAddress(KernelHandle,'TryEnterCriticalSection'));
if not assigned(WinTryEnterCriticalSection) then
WinTryEnterCriticalSection:=@Win95TryEnterCriticalSection;
{$ENDIF SUPPORT_WIN95}
{$ifndef WINCE}
if KernelHandle<>0 then
begin
WinSetThreadDescription:=TSetThreadDescription(WinGetProcAddress(KernelHandle, 'SetThreadDescription'));
end;
{$endif WINCE}
end;