Opt, 废除__YY_Thunks_Process_Terminating弱符号，提高反初始化性能

src/Build.cmd

@@ -30,19 +30,7 @@ cl /O1 /Os /Oi /GS- /std:c++17 /execution-charset:utf-8 /Zc:sizedDealloc- /Zc:tl
 if %ErrorLevel% NEQ 0 exit /b %ErrorLevel%
 
 ::生成weak符号，一些非必须符号安排为weak可以避免链接失败
-LibMaker.exe FixObj "%~dp0..\\objs\\%Platform%\\%1" /WeakExternFix:__security_cookie=%PointType% /WeakExternFix:__YY_Thunks_Process_Terminating=4 /WeakExternFix:__acrt_atexit_table=%PointType% /WeakExternFix:__pfnDllMainCRTStartupForYY_Thunks=%PointType%
-if %ErrorLevel% NEQ 0 exit /b %ErrorLevel%
-if "%3"=="" goto:eof
-set DEF_FILES=%3
-:AppendWeak
-for /f "tokens=1* delims=+" %%a in ("%DEF_FILES%") do (
-    echo "AppendWeak %~dp0def\\%Platform%\\%%a"
-    LibMaker.exe AppendWeak /MACHINE:%Platform% /DEF:"%~dp0def\\%Platform%\\%%a" /OUT:"%~dp0..\\objs\\%Platform%\\%1"
-    if %ErrorLevel% NEQ 0 exit /b %ErrorLevel%
-    set DEF_FILES=%%b
-)
-
-if defined DEF_FILES goto :AppendWeak
+call:FixObj "%~dp0..\\objs\\%Platform%\\%1" %3
 
 goto:eof
 
@@ -57,21 +45,7 @@ cl /O1 /Os /Oi /GS- /std:c++17 /execution-charset:utf-8 /Zc:sizedDealloc- /Zc:tl
 if %ErrorLevel% NEQ 0 exit /b %ErrorLevel%
 
 ::生成weak符号，一些非必须符号安排为weak可以避免链接失败
-LibMaker.exe FixObj "%~dp0..\\Lib\\%1\\%Platform%\\YY_Thunks_for_%1.obj" /WeakExternFix:__security_cookie=%PointType% /WeakExternFix:__YY_Thunks_Process_Terminating=4 /WeakExternFix:__acrt_atexit_table=%PointType% /WeakExternFix:__pfnDllMainCRTStartupForYY_Thunks=%PointType%
-if %ErrorLevel% NEQ 0 exit /b %ErrorLevel%
-
-if "%3"=="" goto:BuildWeak
-set DEF_FILES=%3
-:AppendWeakByLib
-for /f "tokens=1* delims=+" %%a in ("%DEF_FILES%") do (
-    echo "AppendWeak %~dp0def\\%Platform%\\%%a"
-    LibMaker.exe /PREFIX:YY_Thunks_ AppendWeak /MACHINE:%Platform% /DEF:"%~dp0def\\%Platform%\\%%a" /OUT:"%~dp0..\\Lib\\%1\\%Platform%\\YY_Thunks_for_%1.obj"
-    if %ErrorLevel% NEQ 0 exit /b %ErrorLevel%
-    set DEF_FILES=%%b
-)
-
-if defined DEF_FILES goto:AppendWeakByLib
-:BuildWeak
+call:FixObj "%~dp0..\\Lib\\%1\\%Platform%\\YY_Thunks_for_%1.obj" %3
 
 set "SupportApiSet=/SupportApiSet"
 set "WinVersion=%1"
@@ -163,3 +137,20 @@ call:BuildX 10.0.19041.0 YY_Thunks_for_Win10.0.19041.obj __WindowsNT10_19041
 if %ErrorLevel% NEQ 0 exit /b %ErrorLevel%
 
 goto:eof
+
+:: FixObj "XXX\YY_Thunks_for_Vista.obj" 1.def+2.def
+:FixObj
+LibMaker.exe FixObj %1 /WeakExternFix:__security_cookie=%PointType% /WeakExternFix:__acrt_atexit_table=%PointType% /WeakExternFix:__pfnDllMainCRTStartupForYY_Thunks=%PointType%
+if %ErrorLevel% NEQ 0 exit /b %ErrorLevel%
+if "%2"=="" goto:eof
+set DEF_FILES=%2
+:AppendWeak
+for /f "tokens=1* delims=+" %%a in ("%DEF_FILES%") do (
+    echo "AppendWeak %~dp0def\\%Platform%\\%%a" %1
+    LibMaker.exe AppendWeak /MACHINE:%Platform% /DEF:"%~dp0def\\%Platform%\\%%a" /OUT:%1
+    if %ErrorLevel% NEQ 0 exit /b %ErrorLevel%
+    set DEF_FILES=%%b
+)
+
+if defined DEF_FILES goto :AppendWeak
+goto:eof

src/Thunks/DllMainCRTStartup.hpp

@@ -535,9 +535,10 @@ namespace YY::Thunks::internal
             break;
 #endif
         case DLL_PROCESS_DETACH:
-#if (YY_Thunks_Target < __WindowsNT5_1)
-            __YY_Thunks_Process_Terminating = _pReserved != nullptr;
-#endif
+            __if_exists(__YY_Thunks_Process_Terminating)
+            {
+                __YY_Thunks_Process_Terminating = _pReserved != nullptr ? -1 : 1;
+            }
 
 #if YY_Thunks_Target < __WindowsNT6
             if (internal::GetSystemVersion() < internal::MakeVersion(6, 0) && _tls_index_old == 0 && g_TlsMode == TlsMode::ByDllMainCRTStartupForYY_Thunks)
@@ -548,18 +549,15 @@ namespace YY::Thunks::internal
                 if (_pReserved == nullptr)
                 {
                     FreeTlsIndex();
-                    __YY_uninitialize_winapi_thunks();
                 }
+                __YY_uninitialize_winapi_thunks();
                 return _bRet;
             }
             else
 #endif
             {
                 auto _bRet = _pfnDllMainCRTStartup(_hInstance, _uReason, _pReserved);
-                if (_pReserved == nullptr)
-                {
-                    __YY_uninitialize_winapi_thunks();
-                }
+                __YY_uninitialize_winapi_thunks();
                 return _bRet;
             }
             break;

src/Thunks/YY_Thunks.h

@@ -104,34 +104,20 @@ else
 */
 EXTERN_C const UINT64 __YY_Thunks_Installed = YY_Thunks_Target;
 
-/*
-导出一个外部弱符号，指示当前是否处于强行卸载模式。
-
-EXTERN_C BOOL __YY_Thunks_Process_Terminating;
-
-BOOL WINAPI DllMain(HINSTANCE hInstance, DWORD dwReason, LPVOID lpReserved)
-{
-    switch(dwReason)
-    {
-        case DLL_PROCESS_DETACH:
-        //我们可以通过 lpReserved != NULL 判断，当前是否处于强行卸载模式。
-        __YY_Thunks_Process_Terminating = lpReserved != NULL;
-
-        ……
-        break;
-    ……
-*/
-#if (YY_Thunks_Target < __WindowsNT5_1)
-//Windows 2000不支持RtlDllShutdownInProgress，因此依然引入__YY_Thunks_Process_Terminating
-EXTERN_C extern BOOL __YY_Thunks_Process_Terminating;
-#endif
+// 从DllMain缓存RtlDllShutdownInProgress状态，规避退出时调用RtlDllShutdownInProgress。
+// 0：缓存无效
+// 1：模块正常卸载
+// -1：开始进程准备终止
+static int __YY_Thunks_Process_Terminating;
 
 #if (YY_Thunks_Target < __WindowsNT6)
 static HANDLE _GlobalKeyedEventHandle;
 #endif
 
 static uintptr_t __security_cookie_yy_thunks;
 
+extern "C" IMAGE_DOS_HEADER __ImageBase;
+
 #define _APPLY(_SYMBOL, _NAME, ...) \
     constexpr const wchar_t* _CRT_CONCATENATE(module_name_, _SYMBOL) = _CRT_WIDE(_NAME);
     _YY_APPLY_TO_LATE_BOUND_MODULES(_APPLY)
@@ -561,6 +547,25 @@ static UINT_PTR GetSecurityNewCookie()
 
 static volatile ThunksInitStatus s_eThunksStatus /*= ThunksInitStatus::None*/;
 
+static bool __YY_DllShutdownInProgress()
+{
+    __if_exists(__YY_Thunks_Process_Terminating)
+    {
+        if (__YY_Thunks_Process_Terminating != 0)
+            return __YY_Thunks_Process_Terminating == -1;
+    }
+
+#if (YY_Thunks_Target < __WindowsNT5_1) || !defined(__USING_NTDLL_LIB)
+    if (const auto RtlDllShutdownInProgress = (decltype(::RtlDllShutdownInProgress)*)GetProcAddress(try_get_module_ntdll(), "RtlDllShutdownInProgress"))
+#endif
+    {
+        return RtlDllShutdownInProgress();
+    }
+
+    // 按理说不太可能走到这里，难道是老系统时没有被DllMain接管？
+    return false;
+}
+
 static void __cdecl __YY_uninitialize_winapi_thunks()
 {
     // 只反初始化一次
@@ -573,18 +578,8 @@ static void __cdecl __YY_uninitialize_winapi_thunks()
         return;
 
     //当DLL被强行卸载时，我们什么都不做，因为依赖的函数指针可能是无效的。
-    __if_exists(__YY_Thunks_Process_Terminating)
-    {
-        if (__YY_Thunks_Process_Terminating)
-            return;
-    }
-#if (YY_Thunks_Target < __WindowsNT5_1) || !defined(__USING_NTDLL_LIB)
-    if (const auto RtlDllShutdownInProgress = (decltype(::RtlDllShutdownInProgress)*)GetProcAddress(try_get_module_ntdll(), "RtlDllShutdownInProgress"))
-#endif
-    {
-        if (RtlDllShutdownInProgress())
-            return;
-    }
+    if(__YY_DllShutdownInProgress())
+        return;
 
     auto pModule = (HMODULE*)__YY_THUNKS_MODULE_START;
     auto pModuleEnd = (HMODULE*)__YY_THUNKS_FUN_START;
@@ -685,6 +680,11 @@ static int __cdecl __YY_initialize_winapi_thunks()
         return 0;
     }
 
+    // 当前模块是exe不注册反初始化，如果模块就是exe自己，那么反初始化必然代表进程退出
+    // 当进程退出时，关闭句柄或者卸载DLL这些都不是必须进行的，以提高性能。
+    if (PVOID(&__ImageBase) == ((TEB*)NtCurrentTeb())->ProcessEnvironmentBlock->ImageBaseAddress)
+        return 0;
+
     // 如果 == null，那么有2种情况：
     //   1. 非UCRT，比如2008，VC6，这时，调用 atexit是安全的，因为atexit在 XIA初始化完成了。
     //   2. UCRT 并且处于MD状态。这时 atexit初始化 会提与 XIA，这时也是没有问题的。

src/YY-Thunks.UnitTest/weak.c

@@ -1,6 +1,4 @@
 
-const int __YY_Thunks_Process_Terminating;
-
 const void* __acrt_atexit_table;
 
 const void* __pfnDllMainCRTStartupForYY_Thunks;