Use GetTempPath2 on Windows if available

src/coreclr/debug/createdump/createdump.h

@@ -149,6 +149,9 @@ extern MINIDUMP_TYPE GetMiniDumpType(DumpType dumpType);
 
 #ifdef HOST_WINDOWS
 extern std::string GetLastErrorString();
+extern DWORD GetTempPathWrapper(IN DWORD nBufferLength, OUT LPSTR lpBuffer);
+#else
+#define GetTempPathWrapper GetTempPathA
 #endif
 extern void printf_status(const char* format, ...);
 extern void printf_error(const char* format, ...);

src/coreclr/debug/createdump/createdumpmain.cpp

@@ -205,7 +205,7 @@ int createdump_main(const int argc, const char* argv[])
     ArrayHolder<char> tmpPath = new char[MAX_LONGPATH];
     if (options.DumpPathTemplate == nullptr)
     {
-        if (::GetTempPathA(MAX_LONGPATH, tmpPath) == 0)
+        if (GetTempPathWrapper(MAX_LONGPATH, tmpPath) == 0)
         {
             printf_error("GetTempPath failed\n");
             return -1;

src/coreclr/debug/createdump/createdumpwindows.cpp

@@ -135,3 +135,38 @@ GetLastErrorString()
     return result;
 }
 
+
+typedef DWORD(WINAPI *pfnGetTempPathA)(DWORD nBufferLength, LPSTR  lpBuffer);
+
+static volatile pfnGetTempPathA
+g_pfnGetTempPathA = nullptr;
+
+
+DWORD
+GetTempPathWrapper(
+    IN DWORD nBufferLength,
+    OUT LPSTR lpBuffer)
+{
+    if (g_pfnGetTempPathA == nullptr)
+    {
+        HMODULE hKernel32 = LoadLibraryExW(L"kernel32.dll", NULL, LOAD_LIBRARY_SEARCH_SYSTEM32);
+
+        pfnGetTempPathA pLocalGetTempPathA = NULL;
+        if (hKernel32 != NULL)
+        {
+            // store to thread local variable to prevent data race
+            pLocalGetTempPathA = (pfnGetTempPathA)::GetProcAddress(hKernel32, "GetTempPath2A");
+        }
+
+        if (pLocalGetTempPathA == NULL) // method is only available with Windows 10 Creators Update or later
+        {
+            g_pfnGetTempPathA = &GetTempPathA;
+        }
+        else
+        {
+            g_pfnGetTempPathA = pLocalGetTempPathA;
+        }
+    }
+
+    return g_pfnGetTempPathA(nBufferLength, lpBuffer);
+}

src/coreclr/inc/longfilepathwrappers.h

@@ -59,10 +59,6 @@ SearchPathWrapper(
     _Out_opt_ LPWSTR * lpFilePart
     );
 
-DWORD WINAPI GetTempPathWrapper(
-    SString& lpBuffer
-    );
-
 DWORD
 GetModuleFileNameWrapper(
     _In_opt_ HMODULE hModule,

src/coreclr/utilcode/longfilepathwrappers.cpp

@@ -184,47 +184,6 @@ GetModuleFileNameWrapper(
     return ret;
 }
 
-DWORD WINAPI GetTempPathWrapper(
-    SString& lpBuffer
-    )
-{
-    CONTRACTL
-    {
-        NOTHROW;
-    }
-    CONTRACTL_END;
-
-    HRESULT hr = S_OK;
-    DWORD ret = 0;
-    DWORD lastError = 0;
-
-    EX_TRY
-    {
-        //Change the behaviour in Redstone to retry
-        COUNT_T size = MAX_LONGPATH;
-
-        ret = GetTempPathW(
-            size,
-            lpBuffer.OpenUnicodeBuffer(size - 1)
-            );
-
-        lastError = GetLastError();
-        lpBuffer.CloseBuffer(ret);
-    }
-    EX_CATCH_HRESULT(hr);
-
-    if (hr != S_OK)
-    {
-        SetLastError(hr);
-    }
-    else if (ret == 0)
-    {
-        SetLastError(lastError);
-    }
-
-    return ret;
-}
-
 DWORD WINAPI GetEnvironmentVariableWrapper(
     _In_opt_  LPCTSTR lpName,
     _Out_opt_ SString&  lpBuffer

src/native/corehost/hostmisc/pal.windows.cpp

@@ -66,6 +66,38 @@ void pal::out_vprint_line(const pal::char_t* format, va_list vl) {
     print_line_to_handle(&buffer[0], ::GetStdHandle(STD_OUTPUT_HANDLE), stdout);
 }
 
+namespace
+{
+    typedef DWORD(WINAPI *get_temp_path_func_ptr)(DWORD buffer_len, LPWSTR buffer);
+    static volatile get_temp_path_func_ptr s_get_temp_path_func = nullptr;
+
+    DWORD get_temp_path(DWORD buffer_len, LPWSTR buffer)
+    {
+        if (s_get_temp_path_func == nullptr)
+        {
+            HMODULE kernel32 = ::LoadLibraryExW(L"kernel32.dll", NULL, LOAD_LIBRARY_SEARCH_SYSTEM32);
+
+            get_temp_path_func_ptr get_temp_path_func_local = NULL;
+            if (kernel32 != NULL)
+            {
+                // store to thread local variable to prevent data race
+                get_temp_path_func_local = (get_temp_path_func_ptr)::GetProcAddress(kernel32, "GetTempPath2W");
+            }
+
+            if (get_temp_path_func_local == NULL) // method is only available with Windows 10 Creators Update or later
+            {
+                s_get_temp_path_func = &GetTempPathW;
+            }
+            else
+            {
+                s_get_temp_path_func = get_temp_path_func_local;
+            }
+        }
+
+        return s_get_temp_path_func(buffer_len, buffer);
+    }
+}
+
 bool GetModuleFileNameWrapper(HMODULE hModule, pal::string_t* recv)
 {
     pal::string_t path;
@@ -695,7 +727,7 @@ bool get_extraction_base_parent_directory(pal::string_t& directory)
     const size_t max_len = MAX_PATH + 1;
     pal::char_t temp_path[max_len];
 
-    size_t len = GetTempPathW(max_len, temp_path);
+    size_t len = get_temp_path(max_len, temp_path);
     if (len == 0)
     {
         return false;