| Index: base/win/dllmain.cc
|
| ===================================================================
|
| --- base/win/dllmain.cc (revision 113341)
|
| +++ base/win/dllmain.cc (working copy)
|
| @@ -1,131 +0,0 @@
|
| -// Copyright (c) 2011 The Chromium Authors. All rights reserved.
|
| -// Use of this source code is governed by a BSD-style license that can be
|
| -// found in the LICENSE file.
|
| -
|
| -// Windows doesn't support pthread_key_create's destr_function, and in fact
|
| -// it's a bit tricky to get code to run when a thread exits. This is
|
| -// cargo-cult magic from http://www.codeproject.com/threads/tls.asp.
|
| -// We are trying to be compatible with both a LoadLibrary style invocation, as
|
| -// well as static linking. This code only needs to be included if we use
|
| -// LoadLibrary, but it hooks into the "standard" set of TLS callbacks that are
|
| -// provided for static linking.
|
| -
|
| -// This code is deliberately written to match the style of calls seen in
|
| -// base/threading/thread_local_storage_win.cc. Please keep the two in sync if
|
| -// coding conventions are changed.
|
| -
|
| -// WARNING: Do *NOT* try to include this in the construction of the base
|
| -// library, even though it potentially drives code in
|
| -// base/threading/thread_local_storage_win.cc. If you do, some users will end
|
| -// up getting duplicate definition of DllMain() in some of their later links.
|
| -
|
| -// Force a reference to _tls_used to make the linker create the TLS directory
|
| -// if it's not already there (that is, even if __declspec(thread) is not used).
|
| -// To make sure we really traverse the whole list, we put down two elements, and
|
| -// then check that we called both functions when we scanned the list.
|
| -// Force a reference to p_thread_callback_dllmain_first_entry and
|
| -// p_thread_callback_dllmain_first_entry to prevent whole program optimization
|
| -// from discarding the variables.
|
| -
|
| -#include <windows.h>
|
| -
|
| -#include "base/logging.h"
|
| -
|
| -// Indicate if another service is scanning the callbacks. When this becomes
|
| -// set to true, then DllMain() will stop supporting the callback service. This
|
| -// value is set to true the first time any of our callbacks are called, as that
|
| -// shows that some other service is handling callbacks.
|
| -static bool linker_notifications_are_active = false;
|
| -
|
| -// This will be our mostly no-op callback that we'll list (twice). We won't
|
| -// deliberately call it, and if it is called, that means we don't need to do any
|
| -// of the callbacks anymore. We expect such a call to arrive via a
|
| -// THREAD_ATTACH message, long before we'd have to perform our THREAD_DETACH
|
| -// callbacks.
|
| -static void NTAPI on_callback(PVOID h, DWORD reason, PVOID reserved);
|
| -
|
| -#ifdef _WIN64
|
| -
|
| -#pragma comment(linker, "/INCLUDE:_tls_used")
|
| -#pragma comment(linker, "/INCLUDE:p_thread_callback_dllmain_first_entry")
|
| -#pragma comment(linker, "/INCLUDE:p_thread_callback_dllmain_later_entry")
|
| -
|
| -#else // _WIN64
|
| -
|
| -#pragma comment(linker, "/INCLUDE:__tls_used")
|
| -#pragma comment(linker, "/INCLUDE:_p_thread_callback_dllmain_first_entry")
|
| -#pragma comment(linker, "/INCLUDE:_p_thread_callback_dllmain_later_entry")
|
| -
|
| -#endif // _WIN64
|
| -
|
| -// extern "C" suppresses C++ name mangling so we know the symbol names for the
|
| -// linker /INCLUDE:symbol pragmas above.
|
| -extern "C" {
|
| -#ifdef _WIN64
|
| -
|
| -// .CRT section is merged with .rdata on x64 so it must be constant data.
|
| -#pragma data_seg(push, old_seg)
|
| -// Use earliest possible name in the .CRT$XL? list of segments.
|
| -#pragma const_seg(".CRT$XLA")
|
| -// When defining a const variable, it must have external linkage to be sure the
|
| -// linker doesn't discard it.
|
| -extern const PIMAGE_TLS_CALLBACK p_thread_callback_dllmain_first_entry;
|
| -const PIMAGE_TLS_CALLBACK p_thread_callback_dllmain_first_entry = on_callback;
|
| -// The latest possible name in the .CRT$XL? (other than *Z, which has a NULL).
|
| -#pragma const_seg(".CRT$XLY")
|
| -extern const PIMAGE_TLS_CALLBACK p_thread_callback_dllmain_later_entry;
|
| -const PIMAGE_TLS_CALLBACK p_thread_callback_dllmain_later_entry = on_callback;
|
| -#pragma data_seg(pop, old_seg)
|
| -
|
| -#else // _WIN64
|
| -
|
| -#pragma data_seg(push, old_seg)
|
| -// Use earliest possible name in the .CRT$XL? list of segments.
|
| -#pragma data_seg(".CRT$XLA")
|
| -PIMAGE_TLS_CALLBACK p_thread_callback_dllmain_first_entry = on_callback;
|
| -// The latest possible name in the .CRT$XL? (other than *Z, which has a NULL).
|
| -#pragma data_seg(".CRT$XLY")
|
| -PIMAGE_TLS_CALLBACK p_thread_callback_dllmain_later_entry = on_callback;
|
| -#pragma data_seg(pop, old_seg)
|
| -
|
| -#endif // _WIN64
|
| -} // extern "C"
|
| -
|
| -
|
| -// Make DllMain call the listed callbacks. This way any third parties that are
|
| -// linked in will also be called.
|
| -BOOL WINAPI DllMain(PVOID h, DWORD reason, PVOID reserved) {
|
| - if (DLL_THREAD_DETACH != reason && DLL_PROCESS_DETACH != reason)
|
| - return true; // We won't service THREAD_ATTACH calls.
|
| -
|
| - if (linker_notifications_are_active)
|
| - return true; // Some other service is doing this work.
|
| -
|
| - // Use our first entry as a starting point, but don't call it.
|
| - PIMAGE_TLS_CALLBACK* it = &p_thread_callback_dllmain_first_entry;
|
| - while(*++it) {
|
| - if (*it == p_thread_callback_dllmain_later_entry)
|
| - continue; // Don't bother to call our own callbacks.
|
| - (*it)(h, reason, reserved);
|
| - }
|
| - // Guarantee that we did a full list, and didn't get "stuck" on some NULL
|
| - // ahead of time. The fear is that there migtht be another null in ".CRT$XLA"
|
| - // the way there is guaranteed to be a NULL in ".CRT$XLZ"
|
| - // We use a CHECK to ensure that the release bulid, no matter how created, is
|
| - // compliant with this arrangement.
|
| - CHECK_GT(*it, p_thread_callback_dllmain_later_entry);
|
| - return true;
|
| -}
|
| -
|
| -static void NTAPI on_callback(PVOID h, DWORD reason, PVOID reserved) {
|
| - // Do nothing. We were just a place holder in the list used to test that we
|
| - // call all items.
|
| - // If we are called, it means that some other system is scanning the callbacks
|
| - // and we don't need to do so in DllMain().
|
| - linker_notifications_are_active = true;
|
| - // Note: If some other routine some how plays this same game... we could both
|
| - // decide not to do the scanning <sigh>, but this trick should suppress
|
| - // duplicate calls on Vista, where the runtime takes care of the callbacks,
|
| - // and allow us to do the callbacks on XP, where we are currently devoid of
|
| - // callbacks (due to an explicit LoadLibrary call).
|
| -}
|
|
|