Add base::ThreadLocalStorage

base/threading/thread_local_storage_win.cc

+// Copyright 2007 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.
+
+#include "base/threading/thread_local_storage.h"
+
+#include "base/logging.h"
+
+namespace base {
+namespace internal {
+
+bool PlatformThreadLocalStorage::AllocTLS(TLSKey* key) {
+  TLSKey value = TlsAlloc();
+  if (value != TLS_OUT_OF_INDEXES) {
+    *key = value;
+    return true;
+  }
+  return false;
+}
+
+void PlatformThreadLocalStorage::FreeTLS(TLSKey key) {
+  BOOL ret = TlsFree(key);
+  DCHECK(ret);
+}
+
+void* PlatformThreadLocalStorage::GetTLSValue(TLSKey key) {
+  return TlsGetValue(key);
+}
+
+void PlatformThreadLocalStorage::SetTLSValue(TLSKey key, void* value) {
+  BOOL ret = TlsSetValue(key, value);
+  DCHECK(ret);
+}
+
+}  // namespace internal
+}  // namespace base
+
+// Thread Termination Callbacks.
+// Windows doesn't support a per-thread destructor with its
+// TLS primitives.  So, we build it manually by inserting a
+// function to be called on each thread's exit.
+// This magic is from http://www.codeproject.com/threads/tls.asp
+// and it works for VC++ 7.0 and later.
+
+// Force a reference to _tls_used to make the linker create the TLS directory
+// if it's not already there.  (e.g. if __declspec(thread) is not used).
+// Force a reference to p_thread_callback_base to prevent whole program
+// optimization from discarding the variable.
+#ifdef _WIN64
+
+#pragma comment(linker, "/INCLUDE:_tls_used")
+#pragma comment(linker, "/INCLUDE:p_thread_callback_base")
+
+#else  // _WIN64
+
+#pragma comment(linker, "/INCLUDE:__tls_used")
+#pragma comment(linker, "/INCLUDE:_p_thread_callback_base")
+
+#endif  // _WIN64
+
+// Static callback function to call with each thread termination.
+void NTAPI OnThreadExit(PVOID module, DWORD reason, PVOID reserved) {
+  // On XP SP0 & SP1, the DLL_PROCESS_ATTACH is never seen. It is sent on SP2+
+  // and on W2K and W2K3. So don't assume it is sent.
+  if (DLL_THREAD_DETACH == reason || DLL_PROCESS_DETACH == reason)
+    base::internal::PlatformThreadLocalStorage::OnThreadExit();
+}
+
+// .CRT$XLA to .CRT$XLZ is an array of PIMAGE_TLS_CALLBACK pointers that are
+// called automatically by the OS loader code (not the CRT) when the module is
+// loaded and on thread creation. They are NOT called if the module has been
+// loaded by a LoadLibrary() call. It must have implicitly been loaded at
+// process startup.
+// By implicitly loaded, I mean that it is directly referenced by the main EXE
+// or by one of its dependent DLLs. Delay-loaded DLL doesn't count as being
+// implicitly loaded.
+//
+// See VC\crt\src\tlssup.c for reference.
+
+// extern "C" suppresses C++ name mangling so we know the symbol name for the
+// linker /INCLUDE:symbol pragma above.
+extern "C" {
+// The linker must not discard p_thread_callback_base.  (We force a reference
+// to this variable with a linker /INCLUDE:symbol pragma to ensure that.) If
+// this variable is discarded, the OnThreadExit function will never be called.
+#ifdef _WIN64
+
+// .CRT section is merged with .rdata on x64 so it must be constant data.
+#pragma const_seg(".CRT$XLB")
+// When defining a const variable, it must have external linkage to be sure the
+// linker doesn't discard it.
+extern const PIMAGE_TLS_CALLBACK p_thread_callback_base;
+const PIMAGE_TLS_CALLBACK p_thread_callback_base = OnThreadExit;
+
+// Reset the default section.
+#pragma const_seg()
+
+#else  // _WIN64
+
+#pragma data_seg(".CRT$XLB")
+PIMAGE_TLS_CALLBACK p_thread_callback_base = OnThreadExit;
+
+// Reset the default section.
+#pragma data_seg()
+
+#endif  // _WIN64
+}  // extern "C"