| Index: base/thread_local_storage_win.cc
|
| ===================================================================
|
| --- base/thread_local_storage_win.cc (revision 70317)
|
| +++ base/thread_local_storage_win.cc (working copy)
|
| @@ -1,194 +0,0 @@
|
| -// Copyright (c) 2006-2008 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/thread_local_storage.h"
|
| -
|
| -#include <windows.h>
|
| -
|
| -#include "base/logging.h"
|
| -
|
| -// In order to make TLS destructors work, we need to keep function
|
| -// pointers to the destructor for each TLS that we allocate.
|
| -// We make this work by allocating a single OS-level TLS, which
|
| -// contains an array of slots for the application to use. In
|
| -// parallel, we also allocate an array of destructors, which we
|
| -// keep track of and call when threads terminate.
|
| -
|
| -// tls_key_ is the one native TLS that we use. It stores our
|
| -// table.
|
| -long ThreadLocalStorage::tls_key_ = TLS_OUT_OF_INDEXES;
|
| -
|
| -// tls_max_ is the high-water-mark of allocated thread local storage.
|
| -// We intentionally skip 0 so that it is not confused with an
|
| -// unallocated TLS slot.
|
| -long ThreadLocalStorage::tls_max_ = 1;
|
| -
|
| -// An array of destructor function pointers for the slots. If
|
| -// a slot has a destructor, it will be stored in its corresponding
|
| -// entry in this array.
|
| -ThreadLocalStorage::TLSDestructorFunc
|
| - ThreadLocalStorage::tls_destructors_[kThreadLocalStorageSize];
|
| -
|
| -void** ThreadLocalStorage::Initialize() {
|
| - if (tls_key_ == TLS_OUT_OF_INDEXES) {
|
| - long value = TlsAlloc();
|
| - DCHECK(value != TLS_OUT_OF_INDEXES);
|
| -
|
| - // Atomically test-and-set the tls_key. If the key is TLS_OUT_OF_INDEXES,
|
| - // go ahead and set it. Otherwise, do nothing, as another
|
| - // thread already did our dirty work.
|
| - if (InterlockedCompareExchange(&tls_key_, value, TLS_OUT_OF_INDEXES) !=
|
| - TLS_OUT_OF_INDEXES) {
|
| - // We've been shortcut. Another thread replaced tls_key_ first so we need
|
| - // to destroy our index and use the one the other thread got first.
|
| - TlsFree(value);
|
| - }
|
| - }
|
| - DCHECK(TlsGetValue(tls_key_) == NULL);
|
| -
|
| - // Create an array to store our data.
|
| - void** tls_data = new void*[kThreadLocalStorageSize];
|
| - memset(tls_data, 0, sizeof(void*[kThreadLocalStorageSize]));
|
| - TlsSetValue(tls_key_, tls_data);
|
| - return tls_data;
|
| -}
|
| -
|
| -ThreadLocalStorage::Slot::Slot(TLSDestructorFunc destructor)
|
| - : initialized_(false) {
|
| - Initialize(destructor);
|
| -}
|
| -
|
| -bool ThreadLocalStorage::Slot::Initialize(TLSDestructorFunc destructor) {
|
| - if (tls_key_ == TLS_OUT_OF_INDEXES || !TlsGetValue(tls_key_))
|
| - ThreadLocalStorage::Initialize();
|
| -
|
| - // Grab a new slot.
|
| - slot_ = InterlockedIncrement(&tls_max_) - 1;
|
| - if (slot_ >= kThreadLocalStorageSize) {
|
| - NOTREACHED();
|
| - return false;
|
| - }
|
| -
|
| - // Setup our destructor.
|
| - tls_destructors_[slot_] = destructor;
|
| - initialized_ = true;
|
| - return true;
|
| -}
|
| -
|
| -void ThreadLocalStorage::Slot::Free() {
|
| - // At this time, we don't reclaim old indices for TLS slots.
|
| - // So all we need to do is wipe the destructor.
|
| - tls_destructors_[slot_] = NULL;
|
| - initialized_ = false;
|
| -}
|
| -
|
| -void* ThreadLocalStorage::Slot::Get() const {
|
| - void** tls_data = static_cast<void**>(TlsGetValue(tls_key_));
|
| - if (!tls_data)
|
| - tls_data = ThreadLocalStorage::Initialize();
|
| - DCHECK(slot_ >= 0 && slot_ < kThreadLocalStorageSize);
|
| - return tls_data[slot_];
|
| -}
|
| -
|
| -void ThreadLocalStorage::Slot::Set(void* value) {
|
| - void** tls_data = static_cast<void**>(TlsGetValue(tls_key_));
|
| - if (!tls_data)
|
| - tls_data = ThreadLocalStorage::Initialize();
|
| - DCHECK(slot_ >= 0 && slot_ < kThreadLocalStorageSize);
|
| - tls_data[slot_] = value;
|
| -}
|
| -
|
| -void ThreadLocalStorage::ThreadExit() {
|
| - if (tls_key_ == TLS_OUT_OF_INDEXES)
|
| - return;
|
| -
|
| - void** tls_data = static_cast<void**>(TlsGetValue(tls_key_));
|
| -
|
| - // Maybe we have never initialized TLS for this thread.
|
| - if (!tls_data)
|
| - return;
|
| -
|
| - for (int slot = 0; slot < tls_max_; slot++) {
|
| - if (tls_destructors_[slot] != NULL) {
|
| - void* value = tls_data[slot];
|
| - tls_destructors_[slot](value);
|
| - }
|
| - }
|
| -
|
| - delete[] tls_data;
|
| -
|
| - // In case there are other "onexit" handlers...
|
| - TlsSetValue(tls_key_, NULL);
|
| -}
|
| -
|
| -// 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)
|
| - ThreadLocalStorage::ThreadExit();
|
| -}
|
| -
|
| -// .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"
|
|
|