Add ThreadLocalPointer and ThreadLocalBoolean abstractions, that will deprecate the old ThreadLocalStorage / TLSSlot APIs.

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@1678 0039d316-1c4b-4281-b951-d872f2087c98

9 files changed, 383 insertions, 9 deletions

diff --git a/base/SConscript b/base/SConscript
index a2fc266..acd5570 100644
--- a/base/SConscript
+++ b/base/SConscript
@@ -116,6 +116,7 @@ if env['PLATFORM'] == 'win32':
       'shared_memory_win.cc',
       'sys_string_conversions_win.cc',
       'thread_local_storage_win.cc',
+      'thread_local_win.cc',
       'time_win.cc',
       'waitable_event_win.cc',
       'win_util.cc',
@@ -133,6 +134,7 @@ if env['PLATFORM'] in ('darwin', 'posix'):
       'shared_memory_posix.cc',
       'string16.cc',
       'thread_local_storage_posix.cc',
+      'thread_local_posix.cc',
       'time_posix.cc',
       'waitable_event_generic.cc',
   ])
@@ -277,6 +279,7 @@ if env['PLATFORM'] == 'win32':
     'shared_memory_unittest.cc',
     'stats_table_unittest.cc',
     'thread_local_storage_unittest.cc',
+    'thread_local_unittest.cc',
     'watchdog_unittest.cc',
     'gfx/native_theme_unittest.cc',
     'gfx/uniscribe_unittest.cc',
diff --git a/base/build/base.vcproj b/base/build/base.vcproj
index b6fa837..add54fe 100644
--- a/base/build/base.vcproj
+++ b/base/build/base.vcproj
@@ -714,6 +714,14 @@
 			>
 		</File>
 		<File
+			RelativePath="..\thread_local.h"
+			>
+		</File>
+		<File
+			RelativePath="..\thread_local_win.cc"
+			>
+		</File>
+		<File
 			RelativePath="..\time.cc"
 			>
 		</File>
diff --git a/base/build/base_unittests.vcproj b/base/build/base_unittests.vcproj
index 0c22754..dbfd6a4 100644
--- a/base/build/base_unittests.vcproj
+++ b/base/build/base_unittests.vcproj
@@ -312,6 +312,10 @@
 				>
 			</File>
 			<File
+				RelativePath="..\thread_local_unittest.cc"
+				>
+			</File>
+			<File
 				RelativePath="..\thread_unittest.cc"
 				>
 			</File>
diff --git a/base/thread.cc b/base/thread.cc
index 20612d4..4f68546 100644
--- a/base/thread.cc
+++ b/base/thread.cc
@@ -4,7 +4,9 @@
 
 #include "base/thread.h"
 
+#include "base/singleton.h"
 #include "base/string_util.h"
+#include "base/thread_local.h"
 #include "base/waitable_event.h"
 
 namespace base {
@@ -46,21 +48,25 @@ Thread::~Thread() {
 // because its Stop method was called.  This allows us to catch cases where
 // MessageLoop::Quit() is called directly, which is unexpected when using a
 // Thread to setup and run a MessageLoop.
-// Note that if we start doing complex stuff in other static initializers
-// this could cause problems.
-// TODO(evanm): this shouldn't rely on static initialization.
-TLSSlot Thread::tls_index_;
+namespace {
+
+// Use a differentiating type to make sure we don't share our boolean we any
+// other Singleton<ThreadLocalBoolean>'s.
+struct ThreadExitedDummyDiffType { };
+typedef Singleton<ThreadLocalBoolean,
+                  DefaultSingletonTraits<ThreadLocalBoolean>,
+                  ThreadExitedDummyDiffType> ThreadExitedSingleton;
+
+}  // namespace
 
 void Thread::SetThreadWasQuitProperly(bool flag) {
-#ifndef NDEBUG
-  tls_index_.Set(reinterpret_cast<void*>(flag));
-#endif
+  ThreadExitedSingleton::get()->Set(flag);
 }
 
 bool Thread::GetThreadWasQuitProperly() {
   bool quit_properly = true;
 #ifndef NDEBUG
-  quit_properly = (tls_index_.Get() != 0);
+  quit_properly = ThreadExitedSingleton::get()->Get();
 #endif
   return quit_properly;
 }
diff --git a/base/thread.h b/base/thread.h
index 619d2b7..8d08ade 100644
--- a/base/thread.h
+++ b/base/thread.h
@@ -9,7 +9,6 @@
 
 #include "base/message_loop.h"
 #include "base/platform_thread.h"
-#include "base/thread_local_storage.h"
 
 namespace base {
 
diff --git a/base/thread_local.h b/base/thread_local.h
new file mode 100644
index 0000000..7b3c3da
--- /dev/null
+++ b/base/thread_local.h
@@ -0,0 +1,121 @@
+// 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.
+
+// WARNING: Thread local storage is a bit tricky to get right.  Please make
+// sure that this is really the proper solution for what you're trying to
+// achieve.  Don't prematurely optimize, most likely you can just use a Lock.
+// 
+// These classes implement a warpper around the platform's TLS storage
+// mechanism.  On construction, they will allocate a TLS slot, and free the
+// TLS slot on destruction.  No memory management (creation or destruction) is
+// handled.  This means for uses of ThreadLocalPointer, you must correctly
+// manage the memory yourself, these classes will not destroy the pointer for
+// you.  There are no at-thread-exit actions taken by these classes.
+//
+// ThreadLocalPointer<Type> wraps a Type*.  It performs no creation or
+// destruction, so memory management must be handled elsewhere.  The first call
+// to Get() on a thread will return NULL.  You can update the pointer with a
+// call to Set().
+//
+// ThreadLocalBoolean wraps a bool.  It will default to false if it has never
+// been set otherwise with Set().
+//
+// Thread Safety:  An instance of ThreadLocalStorage is completely thread safe
+// once it has been created.  If you want to dynamically create an instance,
+// you must of course properly deal with safety and race conditions.  This
+// means a function-level static initializer is generally inappropiate.
+//
+// Example usage:
+//   // My class is logically attached to a single thread.  We cache a pointer
+//   // on the thread it was created on, so we can implement current().
+//   MyClass::MyClass() {
+//     DCHECK(Singleton<ThreadLocalPointer<MyClass> >::get()->Get() == NULL);
+//     Singleton<ThreadLocalPointer<MyClass> >::get()->Set(this);
+//   }
+//
+//   MyClass::~MyClass() {
+//     DCHECK(Singleton<ThreadLocalPointer<MyClass> >::get()->Get() != NULL);
+//     Singleton<ThreadLocalPointer<MyClass> >::get()->Set(NULL);
+//   }
+//
+//   // Return the current MyClass associated with the calling thread, can be
+//   // NULL if there isn't a MyClass associated.
+//   MyClass* MyClass::current() {
+//     return Singleton<ThreadLocalPointer<MyClass> >::get()->Get();
+//   }
+
+#ifndef BASE_THREAD_LOCAL_H_
+#define BASE_THREAD_LOCAL_H_
+
+#include "base/basictypes.h"
+
+#if defined(OS_POSIX)
+#include <pthread.h>
+#endif
+
+namespace base {
+
+// Helper functions that abstract the cross-platform APIs.  Do not use directly.
+struct ThreadLocalPlatform {
+#if defined(OS_WIN)
+  typedef int SlotType;
+#elif defined(OS_POSIX)
+  typedef pthread_key_t SlotType;
+#endif
+
+  static void AllocateSlot(SlotType& slot);
+  static void FreeSlot(SlotType& slot);
+  static void* GetValueFromSlot(SlotType& slot);
+  static void SetValueInSlot(SlotType& slot, void* value);
+};
+
+template <typename Type>
+class ThreadLocalPointer {
+ public:
+  ThreadLocalPointer() : slot_() {
+    ThreadLocalPlatform::AllocateSlot(slot_);
+  }
+
+  ~ThreadLocalPointer() {
+    ThreadLocalPlatform::FreeSlot(slot_);
+  }
+
+  Type* Get() {
+    return static_cast<Type*>(ThreadLocalPlatform::GetValueFromSlot(slot_));
+  }
+
+  void Set(Type* ptr) {
+    ThreadLocalPlatform::SetValueInSlot(slot_, ptr);
+  }
+
+ private:
+  typedef ThreadLocalPlatform::SlotType SlotType;
+
+  SlotType slot_;
+
+  DISALLOW_COPY_AND_ASSIGN(ThreadLocalPointer<Type>);
+};
+
+class ThreadLocalBoolean {
+ public:
+  ThreadLocalBoolean() { }
+  ~ThreadLocalBoolean() { }
+
+  bool Get() {
+    return tlp_.Get() != NULL;
+  }
+
+  void Set(bool val) {
+    tlp_.Set(reinterpret_cast<void*>(val ? 1 : 0));
+  }
+
+ private:
+  ThreadLocalPointer<void> tlp_;
+
+  DISALLOW_COPY_AND_ASSIGN(ThreadLocalBoolean);
+};
+
+}  // namespace base
+
+#endif  // BASE_THREAD_LOCAL_H_
diff --git a/base/thread_local_posix.cc b/base/thread_local_posix.cc
new file mode 100644
index 0000000..d544069
--- /dev/null
+++ b/base/thread_local_posix.cc
@@ -0,0 +1,36 @@
+// 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.h"
+
+#include <pthread.h>
+
+#include "base/logging.h"
+
+namespace base {
+
+// static
+void ThreadLocalPlatform::AllocateSlot(SlotType& slot) {
+  int error = pthread_key_create(&slot, NULL);
+  CHECK(error == 0);
+}
+
+// static
+void ThreadLocalPlatform::FreeSlot(SlotType& slot) {
+  int error = pthread_key_delete(slot);
+  DCHECK(error == 0);
+}
+
+// static
+void* ThreadLocalPlatform::GetValueFromSlot(SlotType& slot) {
+  return pthread_getspecific(slot_);
+}
+
+// static
+void ThreadLocalPlatform::SetValueInSlot(SlotType& slot, void* value) {
+  int error = pthread_setspecific(slot, value);
+  CHECK(error == 0);
+}
+
+}  // namespace base
diff --git a/base/thread_local_unittest.cc b/base/thread_local_unittest.cc
new file mode 100644
index 0000000..9d6f875
--- /dev/null
+++ b/base/thread_local_unittest.cc
@@ -0,0 +1,159 @@
+// 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/logging.h"
+#include "base/simple_thread.h"
+#include "base/thread_local.h"
+#include "base/waitable_event.h"
+#include "testing/gtest/include/gtest/gtest.h"
+
+namespace {
+
+class ThreadLocalTesterBase : public base::DelegateSimpleThreadPool::Delegate {
+ public:
+  typedef base::ThreadLocalPointer<ThreadLocalTesterBase> TLPType;
+
+  ThreadLocalTesterBase(TLPType* tlp, base::WaitableEvent* done)
+      : tlp_(tlp), done_(done) { }
+  ~ThreadLocalTesterBase() { }
+
+ protected:
+  TLPType* tlp_;
+  base::WaitableEvent* done_;
+};
+
+class SetThreadLocal : public ThreadLocalTesterBase {
+ public:
+  SetThreadLocal(TLPType* tlp, base::WaitableEvent* done)
+      : ThreadLocalTesterBase(tlp, done), val_(NULL) { }
+  ~SetThreadLocal() { }
+  
+  void set_value(ThreadLocalTesterBase* val) { val_ = val; }
+
+  virtual void Run() {
+    DCHECK(!done_->IsSignaled());
+    tlp_->Set(val_);
+    done_->Signal();
+  }
+
+ private:
+  ThreadLocalTesterBase* val_;
+};
+
+class GetThreadLocal : public ThreadLocalTesterBase {
+ public:
+  GetThreadLocal(TLPType* tlp, base::WaitableEvent* done)
+      : ThreadLocalTesterBase(tlp, done), ptr_(NULL) { }
+  ~GetThreadLocal() { }
+  
+  void set_ptr(ThreadLocalTesterBase** ptr) { ptr_ = ptr; }
+
+  virtual void Run() {
+    DCHECK(!done_->IsSignaled());
+    *ptr_ = tlp_->Get();
+    done_->Signal();
+  }
+
+ private:
+  ThreadLocalTesterBase** ptr_;
+};
+
+}  // namespace
+
+// In this test, we start 2 threads which will access a ThreadLocalPointer.  We
+// make sure the default is NULL, and the pointers are unique to the threads.
+TEST(ThreadLocalTest, Pointer) {
+  base::DelegateSimpleThreadPool tp1("ThreadLocalTest tp1", 1);
+  base::DelegateSimpleThreadPool tp2("ThreadLocalTest tp1", 1);
+  tp1.Start();
+  tp2.Start();
+
+  base::ThreadLocalPointer<ThreadLocalTesterBase> tlp;
+  
+  static ThreadLocalTesterBase* const kBogusPointer =
+      reinterpret_cast<ThreadLocalTesterBase*>(0x1234);
+
+  ThreadLocalTesterBase* tls_val;
+  base::WaitableEvent done(true, false);
+
+  GetThreadLocal getter(&tlp, &done);
+  getter.set_ptr(&tls_val);
+
+  // Check that both threads defaulted to NULL.
+  tls_val = kBogusPointer;
+  done.Reset();
+  tp1.AddWork(&getter);
+  done.Wait();
+  EXPECT_EQ(NULL, tls_val);
+
+  tls_val = kBogusPointer;
+  done.Reset();
+  tp2.AddWork(&getter);
+  done.Wait();
+  EXPECT_EQ(NULL, tls_val);
+
+
+  SetThreadLocal setter(&tlp, &done);
+  setter.set_value(kBogusPointer);
+
+  // Have thread 1 set their pointer value to kBogusPointer.
+  done.Reset();
+  tp1.AddWork(&setter);
+  done.Wait();
+
+  tls_val = NULL;
+  done.Reset();
+  tp1.AddWork(&getter);
+  done.Wait();
+  EXPECT_EQ(kBogusPointer, tls_val);
+
+  // Make sure thread 2 is still NULL
+  tls_val = kBogusPointer;
+  done.Reset();
+  tp2.AddWork(&getter);
+  done.Wait();
+  EXPECT_EQ(NULL, tls_val);
+
+  // Set thread 2 to kBogusPointer + 1.
+  setter.set_value(kBogusPointer + 1);
+
+  done.Reset();
+  tp2.AddWork(&setter);
+  done.Wait();
+
+  tls_val = NULL;
+  done.Reset();
+  tp2.AddWork(&getter);
+  done.Wait();
+  EXPECT_EQ(kBogusPointer + 1, tls_val);
+
+  // Make sure thread 1 is still kBogusPointer.
+  tls_val = NULL;
+  done.Reset();
+  tp1.AddWork(&getter);
+  done.Wait();
+  EXPECT_EQ(kBogusPointer, tls_val);
+
+  tp1.JoinAll();
+  tp2.JoinAll();
+}
+
+TEST(ThreadLocalTest, Boolean) {
+  {
+    base::ThreadLocalBoolean tlb;
+    EXPECT_EQ(false, tlb.Get());
+
+    tlb.Set(false);
+    EXPECT_EQ(false, tlb.Get());
+
+    tlb.Set(true);
+    EXPECT_EQ(true, tlb.Get());
+  }
+
+  // Our slot should have been freed, we're all reset.
+  {
+    base::ThreadLocalBoolean tlb;
+    EXPECT_EQ(false, tlb.Get());
+  }
+}
diff --git a/base/thread_local_win.cc b/base/thread_local_win.cc
new file mode 100644
index 0000000..2da3cfd
--- /dev/null
+++ b/base/thread_local_win.cc
@@ -0,0 +1,38 @@
+// 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.h"
+
+#include <windows.h>
+
+#include "base/logging.h"
+
+namespace base {
+
+// static
+void ThreadLocalPlatform::AllocateSlot(SlotType& slot) {
+  slot = TlsAlloc();
+  CHECK(slot != TLS_OUT_OF_INDEXES);
+}
+
+// static
+void ThreadLocalPlatform::FreeSlot(SlotType& slot) {
+  if (!TlsFree(slot)) {
+    NOTREACHED() << "Failed to deallocate tls slot with TlsFree().";
+  }
+}
+
+// static
+void* ThreadLocalPlatform::GetValueFromSlot(SlotType& slot) {
+  return TlsGetValue(slot);
+}
+
+// static
+void ThreadLocalPlatform::SetValueInSlot(SlotType& slot, void* value) {
+  if (!TlsSetValue(slot, value)) {
+    CHECK(false) << "Failed to TlsSetValue().";
+  }
+}
+
+}  // namespace base