diff options
Diffstat (limited to 'security/sandbox/chromium/base/lazy_instance.cc')
-rw-r--r-- | security/sandbox/chromium/base/lazy_instance.cc | 54 |
1 files changed, 0 insertions, 54 deletions
diff --git a/security/sandbox/chromium/base/lazy_instance.cc b/security/sandbox/chromium/base/lazy_instance.cc deleted file mode 100644 index 54680655a..000000000 --- a/security/sandbox/chromium/base/lazy_instance.cc +++ /dev/null @@ -1,54 +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. - -#include "base/lazy_instance.h" - -#include "base/at_exit.h" -#include "base/atomicops.h" -#include "base/threading/platform_thread.h" - -namespace base { -namespace internal { - -// TODO(joth): This function could be shared with Singleton, in place of its -// WaitForInstance() call. -bool NeedsLazyInstance(subtle::AtomicWord* state) { - // Try to create the instance, if we're the first, will go from 0 to - // kLazyInstanceStateCreating, otherwise we've already been beaten here. - // The memory access has no memory ordering as state 0 and - // kLazyInstanceStateCreating have no associated data (memory barriers are - // all about ordering of memory accesses to *associated* data). - if (subtle::NoBarrier_CompareAndSwap(state, 0, - kLazyInstanceStateCreating) == 0) - // Caller must create instance - return true; - - // It's either in the process of being created, or already created. Spin. - // The load has acquire memory ordering as a thread which sees - // state_ == STATE_CREATED needs to acquire visibility over - // the associated data (buf_). Pairing Release_Store is in - // CompleteLazyInstance(). - while (subtle::Acquire_Load(state) == kLazyInstanceStateCreating) { - PlatformThread::YieldCurrentThread(); - } - // Someone else created the instance. - return false; -} - -void CompleteLazyInstance(subtle::AtomicWord* state, - subtle::AtomicWord new_instance, - void* lazy_instance, - void (*dtor)(void*)) { - // Instance is created, go from CREATING to CREATED. - // Releases visibility over private_buf_ to readers. Pairing Acquire_Load's - // are in NeedsInstance() and Pointer(). - subtle::Release_Store(state, new_instance); - - // Make sure that the lazily instantiated object will get destroyed at exit. - if (dtor) - AtExitManager::RegisterCallback(dtor, lazy_instance); -} - -} // namespace internal -} // namespace base |