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Diffstat (limited to 'src/google/protobuf/stubs/once.cc')
-rw-r--r-- | src/google/protobuf/stubs/once.cc | 99 |
1 files changed, 0 insertions, 99 deletions
diff --git a/src/google/protobuf/stubs/once.cc b/src/google/protobuf/stubs/once.cc deleted file mode 100644 index 889c6476..00000000 --- a/src/google/protobuf/stubs/once.cc +++ /dev/null @@ -1,99 +0,0 @@ -// Protocol Buffers - Google's data interchange format -// Copyright 2008 Google Inc. All rights reserved. -// https://developers.google.com/protocol-buffers/ -// -// Redistribution and use in source and binary forms, with or without -// modification, are permitted provided that the following conditions are -// met: -// -// * Redistributions of source code must retain the above copyright -// notice, this list of conditions and the following disclaimer. -// * Redistributions in binary form must reproduce the above -// copyright notice, this list of conditions and the following disclaimer -// in the documentation and/or other materials provided with the -// distribution. -// * Neither the name of Google Inc. nor the names of its -// contributors may be used to endorse or promote products derived from -// this software without specific prior written permission. -// -// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS -// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT -// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR -// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT -// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, -// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT -// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, -// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY -// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT -// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE -// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. - -// Author: kenton@google.com (Kenton Varda) -// -// emulates google3/base/once.h -// -// This header is intended to be included only by internal .cc files and -// generated .pb.cc files. Users should not use this directly. - -#include <google/protobuf/stubs/once.h> - -#ifndef GOOGLE_PROTOBUF_NO_THREAD_SAFETY - -#ifdef _WIN32 -#include <windows.h> -#else -#include <sched.h> -#endif - -#include <google/protobuf/stubs/atomicops.h> - -namespace google { -namespace protobuf { - -namespace { - -void SchedYield() { -#ifdef _WIN32 - Sleep(0); -#else // POSIX - sched_yield(); -#endif -} - -} // namespace - -void GoogleOnceInitImpl(ProtobufOnceType* once, Closure* closure) { - internal::AtomicWord state = internal::Acquire_Load(once); - // Fast path. The provided closure was already executed. - if (state == ONCE_STATE_DONE) { - return; - } - // The closure execution did not complete yet. The once object can be in one - // of the two following states: - // - UNINITIALIZED: We are the first thread calling this function. - // - EXECUTING_CLOSURE: Another thread is already executing the closure. - // - // First, try to change the state from UNINITIALIZED to EXECUTING_CLOSURE - // atomically. - state = internal::Acquire_CompareAndSwap( - once, ONCE_STATE_UNINITIALIZED, ONCE_STATE_EXECUTING_CLOSURE); - if (state == ONCE_STATE_UNINITIALIZED) { - // We are the first thread to call this function, so we have to call the - // closure. - closure->Run(); - internal::Release_Store(once, ONCE_STATE_DONE); - } else { - // Another thread has already started executing the closure. We need to - // wait until it completes the initialization. - while (state == ONCE_STATE_EXECUTING_CLOSURE) { - // Note that futex() could be used here on Linux as an improvement. - SchedYield(); - state = internal::Acquire_Load(once); - } - } -} - -} // namespace protobuf -} // namespace google - -#endif // GOOGLE_PROTOBUF_NO_THREAD_SAFETY |