Integrate recent changes from Google-internal code tree. See CHANGES.txt

for details.

6 files changed, 505 insertions, 0 deletions

diff --git a/src/google/protobuf/stubs/common.h b/src/google/protobuf/stubs/common.h
index cadb3b93..4a55e004 100644
--- a/src/google/protobuf/stubs/common.h
+++ b/src/google/protobuf/stubs/common.h
@@ -1039,6 +1039,10 @@ class LIBPROTOBUF_EXPORT MutexLock {
   GOOGLE_DISALLOW_EVIL_CONSTRUCTORS(MutexLock);
 };
 
+// TODO(kenton):  Implement these?  Hard to implement portably.
+typedef MutexLock ReaderMutexLock;
+typedef MutexLock WriterMutexLock;
+
 // MutexLockMaybe is like MutexLock, but is a no-op when mu is NULL.
 class LIBPROTOBUF_EXPORT MutexLockMaybe {
  public:
@@ -1056,6 +1060,8 @@ class LIBPROTOBUF_EXPORT MutexLockMaybe {
 // but we don't want to stick "internal::" in front of them everywhere.
 using internal::Mutex;
 using internal::MutexLock;
+using internal::ReaderMutexLock;
+using internal::WriterMutexLock;
 using internal::MutexLockMaybe;
 
 // ===================================================================
diff --git a/src/google/protobuf/stubs/hash.h b/src/google/protobuf/stubs/hash.h
index efbeeedd..c3414138 100644
--- a/src/google/protobuf/stubs/hash.h
+++ b/src/google/protobuf/stubs/hash.h
@@ -178,6 +178,33 @@ struct hash<string> {
   }
 };
 
+template <typename First, typename Second>
+struct hash<pair<First, Second> > {
+  inline size_t operator()(const pair<First, Second>& key) const {
+    size_t first_hash = hash<First>()(key.first);
+    size_t second_hash = hash<Second>()(key.second);
+
+    // FIXME(kenton):  What is the best way to compute this hash?  I have
+    // no idea!  This seems a bit better than an XOR.
+    return first_hash * ((1 << 16) - 1) + second_hash;
+  }
+
+  static const size_t bucket_size = 4;
+  static const size_t min_buckets = 8;
+  inline size_t operator()(const pair<First, Second>& a,
+                           const pair<First, Second>& b) const {
+    return a < b;
+  }
+};
+
+// Used by GCC/SGI STL only.  (Why isn't this provided by the standard
+// library?  :( )
+struct streq {
+  inline bool operator()(const char* a, const char* b) const {
+    return strcmp(a, b) == 0;
+  }
+};
+
 }  // namespace protobuf
 }  // namespace google
 
diff --git a/src/google/protobuf/stubs/map-util.h b/src/google/protobuf/stubs/map-util.h
index 3ceecec5..f5c9d6b6 100644
--- a/src/google/protobuf/stubs/map-util.h
+++ b/src/google/protobuf/stubs/map-util.h
@@ -40,6 +40,21 @@ namespace google {
 namespace protobuf {
 
 // Perform a lookup in a map or hash_map.
+// If the key is present in the map then the value associated with that
+// key is returned, otherwise the value passed as a default is returned.
+template <class Collection>
+const typename Collection::value_type::second_type&
+FindWithDefault(const Collection& collection,
+                const typename Collection::value_type::first_type& key,
+                const typename Collection::value_type::second_type& value) {
+  typename Collection::const_iterator it = collection.find(key);
+  if (it == collection.end()) {
+    return value;
+  }
+  return it->second;
+}
+
+// Perform a lookup in a map or hash_map.
 // If the key is present a const pointer to the associated value is returned,
 // otherwise a NULL pointer is returned.
 template <class Collection>
diff --git a/src/google/protobuf/stubs/once.cc b/src/google/protobuf/stubs/once.cc
new file mode 100644
index 00000000..b47a031c
--- /dev/null
+++ b/src/google/protobuf/stubs/once.cc
@@ -0,0 +1,82 @@
+// Protocol Buffers - Google's data interchange format
+// Copyright 2008 Google Inc.  All rights reserved.
+// http://code.google.com/p/protobuf/
+//
+// 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.
+
+#ifdef _WIN32
+#include <windows.h>
+#endif
+
+#include <google/protobuf/stubs/once.h>
+
+namespace google {
+namespace protobuf {
+
+#ifdef _WIN32
+
+struct GoogleOnceInternal {
+  GoogleOnceInternal() {
+    InitializeCriticalSection(&critical_section);
+  }
+  ~GoogleOnceInternal() {
+    DeleteCriticalSection(&critical_section);
+  }
+  CRITICAL_SECTION critical_section;
+};
+
+GoogleOnceType::GoogleOnceType() {
+  // internal_ may be non-NULL if Init() was already called.
+  if (internal_ == NULL) internal_ = new GoogleOnceInternal;
+}
+
+void GoogleOnceType::Init(void (*init_func)()) {
+  // internal_ may be NULL if we're still in dynamic initialization and the
+  // constructor has not been called yet.  As mentioned in once.h, we assume
+  // that the program is still single-threaded at this time, and therefore it
+  // should be safe to initialize internal_ like so.
+  if (internal_ == NULL) internal_ = new GoogleOnceInternal;
+
+  EnterCriticalSection(&internal_->critical_section);
+  if (!initialized_) {
+    init_func();
+    initialized_ = true;
+  }
+  LeaveCriticalSection(&internal_->critical_section);
+}
+
+#endif
+
+}  // namespace protobuf
+}  // namespace google
diff --git a/src/google/protobuf/stubs/once.h b/src/google/protobuf/stubs/once.h
new file mode 100644
index 00000000..58f1ea91
--- /dev/null
+++ b/src/google/protobuf/stubs/once.h
@@ -0,0 +1,122 @@
+// Protocol Buffers - Google's data interchange format
+// Copyright 2008 Google Inc.  All rights reserved.
+// http://code.google.com/p/protobuf/
+//
+// 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.
+//
+// This is basically a portable version of pthread_once().
+//
+// This header declares three things:
+// * A type called GoogleOnceType.
+// * A macro GOOGLE_PROTOBUF_DECLARE_ONCE() which declares a variable of type
+//   GoogleOnceType.  This is the only legal way to declare such a variable.
+//   The macro may only be used at the global scope (you cannot create local
+//   or class member variables of this type).
+// * A function GogoleOnceInit(GoogleOnceType* once, void (*init_func)()).
+//   This function, when invoked multiple times given the same GoogleOnceType
+//   object, will invoke init_func on the first call only, and will make sure
+//   none of the calls return before that first call to init_func has finished.
+//
+// This implements a way to perform lazy initialization.  It's more efficient
+// than using mutexes as no lock is needed if initialization has already
+// happened.
+//
+// Example usage:
+//   void Init();
+//   GOOGLE_PROTOBUF_DECLARE_ONCE(once_init);
+//
+//   // Calls Init() exactly once.
+//   void InitOnce() {
+//     GoogleOnceInit(&once_init, &Init);
+//   }
+//
+// Note that if GoogleOnceInit() is called before main() has begun, it must
+// only be called by the thread that will eventually call main() -- that is,
+// the thread that performs dynamic initialization.  In general this is a safe
+// assumption since people don't usually construct threads before main() starts,
+// but it is technically not guaranteed.  Unfortunately, Win32 provides no way
+// whatsoever to statically-initialize its synchronization primitives, so our
+// only choice is to assume that dynamic initialization is single-threaded.
+
+#ifndef GOOGLE_PROTOBUF_STUBS_ONCE_H__
+#define GOOGLE_PROTOBUF_STUBS_ONCE_H__
+
+#include <google/protobuf/stubs/common.h>
+
+#ifndef _WIN32
+#include <pthread.h>
+#endif
+
+namespace google {
+namespace protobuf {
+
+#ifdef _WIN32
+
+struct GoogleOnceInternal;
+
+struct GoogleOnceType {
+  GoogleOnceType();
+  void Init(void (*init_func)());
+
+  volatile bool initialized_;
+  GoogleOnceInternal* internal_;
+};
+
+#define GOOGLE_PROTOBUF_DECLARE_ONCE(NAME)                    \
+  ::google::protobuf::GoogleOnceType NAME
+
+inline void GoogleOnceInit(GoogleOnceType* once, void (*init_func)()) {
+  // Note:  Double-checked locking is safe on x86.
+  if (!once->initialized_) {
+    once->Init(init_func);
+  }
+}
+
+#else
+
+typedef pthread_once_t GoogleOnceType;
+
+#define GOOGLE_PROTOBUF_DECLARE_ONCE(NAME)                    \
+  pthread_once_t NAME = PTHREAD_ONCE_INIT
+
+inline void GoogleOnceInit(GoogleOnceType* once, void (*init_func)()) {
+  pthread_once(once, init_func);
+}
+
+#endif
+
+}  // namespace protobuf
+}  // namespace google
+
+#endif  // GOOGLE_PROTOBUF_STUBS_ONCE_H__
diff --git a/src/google/protobuf/stubs/once_unittest.cc b/src/google/protobuf/stubs/once_unittest.cc
new file mode 100644
index 00000000..86e06478
--- /dev/null
+++ b/src/google/protobuf/stubs/once_unittest.cc
@@ -0,0 +1,253 @@
+// Protocol Buffers - Google's data interchange format
+// Copyright 2008 Google Inc.  All rights reserved.
+// http://code.google.com/p/protobuf/
+//
+// 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)
+
+#ifdef _WIN32
+#include <windows.h>
+#else
+#include <unistd.h>
+#include <pthread.h>
+#endif
+
+#include <google/protobuf/stubs/once.h>
+#include <google/protobuf/testing/googletest.h>
+#include <gtest/gtest.h>
+
+namespace google {
+namespace protobuf {
+namespace {
+
+class OnceInitTest : public testing::Test {
+ protected:
+  void SetUp() {
+    state_ = INIT_NOT_STARTED;
+    current_test_ = this;
+  }
+
+  // Since GoogleOnceType is only allowed to be allocated in static storage,
+  // each test must use a different pair of GoogleOnceType objects which it
+  // must declare itself.
+  void SetOnces(GoogleOnceType* once, GoogleOnceType* recursive_once) {
+    once_ = once;
+    recursive_once_ = recursive_once;
+  }
+
+  void InitOnce() {
+    GoogleOnceInit(once_, &InitStatic);
+  }
+  void InitRecursiveOnce() {
+    GoogleOnceInit(recursive_once_, &InitRecursiveStatic);
+  }
+
+  void BlockInit() { init_blocker_.Lock(); }
+  void UnblockInit() { init_blocker_.Unlock(); }
+
+  class TestThread {
+   public:
+    TestThread(Closure* callback)
+        : done_(false), joined_(false), callback_(callback) {
+#ifdef _WIN32
+      thread_ = CreateThread(NULL, 0, &Start, this, 0, NULL);
+#else
+      pthread_create(&thread_, NULL, &Start, this);
+#endif
+    }
+    ~TestThread() {
+      if (!joined_) Join();
+    }
+
+    bool IsDone() {
+      MutexLock lock(&done_mutex_);
+      return done_;
+    }
+    void Join() {
+      joined_ = true;
+#ifdef _WIN32
+      WaitForSingleObject(thread_, INFINITE);
+      CloseHandle(thread_);
+#else
+      pthread_join(thread_, NULL);
+#endif
+    }
+
+   private:
+#ifdef _WIN32
+    HANDLE thread_;
+#else
+    pthread_t thread_;
+#endif
+
+    Mutex done_mutex_;
+    bool done_;
+    bool joined_;
+    Closure* callback_;
+
+#ifdef _WIN32
+    static DWORD WINAPI Start(LPVOID arg) {
+#else
+    static void* Start(void* arg) {
+#endif
+      reinterpret_cast<TestThread*>(arg)->Run();
+      return 0;
+    }
+
+    void Run() {
+      callback_->Run();
+      MutexLock lock(&done_mutex_);
+      done_ = true;
+    }
+  };
+
+  TestThread* RunInitOnceInNewThread() {
+    return new TestThread(NewCallback(this, &OnceInitTest::InitOnce));
+  }
+  TestThread* RunInitRecursiveOnceInNewThread() {
+    return new TestThread(NewCallback(this, &OnceInitTest::InitRecursiveOnce));
+  }
+
+  enum State {
+    INIT_NOT_STARTED,
+    INIT_STARTED,
+    INIT_DONE
+  };
+  State CurrentState() {
+    MutexLock lock(&mutex_);
+    return state_;
+  }
+
+  void WaitABit() {
+#ifdef _WIN32
+    Sleep(1000);
+#else
+    sleep(1);
+#endif
+  }
+
+ private:
+  Mutex mutex_;
+  Mutex init_blocker_;
+  State state_;
+  GoogleOnceType* once_;
+  GoogleOnceType* recursive_once_;
+
+  void Init() {
+    MutexLock lock(&mutex_);
+    EXPECT_EQ(INIT_NOT_STARTED, state_);
+    state_ = INIT_STARTED;
+    mutex_.Unlock();
+    init_blocker_.Lock();
+    init_blocker_.Unlock();
+    mutex_.Lock();
+    state_ = INIT_DONE;
+  }
+
+  static OnceInitTest* current_test_;
+  static void InitStatic() { current_test_->Init(); }
+  static void InitRecursiveStatic() { current_test_->InitOnce(); }
+};
+
+OnceInitTest* OnceInitTest::current_test_ = NULL;
+
+GOOGLE_PROTOBUF_DECLARE_ONCE(simple_once);
+
+TEST_F(OnceInitTest, Simple) {
+  SetOnces(&simple_once, NULL);
+
+  EXPECT_EQ(INIT_NOT_STARTED, CurrentState());
+  InitOnce();
+  EXPECT_EQ(INIT_DONE, CurrentState());
+
+  // Calling again has no effect.
+  InitOnce();
+  EXPECT_EQ(INIT_DONE, CurrentState());
+}
+
+GOOGLE_PROTOBUF_DECLARE_ONCE(recursive_once1);
+GOOGLE_PROTOBUF_DECLARE_ONCE(recursive_once2);
+
+TEST_F(OnceInitTest, Recursive) {
+  SetOnces(&recursive_once1, &recursive_once2);
+
+  EXPECT_EQ(INIT_NOT_STARTED, CurrentState());
+  InitRecursiveOnce();
+  EXPECT_EQ(INIT_DONE, CurrentState());
+}
+
+GOOGLE_PROTOBUF_DECLARE_ONCE(multiple_threads_once);
+
+TEST_F(OnceInitTest, MultipleThreads) {
+  SetOnces(&multiple_threads_once, NULL);
+
+  scoped_ptr<TestThread> threads[4];
+  EXPECT_EQ(INIT_NOT_STARTED, CurrentState());
+  for (int i = 0; i < 4; i++) {
+    threads[i].reset(RunInitOnceInNewThread());
+  }
+  for (int i = 0; i < 4; i++) {
+    threads[i]->Join();
+  }
+  EXPECT_EQ(INIT_DONE, CurrentState());
+}
+
+GOOGLE_PROTOBUF_DECLARE_ONCE(multiple_threads_blocked_once1);
+GOOGLE_PROTOBUF_DECLARE_ONCE(multiple_threads_blocked_once2);
+
+TEST_F(OnceInitTest, MultipleThreadsBlocked) {
+  SetOnces(&multiple_threads_blocked_once1, &multiple_threads_blocked_once2);
+
+  scoped_ptr<TestThread> threads[8];
+  EXPECT_EQ(INIT_NOT_STARTED, CurrentState());
+
+  BlockInit();
+  for (int i = 0; i < 4; i++) {
+    threads[i].reset(RunInitOnceInNewThread());
+  }
+  for (int i = 4; i < 8; i++) {
+    threads[i].reset(RunInitRecursiveOnceInNewThread());
+  }
+
+  WaitABit();
+
+  // We should now have one thread blocked inside Init(), four blocked waiting
+  // for Init() to complete, and three blocked waiting for InitRecursive() to
+  // complete.
+  EXPECT_EQ(INIT_STARTED, CurrentState());
+  UnblockInit();
+
+  for (int i = 0; i < 8; i++) {
+    threads[i]->Join();
+  }
+  EXPECT_EQ(INIT_DONE, CurrentState());
+}
+
+}  // anonymous namespace
+}  // namespace protobuf
+}  // namespace google