Add base to the repository.

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@8 0039d316-1c4b-4281-b951-d872f2087c98

1 files changed, 258 insertions, 0 deletions

diff --git a/base/thread.cc b/base/thread.cc
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+++ b/base/thread.cc
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+// Copyright 2008, Google Inc.
+// All rights reserved.
+//
+// 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.
+
+#include <process.h>
+#include <windows.h>
+
+#include "base/thread.h"
+
+#include "base/message_loop.h"
+#include "base/ref_counted.h"
+#include "base/string_util.h"
+#include "base/win_util.h"
+
+// This class is used when starting a thread.  It passes information to the
+// thread function.  It is referenced counted so we can cleanup the event
+// object used to synchronize thread startup properly.
+class ThreadStartInfo : public base::RefCountedThreadSafe<ThreadStartInfo> {
+ public:
+  Thread* self;
+  HANDLE start_event;
+
+  explicit ThreadStartInfo(Thread* t)
+      : self(t),
+        start_event(CreateEvent(NULL, FALSE, FALSE, NULL)) {
+  }
+
+  ~ThreadStartInfo() {
+    CloseHandle(start_event);
+  }
+};
+
+// This task is used to trigger the message loop to exit.
+class ThreadQuitTask : public Task {
+ public:
+  virtual void Run() {
+    MessageLoop::current()->Quit();
+    Thread::SetThreadWasQuitProperly(true);
+  }
+};
+
+// Once an object is signaled, quits the current inner message loop.
+class QuitOnSignal : public MessageLoop::Watcher {
+ public:
+  explicit QuitOnSignal(HANDLE signal) : signal_(signal) {
+  }
+  virtual void OnObjectSignaled(HANDLE object) {
+    DCHECK_EQ(object, signal_);
+    MessageLoop::current()->WatchObject(signal_, NULL);
+    MessageLoop::current()->Quit();
+  }
+ private:
+  HANDLE signal_;
+  DISALLOW_EVIL_CONSTRUCTORS(QuitOnSignal);
+};
+
+Thread::Thread(const char *name)
+    : thread_(NULL),
+      thread_id_(0),
+      message_loop_(NULL),
+      name_(name) {
+  DCHECK(tls_index_) << "static initializer failed";
+}
+
+Thread::~Thread() {
+  Stop();
+}
+
+// We use this thread-local variable to record whether or not a thread exited
+// 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.
+TLSSlot Thread::tls_index_ = ThreadLocalStorage::Alloc();
+
+void Thread::SetThreadWasQuitProperly(bool flag) {
+#ifndef NDEBUG
+  ThreadLocalStorage::Set(tls_index_, reinterpret_cast<void*>(flag));
+#endif
+}
+
+bool Thread::GetThreadWasQuitProperly() {
+  bool quit_properly = true;
+#ifndef NDEBUG
+  quit_properly = (ThreadLocalStorage::Get(tls_index_) != 0);
+#endif
+  return quit_properly;
+}
+
+// The information on how to set the thread name comes from
+// a MSDN article: http://msdn2.microsoft.com/en-us/library/xcb2z8hs.aspx
+#define MS_VC_EXCEPTION 0x406D1388
+
+typedef struct tagTHREADNAME_INFO {
+  DWORD dwType;  // Must be 0x1000.
+  LPCSTR szName;  // Pointer to name (in user addr space).
+  DWORD dwThreadID;  // Thread ID (-1=caller thread).
+  DWORD dwFlags;  // Reserved for future use, must be zero.
+} THREADNAME_INFO;
+
+
+// On XP, you can only get the ThreadId of the current
+// thread.  So it is expected that you'll call this after the
+// thread starts up; hence, it is static.
+void Thread::SetThreadName(const char* name, DWORD tid) {
+  THREADNAME_INFO info;
+  info.dwType = 0x1000;
+  info.szName = name;
+  info.dwThreadID = tid;
+  info.dwFlags = 0;
+
+  __try {
+    RaiseException(MS_VC_EXCEPTION, 0,
+                   sizeof(info)/sizeof(DWORD),
+                   reinterpret_cast<DWORD*>(&info));
+  } __except(EXCEPTION_CONTINUE_EXECUTION) {
+  }
+}
+
+
+bool Thread::Start() {
+  return StartWithStackSize(0);
+}
+
+bool Thread::StartWithStackSize(size_t stack_size) {
+  DCHECK(!thread_id_ && !thread_);
+  SetThreadWasQuitProperly(false);
+  scoped_refptr<ThreadStartInfo> info = new ThreadStartInfo(this);
+
+  unsigned int flags = 0;
+  if (win_util::GetWinVersion() >= win_util::WINVERSION_XP && stack_size) {
+    flags = STACK_SIZE_PARAM_IS_A_RESERVATION;
+  } else {
+    stack_size = 0;
+  }
+  thread_ = reinterpret_cast<HANDLE>(
+      _beginthreadex(NULL,
+                     static_cast<unsigned int>(stack_size),
+                     ThreadFunc,
+                     info,
+                     flags,
+                     &thread_id_));
+  if (!thread_) {
+    DLOG(ERROR) << "failed to create thread";
+    return false;
+  }
+
+  // Wait for the thread to start and initialize message_loop_
+  WaitForSingleObject(info->start_event, INFINITE);
+  return true;
+}
+
+void Thread::Stop() {
+  InternalStop(false);
+}
+
+void Thread::NonBlockingStop() {
+  InternalStop(true);
+}
+
+void Thread::InternalStop(bool run_message_loop) {
+  if (!thread_)
+    return;
+
+  DCHECK_NE(thread_id_, GetCurrentThreadId()) << "Can't call Stop() on itself";
+
+  // We had better have a message loop at this point!  If we do not, then it
+  // most likely means that the thread terminated unexpectedly, probably due
+  // to someone calling Quit() on our message loop directly.
+  DCHECK(message_loop_);
+
+  message_loop_->PostTask(FROM_HERE, new ThreadQuitTask());
+
+  if (run_message_loop) {
+    QuitOnSignal signal_watcher(thread_);
+    MessageLoop::current()->WatchObject(thread_, &signal_watcher);
+    bool old_state = MessageLoop::current()->NestableTasksAllowed();
+    MessageLoop::current()->SetNestableTasksAllowed(true);
+    MessageLoop::current()->Run();
+    // Restore task state.
+    MessageLoop::current()->SetNestableTasksAllowed(old_state);
+  } else {
+    // Wait for the thread to exit.
+    WaitForSingleObject(thread_, INFINITE);
+  }
+  CloseHandle(thread_);
+
+  // Reset state.
+  thread_ = NULL;
+  message_loop_ = NULL;
+}
+
+/*static*/
+unsigned __stdcall Thread::ThreadFunc(void* param) {
+  // The message loop for this thread.
+  MessageLoop message_loop;
+
+  Thread* self;
+
+  // Complete the initialization of our Thread object.  We grab an owning
+  // reference to the ThreadStartInfo object to ensure that the start_event
+  // object is not prematurely closed.
+  {
+    scoped_refptr<ThreadStartInfo> info = static_cast<ThreadStartInfo*>(param);
+    self = info->self;
+    self->message_loop_ = &message_loop;
+    SetThreadName(self->thread_name().c_str(), GetCurrentThreadId());
+    message_loop.SetThreadName(self->thread_name());
+    SetEvent(info->start_event);
+  }
+
+  // Let the thread do extra initialization.
+  self->Init();
+
+  message_loop.Run();
+
+  // Let the thread do extra cleanup.
+  self->CleanUp();
+
+  // Assert that MessageLoop::Quit was called by ThreadQuitTask.
+  DCHECK(Thread::GetThreadWasQuitProperly());
+
+  // Clearing this here should be unnecessary since we should only be here if
+  // Thread::Stop was called (the above DCHECK asserts that).  However, to help
+  // make it easier to track down problems in release builds, we null out the
+  // message_loop_ pointer.
+  self->message_loop_ = NULL;
+
+  // We can't receive messages anymore.
+  self->thread_id_ = 0;
+  return 0;
+}