The Tor Browser: ipc/chromium/src/base/simple_thread.h@6474c204b198 (annotated)

ipc/chromium/src/base/simple_thread.h@6474c204b198 (annotated)

ipc/chromium/src/base/simple_thread.h

Wed, 31 Dec 2014 06:09:35 +0100

author: Michael Schloh von Bennewitz <michael@schloh.com>
date: Wed, 31 Dec 2014 06:09:35 +0100
changeset 0: 6474c204b198
permissions: -rw-r--r--

Cloned upstream origin tor-browser at tor-browser-31.3.0esr-4.5-1-build1
revision ID fc1c9ff7c1b2defdbc039f12214767608f46423f for hacking purpose.

 // 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: You should probably be using Thread (thread.h) instead.  Thread is
 //          Chrome's message-loop based Thread abstraction, and if you are a
 //          thread running in the browser, there will likely be assumptions
 //          that your thread will have an associated message loop.
 //
 // This is a simple thread interface that backs to a native operating system
 // thread.  You should use this only when you want a thread that does not have
 // an associated MessageLoop.  Unittesting is the best example of this.
 //
 // The simplest interface to use is DelegateSimpleThread, which will create
 // a new thread, and execute the Delegate's virtual Run() in this new thread
 // until it has completed, exiting the thread.
 //
 // NOTE: You *MUST* call Join on the thread to clean up the underlying thread
 // resources.  You are also responsible for destructing the SimpleThread object.
 // It is invalid to destroy a SimpleThread while it is running, or without
 // Start() having been called (and a thread never created).  The Delegate
 // object should live as long as a DelegateSimpleThread.
 //
 // Thread Safety: A SimpleThread is not completely thread safe.  It is safe to
 // access it from the creating thread or from the newly created thread.  This
 // implies that the creator thread should be the thread that calls Join.
 //
 // Example:
 //   class MyThreadRunner : public DelegateSimpleThread::Delegate { ... };
 //   MyThreadRunner runner;
 //   DelegateSimpleThread thread(&runner, "good_name_here");
 //   thread.Start();
 //   // Start will return after the Thread has been successfully started and
 //   // initialized.  The newly created thread will invoke runner->Run(), and
 //   // run until it returns.
 //   thread.Join();  // Wait until the thread has exited.  You *MUST* Join!
 //   // The SimpleThread object is still valid, however you may not call Join
 //   // or Start again.
 #ifndef BASE_SIMPLE_THREAD_H_
 #define BASE_SIMPLE_THREAD_H_
 #include <string>
 #include <queue>
 #include <vector>
 #include "base/basictypes.h"
 #include "base/lock.h"
 #include "base/waitable_event.h"
 #include "base/platform_thread.h"
 namespace base {
 // This is the base SimpleThread.  You can derive from it and implement the
 // virtual Run method, or you can use the DelegateSimpleThread interface.
 class SimpleThread : public PlatformThread::Delegate {
  public:
   class Options {
    public:
     Options() : stack_size_(0) { }
     ~Options() { }
     // We use the standard compiler-supplied copy constructor.
     // A custom stack size, or 0 for the system default.
     void set_stack_size(size_t size) { stack_size_ = size; }
     size_t stack_size() const { return stack_size_; }
    private:
     size_t stack_size_;
   };
   // Create a SimpleThread.  |options| should be used to manage any specific
   // configuration involving the thread creation and management.
   // Every thread has a name, in the form of |name_prefix|/TID, for example
   // "my_thread/321".  The thread will not be created until Start() is called.
   explicit SimpleThread(const std::string& name_prefix)
       : name_prefix_(name_prefix), name_(name_prefix),
         thread_(), event_(true, false), tid_(0), joined_(false) { }
   SimpleThread(const std::string& name_prefix, const Options& options)
       : name_prefix_(name_prefix), name_(name_prefix), options_(options),
         thread_(), event_(true, false), tid_(0), joined_(false) { }
   virtual ~SimpleThread();
   virtual void Start();
   virtual void Join();
   // We follow the PlatformThread Delegate interface.
   virtual void ThreadMain();
   // Subclasses should override the Run method.
   virtual void Run() = 0;
   // Return the thread name prefix, or "unnamed" if none was supplied.
   std::string name_prefix() { return name_prefix_; }
   // Return the completed name including TID, only valid after Start().
   std::string name() { return name_; }
   // Return the thread id, only valid after Start().
   PlatformThreadId tid() { return tid_; }
   // Return True if Start() has ever been called.
   bool HasBeenStarted() { return event_.IsSignaled(); }
   // Return True if Join() has evern been called.
   bool HasBeenJoined() { return joined_; }
  private:
   const std::string name_prefix_;
   std::string name_;
   const Options options_;
   PlatformThreadHandle thread_;  // PlatformThread handle, invalid after Join!
   WaitableEvent event_;          // Signaled if Start() was ever called.
   PlatformThreadId tid_;         // The backing thread's id.
   bool joined_;                  // True if Join has been called.
 };
 class DelegateSimpleThread : public SimpleThread {
  public:
   class Delegate {
    public:
     Delegate() { }
     virtual ~Delegate() { }
     virtual void Run() = 0;
   };
   DelegateSimpleThread(Delegate* delegate,
                        const std::string& name_prefix)
       : SimpleThread(name_prefix), delegate_(delegate) { }
   DelegateSimpleThread(Delegate* delegate,
                        const std::string& name_prefix,
                        const Options& options)
       : SimpleThread(name_prefix, options), delegate_(delegate) { }
   virtual ~DelegateSimpleThread() { }
   virtual void Run();
  private:
   Delegate* delegate_;
 };
 // DelegateSimpleThreadPool allows you to start up a fixed number of threads,
 // and then add jobs which will be dispatched to the threads.  This is
 // convenient when you have a lot of small work that you want done
 // multi-threaded, but don't want to spawn a thread for each small bit of work.
 //
 // You just call AddWork() to add a delegate to the list of work to be done.
 // JoinAll() will make sure that all outstanding work is processed, and wait
 // for everything to finish.  You can reuse a pool, so you can call Start()
 // again after you've called JoinAll().
 class DelegateSimpleThreadPool : public DelegateSimpleThread::Delegate {
  public:
   typedef DelegateSimpleThread::Delegate Delegate;
   DelegateSimpleThreadPool(const std::string name_prefix, int num_threads)
       : name_prefix_(name_prefix), num_threads_(num_threads),
         dry_(true, false) { }
   ~DelegateSimpleThreadPool();
   // Start up all of the underlying threads, and start processing work if we
   // have any.
   void Start();
   // Make sure all outstanding work is finished, and wait for and destroy all
   // of the underlying threads in the pool.
   void JoinAll();
   // It is safe to AddWork() any time, before or after Start().
   // Delegate* should always be a valid pointer, NULL is reserved internally.
   void AddWork(Delegate* work, int repeat_count);
   void AddWork(Delegate* work) {
     AddWork(work, 1);
   }
   // We implement the Delegate interface, for running our internal threads.
   virtual void Run();
  private:
   const std::string name_prefix_;
   int num_threads_;
   std::vector<DelegateSimpleThread*> threads_;
   std::queue<Delegate*> delegates_;
   Lock lock_;            // Locks delegates_
   WaitableEvent dry_;    // Not signaled when there is no work to do.
 };
 }  // namespace base
 #endif  // BASE_SIMPLE_THREAD_H_

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ipc/chromium/src/base/simple_thread.h@6474c204b198 (annotated)

ipc/chromium/src/base/simple_thread.h