Adds a modified copy of talk/base to webrtc/base. It is the first step in migrating talk/base to webrtc/base.

BUG=N/A
R=andrew@webrtc.org, wu@webrtc.org

Review URL: https://webrtc-codereview.appspot.com/12199004

git-svn-id: http://webrtc.googlecode.com/svn/trunk@6107 4adac7df-926f-26a2-2b94-8c16560cd09d

webrtc/base/messagequeue.cc

@@ -0,0 +1,395 @@
+/*
+ *  Copyright 2004 The WebRTC Project Authors. All rights reserved.
+ *
+ *  Use of this source code is governed by a BSD-style license
+ *  that can be found in the LICENSE file in the root of the source
+ *  tree. An additional intellectual property rights grant can be found
+ *  in the file PATENTS.  All contributing project authors may
+ *  be found in the AUTHORS file in the root of the source tree.
+ */
+
+#if defined(WEBRTC_POSIX)
+#include <sys/time.h>
+#endif
+
+#include "webrtc/base/common.h"
+#include "webrtc/base/logging.h"
+#include "webrtc/base/messagequeue.h"
+#if defined(__native_client__)
+#include "webrtc/base/nullsocketserver.h"
+typedef rtc::NullSocketServer DefaultSocketServer;
+#else
+#include "webrtc/base/physicalsocketserver.h"
+typedef rtc::PhysicalSocketServer DefaultSocketServer;
+#endif
+
+namespace rtc {
+
+const uint32 kMaxMsgLatency = 150;  // 150 ms
+
+//------------------------------------------------------------------
+// MessageQueueManager
+
+MessageQueueManager* MessageQueueManager::instance_ = NULL;
+
+MessageQueueManager* MessageQueueManager::Instance() {
+  // Note: This is not thread safe, but it is first called before threads are
+  // spawned.
+  if (!instance_)
+    instance_ = new MessageQueueManager;
+  return instance_;
+}
+
+bool MessageQueueManager::IsInitialized() {
+  return instance_ != NULL;
+}
+
+MessageQueueManager::MessageQueueManager() {
+}
+
+MessageQueueManager::~MessageQueueManager() {
+}
+
+void MessageQueueManager::Add(MessageQueue *message_queue) {
+  return Instance()->AddInternal(message_queue);
+}
+void MessageQueueManager::AddInternal(MessageQueue *message_queue) {
+  // MessageQueueManager methods should be non-reentrant, so we
+  // ASSERT that is the case.  If any of these ASSERT, please
+  // contact bpm or jbeda.
+  ASSERT(!crit_.CurrentThreadIsOwner());
+  CritScope cs(&crit_);
+  message_queues_.push_back(message_queue);
+}
+
+void MessageQueueManager::Remove(MessageQueue *message_queue) {
+  // If there isn't a message queue manager instance, then there isn't a queue
+  // to remove.
+  if (!instance_) return;
+  return Instance()->RemoveInternal(message_queue);
+}
+void MessageQueueManager::RemoveInternal(MessageQueue *message_queue) {
+  ASSERT(!crit_.CurrentThreadIsOwner());  // See note above.
+  // If this is the last MessageQueue, destroy the manager as well so that
+  // we don't leak this object at program shutdown. As mentioned above, this is
+  // not thread-safe, but this should only happen at program termination (when
+  // the ThreadManager is destroyed, and threads are no longer active).
+  bool destroy = false;
+  {
+    CritScope cs(&crit_);
+    std::vector<MessageQueue *>::iterator iter;
+    iter = std::find(message_queues_.begin(), message_queues_.end(),
+                     message_queue);
+    if (iter != message_queues_.end()) {
+      message_queues_.erase(iter);
+    }
+    destroy = message_queues_.empty();
+  }
+  if (destroy) {
+    instance_ = NULL;
+    delete this;
+  }
+}
+
+void MessageQueueManager::Clear(MessageHandler *handler) {
+  // If there isn't a message queue manager instance, then there aren't any
+  // queues to remove this handler from.
+  if (!instance_) return;
+  return Instance()->ClearInternal(handler);
+}
+void MessageQueueManager::ClearInternal(MessageHandler *handler) {
+  ASSERT(!crit_.CurrentThreadIsOwner());  // See note above.
+  CritScope cs(&crit_);
+  std::vector<MessageQueue *>::iterator iter;
+  for (iter = message_queues_.begin(); iter != message_queues_.end(); iter++)
+    (*iter)->Clear(handler);
+}
+
+//------------------------------------------------------------------
+// MessageQueue
+
+MessageQueue::MessageQueue(SocketServer* ss)
+    : ss_(ss), fStop_(false), fPeekKeep_(false), active_(false),
+      dmsgq_next_num_(0) {
+  if (!ss_) {
+    // Currently, MessageQueue holds a socket server, and is the base class for
+    // Thread.  It seems like it makes more sense for Thread to hold the socket
+    // server, and provide it to the MessageQueue, since the Thread controls
+    // the I/O model, and MQ is agnostic to those details.  Anyway, this causes
+    // messagequeue_unittest to depend on network libraries... yuck.
+    default_ss_.reset(new DefaultSocketServer());
+    ss_ = default_ss_.get();
+  }
+  ss_->SetMessageQueue(this);
+}
+
+MessageQueue::~MessageQueue() {
+  // The signal is done from here to ensure
+  // that it always gets called when the queue
+  // is going away.
+  SignalQueueDestroyed();
+  if (active_) {
+    MessageQueueManager::Remove(this);
+    Clear(NULL);
+  }
+  if (ss_) {
+    ss_->SetMessageQueue(NULL);
+  }
+}
+
+void MessageQueue::set_socketserver(SocketServer* ss) {
+  ss_ = ss ? ss : default_ss_.get();
+  ss_->SetMessageQueue(this);
+}
+
+void MessageQueue::Quit() {
+  fStop_ = true;
+  ss_->WakeUp();
+}
+
+bool MessageQueue::IsQuitting() {
+  return fStop_;
+}
+
+void MessageQueue::Restart() {
+  fStop_ = false;
+}
+
+bool MessageQueue::Peek(Message *pmsg, int cmsWait) {
+  if (fPeekKeep_) {
+    *pmsg = msgPeek_;
+    return true;
+  }
+  if (!Get(pmsg, cmsWait))
+    return false;
+  msgPeek_ = *pmsg;
+  fPeekKeep_ = true;
+  return true;
+}
+
+bool MessageQueue::Get(Message *pmsg, int cmsWait, bool process_io) {
+  // Return and clear peek if present
+  // Always return the peek if it exists so there is Peek/Get symmetry
+
+  if (fPeekKeep_) {
+    *pmsg = msgPeek_;
+    fPeekKeep_ = false;
+    return true;
+  }
+
+  // Get w/wait + timer scan / dispatch + socket / event multiplexer dispatch
+
+  int cmsTotal = cmsWait;
+  int cmsElapsed = 0;
+  uint32 msStart = Time();
+  uint32 msCurrent = msStart;
+  while (true) {
+    // Check for sent messages
+    ReceiveSends();
+
+    // Check for posted events
+    int cmsDelayNext = kForever;
+    bool first_pass = true;
+    while (true) {
+      // All queue operations need to be locked, but nothing else in this loop
+      // (specifically handling disposed message) can happen inside the crit.
+      // Otherwise, disposed MessageHandlers will cause deadlocks.
+      {
+        CritScope cs(&crit_);
+        // On the first pass, check for delayed messages that have been
+        // triggered and calculate the next trigger time.
+        if (first_pass) {
+          first_pass = false;
+          while (!dmsgq_.empty()) {
+            if (TimeIsLater(msCurrent, dmsgq_.top().msTrigger_)) {
+              cmsDelayNext = TimeDiff(dmsgq_.top().msTrigger_, msCurrent);
+              break;
+            }
+            msgq_.push_back(dmsgq_.top().msg_);
+            dmsgq_.pop();
+          }
+        }
+        // Pull a message off the message queue, if available.
+        if (msgq_.empty()) {
+          break;
+        } else {
+          *pmsg = msgq_.front();
+          msgq_.pop_front();
+        }
+      }  // crit_ is released here.
+
+      // Log a warning for time-sensitive messages that we're late to deliver.
+      if (pmsg->ts_sensitive) {
+        int32 delay = TimeDiff(msCurrent, pmsg->ts_sensitive);
+        if (delay > 0) {
+          LOG_F(LS_WARNING) << "id: " << pmsg->message_id << "  delay: "
+                            << (delay + kMaxMsgLatency) << "ms";
+        }
+      }
+      // If this was a dispose message, delete it and skip it.
+      if (MQID_DISPOSE == pmsg->message_id) {
+        ASSERT(NULL == pmsg->phandler);
+        delete pmsg->pdata;
+        *pmsg = Message();
+        continue;
+      }
+      return true;
+    }
+
+    if (fStop_)
+      break;
+
+    // Which is shorter, the delay wait or the asked wait?
+
+    int cmsNext;
+    if (cmsWait == kForever) {
+      cmsNext = cmsDelayNext;
+    } else {
+      cmsNext = _max(0, cmsTotal - cmsElapsed);
+      if ((cmsDelayNext != kForever) && (cmsDelayNext < cmsNext))
+        cmsNext = cmsDelayNext;
+    }
+
+    // Wait and multiplex in the meantime
+    if (!ss_->Wait(cmsNext, process_io))
+      return false;
+
+    // If the specified timeout expired, return
+
+    msCurrent = Time();
+    cmsElapsed = TimeDiff(msCurrent, msStart);
+    if (cmsWait != kForever) {
+      if (cmsElapsed >= cmsWait)
+        return false;
+    }
+  }
+  return false;
+}
+
+void MessageQueue::ReceiveSends() {
+}
+
+void MessageQueue::Post(MessageHandler *phandler, uint32 id,
+    MessageData *pdata, bool time_sensitive) {
+  if (fStop_)
+    return;
+
+  // Keep thread safe
+  // Add the message to the end of the queue
+  // Signal for the multiplexer to return
+
+  CritScope cs(&crit_);
+  EnsureActive();
+  Message msg;
+  msg.phandler = phandler;
+  msg.message_id = id;
+  msg.pdata = pdata;
+  if (time_sensitive) {
+    msg.ts_sensitive = Time() + kMaxMsgLatency;
+  }
+  msgq_.push_back(msg);
+  ss_->WakeUp();
+}
+
+void MessageQueue::DoDelayPost(int cmsDelay, uint32 tstamp,
+    MessageHandler *phandler, uint32 id, MessageData* pdata) {
+  if (fStop_)
+    return;
+
+  // Keep thread safe
+  // Add to the priority queue. Gets sorted soonest first.
+  // Signal for the multiplexer to return.
+
+  CritScope cs(&crit_);
+  EnsureActive();
+  Message msg;
+  msg.phandler = phandler;
+  msg.message_id = id;
+  msg.pdata = pdata;
+  DelayedMessage dmsg(cmsDelay, tstamp, dmsgq_next_num_, msg);
+  dmsgq_.push(dmsg);
+  // If this message queue processes 1 message every millisecond for 50 days,
+  // we will wrap this number.  Even then, only messages with identical times
+  // will be misordered, and then only briefly.  This is probably ok.
+  VERIFY(0 != ++dmsgq_next_num_);
+  ss_->WakeUp();
+}
+
+int MessageQueue::GetDelay() {
+  CritScope cs(&crit_);
+
+  if (!msgq_.empty())
+    return 0;
+
+  if (!dmsgq_.empty()) {
+    int delay = TimeUntil(dmsgq_.top().msTrigger_);
+    if (delay < 0)
+      delay = 0;
+    return delay;
+  }
+
+  return kForever;
+}
+
+void MessageQueue::Clear(MessageHandler *phandler, uint32 id,
+                         MessageList* removed) {
+  CritScope cs(&crit_);
+
+  // Remove messages with phandler
+
+  if (fPeekKeep_ && msgPeek_.Match(phandler, id)) {
+    if (removed) {
+      removed->push_back(msgPeek_);
+    } else {
+      delete msgPeek_.pdata;
+    }
+    fPeekKeep_ = false;
+  }
+
+  // Remove from ordered message queue
+
+  for (MessageList::iterator it = msgq_.begin(); it != msgq_.end();) {
+    if (it->Match(phandler, id)) {
+      if (removed) {
+        removed->push_back(*it);
+      } else {
+        delete it->pdata;
+      }
+      it = msgq_.erase(it);
+    } else {
+      ++it;
+    }
+  }
+
+  // Remove from priority queue. Not directly iterable, so use this approach
+
+  PriorityQueue::container_type::iterator new_end = dmsgq_.container().begin();
+  for (PriorityQueue::container_type::iterator it = new_end;
+       it != dmsgq_.container().end(); ++it) {
+    if (it->msg_.Match(phandler, id)) {
+      if (removed) {
+        removed->push_back(it->msg_);
+      } else {
+        delete it->msg_.pdata;
+      }
+    } else {
+      *new_end++ = *it;
+    }
+  }
+  dmsgq_.container().erase(new_end, dmsgq_.container().end());
+  dmsgq_.reheap();
+}
+
+void MessageQueue::Dispatch(Message *pmsg) {
+  pmsg->phandler->OnMessage(pmsg);
+}
+
+void MessageQueue::EnsureActive() {
+  ASSERT(crit_.CurrentThreadIsOwner());
+  if (!active_) {
+    active_ = true;
+    MessageQueueManager::Add(this);
+  }
+}
+
+}  // namespace rtc