 28e2075280
			
		
	
	28e2075280
	
	
	
		
			
			trunk/talk git-svn-id: http://webrtc.googlecode.com/svn/trunk@4318 4adac7df-926f-26a2-2b94-8c16560cd09d
		
			
				
	
	
		
			290 lines
		
	
	
		
			7.3 KiB
		
	
	
	
		
			C++
		
	
	
	
	
	
			
		
		
	
	
			290 lines
		
	
	
		
			7.3 KiB
		
	
	
	
		
			C++
		
	
	
	
	
	
| /*
 | |
|  * libjingle
 | |
|  * Copyright 2004--2006, Google Inc.
 | |
|  *
 | |
|  * Redistribution and use in source and binary forms, with or without 
 | |
|  * modification, are permitted provided that the following conditions are met:
 | |
|  *
 | |
|  *  1. Redistributions of source code must retain the above copyright notice, 
 | |
|  *     this list of conditions and the following disclaimer.
 | |
|  *  2. 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.
 | |
|  *  3. The name of the author may not be used to endorse or promote products 
 | |
|  *     derived from this software without specific prior written permission.
 | |
|  *
 | |
|  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``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 AUTHOR 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 "talk/base/task.h"
 | |
| #include "talk/base/common.h"
 | |
| #include "talk/base/taskrunner.h"
 | |
| 
 | |
| namespace talk_base {
 | |
| 
 | |
| int32 Task::unique_id_seed_ = 0;
 | |
| 
 | |
| Task::Task(TaskParent *parent)
 | |
|     : TaskParent(this, parent),
 | |
|       state_(STATE_INIT),
 | |
|       blocked_(false),
 | |
|       done_(false),
 | |
|       aborted_(false),
 | |
|       busy_(false),
 | |
|       error_(false),
 | |
|       start_time_(0),
 | |
|       timeout_time_(0),
 | |
|       timeout_seconds_(0),
 | |
|       timeout_suspended_(false)  {
 | |
|   unique_id_ = unique_id_seed_++;
 | |
| 
 | |
|   // sanity check that we didn't roll-over our id seed
 | |
|   ASSERT(unique_id_ < unique_id_seed_);
 | |
| }
 | |
| 
 | |
| Task::~Task() {
 | |
|   // Is this task being deleted in the correct manner?
 | |
|   ASSERT(!done_ || GetRunner()->is_ok_to_delete(this));
 | |
|   ASSERT(state_ == STATE_INIT || done_);
 | |
|   ASSERT(state_ == STATE_INIT || blocked_);
 | |
| 
 | |
|   // If the task is being deleted without being done, it
 | |
|   // means that it hasn't been removed from its parent.
 | |
|   // This happens if a task is deleted outside of TaskRunner.
 | |
|   if (!done_) {
 | |
|     Stop();
 | |
|   }
 | |
| }
 | |
| 
 | |
| int64 Task::CurrentTime() {
 | |
|   return GetRunner()->CurrentTime();
 | |
| }
 | |
| 
 | |
| int64 Task::ElapsedTime() {
 | |
|   return CurrentTime() - start_time_;
 | |
| }
 | |
| 
 | |
| void Task::Start() {
 | |
|   if (state_ != STATE_INIT)
 | |
|     return;
 | |
|   // Set the start time before starting the task.  Otherwise if the task
 | |
|   // finishes quickly and deletes the Task object, setting start_time_
 | |
|   // will crash.
 | |
|   start_time_ = CurrentTime();
 | |
|   GetRunner()->StartTask(this);
 | |
| }
 | |
| 
 | |
| void Task::Step() {
 | |
|   if (done_) {
 | |
| #ifdef _DEBUG
 | |
|     // we do not know how !blocked_ happens when done_ - should be impossible.
 | |
|     // But it causes problems, so in retail build, we force blocked_, and
 | |
|     // under debug we assert.
 | |
|     ASSERT(blocked_);
 | |
| #else
 | |
|     blocked_ = true;
 | |
| #endif
 | |
|     return;
 | |
|   }
 | |
| 
 | |
|   // Async Error() was called
 | |
|   if (error_) {
 | |
|     done_ = true;
 | |
|     state_ = STATE_ERROR;
 | |
|     blocked_ = true;
 | |
| //   obsolete - an errored task is not considered done now
 | |
| //   SignalDone();
 | |
| 
 | |
|     Stop();
 | |
| #ifdef _DEBUG
 | |
|     // verify that stop removed this from its parent
 | |
|     ASSERT(!parent()->IsChildTask(this));
 | |
| #endif
 | |
|     return;
 | |
|   }
 | |
| 
 | |
|   busy_ = true;
 | |
|   int new_state = Process(state_);
 | |
|   busy_ = false;
 | |
| 
 | |
|   if (aborted_) {
 | |
|     Abort(true);  // no need to wake because we're awake
 | |
|     return;
 | |
|   }
 | |
| 
 | |
|   if (new_state == STATE_BLOCKED) {
 | |
|     blocked_ = true;
 | |
|     // Let the timeout continue
 | |
|   } else {
 | |
|     state_ = new_state;
 | |
|     blocked_ = false;
 | |
|     ResetTimeout();
 | |
|   }
 | |
| 
 | |
|   if (new_state == STATE_DONE) {
 | |
|     done_ = true;
 | |
|   } else if (new_state == STATE_ERROR) {
 | |
|     done_ = true;
 | |
|     error_ = true;
 | |
|   }
 | |
| 
 | |
|   if (done_) {
 | |
| //  obsolete - call this yourself
 | |
| //    SignalDone();
 | |
| 
 | |
|     Stop();
 | |
| #if _DEBUG
 | |
|     // verify that stop removed this from its parent
 | |
|     ASSERT(!parent()->IsChildTask(this));
 | |
| #endif
 | |
|     blocked_ = true;
 | |
|   }
 | |
| }
 | |
| 
 | |
| void Task::Abort(bool nowake) {
 | |
|   // Why only check for done_ (instead of "aborted_ || done_")?
 | |
|   //
 | |
|   // If aborted_ && !done_, it means the logic for aborting still
 | |
|   // needs to be executed (because busy_ must have been true when
 | |
|   // Abort() was previously called).
 | |
|   if (done_)
 | |
|     return;
 | |
|   aborted_ = true;
 | |
|   if (!busy_) {
 | |
|     done_ = true;
 | |
|     blocked_ = true;
 | |
|     error_ = true;
 | |
| 
 | |
|     // "done_" is set before calling "Stop()" to ensure that this code 
 | |
|     // doesn't execute more than once (recursively) for the same task.
 | |
|     Stop();
 | |
| #ifdef _DEBUG
 | |
|     // verify that stop removed this from its parent
 | |
|     ASSERT(!parent()->IsChildTask(this));
 | |
| #endif
 | |
|     if (!nowake) {
 | |
|       // WakeTasks to self-delete.
 | |
|       // Don't call Wake() because it is a no-op after "done_" is set.
 | |
|       // Even if Wake() did run, it clears "blocked_" which isn't desireable.
 | |
|       GetRunner()->WakeTasks();
 | |
|     }
 | |
|   }
 | |
| }
 | |
| 
 | |
| void Task::Wake() {
 | |
|   if (done_)
 | |
|     return;
 | |
|   if (blocked_) {
 | |
|     blocked_ = false;
 | |
|     GetRunner()->WakeTasks();
 | |
|   }
 | |
| }
 | |
| 
 | |
| void Task::Error() {
 | |
|   if (error_ || done_)
 | |
|     return;
 | |
|   error_ = true;
 | |
|   Wake();
 | |
| }
 | |
| 
 | |
| std::string Task::GetStateName(int state) const {
 | |
|   switch (state) {
 | |
|     case STATE_BLOCKED: return "BLOCKED";
 | |
|     case STATE_INIT: return "INIT";
 | |
|     case STATE_START: return "START";
 | |
|     case STATE_DONE: return "DONE";
 | |
|     case STATE_ERROR: return "ERROR";
 | |
|     case STATE_RESPONSE: return "RESPONSE";
 | |
|   }
 | |
|   return "??";
 | |
| }
 | |
| 
 | |
| int Task::Process(int state) {
 | |
|   int newstate = STATE_ERROR;
 | |
| 
 | |
|   if (TimedOut()) {
 | |
|     ClearTimeout();
 | |
|     newstate = OnTimeout();
 | |
|     SignalTimeout();
 | |
|   } else {
 | |
|     switch (state) {
 | |
|       case STATE_INIT:
 | |
|         newstate = STATE_START;
 | |
|         break;
 | |
|       case STATE_START:
 | |
|         newstate = ProcessStart();
 | |
|         break;
 | |
|       case STATE_RESPONSE:
 | |
|         newstate = ProcessResponse();
 | |
|         break;
 | |
|       case STATE_DONE:
 | |
|       case STATE_ERROR:
 | |
|         newstate = STATE_BLOCKED;
 | |
|         break;
 | |
|     }
 | |
|   }
 | |
| 
 | |
|   return newstate;
 | |
| }
 | |
| 
 | |
| void Task::Stop() {
 | |
|   // No need to wake because we're either awake or in abort
 | |
|   TaskParent::OnStopped(this);
 | |
| }
 | |
| 
 | |
| void Task::set_timeout_seconds(const int timeout_seconds) {
 | |
|   timeout_seconds_ = timeout_seconds;
 | |
|   ResetTimeout();
 | |
| }
 | |
| 
 | |
| bool Task::TimedOut() {
 | |
|   return timeout_seconds_ &&
 | |
|     timeout_time_ &&
 | |
|     CurrentTime() >= timeout_time_;
 | |
| }
 | |
| 
 | |
| void Task::ResetTimeout() {
 | |
|   int64 previous_timeout_time = timeout_time_;
 | |
|   bool timeout_allowed = (state_ != STATE_INIT)
 | |
|                       && (state_ != STATE_DONE)
 | |
|                       && (state_ != STATE_ERROR);
 | |
|   if (timeout_seconds_ && timeout_allowed && !timeout_suspended_)
 | |
|     timeout_time_ = CurrentTime() +
 | |
|                     (timeout_seconds_ * kSecToMsec * kMsecTo100ns);
 | |
|   else
 | |
|     timeout_time_ = 0;
 | |
| 
 | |
|   GetRunner()->UpdateTaskTimeout(this, previous_timeout_time);
 | |
| }
 | |
| 
 | |
| void Task::ClearTimeout() {
 | |
|   int64 previous_timeout_time = timeout_time_;
 | |
|   timeout_time_ = 0;
 | |
|   GetRunner()->UpdateTaskTimeout(this, previous_timeout_time);
 | |
| }
 | |
| 
 | |
| void Task::SuspendTimeout() {
 | |
|   if (!timeout_suspended_) {
 | |
|     timeout_suspended_ = true;
 | |
|     ResetTimeout();
 | |
|   }
 | |
| }
 | |
| 
 | |
| void Task::ResumeTimeout() {
 | |
|   if (timeout_suspended_) {
 | |
|     timeout_suspended_ = false;
 | |
|     ResetTimeout();
 | |
|   }
 | |
| }
 | |
| 
 | |
| } // namespace talk_base
 |