third_party/blink/renderer/core/script/script_runner.cc - chromium/src - Git at Google

 /*
  * Copyright (C) 2010 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:
  * 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.
  *
  * THIS SOFTWARE IS PROVIDED BY APPLE INC. ``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 APPLE INC. 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 "third_party/blink/renderer/core/script/script_runner.h"

 #include <algorithm>
 #include "third_party/blink/public/platform/platform.h"
 #include "third_party/blink/public/platform/task_type.h"
 #include "third_party/blink/renderer/core/dom/document.h"
 #include "third_party/blink/renderer/core/script/script_loader.h"
 #include "third_party/blink/renderer/platform/heap/handle.h"
 #include "third_party/blink/renderer/platform/runtime_enabled_features.h"
 #include "third_party/blink/renderer/platform/scheduler/public/thread.h"
 #include "third_party/blink/renderer/platform/scheduler/public/thread_scheduler.h"

 namespace blink {

 ScriptRunner::ScriptRunner(Document* document)
     : document_(document),
       task_runner_(document->GetTaskRunner(TaskType::kNetworking)) {
   DCHECK(document);
 }

 void ScriptRunner::QueueScriptForExecution(PendingScript* pending_script) {
   DCHECK(pending_script);
   document_->IncrementLoadEventDelayCount();
   switch (pending_script->GetSchedulingType()) {
     case ScriptSchedulingType::kAsync:
       pending_async_scripts_.insert(pending_script);
       if (!is_suspended_) {
         pending_script->StartStreamingIfPossible();
       }
       break;

     case ScriptSchedulingType::kInOrder:
       pending_in_order_scripts_.push_back(pending_script);
       number_of_in_order_scripts_with_pending_notification_++;
       break;

     default:
       NOTREACHED();
       break;
   }
 }

 void ScriptRunner::PostTask(const base::Location& web_trace_location) {
   task_runner_->PostTask(
       web_trace_location,
       WTF::Bind(&ScriptRunner::ExecuteTask, WrapWeakPersistent(this)));
 }

 void ScriptRunner::Suspend() {
 #ifndef NDEBUG
   // Resume will re-post tasks for all available scripts.
   number_of_extra_tasks_ += async_scripts_to_execute_soon_.size() +
                             in_order_scripts_to_execute_soon_.size();
 #endif

   is_suspended_ = true;
 }

 void ScriptRunner::Resume() {
   DCHECK(is_suspended_);

   is_suspended_ = false;

   for (size_t i = 0; i < async_scripts_to_execute_soon_.size(); ++i) {
     PostTask(FROM_HERE);
   }
   for (size_t i = 0; i < in_order_scripts_to_execute_soon_.size(); ++i) {
     PostTask(FROM_HERE);
   }
 }

 void ScriptRunner::ScheduleReadyInOrderScripts() {
   while (!pending_in_order_scripts_.IsEmpty() &&
          pending_in_order_scripts_.front()
              ->IsReady()) {
     in_order_scripts_to_execute_soon_.push_back(
         pending_in_order_scripts_.TakeFirst());
     PostTask(FROM_HERE);
   }
 }

 void ScriptRunner::NotifyScriptReady(PendingScript* pending_script) {
   SECURITY_CHECK(pending_script);
   switch (pending_script->GetSchedulingType()) {
     case ScriptSchedulingType::kAsync:
       // SECURITY_CHECK() makes us crash in a controlled way in error cases
       // where the PendingScript is associated with the wrong ScriptRunner
       // (otherwise we'd cause a use-after-free in ~ScriptRunner when it tries
       // to detach).
       SECURITY_CHECK(pending_async_scripts_.Contains(pending_script));

       pending_async_scripts_.erase(pending_script);
       async_scripts_to_execute_soon_.push_back(pending_script);

       PostTask(FROM_HERE);
       break;

     case ScriptSchedulingType::kInOrder:
       SECURITY_CHECK(number_of_in_order_scripts_with_pending_notification_ > 0);
       number_of_in_order_scripts_with_pending_notification_--;

       ScheduleReadyInOrderScripts();

       break;

     default:
       NOTREACHED();
       break;
   }
 }

 bool ScriptRunner::RemovePendingInOrderScript(PendingScript* pending_script) {
   auto it = std::find(pending_in_order_scripts_.begin(),
                       pending_in_order_scripts_.end(), pending_script);
   if (it == pending_in_order_scripts_.end())
     return false;
   pending_in_order_scripts_.erase(it);
   SECURITY_CHECK(number_of_in_order_scripts_with_pending_notification_ > 0);
   number_of_in_order_scripts_with_pending_notification_--;
   return true;
 }

 void ScriptRunner::MovePendingScript(Document& old_document,
                                      Document& new_document,
                                      ScriptLoader* script_loader) {
   Document* new_context_document = new_document.ContextDocument();
   if (!new_context_document) {
     // Document's contextDocument() method will return no Document if the
     // following conditions both hold:
     //
     //   - The Document wasn't created with an explicit context document
     //     and that document is otherwise kept alive.
     //   - The Document itself is detached from its frame.
     //
     // The script element's loader is in that case moved to document() and
     // its script runner, which is the non-null Document that contextDocument()
     // would return if not detached.
     DCHECK(!new_document.GetFrame());
     new_context_document = &new_document;
   }
   Document* old_context_document = old_document.ContextDocument();
   if (!old_context_document) {
     DCHECK(!old_document.GetFrame());
     old_context_document = &old_document;
   }

   if (old_context_document == new_context_document)
     return;

   PendingScript* pending_script =
       script_loader
           ->GetPendingScriptIfControlledByScriptRunnerForCrossDocMove();
   if (!pending_script) {
     // The ScriptLoader is not controlled by ScriptRunner. This can happen
     // because MovePendingScript() is called for all <script> elements
     // moved between Documents, not only for those controlled by ScriptRunner.
     return;
   }

   old_context_document->GetScriptRunner()->MovePendingScript(
       new_context_document->GetScriptRunner(), pending_script);
 }

 void ScriptRunner::MovePendingScript(ScriptRunner* new_runner,
                                      PendingScript* pending_script) {
   auto it = pending_async_scripts_.find(pending_script);
   if (it != pending_async_scripts_.end()) {
     new_runner->QueueScriptForExecution(pending_script);
     pending_async_scripts_.erase(it);
     document_->DecrementLoadEventDelayCount();
     return;
   }
   if (RemovePendingInOrderScript(pending_script)) {
     new_runner->QueueScriptForExecution(pending_script);
     document_->DecrementLoadEventDelayCount();
   }
 }

 bool ScriptRunner::ExecuteInOrderTask() {
   TRACE_EVENT0("blink", "ScriptRunner::ExecuteInOrderTask");
   if (in_order_scripts_to_execute_soon_.IsEmpty())
     return false;

   PendingScript* pending_script = in_order_scripts_to_execute_soon_.TakeFirst();
   DCHECK(pending_script);
   DCHECK_EQ(pending_script->GetSchedulingType(), ScriptSchedulingType::kInOrder)
       << "In-order scripts queue should not contain any async script.";

   pending_script->ExecuteScriptBlock(NullURL());

   document_->DecrementLoadEventDelayCount();
   return true;
 }

 bool ScriptRunner::ExecuteAsyncTask() {
   TRACE_EVENT0("blink", "ScriptRunner::ExecuteAsyncTask");
   if (async_scripts_to_execute_soon_.IsEmpty())
     return false;

   // Remove the async script loader from the ready-to-exec set and execute.
   PendingScript* pending_script = async_scripts_to_execute_soon_.TakeFirst();

   DCHECK_EQ(pending_script->GetSchedulingType(), ScriptSchedulingType::kAsync)
       << "Async scripts queue should not contain any in-order script.";

   pending_script->ExecuteScriptBlock(NullURL());

   document_->DecrementLoadEventDelayCount();
   return true;
 }

 void ScriptRunner::ExecuteTask() {
   if (is_suspended_)
     return;

   if (ExecuteAsyncTask())
     return;

   if (ExecuteInOrderTask())
     return;

 #ifndef NDEBUG
   // Extra tasks should be posted only when we resume after suspending. These
   // should all be accounted for in number_of_extra_tasks_.
   DCHECK_GT(number_of_extra_tasks_--, 0);
 #endif
 }

 void ScriptRunner::Trace(blink::Visitor* visitor) {
   visitor->Trace(document_);
   visitor->Trace(pending_in_order_scripts_);
   visitor->Trace(pending_async_scripts_);
   visitor->Trace(async_scripts_to_execute_soon_);
   visitor->Trace(in_order_scripts_to_execute_soon_);
 }

 }  // namespace blink
	/*
	* Copyright (C) 2010 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:
	* 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.
	*
	* THIS SOFTWARE IS PROVIDED BY APPLE INC. ``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 APPLE INC. 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 "third_party/blink/renderer/core/script/script_runner.h"

	#include <algorithm>
	#include "third_party/blink/public/platform/platform.h"
	#include "third_party/blink/public/platform/task_type.h"
	#include "third_party/blink/renderer/core/dom/document.h"
	#include "third_party/blink/renderer/core/script/script_loader.h"
	#include "third_party/blink/renderer/platform/heap/handle.h"
	#include "third_party/blink/renderer/platform/runtime_enabled_features.h"
	#include "third_party/blink/renderer/platform/scheduler/public/thread.h"
	#include "third_party/blink/renderer/platform/scheduler/public/thread_scheduler.h"

	namespace blink {

	ScriptRunner::ScriptRunner(Document* document)
	: document_(document),
	task_runner_(document->GetTaskRunner(TaskType::kNetworking)) {
	DCHECK(document);
	}

	void ScriptRunner::QueueScriptForExecution(PendingScript* pending_script) {
	DCHECK(pending_script);
	document_->IncrementLoadEventDelayCount();
	switch (pending_script->GetSchedulingType()) {
	case ScriptSchedulingType::kAsync:
	pending_async_scripts_.insert(pending_script);
	if (!is_suspended_) {
	pending_script->StartStreamingIfPossible();
	}
	break;

	case ScriptSchedulingType::kInOrder:
	pending_in_order_scripts_.push_back(pending_script);
	number_of_in_order_scripts_with_pending_notification_++;
	break;

	default:
	NOTREACHED();
	break;
	}
	}

	void ScriptRunner::PostTask(const base::Location& web_trace_location) {
	task_runner_->PostTask(
	web_trace_location,
	WTF::Bind(&ScriptRunner::ExecuteTask, WrapWeakPersistent(this)));
	}

	void ScriptRunner::Suspend() {
	#ifndef NDEBUG
	// Resume will re-post tasks for all available scripts.
	number_of_extra_tasks_ += async_scripts_to_execute_soon_.size() +
	in_order_scripts_to_execute_soon_.size();
	#endif

	is_suspended_ = true;
	}

	void ScriptRunner::Resume() {
	DCHECK(is_suspended_);

	is_suspended_ = false;

	for (size_t i = 0; i < async_scripts_to_execute_soon_.size(); ++i) {
	PostTask(FROM_HERE);
	}
	for (size_t i = 0; i < in_order_scripts_to_execute_soon_.size(); ++i) {
	PostTask(FROM_HERE);
	}
	}

	void ScriptRunner::ScheduleReadyInOrderScripts() {
	while (!pending_in_order_scripts_.IsEmpty() &&
	pending_in_order_scripts_.front()
	->IsReady()) {
	in_order_scripts_to_execute_soon_.push_back(
	pending_in_order_scripts_.TakeFirst());
	PostTask(FROM_HERE);
	}
	}

	void ScriptRunner::NotifyScriptReady(PendingScript* pending_script) {
	SECURITY_CHECK(pending_script);
	switch (pending_script->GetSchedulingType()) {
	case ScriptSchedulingType::kAsync:
	// SECURITY_CHECK() makes us crash in a controlled way in error cases
	// where the PendingScript is associated with the wrong ScriptRunner
	// (otherwise we'd cause a use-after-free in ~ScriptRunner when it tries
	// to detach).
	SECURITY_CHECK(pending_async_scripts_.Contains(pending_script));

	pending_async_scripts_.erase(pending_script);
	async_scripts_to_execute_soon_.push_back(pending_script);

	PostTask(FROM_HERE);
	break;

	case ScriptSchedulingType::kInOrder:
	SECURITY_CHECK(number_of_in_order_scripts_with_pending_notification_ > 0);
	number_of_in_order_scripts_with_pending_notification_--;

	ScheduleReadyInOrderScripts();

	break;

	default:
	NOTREACHED();
	break;
	}
	}

	bool ScriptRunner::RemovePendingInOrderScript(PendingScript* pending_script) {
	auto it = std::find(pending_in_order_scripts_.begin(),
	pending_in_order_scripts_.end(), pending_script);
	if (it == pending_in_order_scripts_.end())
	return false;
	pending_in_order_scripts_.erase(it);
	SECURITY_CHECK(number_of_in_order_scripts_with_pending_notification_ > 0);
	number_of_in_order_scripts_with_pending_notification_--;
	return true;
	}

	void ScriptRunner::MovePendingScript(Document& old_document,
	Document& new_document,
	ScriptLoader* script_loader) {
	Document* new_context_document = new_document.ContextDocument();
	if (!new_context_document) {
	// Document's contextDocument() method will return no Document if the
	// following conditions both hold:
	//
	// - The Document wasn't created with an explicit context document
	// and that document is otherwise kept alive.
	// - The Document itself is detached from its frame.
	//
	// The script element's loader is in that case moved to document() and
	// its script runner, which is the non-null Document that contextDocument()
	// would return if not detached.
	DCHECK(!new_document.GetFrame());
	new_context_document = &new_document;
	}
	Document* old_context_document = old_document.ContextDocument();
	if (!old_context_document) {
	DCHECK(!old_document.GetFrame());
	old_context_document = &old_document;
	}

	if (old_context_document == new_context_document)
	return;

	PendingScript* pending_script =
	script_loader
	->GetPendingScriptIfControlledByScriptRunnerForCrossDocMove();
	if (!pending_script) {
	// The ScriptLoader is not controlled by ScriptRunner. This can happen
	// because MovePendingScript() is called for all <script> elements
	// moved between Documents, not only for those controlled by ScriptRunner.
	return;
	}

	old_context_document->GetScriptRunner()->MovePendingScript(
	new_context_document->GetScriptRunner(), pending_script);
	}

	void ScriptRunner::MovePendingScript(ScriptRunner* new_runner,
	PendingScript* pending_script) {
	auto it = pending_async_scripts_.find(pending_script);
	if (it != pending_async_scripts_.end()) {
	new_runner->QueueScriptForExecution(pending_script);
	pending_async_scripts_.erase(it);
	document_->DecrementLoadEventDelayCount();
	return;
	}
	if (RemovePendingInOrderScript(pending_script)) {
	new_runner->QueueScriptForExecution(pending_script);
	document_->DecrementLoadEventDelayCount();
	}
	}

	bool ScriptRunner::ExecuteInOrderTask() {
	TRACE_EVENT0("blink", "ScriptRunner::ExecuteInOrderTask");
	if (in_order_scripts_to_execute_soon_.IsEmpty())
	return false;

	PendingScript* pending_script = in_order_scripts_to_execute_soon_.TakeFirst();
	DCHECK(pending_script);
	DCHECK_EQ(pending_script->GetSchedulingType(), ScriptSchedulingType::kInOrder)
	<< "In-order scripts queue should not contain any async script.";

	pending_script->ExecuteScriptBlock(NullURL());

	document_->DecrementLoadEventDelayCount();
	return true;
	}

	bool ScriptRunner::ExecuteAsyncTask() {
	TRACE_EVENT0("blink", "ScriptRunner::ExecuteAsyncTask");
	if (async_scripts_to_execute_soon_.IsEmpty())
	return false;

	// Remove the async script loader from the ready-to-exec set and execute.
	PendingScript* pending_script = async_scripts_to_execute_soon_.TakeFirst();

	DCHECK_EQ(pending_script->GetSchedulingType(), ScriptSchedulingType::kAsync)
	<< "Async scripts queue should not contain any in-order script.";

	pending_script->ExecuteScriptBlock(NullURL());

	document_->DecrementLoadEventDelayCount();
	return true;
	}

	void ScriptRunner::ExecuteTask() {
	if (is_suspended_)
	return;

	if (ExecuteAsyncTask())
	return;

	if (ExecuteInOrderTask())
	return;

	#ifndef NDEBUG
	// Extra tasks should be posted only when we resume after suspending. These
	// should all be accounted for in number_of_extra_tasks_.
	DCHECK_GT(number_of_extra_tasks_--, 0);
	#endif
	}

	void ScriptRunner::Trace(blink::Visitor* visitor) {
	visitor->Trace(document_);
	visitor->Trace(pending_in_order_scripts_);
	visitor->Trace(pending_async_scripts_);
	visitor->Trace(async_scripts_to_execute_soon_);
	visitor->Trace(in_order_scripts_to_execute_soon_);
	}

	} // namespace blink