Source/JavaScriptCore/inspector/agents/InspectorHeapAgent.cpp - WebKit - Git at Google

 /*
  * Copyright (C) 2015-2016 Apple 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 "config.h"
 #include "InspectorHeapAgent.h"

 #include "HeapProfiler.h"
 #include "HeapSnapshot.h"
 #include "InjectedScript.h"
 #include "InjectedScriptManager.h"
 #include "InspectorEnvironment.h"
 #include "JSCInlines.h"
 #include "VM.h"
 #include <wtf/Stopwatch.h>

 using namespace JSC;

 namespace Inspector {

 InspectorHeapAgent::InspectorHeapAgent(AgentContext& context)
     : InspectorAgentBase("Heap"_s)
     , m_injectedScriptManager(context.injectedScriptManager)
     , m_frontendDispatcher(std::make_unique<HeapFrontendDispatcher>(context.frontendRouter))
     , m_backendDispatcher(HeapBackendDispatcher::create(context.backendDispatcher, this))
     , m_environment(context.environment)
 {
 }

 void InspectorHeapAgent::didCreateFrontendAndBackend(FrontendRouter*, BackendDispatcher*)
 {
 }

 void InspectorHeapAgent::willDestroyFrontendAndBackend(DisconnectReason)
 {
     // Stop tracking without taking a snapshot.
     m_tracking = false;

     ErrorString ignored;
     disable(ignored);
 }

 void InspectorHeapAgent::enable(ErrorString&)
 {
     if (m_enabled)
         return;

     m_enabled = true;

     m_environment.vm().heap.addObserver(this);
 }

 void InspectorHeapAgent::disable(ErrorString&)
 {
     if (!m_enabled)
         return;

     m_enabled = false;

     m_environment.vm().heap.removeObserver(this);

     clearHeapSnapshots();
 }

 void InspectorHeapAgent::gc(ErrorString&)
 {
     VM& vm = m_environment.vm();
     JSLockHolder lock(vm);
     sanitizeStackForVM(&vm);
     vm.heap.collectNow(Sync, CollectionScope::Full);
 }

 void InspectorHeapAgent::snapshot(ErrorString&, double* timestamp, String* snapshotData)
 {
     VM& vm = m_environment.vm();
     JSLockHolder lock(vm);

     HeapSnapshotBuilder snapshotBuilder(vm.ensureHeapProfiler());
     snapshotBuilder.buildSnapshot();

     *timestamp = m_environment.executionStopwatch()->elapsedTime().seconds();
     *snapshotData = snapshotBuilder.json([&] (const HeapSnapshotNode& node) {
         if (Structure* structure = node.cell->structure(vm)) {
             if (JSGlobalObject* globalObject = structure->globalObject()) {
                 if (!m_environment.canAccessInspectedScriptState(globalObject->globalExec()))
                     return false;
             }
         }
         return true;
     });
 }

 void InspectorHeapAgent::startTracking(ErrorString& errorString)
 {
     if (m_tracking)
         return;

     m_tracking = true;

     double timestamp;
     String snapshotData;
     snapshot(errorString, &timestamp, &snapshotData);

     m_frontendDispatcher->trackingStart(timestamp, snapshotData);
 }

 void InspectorHeapAgent::stopTracking(ErrorString& errorString)
 {
     if (!m_tracking)
         return;

     m_tracking = false;

     double timestamp;
     String snapshotData;
     snapshot(errorString, &timestamp, &snapshotData);

     m_frontendDispatcher->trackingComplete(timestamp, snapshotData);
 }

 Optional<HeapSnapshotNode> InspectorHeapAgent::nodeForHeapObjectIdentifier(ErrorString& errorString, unsigned heapObjectIdentifier)
 {
     HeapProfiler* heapProfiler = m_environment.vm().heapProfiler();
     if (!heapProfiler) {
         errorString = "No heap snapshot"_s;
         return WTF::nullopt;
     }

     HeapSnapshot* snapshot = heapProfiler->mostRecentSnapshot();
     if (!snapshot) {
         errorString = "No heap snapshot"_s;
         return WTF::nullopt;
     }

     const Optional<HeapSnapshotNode> optionalNode = snapshot->nodeForObjectIdentifier(heapObjectIdentifier);
     if (!optionalNode) {
         errorString = "No object for identifier, it may have been collected"_s;
         return WTF::nullopt;
     }

     return optionalNode;
 }

 void InspectorHeapAgent::getPreview(ErrorString& errorString, int heapObjectId, Optional<String>& resultString, RefPtr<Protocol::Debugger::FunctionDetails>& functionDetails, RefPtr<Protocol::Runtime::ObjectPreview>& objectPreview)
 {
     // Prevent the cell from getting collected as we look it up.
     VM& vm = m_environment.vm();
     JSLockHolder lock(vm);
     DeferGC deferGC(vm.heap);

     unsigned heapObjectIdentifier = static_cast<unsigned>(heapObjectId);
     const Optional<HeapSnapshotNode> optionalNode = nodeForHeapObjectIdentifier(errorString, heapObjectIdentifier);
     if (!optionalNode)
         return;

     // String preview.
     JSCell* cell = optionalNode->cell;
     if (cell->isString()) {
         resultString = asString(cell)->tryGetValue();
         return;
     }

     // FIXME: Provide preview information for Internal Objects? CodeBlock, Executable, etc.

     Structure* structure = cell->structure(vm);
     if (!structure) {
         errorString = "Unable to get object details - Structure"_s;
         return;
     }

     JSGlobalObject* globalObject = structure->globalObject();
     if (!globalObject) {
         errorString = "Unable to get object details - GlobalObject"_s;
         return;
     }

     InjectedScript injectedScript = m_injectedScriptManager.injectedScriptFor(globalObject->globalExec());
     if (injectedScript.hasNoValue()) {
         errorString = "Unable to get object details - InjectedScript"_s;
         return;
     }

     // Function preview.
     if (cell->inherits<JSFunction>(vm)) {
         injectedScript.functionDetails(errorString, cell, functionDetails);
         return;
     }

     // Object preview.
     objectPreview = injectedScript.previewValue(cell);
 }

 void InspectorHeapAgent::getRemoteObject(ErrorString& errorString, int heapObjectId, const String* optionalObjectGroup, RefPtr<Protocol::Runtime::RemoteObject>& result)
 {
     // Prevent the cell from getting collected as we look it up.
     VM& vm = m_environment.vm();
     JSLockHolder lock(vm);
     DeferGC deferGC(vm.heap);

     unsigned heapObjectIdentifier = static_cast<unsigned>(heapObjectId);
     const Optional<HeapSnapshotNode> optionalNode = nodeForHeapObjectIdentifier(errorString, heapObjectIdentifier);
     if (!optionalNode)
         return;

     JSCell* cell = optionalNode->cell;
     Structure* structure = cell->structure(vm);
     if (!structure) {
         errorString = "Unable to get object details"_s;
         return;
     }

     JSGlobalObject* globalObject = structure->globalObject();
     if (!globalObject) {
         errorString = "Unable to get object details"_s;
         return;
     }

     InjectedScript injectedScript = m_injectedScriptManager.injectedScriptFor(globalObject->globalExec());
     if (injectedScript.hasNoValue()) {
         errorString = "Unable to get object details - InjectedScript"_s;
         return;
     }

     String objectGroup = optionalObjectGroup ? *optionalObjectGroup : String();
     result = injectedScript.wrapObject(cell, objectGroup, true);
 }

 static Protocol::Heap::GarbageCollection::Type protocolTypeForHeapOperation(CollectionScope scope)
 {
     switch (scope) {
     case CollectionScope::Full:
         return Protocol::Heap::GarbageCollection::Type::Full;
     case CollectionScope::Eden:
         return Protocol::Heap::GarbageCollection::Type::Partial;
     }
     ASSERT_NOT_REACHED();
     return Protocol::Heap::GarbageCollection::Type::Full;
 }

 void InspectorHeapAgent::willGarbageCollect()
 {
     if (!m_enabled)
         return;

     m_gcStartTime = m_environment.executionStopwatch()->elapsedTime();
 }

 void InspectorHeapAgent::didGarbageCollect(CollectionScope scope)
 {
     if (!m_enabled) {
         m_gcStartTime = Seconds::nan();
         return;
     }

     if (std::isnan(m_gcStartTime)) {
         // We were not enabled when the GC began.
         return;
     }

     // FIXME: Include number of bytes freed by collection.

     Seconds endTime = m_environment.executionStopwatch()->elapsedTime();
     dispatchGarbageCollectedEvent(protocolTypeForHeapOperation(scope), m_gcStartTime, endTime);

     m_gcStartTime = Seconds::nan();
 }

 void InspectorHeapAgent::clearHeapSnapshots()
 {
     VM& vm = m_environment.vm();
     JSLockHolder lock(vm);

     if (HeapProfiler* heapProfiler = vm.heapProfiler()) {
         heapProfiler->clearSnapshots();
         HeapSnapshotBuilder::resetNextAvailableObjectIdentifier();
     }
 }

 void InspectorHeapAgent::dispatchGarbageCollectedEvent(Protocol::Heap::GarbageCollection::Type type, Seconds startTime, Seconds endTime)
 {
     auto protocolObject = Protocol::Heap::GarbageCollection::create()
         .setType(type)
         .setStartTime(startTime.seconds())
         .setEndTime(endTime.seconds())
         .release();

     m_frontendDispatcher->garbageCollected(WTFMove(protocolObject));
 }

 } // namespace Inspector
	/*
	* Copyright (C) 2015-2016 Apple 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 "config.h"
	#include "InspectorHeapAgent.h"

	#include "HeapProfiler.h"
	#include "HeapSnapshot.h"
	#include "InjectedScript.h"
	#include "InjectedScriptManager.h"
	#include "InspectorEnvironment.h"
	#include "JSCInlines.h"
	#include "VM.h"
	#include <wtf/Stopwatch.h>

	using namespace JSC;

	namespace Inspector {

	InspectorHeapAgent::InspectorHeapAgent(AgentContext& context)
	: InspectorAgentBase("Heap"_s)
	, m_injectedScriptManager(context.injectedScriptManager)
	, m_frontendDispatcher(std::make_unique<HeapFrontendDispatcher>(context.frontendRouter))
	, m_backendDispatcher(HeapBackendDispatcher::create(context.backendDispatcher, this))
	, m_environment(context.environment)
	{
	}

	void InspectorHeapAgent::didCreateFrontendAndBackend(FrontendRouter, BackendDispatcher)
	{
	}

	void InspectorHeapAgent::willDestroyFrontendAndBackend(DisconnectReason)
	{
	// Stop tracking without taking a snapshot.
	m_tracking = false;

	ErrorString ignored;
	disable(ignored);
	}

	void InspectorHeapAgent::enable(ErrorString&)
	{
	if (m_enabled)
	return;

	m_enabled = true;

	m_environment.vm().heap.addObserver(this);
	}

	void InspectorHeapAgent::disable(ErrorString&)
	{
	if (!m_enabled)
	return;

	m_enabled = false;

	m_environment.vm().heap.removeObserver(this);

	clearHeapSnapshots();
	}

	void InspectorHeapAgent::gc(ErrorString&)
	{
	VM& vm = m_environment.vm();
	JSLockHolder lock(vm);
	sanitizeStackForVM(&vm);
	vm.heap.collectNow(Sync, CollectionScope::Full);
	}

	void InspectorHeapAgent::snapshot(ErrorString&, double* timestamp, String* snapshotData)
	{
	VM& vm = m_environment.vm();
	JSLockHolder lock(vm);

	HeapSnapshotBuilder snapshotBuilder(vm.ensureHeapProfiler());
	snapshotBuilder.buildSnapshot();

	*timestamp = m_environment.executionStopwatch()->elapsedTime().seconds();
	*snapshotData = snapshotBuilder.json([&] (const HeapSnapshotNode& node) {
	if (Structure* structure = node.cell->structure(vm)) {
	if (JSGlobalObject* globalObject = structure->globalObject()) {
	if (!m_environment.canAccessInspectedScriptState(globalObject->globalExec()))
	return false;
	}
	}
	return true;
	});
	}

	void InspectorHeapAgent::startTracking(ErrorString& errorString)
	{
	if (m_tracking)
	return;

	m_tracking = true;

	double timestamp;
	String snapshotData;
	snapshot(errorString, &timestamp, &snapshotData);

	m_frontendDispatcher->trackingStart(timestamp, snapshotData);
	}

	void InspectorHeapAgent::stopTracking(ErrorString& errorString)
	{
	if (!m_tracking)
	return;

	m_tracking = false;

	double timestamp;
	String snapshotData;
	snapshot(errorString, &timestamp, &snapshotData);

	m_frontendDispatcher->trackingComplete(timestamp, snapshotData);
	}

	Optional<HeapSnapshotNode> InspectorHeapAgent::nodeForHeapObjectIdentifier(ErrorString& errorString, unsigned heapObjectIdentifier)
	{
	HeapProfiler* heapProfiler = m_environment.vm().heapProfiler();
	if (!heapProfiler) {
	errorString = "No heap snapshot"_s;
	return WTF::nullopt;
	}

	HeapSnapshot* snapshot = heapProfiler->mostRecentSnapshot();
	if (!snapshot) {
	errorString = "No heap snapshot"_s;
	return WTF::nullopt;
	}

	const Optional<HeapSnapshotNode> optionalNode = snapshot->nodeForObjectIdentifier(heapObjectIdentifier);
	if (!optionalNode) {
	errorString = "No object for identifier, it may have been collected"_s;
	return WTF::nullopt;
	}

	return optionalNode;
	}

	void InspectorHeapAgent::getPreview(ErrorString& errorString, int heapObjectId, Optional<String>& resultString, RefPtr<Protocol::Debugger::FunctionDetails>& functionDetails, RefPtr<Protocol::Runtime::ObjectPreview>& objectPreview)
	{
	// Prevent the cell from getting collected as we look it up.
	VM& vm = m_environment.vm();
	JSLockHolder lock(vm);
	DeferGC deferGC(vm.heap);

	unsigned heapObjectIdentifier = static_cast<unsigned>(heapObjectId);
	const Optional<HeapSnapshotNode> optionalNode = nodeForHeapObjectIdentifier(errorString, heapObjectIdentifier);
	if (!optionalNode)
	return;

	// String preview.
	JSCell* cell = optionalNode->cell;
	if (cell->isString()) {
	resultString = asString(cell)->tryGetValue();
	return;
	}

	// FIXME: Provide preview information for Internal Objects? CodeBlock, Executable, etc.

	Structure* structure = cell->structure(vm);
	if (!structure) {
	errorString = "Unable to get object details - Structure"_s;
	return;
	}

	JSGlobalObject* globalObject = structure->globalObject();
	if (!globalObject) {
	errorString = "Unable to get object details - GlobalObject"_s;
	return;
	}

	InjectedScript injectedScript = m_injectedScriptManager.injectedScriptFor(globalObject->globalExec());
	if (injectedScript.hasNoValue()) {
	errorString = "Unable to get object details - InjectedScript"_s;
	return;
	}

	// Function preview.
	if (cell->inherits<JSFunction>(vm)) {
	injectedScript.functionDetails(errorString, cell, functionDetails);
	return;
	}

	// Object preview.
	objectPreview = injectedScript.previewValue(cell);
	}

	void InspectorHeapAgent::getRemoteObject(ErrorString& errorString, int heapObjectId, const String* optionalObjectGroup, RefPtr<Protocol::Runtime::RemoteObject>& result)
	{
	// Prevent the cell from getting collected as we look it up.
	VM& vm = m_environment.vm();
	JSLockHolder lock(vm);
	DeferGC deferGC(vm.heap);

	unsigned heapObjectIdentifier = static_cast<unsigned>(heapObjectId);
	const Optional<HeapSnapshotNode> optionalNode = nodeForHeapObjectIdentifier(errorString, heapObjectIdentifier);
	if (!optionalNode)
	return;

	JSCell* cell = optionalNode->cell;
	Structure* structure = cell->structure(vm);
	if (!structure) {
	errorString = "Unable to get object details"_s;
	return;
	}

	JSGlobalObject* globalObject = structure->globalObject();
	if (!globalObject) {
	errorString = "Unable to get object details"_s;
	return;
	}

	InjectedScript injectedScript = m_injectedScriptManager.injectedScriptFor(globalObject->globalExec());
	if (injectedScript.hasNoValue()) {
	errorString = "Unable to get object details - InjectedScript"_s;
	return;
	}

	String objectGroup = optionalObjectGroup ? *optionalObjectGroup : String();
	result = injectedScript.wrapObject(cell, objectGroup, true);
	}

	static Protocol::Heap::GarbageCollection::Type protocolTypeForHeapOperation(CollectionScope scope)
	{
	switch (scope) {
	case CollectionScope::Full:
	return Protocol::Heap::GarbageCollection::Type::Full;
	case CollectionScope::Eden:
	return Protocol::Heap::GarbageCollection::Type::Partial;
	}
	ASSERT_NOT_REACHED();
	return Protocol::Heap::GarbageCollection::Type::Full;
	}

	void InspectorHeapAgent::willGarbageCollect()
	{
	if (!m_enabled)
	return;

	m_gcStartTime = m_environment.executionStopwatch()->elapsedTime();
	}

	void InspectorHeapAgent::didGarbageCollect(CollectionScope scope)
	{
	if (!m_enabled) {
	m_gcStartTime = Seconds::nan();
	return;
	}

	if (std::isnan(m_gcStartTime)) {
	// We were not enabled when the GC began.
	return;
	}

	// FIXME: Include number of bytes freed by collection.

	Seconds endTime = m_environment.executionStopwatch()->elapsedTime();
	dispatchGarbageCollectedEvent(protocolTypeForHeapOperation(scope), m_gcStartTime, endTime);

	m_gcStartTime = Seconds::nan();
	}

	void InspectorHeapAgent::clearHeapSnapshots()
	{
	VM& vm = m_environment.vm();
	JSLockHolder lock(vm);

	if (HeapProfiler* heapProfiler = vm.heapProfiler()) {
	heapProfiler->clearSnapshots();
	HeapSnapshotBuilder::resetNextAvailableObjectIdentifier();
	}
	}

	void InspectorHeapAgent::dispatchGarbageCollectedEvent(Protocol::Heap::GarbageCollection::Type type, Seconds startTime, Seconds endTime)
	{
	auto protocolObject = Protocol::Heap::GarbageCollection::create()
	.setType(type)
	.setStartTime(startTime.seconds())
	.setEndTime(endTime.seconds())
	.release();

	m_frontendDispatcher->garbageCollected(WTFMove(protocolObject));
	}

	} // namespace Inspector