[PM] Add a mechanism to emit freezing votes from the UI thread.
Bug: 1144025
Change-Id: I7371085cfca50eb94c55e637597fd8acdf3dae25
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2593767
Commit-Queue: François Doray <[email protected]>
Reviewed-by: François Doray <[email protected]>
Cr-Commit-Position: refs/heads/master@{#838088}
diff --git a/components/performance_manager/freezing/freezing.cc b/components/performance_manager/freezing/freezing.cc
new file mode 100644
index 0000000..90bb84f7
--- /dev/null
+++ b/components/performance_manager/freezing/freezing.cc
@@ -0,0 +1,141 @@
+// Copyright 2020 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.
+
+#include "components/performance_manager/public/freezing/freezing.h"
+
+#include <memory>
+
+#include "base/bind.h"
+#include "base/sequence_checker.h"
+#include "base/sequenced_task_runner.h"
+#include "base/task/post_task.h"
+#include "components/performance_manager/freezing/freezing_vote_aggregator.h"
+#include "components/performance_manager/performance_manager_impl.h"
+#include "components/performance_manager/public/graph/page_node.h"
+#include "components/performance_manager/public/performance_manager.h"
+#include "content/public/browser/web_contents.h"
+
+namespace performance_manager {
+
+namespace freezing {
+
+namespace {
+
+// The counterpart of a FreezingVoteToken that lives on the PM sequence.
+class FreezingVoteTokenPMImpl : public PageNode::ObserverDefaultImpl {
+ public:
+ FreezingVoteTokenPMImpl(content::WebContents* content,
+ FreezingVoteValue vote_value,
+ const char* vote_reason);
+ ~FreezingVoteTokenPMImpl() override;
+ FreezingVoteTokenPMImpl(const FreezingVoteTokenPMImpl& other) = delete;
+ FreezingVoteTokenPMImpl& operator=(const FreezingVoteTokenPMImpl&) = delete;
+
+ // PageNodeObserver:
+ void OnBeforePageNodeRemoved(const PageNode* page_node) override;
+
+ private:
+ const PageNode* page_node_ = nullptr;
+ Graph* graph_ = nullptr;
+
+ // Voting channel wrapper. This objects should only be used on the PM
+ // sequence.
+ std::unique_ptr<FreezingVotingChannelWrapper> voter_;
+
+ SEQUENCE_CHECKER(sequence_checker_);
+};
+
+// Concrete implementation of a FreezingVoteToken.
+class FreezingVoteTokenImpl : public FreezingVoteToken {
+ public:
+ FreezingVoteTokenImpl(content::WebContents* content,
+ FreezingVoteValue vote_value,
+ const char* vote_reason);
+ ~FreezingVoteTokenImpl() override;
+ FreezingVoteTokenImpl(const FreezingVoteTokenImpl& other) = delete;
+ FreezingVoteTokenImpl& operator=(const FreezingVoteTokenImpl&) = delete;
+
+ private:
+ // Voting channel wrapper. This objects should only be used on the PM
+ // sequence.
+ std::unique_ptr<FreezingVoteTokenPMImpl, base::OnTaskRunnerDeleter> pm_impl_;
+};
+
+} // namespace
+
+FreezingVoteToken::FreezingVoteToken() = default;
+FreezingVoteToken::~FreezingVoteToken() = default;
+
+FreezingVoteTokenPMImpl::FreezingVoteTokenPMImpl(content::WebContents* content,
+ FreezingVoteValue vote_value,
+ const char* vote_reason) {
+ DETACH_FROM_SEQUENCE(sequence_checker_);
+ // Register the vote on the PM sequence.
+ PerformanceManager::CallOnGraph(
+ FROM_HERE,
+ base::BindOnce(
+ [](base::WeakPtr<PageNode> page_node, FreezingVoteValue vote_value,
+ const char* vote_reason, FreezingVoteTokenPMImpl* voter_pm_impl,
+ Graph* graph) {
+ voter_pm_impl->voter_ =
+ std::make_unique<FreezingVotingChannelWrapper>();
+ voter_pm_impl->graph_ = graph;
+ graph->AddPageNodeObserver(voter_pm_impl);
+ voter_pm_impl->voter_->SetVotingChannel(
+ graph->GetRegisteredObjectAs<FreezingVoteAggregator>()
+ ->GetVotingChannel());
+ if (page_node) {
+ voter_pm_impl->voter_->SubmitVote(page_node.get(),
+ {vote_value, vote_reason});
+ voter_pm_impl->page_node_ = page_node.get();
+ }
+ },
+ PerformanceManager::GetPageNodeForWebContents(content), vote_value,
+ // It's safe to use Unretained because |vote_reason| is a static
+ // string.
+ base::Unretained(vote_reason),
+ // It's safe to use Unretained because |this| can only be deleted
+ // from a task running on the PM sequence after this callback.
+ base::Unretained(this)));
+}
+
+FreezingVoteTokenPMImpl::~FreezingVoteTokenPMImpl() {
+ DCHECK_CALLED_ON_VALID_SEQUENCE(sequence_checker_);
+ if (graph_)
+ graph_->RemovePageNodeObserver(this);
+}
+
+void FreezingVoteTokenPMImpl::OnBeforePageNodeRemoved(
+ const PageNode* page_node) {
+ DCHECK_CALLED_ON_VALID_SEQUENCE(sequence_checker_);
+ if (page_node == page_node_) {
+ // Invalidate the vote if its associated page node is destroyed. This can
+ // happen if a freezing vote token is released after the destruction of the
+ // WebContents it's associated with.
+ voter_->InvalidateVote(page_node);
+ page_node_ = nullptr;
+ graph_->RemovePageNodeObserver(this);
+ graph_ = nullptr;
+ }
+}
+
+FreezingVoteTokenImpl::FreezingVoteTokenImpl(content::WebContents* content,
+ FreezingVoteValue vote_value,
+ const char* vote_reason)
+ : pm_impl_(new FreezingVoteTokenPMImpl(content, vote_value, vote_reason),
+ base::OnTaskRunnerDeleter(PerformanceManager::GetTaskRunner())) {
+}
+
+FreezingVoteTokenImpl::~FreezingVoteTokenImpl() = default;
+
+std::unique_ptr<FreezingVoteToken> EmitFreezingVoteForWebContents(
+ content::WebContents* content,
+ FreezingVoteValue vote_value,
+ const char* vote_reason) {
+ return std::make_unique<FreezingVoteTokenImpl>(content, vote_value,
+ vote_reason);
+}
+
+} // namespace freezing
+} // namespace performance_manager
\ No newline at end of file
