update_engine: Pass Action ownership to ActionProcessor

Currently, an object that uses an ActionProcessor for processing one or more
actions has to own the Actions. This is problematic, because if we want to
create an action on the fly and use an ActionProcessor to perform it, we have to
own the Action until it is finished. Furthermore, if someone forget to own the
action, there will be memory leaks because ActionProcessor does not delete the
Action.

This patch passes the ownership of the Actions to the ActionProcessor through
unique pointers. If an object wants to have access to the Action, it can get it
when ActionComplete() is called.

BUG=chromium:807976
TEST=unittests
TEST=cros flash
TEST=precq

Change-Id: I28f7e9fd3425f17cc51b4db4a4abc130a7d6ef8f
Reviewed-on: https://chromium-review.googlesource.com/1065113
Commit-Ready: Amin Hassani <ahassani@chromium.org>
Tested-by: Amin Hassani <ahassani@chromium.org>
Reviewed-by: Xiaochu Liu <xiaochu@chromium.org>

1 files changed, 14 insertions, 14 deletions

diff --git a/common/action_processor.cc b/common/action_processor.cc
index 3549e080..ead99c44 100644
--- a/common/action_processor.cc
+++ b/common/action_processor.cc
@@ -17,6 +17,7 @@
 #include "update_engine/common/action_processor.h"
 
 #include <string>
+#include <utility>
 
 #include <base/logging.h>
 
@@ -24,27 +25,30 @@
 #include "update_engine/common/error_code_utils.h"
 
 using std::string;
+using std::unique_ptr;
 
 namespace chromeos_update_engine {
 
 ActionProcessor::~ActionProcessor() {
   if (IsRunning())
     StopProcessing();
-  for (auto action : actions_)
-    action->SetProcessor(nullptr);
 }
 
-void ActionProcessor::EnqueueAction(AbstractAction* action) {
-  actions_.push_back(action);
+void ActionProcessor::EnqueueAction(unique_ptr<AbstractAction> action) {
   action->SetProcessor(this);
+  actions_.push_back(std::move(action));
+}
+
+bool ActionProcessor::IsRunning() const {
+  return current_action_ != nullptr || suspended_;
 }
 
 void ActionProcessor::StartProcessing() {
   CHECK(!IsRunning());
   if (!actions_.empty()) {
-    current_action_ = actions_.front();
-    LOG(INFO) << "ActionProcessor: starting " << current_action_->Type();
+    current_action_ = std::move(actions_.front());
     actions_.pop_front();
+    LOG(INFO) << "ActionProcessor: starting " << current_action_->Type();
     current_action_->PerformAction();
   }
 }
@@ -53,16 +57,13 @@ void ActionProcessor::StopProcessing() {
   CHECK(IsRunning());
   if (current_action_) {
     current_action_->TerminateProcessing();
-    current_action_->SetProcessor(nullptr);
   }
   LOG(INFO) << "ActionProcessor: aborted "
             << (current_action_ ? current_action_->Type() : "")
             << (suspended_ ? " while suspended" : "");
-  current_action_ = nullptr;
+  current_action_.reset();
   suspended_ = false;
   // Delete all the actions before calling the delegate.
-  for (auto action : actions_)
-    action->SetProcessor(nullptr);
   actions_.clear();
   if (delegate_)
     delegate_->ProcessingStopped(this);
@@ -106,13 +107,12 @@ void ActionProcessor::ResumeProcessing() {
 
 void ActionProcessor::ActionComplete(AbstractAction* actionptr,
                                      ErrorCode code) {
-  CHECK_EQ(actionptr, current_action_);
+  CHECK_EQ(actionptr, current_action_.get());
   if (delegate_)
     delegate_->ActionCompleted(this, actionptr, code);
   string old_type = current_action_->Type();
   current_action_->ActionCompleted(code);
-  current_action_->SetProcessor(nullptr);
-  current_action_ = nullptr;
+  current_action_.reset();
   LOG(INFO) << "ActionProcessor: finished "
             << (actions_.empty() ? "last action " : "") << old_type
             << (suspended_ ? " while suspended" : "")
@@ -138,7 +138,7 @@ void ActionProcessor::StartNextActionOrFinish(ErrorCode code) {
     }
     return;
   }
-  current_action_ = actions_.front();
+  current_action_ = std::move(actions_.front());
   actions_.pop_front();
   LOG(INFO) << "ActionProcessor: starting " << current_action_->Type();
   current_action_->PerformAction();