Updater: Introduce a queue of tasks in UpdateServiceInternalImpl.

Bug: 1148839
Change-Id: I79e98003e07ad15fbdf507e03aecd8699ee9d826
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2569103Reviewed-by: Sorin Jianu <sorin@chromium.org>
Reviewed-by: Joshua Pawlicki <waffles@chromium.org>
Commit-Queue: Mila Green <milagreen@chromium.org>
Cr-Commit-Position: refs/heads/master@{#834528}

chrome/updater/update_service_internal_impl.h

@@ -10,21 +10,16 @@
 
 #include "base/callback.h"
 #include "base/callback_forward.h"
+#include "base/containers/queue.h"
 #include "base/files/file_path.h"
 #include "base/memory/scoped_refptr.h"
 #include "base/sequence_checker.h"
 #include "base/version.h"
 #include "chrome/updater/update_service_internal.h"
 
-namespace update_client {
-enum class Error;
-class UpdateClient;
-}  // namespace update_client
-
 namespace updater {
 
 class Configurator;
-class PersistedData;
 
 // All functions and callbacks must be called on the same sequence.
 class UpdateServiceInternalImpl : public UpdateServiceInternal {
@@ -38,68 +33,30 @@ class UpdateServiceInternalImpl : public UpdateServiceInternal {
 
   void Uninitialize() override;
 
- private:
-  ~UpdateServiceInternalImpl() override;
-
-  SEQUENCE_CHECKER(sequence_checker_);
+  class Task : public base::RefCountedThreadSafe<Task> {
+   public:
+    virtual void Run() = 0;
 
-  struct AppInfo {
-    AppInfo(const std::string& app_id,
-            const base::Version& app_version,
-            const base::FilePath& ecp)
-        : app_id_(app_id), app_version_(app_version), ecp_(ecp) {}
-    std::string app_id_;
-    base::Version app_version_;
-    base::FilePath ecp_;
-  };
+   protected:
+    friend class base::RefCountedThreadSafe<Task>;
 
-  struct PingInfo {
-    PingInfo(const std::string& app_id,
-             const base::Version& app_version,
-             int ping_reason)
-        : app_id_(app_id),
-          app_version_(app_version),
-          ping_reason_(ping_reason) {}
-    std::string app_id_;
-    base::Version app_version_;
-    int ping_reason_;
+    virtual ~Task() = default;
   };
 
-  // Checks for updates of all registered applications if it has been longer
-  // than the last check time by NextCheckDelay() amount defined in the config.
-  void MaybeCheckForUpdates();
-
-  // Returns a list of apps registered with the updater.
-  std::vector<AppInfo> GetRegisteredApps();
-
-  void UnregisterMissingAppsDone();
+  // Callback to run after a `Task` has finished.
+  void TaskDone(base::OnceClosure callback);
 
-  // Provides a way to remove apps from the persisted data if the app is no
-  // longer installed on the machine.
-  void UnregisterMissingApps(const std::vector<AppInfo>& apps);
-
-  // After an uninstall ping has been processed, reduces the number of pings
-  // that we need to wait on before checking for updates.
-  void UninstallPingSent(update_client::Error error);
-
-  // Returns true if there are uninstall ping tasks which haven't finished.
-  // Returns false if |number_of_pings_remaining_| is 0.
-  bool WaitingOnUninstallPings() const;
-
-  // Returns a list of apps that need to be unregistered.
-  std::vector<UpdateServiceInternalImpl::PingInfo> GetAppIDsToRemove(
-      const std::vector<AppInfo>& apps);
+ private:
+  ~UpdateServiceInternalImpl() override;
 
-  // Unregisters the apps in |app_ids_to_remove| and starts an update check
-  // if necessary.
-  void RemoveAppIDsAndSendUninstallPings(
-      const std::vector<PingInfo>& app_ids_to_remove);
+  void RunNextTask();
 
+  SEQUENCE_CHECKER(sequence_checker_);
   scoped_refptr<updater::Configurator> config_;
-  scoped_refptr<updater::PersistedData> persisted_data_;
-  scoped_refptr<update_client::UpdateClient> update_client_;
-  base::OnceClosure callback_;
-  int number_of_pings_remaining_;
+
+  // The queue prevents multiple Task instances from running simultaneously and
+  // processes them sequentially.
+  base::queue<scoped_refptr<Task>> tasks_;
 };
 
 }  // namespace updater