Create WorkerThread, an abstraction to perform some work on an interval.

handler/crash_report_upload_thread.h

 // Copyright 2015 The Crashpad Authors. All rights reserved.
 //
 // Licensed under the Apache License, Version 2.0 (the "License");
 // you may not use this file except in compliance with the License.
 // You may obtain a copy of the License at
 //
 //     http://www.apache.org/licenses/LICENSE-2.0
 //
 // Unless required by applicable law or agreed to in writing, software
 // distributed under the License is distributed on an "AS IS" BASIS,
 // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 // See the License for the specific language governing permissions and
 // limitations under the License.
 
 #ifndef CRASHPAD_HANDLER_CRASH_REPORT_UPLOAD_THREAD_H_
 #define CRASHPAD_HANDLER_CRASH_REPORT_UPLOAD_THREAD_H_
 
 #include "base/basictypes.h"
 
 #include <string>
 
 #include "base/memory/scoped_ptr.h"
 #include "client/crash_report_database.h"
-#include "util/synchronization/semaphore.h"
+#include "util/thread/worker_thread.h"
 
 namespace crashpad {
 
-namespace internal {
-class CrashReportUploadHelperThread;
-}  // namespace internal
-
 //! \brief A thread that processes pending crash reports in a
 //!     CrashReportDatabase by uploading them or marking them as completed
 //!     without upload, as desired.
 //!
 //! A producer of crash reports should notify an object of this class that a new
 //! report has been added to the database by calling ReportPending().
 //!
 //! Independently of being triggered by ReportPending(), objects of this class
 //! periodically examine the database for pending reports. This allows failed
 //! upload attempts for reports left in the pending state to be retried. It also
 //! catches reports that are added without a ReportPending() signal being
 //! caught. This may happen if crash reports are added to the database by other
 //! processes.
-class CrashReportUploadThread {
+class CrashReportUploadThread : public WorkerThread::Delegate {
  public:
   //! \brief Constructs a new object.
   //!
   //! \param[in] database The database to upload crash reports from.
   //! \param[in] url The URL of the server to upload crash reports to.
   CrashReportUploadThread(CrashReportDatabase* database,
                           const std::string& url);
   ~CrashReportUploadThread();
 
   //! \brief Starts a dedicated upload thread, which executes ThreadMain().
@@ skipping 16 matching lines @@
   //! It is expected to only be called from the same thread that called Start().
   void Stop();
 
   //! \brief Informs the upload thread that a new pending report has been added
   //!     to the database.
   //!
   //! This method may be called from any thread.
   void ReportPending();
 
  private:
-  friend internal::CrashReportUploadHelperThread;
-
   //! \brief The result code from UploadReport().
   enum class UploadResult {
     //! \brief The crash report was uploaded successfully.
     kSuccess,
 
     //! \brief The crash report upload failed in such a way that recovery is
     //!     impossible.
     //!
     //! No further upload attempts should be made for the report.
     kPermanentFailure,
 
     //! \brief The crash report upload failed, but it might succeed again if
     //!     retried in the future.
     //!
     //! If the report has not already been retried too many times, the caller
     //! may arrange to call UploadReport() for the report again in the future,
     //! after a suitable delay.
     kRetry,
   };
 
-  //! \brief Calls ProcessPendingReports() in response to ReportPending() having
-  //!     been called on any thread, as well as periodically on a timer.
-  void ThreadMain();
-
   //! \brief Obtains all pending reports from the database, and calls
   //!     ProcessPendingReport() to process each one.
   void ProcessPendingReports();
 
   //! \brief Processes a single pending report from the database.
   //!
   //! \param[in] report The crash report to process.
   //!
   //! If report upload is enabled, this method attempts to upload \a report by
   //! calling UplaodReport(). If the upload is successful, the report will be
@@ skipping 13 matching lines @@
   //!     CrashReportDatabase::RecordUploadAttempt() after calling this method.
   //! \param[out] response_body If the upload attempt is successful, this will
   //!     be set to the response body sent by the server. Breakpad-type servers
   //!     provide the crash ID assigned by the server in the response body.
   //!
   //! \return A member of UploadResult indicating the result of the upload
   //!    attempt.
   UploadResult UploadReport(const CrashReportDatabase::Report* report,
                             std::string* response_body);
 
+  // WorkerThread::Delegate:
+  //! \brief Calls ProcessPendingReports() in response to ReportPending() having
+  //!     been called on any thread, as well as periodically on a timer.
+  void DoWork(const WorkerThread* thread) override;
+
   std::string url_;
+  WorkerThread thread_;
   CrashReportDatabase* database_;  // weak
-  Semaphore semaphore_;  // TODO(mark): Use a condition variable instead?
-  scoped_ptr<internal::CrashReportUploadHelperThread> thread_;
-  bool running_;
 };
 
 }  // namespace crashpad
 
 #endif  // CRASHPAD_HANDLER_CRASH_REPORT_UPLOAD_THREAD_H_