include/comphelper/threadpool.hxx

   1 /* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*- */
   2 /*
   3  * This file is part of the LibreOffice project.
   4  *
   5  * This Source Code Form is subject to the terms of the Mozilla Public
   6  * License, v. 2.0. If a copy of the MPL was not distributed with this
   7  * file, You can obtain one at http://mozilla.org/MPL/2.0/.
   8  */
   9
  10 #ifndef INCLUDED_COMPHELPER_THREADPOOL_HXX
  11 #define INCLUDED_COMPHELPER_THREADPOOL_HXX
  12
  13 #include <sal/config.h>
  14 #include <salhelper/thread.hxx>
  15 #include <osl/mutex.hxx>
  16 #include <osl/conditn.hxx>
  17 #include <rtl/ref.hxx>
  18 #include <vector>
  19 #include <comphelper/comphelperdllapi.h>
  20
  21 namespace comphelper
  22 {
  23
  24 class COMPHELPER_DLLPUBLIC ThreadTask
  25 {
  26 public:
  27     virtual      ~ThreadTask() {}
  28     virtual void doWork() = 0;
  29 };
  30
  31 /// A very basic thread pool implementation
  32 class COMPHELPER_DLLPUBLIC ThreadPool
  33 {
  34 public:
  35     /// returns a pointer to a shared pool with optimal thread
  36     /// count for the CPU
  37     static      ThreadPool& getSharedOptimalPool();
  38
  39                 ThreadPool( sal_Int32 nWorkers );
  40     virtual    ~ThreadPool();
  41
  42     /// push a new task onto the work queue
  43     void        pushTask( ThreadTask *pTask /* takes ownership */ );
  44
  45     /// wait until all queued tasks are completed
  46     void        waitUntilEmpty();
  47
  48     /// return the number of live worker threads
  49     sal_Int32   getWorkerCount() const { return maWorkers.size(); }
  50
  51 private:
  52     ThreadPool(const ThreadPool&) SAL_DELETED_FUNCTION;
  53     ThreadPool& operator=(const ThreadPool&) SAL_DELETED_FUNCTION;
  54
  55     class ThreadWorker;
  56     friend class ThreadWorker;
  57
  58     /// wait until all work is completed, then join all threads
  59     void        waitAndCleanupWorkers();
  60
  61     ThreadTask *waitForWork( osl::Condition &rNewWork );
  62     ThreadTask *popWork();
  63     void        startWork();
  64     void        stopWork();
  65
  66     osl::Mutex     maGuard;
  67     sal_Int32      mnThreadsWorking;
  68     /// signalled when all in-progress tasks are complete
  69     osl::Condition maTasksComplete;
  70     bool           mbTerminate;
  71     std::vector< rtl::Reference< ThreadWorker > > maWorkers;
  72     std::vector< ThreadTask * >   maTasks;
  73 };
  74
  75 } // namespace comphelper
  76
  77 #endif // INCLUDED_COMPHELPER_THREADPOOL_HXX
  78
  79 /* vim:set shiftwidth=4 softtabstop=4 expandtab: */