src/kernel/activity/BarrierImpl.hpp

   1 /* Copyright (c) 2012-2022. The SimGrid Team. All rights reserved.          */
   2
   3 /* This program is free software; you can redistribute it and/or modify it
   4  * under the terms of the license (GNU LGPL) which comes with this package. */
   5
   6 #ifndef SIMGRID_KERNEL_ACTIVITY_BARRIER_HPP
   7 #define SIMGRID_KERNEL_ACTIVITY_BARRIER_HPP
   8
   9 #include "simgrid/s4u/Barrier.hpp"
  10 #include "src/kernel/activity/ActivityImpl.hpp"
  11 #include "src/kernel/actor/ActorImpl.hpp"
  12 #include "src/kernel/actor/SynchroObserver.hpp"
  13
  14 namespace simgrid {
  15 namespace kernel {
  16 namespace activity {
  17 /** Barrier Acquisition: the act / process of acquiring the barrier.
  18  *
  19  * This is the asynchronous activity associated to Barriers. See the doc of MutexImpl for more details on the rationnal.
  20  */
  21 class XBT_PUBLIC BarrierAcquisitionImpl : public ActivityImpl_T<BarrierAcquisitionImpl> {
  22   actor::ActorImpl* issuer_ = nullptr;
  23   BarrierImpl* barrier_     = nullptr;
  24   bool granted_             = false;
  25
  26   friend actor::BarrierObserver;
  27   friend BarrierImpl;
  28
  29 public:
  30   BarrierAcquisitionImpl(actor::ActorImpl* issuer, BarrierImpl* bar) : issuer_(issuer), barrier_(bar) {}
  31   BarrierImplPtr get_barrier() { return barrier_; }
  32   actor::ActorImpl* get_issuer() { return issuer_; }
  33
  34   bool test(actor::ActorImpl* issuer = nullptr) override;
  35   void wait_for(actor::ActorImpl* issuer, double timeout) override;
  36   void post() override
  37   { /*no surf action*/
  38   }
  39   void finish() override;
  40   void set_exception(actor::ActorImpl* issuer) override
  41   { /* nothing to do */
  42   }
  43 };
  44
  45 class XBT_PUBLIC BarrierImpl {
  46   std::atomic_int_fast32_t refcount_{1};
  47   s4u::Barrier piface_;
  48   unsigned int expected_actors_;
  49   std::deque<BarrierAcquisitionImplPtr> ongoing_acquisitions_;
  50   static unsigned next_id_;
  51   unsigned id_ = next_id_++;
  52
  53   friend BarrierAcquisitionImpl;
  54   friend s4u::Barrier;
  55
  56 public:
  57   explicit BarrierImpl(int expected_actors) : piface_(this), expected_actors_(expected_actors) {}
  58   BarrierImpl(BarrierImpl const&) = delete;
  59   BarrierImpl& operator=(BarrierImpl const&) = delete;
  60
  61   BarrierAcquisitionImplPtr acquire_async(actor::ActorImpl* issuer);
  62   unsigned get_id() const { return id_; }
  63
  64   friend void intrusive_ptr_add_ref(BarrierImpl* barrier)
  65   {
  66     XBT_ATTRIB_UNUSED auto previous = barrier->refcount_.fetch_add(1);
  67     xbt_assert(previous != 0);
  68   }
  69
  70   friend void intrusive_ptr_release(BarrierImpl* barrier)
  71   {
  72     if (barrier->refcount_.fetch_sub(1) == 1)
  73       delete barrier;
  74   }
  75
  76   s4u::Barrier& get_iface() { return piface_; }
  77 };
  78 } // namespace activity
  79 } // namespace kernel
  80 } // namespace simgrid
  81 #endif