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::kernel::activity {
  15 /** Barrier Acquisition: the act / process of acquiring the barrier.
  16  *
  17  * This is the asynchronous activity associated to Barriers. See the doc of MutexImpl for more details on the rationnal.
  18  */
  19 class XBT_PUBLIC BarrierAcquisitionImpl : public ActivityImpl_T<BarrierAcquisitionImpl> {
  20   actor::ActorImpl* issuer_ = nullptr;
  21   BarrierImpl* barrier_     = nullptr;
  22   bool granted_             = false;
  23
  24   friend actor::BarrierObserver;
  25   friend BarrierImpl;
  26
  27 public:
  28   BarrierAcquisitionImpl(actor::ActorImpl* issuer, BarrierImpl* bar) : issuer_(issuer), barrier_(bar) {}
  29   BarrierImplPtr get_barrier() { return barrier_; }
  30   actor::ActorImpl* get_issuer() { return issuer_; }
  31
  32   bool test(actor::ActorImpl* issuer = nullptr) override;
  33   void wait_for(actor::ActorImpl* issuer, double timeout) override;
  34   void post() override
  35   { /*no surf action*/
  36   }
  37   void finish() override;
  38   void set_exception(actor::ActorImpl* issuer) override
  39   { /* nothing to do */
  40   }
  41 };
  42
  43 class XBT_PUBLIC BarrierImpl {
  44   std::atomic_int_fast32_t refcount_{1};
  45   s4u::Barrier piface_;
  46   unsigned int expected_actors_;
  47   std::deque<BarrierAcquisitionImplPtr> ongoing_acquisitions_;
  48   static unsigned next_id_;
  49   unsigned id_ = next_id_++;
  50
  51   friend BarrierAcquisitionImpl;
  52   friend s4u::Barrier;
  53
  54 public:
  55   explicit BarrierImpl(int expected_actors) : piface_(this), expected_actors_(expected_actors) {}
  56   BarrierImpl(BarrierImpl const&) = delete;
  57   BarrierImpl& operator=(BarrierImpl const&) = delete;
  58
  59   BarrierAcquisitionImplPtr acquire_async(actor::ActorImpl* issuer);
  60   unsigned get_id() const { return id_; }
  61
  62   friend void intrusive_ptr_add_ref(BarrierImpl* barrier)
  63   {
  64     XBT_ATTRIB_UNUSED auto previous = barrier->refcount_.fetch_add(1);
  65     xbt_assert(previous != 0);
  66   }
  67
  68   friend void intrusive_ptr_release(BarrierImpl* barrier)
  69   {
  70     if (barrier->refcount_.fetch_sub(1) == 1)
  71       delete barrier;
  72   }
  73
  74   s4u::Barrier& get_iface() { return piface_; }
  75
  76   std::string to_string() const
  77   {
  78     return xbt::string_printf("Barrier %u: %zu of %u", id_, ongoing_acquisitions_.size(), expected_actors_);
  79   }
  80 };
  81 } // namespace simgrid::kernel::activity
  82 #endif