src/kernel/context/ContextBoost.cpp

   1 /* Copyright (c) 2015-2018. 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 #include "ContextBoost.hpp"
   7 #include "context_private.hpp"
   8 #include "simgrid/Exception.hpp"
   9 #include "src/simix/smx_private.hpp"
  10
  11 XBT_LOG_EXTERNAL_DEFAULT_CATEGORY(simix_context);
  12
  13 namespace simgrid {
  14 namespace kernel {
  15 namespace context {
  16
  17 // BoostContextFactory
  18
  19 BoostContextFactory::BoostContextFactory()
  20     : ContextFactory("BoostContextFactory"), parallel_(SIMIX_context_is_parallel())
  21 {
  22   BoostContext::set_maestro(nullptr);
  23   if (parallel_)
  24     ParallelBoostContext::initialize();
  25 }
  26
  27 BoostContextFactory::~BoostContextFactory()
  28 {
  29   if (parallel_)
  30     ParallelBoostContext::finalize();
  31 }
  32
  33 smx_context_t BoostContextFactory::create_context(std::function<void()> code, void_pfn_smxprocess_t cleanup_func,
  34                                                   smx_actor_t process)
  35 {
  36   if (parallel_)
  37     return this->new_context<ParallelBoostContext>(std::move(code), cleanup_func, process);
  38   return this->new_context<BoostContext>(std::move(code), cleanup_func, process);
  39 }
  40
  41 void BoostContextFactory::run_all()
  42 {
  43   if (parallel_)
  44     ParallelBoostContext::run_all();
  45   else
  46     SwappedContext::run_all();
  47 }
  48
  49 // BoostContext
  50
  51 BoostContext::BoostContext(std::function<void()> code, void_pfn_smxprocess_t cleanup_func, smx_actor_t process)
  52     : SwappedContext(std::move(code), cleanup_func, process)
  53 {
  54
  55   /* if the user provided a function for the process then use it, otherwise it is the context for maestro */
  56   if (has_code()) {
  57     /* We need to pass the bottom of the stack to make_fcontext,
  58        depending on the stack direction it may be the lower or higher address: */
  59 #if PTH_STACKGROWTH == -1
  60     void* stack = static_cast<char*>(this->stack_) + smx_context_usable_stack_size;
  61 #else
  62     void* stack = this->stack_;
  63 #endif
  64     ASAN_ONLY(this->asan_stack_ = stack);
  65 #if BOOST_VERSION < 106100
  66     this->fc_ = boost::context::make_fcontext(stack, smx_context_usable_stack_size, BoostContext::wrapper);
  67 #else
  68     this->fc_ = boost::context::detail::make_fcontext(stack, smx_context_usable_stack_size, BoostContext::wrapper);
  69 #endif
  70   } else {
  71 #if BOOST_VERSION < 105600
  72     this->fc_ = new boost::context::fcontext_t();
  73 #endif
  74     if (get_maestro() == nullptr)
  75       set_maestro(this);
  76   }
  77 }
  78
  79 BoostContext::~BoostContext()
  80 {
  81 #if BOOST_VERSION < 105600
  82   if (not this->stack_)
  83     delete this->fc_;
  84 #endif
  85   if (this == get_maestro())
  86     set_maestro(nullptr);
  87 }
  88
  89 void BoostContext::wrapper(BoostContext::arg_type arg)
  90 {
  91 #if BOOST_VERSION < 106100
  92   BoostContext* context = reinterpret_cast<BoostContext*>(arg);
  93 #else
  94   BoostContext* context = static_cast<BoostContext**>(arg.data)[1];
  95   ASAN_ONLY(xbt_assert(context->asan_ctx_ == static_cast<BoostContext**>(arg.data)[0]));
  96   ASAN_FINISH_SWITCH(nullptr, &context->asan_ctx_->asan_stack_, &context->asan_ctx_->asan_stack_size_);
  97   static_cast<BoostContext**>(arg.data)[0]->fc_ = arg.fctx;
  98 #endif
  99   try {
 100     (*context)();
 101   } catch (StopRequest const&) {
 102     XBT_DEBUG("Caught a StopRequest");
 103   } catch (simgrid::Exception const& e) {
 104     XBT_INFO("Actor killed by an uncatched exception %s", simgrid::xbt::demangle(typeid(e).name()).get());
 105     throw;
 106   }
 107   context->Context::stop();
 108   ASAN_ONLY(context->asan_stop_ = true);
 109   context->suspend();
 110 }
 111
 112 void BoostContext::swap_into(SwappedContext* to_)
 113 {
 114   BoostContext* to = static_cast<BoostContext*>(to_);
 115 #if BOOST_VERSION < 105600
 116   boost::context::jump_fcontext(this->fc_, to->fc_, reinterpret_cast<intptr_t>(to));
 117 #elif BOOST_VERSION < 106100
 118   boost::context::jump_fcontext(&this->fc_, to->fc_, reinterpret_cast<intptr_t>(to));
 119 #else
 120   BoostContext* ctx[2] = {this, to};
 121   ASAN_ONLY(void* fake_stack = nullptr);
 122   ASAN_ONLY(to->asan_ctx_ = from);
 123   ASAN_START_SWITCH(from->asan_stop_ ? nullptr : &fake_stack, to->asan_stack_, to->asan_stack_size_);
 124   boost::context::detail::transfer_t arg = boost::context::detail::jump_fcontext(to->fc_, ctx);
 125   ASAN_ONLY(xbt_assert(from->asan_ctx_ == static_cast<BoostContext**>(arg.data)[0]));
 126   ASAN_FINISH_SWITCH(fake_stack, &from->asan_ctx_->asan_stack_, &from->asan_ctx_->asan_stack_size_);
 127   static_cast<BoostContext**>(arg.data)[0]->fc_ = arg.fctx;
 128 #endif
 129 }
 130
 131 void BoostContext::stop()
 132 {
 133   Context::stop();
 134   throw StopRequest();
 135 }
 136
 137 // ParallelBoostContext
 138
 139 simgrid::xbt::Parmap<smx_actor_t>* ParallelBoostContext::parmap_;
 140 std::atomic<uintptr_t> ParallelBoostContext::threads_working_;
 141 thread_local uintptr_t ParallelBoostContext::worker_id_;
 142 std::vector<ParallelBoostContext*> ParallelBoostContext::workers_context_;
 143
 144 void ParallelBoostContext::initialize()
 145 {
 146   parmap_ = nullptr;
 147   workers_context_.clear();
 148   workers_context_.resize(SIMIX_context_get_nthreads(), nullptr);
 149 }
 150
 151 void ParallelBoostContext::finalize()
 152 {
 153   delete parmap_;
 154   parmap_ = nullptr;
 155   workers_context_.clear();
 156 }
 157
 158 void ParallelBoostContext::run_all()
 159 {
 160   threads_working_ = 0;
 161   if (parmap_ == nullptr)
 162     parmap_ = new simgrid::xbt::Parmap<smx_actor_t>(SIMIX_context_get_nthreads(), SIMIX_context_get_parallel_mode());
 163   parmap_->apply(
 164       [](smx_actor_t process) {
 165         ParallelBoostContext* context = static_cast<ParallelBoostContext*>(process->context_);
 166         context->resume();
 167       },
 168       simix_global->process_to_run);
 169 }
 170
 171 void ParallelBoostContext::suspend()
 172 {
 173   boost::optional<smx_actor_t> next_work = parmap_->next();
 174   ParallelBoostContext* next_context;
 175   if (next_work) {
 176     XBT_DEBUG("Run next process");
 177     next_context = static_cast<ParallelBoostContext*>(next_work.get()->context_);
 178   } else {
 179     XBT_DEBUG("No more processes to run");
 180     next_context = workers_context_[worker_id_];
 181   }
 182
 183   Context::set_current(next_context);
 184   this->swap_into(next_context);
 185 }
 186
 187 void ParallelBoostContext::resume()
 188 {
 189   worker_id_ = threads_working_.fetch_add(1, std::memory_order_relaxed);
 190
 191   ParallelBoostContext* worker_context = static_cast<ParallelBoostContext*>(self());
 192   workers_context_[worker_id_]         = worker_context;
 193
 194   Context::set_current(this);
 195   worker_context->swap_into(this);
 196 }
 197
 198
 199 XBT_PRIVATE ContextFactory* boost_factory()
 200 {
 201   XBT_VERB("Using Boost contexts. Welcome to the 21th century.");
 202   return new BoostContextFactory();
 203 }
 204 }}} // namespace