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<SerialBoostContext>(std::move(code), cleanup_func, process);
  39 }
  40
  41 void BoostContextFactory::run_all()
  42 {
  43   if (parallel_)
  44     ParallelBoostContext::run_all();
  45   else
  46     SerialBoostContext::run_all();
  47 }
  48
  49 // BoostContext
  50
  51 BoostContext* BoostContext::maestro_context_ = nullptr;
  52
  53 BoostContext::BoostContext(std::function<void()> code, void_pfn_smxprocess_t cleanup_func, smx_actor_t process)
  54     : Context(std::move(code), cleanup_func, process)
  55 {
  56
  57   /* if the user provided a function for the process then use it, otherwise it is the context for maestro */
  58   if (has_code()) {
  59     this->stack_ = SIMIX_context_stack_new();
  60     /* We need to pass the bottom of the stack to make_fcontext,
  61        depending on the stack direction it may be the lower or higher address: */
  62 #if PTH_STACKGROWTH == -1
  63     void* stack = static_cast<char*>(this->stack_) + smx_context_usable_stack_size;
  64 #else
  65     void* stack = this->stack_;
  66 #endif
  67     ASAN_ONLY(this->asan_stack_ = stack);
  68 #if BOOST_VERSION < 106100
  69     this->fc_ = boost::context::make_fcontext(stack, smx_context_usable_stack_size, BoostContext::wrapper);
  70 #else
  71     this->fc_ = boost::context::detail::make_fcontext(stack, smx_context_usable_stack_size, BoostContext::wrapper);
  72 #endif
  73   } else {
  74 #if BOOST_VERSION < 105600
  75     this->fc_ = new boost::context::fcontext_t();
  76 #endif
  77     if (BoostContext::maestro_context_ == nullptr)
  78       BoostContext::maestro_context_ = this;
  79   }
  80 }
  81
  82 BoostContext::~BoostContext()
  83 {
  84 #if BOOST_VERSION < 105600
  85   if (not this->stack_)
  86     delete this->fc_;
  87 #endif
  88   if (this == maestro_context_)
  89     maestro_context_ = nullptr;
  90   SIMIX_context_stack_delete(this->stack_);
  91 }
  92
  93 void BoostContext::wrapper(BoostContext::arg_type arg)
  94 {
  95 #if BOOST_VERSION < 106100
  96   BoostContext* context = reinterpret_cast<BoostContext*>(arg);
  97 #else
  98   BoostContext* context = static_cast<BoostContext**>(arg.data)[1];
  99   ASAN_ONLY(xbt_assert(context->asan_ctx_ == static_cast<BoostContext**>(arg.data)[0]));
 100   ASAN_FINISH_SWITCH(nullptr, &context->asan_ctx_->asan_stack_, &context->asan_ctx_->asan_stack_size_);
 101   static_cast<BoostContext**>(arg.data)[0]->fc_ = arg.fctx;
 102 #endif
 103   try {
 104     (*context)();
 105   } catch (StopRequest const&) {
 106     XBT_DEBUG("Caught a StopRequest");
 107   } catch (simgrid::Exception const& e) {
 108     XBT_INFO("Actor killed by an uncatched exception %s", simgrid::xbt::demangle(typeid(e).name()).get());
 109     throw;
 110   }
 111   context->Context::stop();
 112   ASAN_ONLY(context->asan_stop_ = true);
 113   context->suspend();
 114 }
 115
 116 inline void BoostContext::swap(BoostContext* from, BoostContext* to)
 117 {
 118 #if BOOST_VERSION < 105600
 119   boost::context::jump_fcontext(from->fc_, to->fc_, reinterpret_cast<intptr_t>(to));
 120 #elif BOOST_VERSION < 106100
 121   boost::context::jump_fcontext(&from->fc_, to->fc_, reinterpret_cast<intptr_t>(to));
 122 #else
 123   BoostContext* ctx[2] = {from, to};
 124   ASAN_ONLY(void* fake_stack = nullptr);
 125   ASAN_ONLY(to->asan_ctx_ = from);
 126   ASAN_START_SWITCH(from->asan_stop_ ? nullptr : &fake_stack, to->asan_stack_, to->asan_stack_size_);
 127   boost::context::detail::transfer_t arg = boost::context::detail::jump_fcontext(to->fc_, ctx);
 128   ASAN_ONLY(xbt_assert(from->asan_ctx_ == static_cast<BoostContext**>(arg.data)[0]));
 129   ASAN_FINISH_SWITCH(fake_stack, &from->asan_ctx_->asan_stack_, &from->asan_ctx_->asan_stack_size_);
 130   static_cast<BoostContext**>(arg.data)[0]->fc_ = arg.fctx;
 131 #endif
 132 }
 133
 134 void BoostContext::stop()
 135 {
 136   Context::stop();
 137   throw StopRequest();
 138 }
 139
 140 // SerialBoostContext
 141
 142 unsigned long SerialBoostContext::process_index_;
 143
 144 void SerialBoostContext::suspend()
 145 {
 146   /* determine the next context */
 147   SerialBoostContext* next_context;
 148   unsigned long int i = process_index_;
 149   process_index_++;
 150
 151   if (i < simix_global->process_to_run.size()) {
 152     /* execute the next process */
 153     XBT_DEBUG("Run next process");
 154     next_context = static_cast<SerialBoostContext*>(simix_global->process_to_run[i]->context_);
 155   } else {
 156     /* all processes were run, return to maestro */
 157     XBT_DEBUG("No more process to run");
 158     next_context = static_cast<SerialBoostContext*>(BoostContext::get_maestro());
 159   }
 160   Context::set_current(next_context);
 161   BoostContext::swap(this, next_context);
 162 }
 163
 164 void SerialBoostContext::resume()
 165 {
 166   BoostContext* old = static_cast<BoostContext*>(self());
 167   Context::set_current(this);
 168   BoostContext::swap(old, this);
 169 }
 170
 171 void SerialBoostContext::run_all()
 172 {
 173   if (simix_global->process_to_run.empty())
 174     return;
 175   smx_actor_t first_process = simix_global->process_to_run.front();
 176   process_index_            = 1;
 177   /* execute the first process */
 178   static_cast<SerialBoostContext*>(first_process->context_)->resume();
 179 }
 180
 181 // ParallelBoostContext
 182
 183 simgrid::xbt::Parmap<smx_actor_t>* ParallelBoostContext::parmap_;
 184 std::atomic<uintptr_t> ParallelBoostContext::threads_working_;
 185 thread_local uintptr_t ParallelBoostContext::worker_id_;
 186 std::vector<ParallelBoostContext*> ParallelBoostContext::workers_context_;
 187
 188 void ParallelBoostContext::initialize()
 189 {
 190   parmap_ = nullptr;
 191   workers_context_.clear();
 192   workers_context_.resize(SIMIX_context_get_nthreads(), nullptr);
 193 }
 194
 195 void ParallelBoostContext::finalize()
 196 {
 197   delete parmap_;
 198   parmap_ = nullptr;
 199   workers_context_.clear();
 200 }
 201
 202 void ParallelBoostContext::run_all()
 203 {
 204   threads_working_ = 0;
 205   if (parmap_ == nullptr)
 206     parmap_ = new simgrid::xbt::Parmap<smx_actor_t>(SIMIX_context_get_nthreads(), SIMIX_context_get_parallel_mode());
 207   parmap_->apply(
 208       [](smx_actor_t process) {
 209         ParallelBoostContext* context = static_cast<ParallelBoostContext*>(process->context_);
 210         context->resume();
 211       },
 212       simix_global->process_to_run);
 213 }
 214
 215 void ParallelBoostContext::suspend()
 216 {
 217   boost::optional<smx_actor_t> next_work = parmap_->next();
 218   ParallelBoostContext* next_context;
 219   if (next_work) {
 220     XBT_DEBUG("Run next process");
 221     next_context = static_cast<ParallelBoostContext*>(next_work.get()->context_);
 222   } else {
 223     XBT_DEBUG("No more processes to run");
 224     next_context = workers_context_[worker_id_];
 225   }
 226
 227   Context::set_current(next_context);
 228   BoostContext::swap(this, next_context);
 229 }
 230
 231 void ParallelBoostContext::resume()
 232 {
 233   worker_id_ = threads_working_.fetch_add(1, std::memory_order_relaxed);
 234
 235   ParallelBoostContext* worker_context = static_cast<ParallelBoostContext*>(self());
 236   workers_context_[worker_id_]         = worker_context;
 237
 238   Context::set_current(this);
 239   BoostContext::swap(worker_context, this);
 240 }
 241
 242
 243 XBT_PRIVATE ContextFactory* boost_factory()
 244 {
 245   XBT_VERB("Using Boost contexts. Welcome to the 21th century.");
 246   return new BoostContextFactory();
 247 }
 248 }}} // namespace