src/kernel/context/ContextBoost.cpp

   1 /* Copyright (c) 2015-2017. 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
   8 #include <utility>
   9 #include <xbt/log.h>
  10
  11 #if HAVE_SANITIZE_ADDRESS_FIBER_SUPPORT
  12 #include <sanitizer/asan_interface.h>
  13 #define ASAN_EVAL(expr) (expr)
  14 #define ASAN_START_SWITCH(fake_stack_save, bottom, size) __sanitizer_start_switch_fiber(fake_stack_save, bottom, size)
  15 #define ASAN_FINISH_SWITCH(fake_stack_save, bottom_old, size_old)                                                      \
  16   __sanitizer_finish_switch_fiber(fake_stack_save, bottom_old, size_old)
  17 #else
  18 #define ASAN_EVAL(expr) (void)0
  19 #define ASAN_START_SWITCH(fake_stack_save, bottom, size) (void)0
  20 #define ASAN_FINISH_SWITCH(fake_stack_save, bottom_old, size_old) (void)(fake_stack_save)
  21 #endif
  22
  23 XBT_LOG_EXTERNAL_DEFAULT_CATEGORY(simix_context);
  24
  25 namespace simgrid {
  26 namespace kernel {
  27 namespace context {
  28
  29 // BoostContextFactory
  30
  31 BoostContextFactory::BoostContextFactory()
  32     : ContextFactory("BoostContextFactory"), parallel_(SIMIX_context_is_parallel())
  33 {
  34   BoostContext::setMaestro(nullptr);
  35   if (parallel_) {
  36 #if HAVE_THREAD_CONTEXTS
  37     ParallelBoostContext::initialize();
  38 #else
  39     xbt_die("No thread support for parallel context execution");
  40 #endif
  41   }
  42 }
  43
  44 BoostContextFactory::~BoostContextFactory()
  45 {
  46 #if HAVE_THREAD_CONTEXTS
  47   if (parallel_)
  48     ParallelBoostContext::finalize();
  49 #endif
  50 }
  51
  52 smx_context_t BoostContextFactory::create_context(std::function<void()> code, void_pfn_smxprocess_t cleanup_func,
  53                                                   smx_actor_t process)
  54 {
  55 #if HAVE_THREAD_CONTEXTS
  56   if (parallel_)
  57     return this->new_context<ParallelBoostContext>(std::move(code), cleanup_func, process);
  58 #endif
  59
  60   return this->new_context<SerialBoostContext>(std::move(code), cleanup_func, process);
  61 }
  62
  63 void BoostContextFactory::run_all()
  64 {
  65 #if HAVE_THREAD_CONTEXTS
  66   if (parallel_)
  67     ParallelBoostContext::run_all();
  68   else
  69 #endif
  70     SerialBoostContext::run_all();
  71 }
  72
  73 // BoostContext
  74
  75 BoostContext* BoostContext::maestro_context_ = nullptr;
  76
  77 BoostContext::BoostContext(std::function<void()> code, void_pfn_smxprocess_t cleanup_func, smx_actor_t process)
  78     : Context(std::move(code), cleanup_func, process)
  79 {
  80
  81   /* if the user provided a function for the process then use it, otherwise it is the context for maestro */
  82   if (has_code()) {
  83     this->stack_ = SIMIX_context_stack_new();
  84     /* We need to pass the bottom of the stack to make_fcontext,
  85        depending on the stack direction it may be the lower or higher address: */
  86 #if PTH_STACKGROWTH == -1
  87     void* stack = static_cast<char*>(this->stack_) + smx_context_usable_stack_size;
  88 #else
  89     void* stack = this->stack_;
  90 #endif
  91     ASAN_EVAL(this->asan_stack_ = stack);
  92 #if BOOST_VERSION < 106100
  93     this->fc_ = boost::context::make_fcontext(stack, smx_context_usable_stack_size, BoostContext::wrapper);
  94 #else
  95     this->fc_ = boost::context::detail::make_fcontext(stack, smx_context_usable_stack_size, BoostContext::wrapper);
  96 #endif
  97   } else {
  98 #if BOOST_VERSION < 105600
  99     this->fc_ = new boost::context::fcontext_t();
 100 #endif
 101     if (BoostContext::maestro_context_ == nullptr)
 102       BoostContext::maestro_context_ = this;
 103   }
 104 }
 105
 106 BoostContext::~BoostContext()
 107 {
 108 #if BOOST_VERSION < 105600
 109   if (not this->stack_)
 110     delete this->fc_;
 111 #endif
 112   if (this == maestro_context_)
 113     maestro_context_ = nullptr;
 114   SIMIX_context_stack_delete(this->stack_);
 115 }
 116
 117 void BoostContext::wrapper(BoostContext::arg_type arg)
 118 {
 119 #if BOOST_VERSION < 106100
 120   BoostContext* context = reinterpret_cast<BoostContext*>(arg);
 121 #else
 122   ASAN_FINISH_SWITCH(nullptr, &static_cast<BoostContext**>(arg.data)[0]->asan_stack_,
 123                      &static_cast<BoostContext**>(arg.data)[0]->asan_stack_size_);
 124   static_cast<BoostContext**>(arg.data)[0]->fc_ = arg.fctx;
 125   BoostContext* context                         = static_cast<BoostContext**>(arg.data)[1];
 126 #endif
 127   try {
 128     (*context)();
 129     context->Context::stop();
 130   } catch (StopRequest const&) {
 131     XBT_DEBUG("Caught a StopRequest");
 132   }
 133   ASAN_EVAL(context->asan_stop_ = true);
 134   context->suspend();
 135 }
 136
 137 inline void BoostContext::swap(BoostContext* from, BoostContext* to)
 138 {
 139 #if BOOST_VERSION < 105600
 140   boost::context::jump_fcontext(from->fc_, to->fc_, reinterpret_cast<intptr_t>(to));
 141 #elif BOOST_VERSION < 106100
 142   boost::context::jump_fcontext(&from->fc_, to->fc_, reinterpret_cast<intptr_t>(to));
 143 #else
 144   BoostContext* ctx[2] = {from, to};
 145   void* fake_stack;
 146   ASAN_START_SWITCH(from->asan_stop_ ? nullptr : &fake_stack, to->asan_stack_, to->asan_stack_size_);
 147   boost::context::detail::transfer_t arg = boost::context::detail::jump_fcontext(to->fc_, ctx);
 148   ASAN_FINISH_SWITCH(fake_stack, &static_cast<BoostContext**>(arg.data)[0]->asan_stack_,
 149                      &static_cast<BoostContext**>(arg.data)[0]->asan_stack_size_);
 150   static_cast<BoostContext**>(arg.data)[0]->fc_ = arg.fctx;
 151 #endif
 152 }
 153
 154 void BoostContext::stop()
 155 {
 156   Context::stop();
 157   throw StopRequest();
 158 }
 159
 160 // SerialBoostContext
 161
 162 unsigned long SerialBoostContext::process_index_;
 163
 164 void SerialBoostContext::suspend()
 165 {
 166   /* determine the next context */
 167   SerialBoostContext* next_context;
 168   unsigned long int i = process_index_;
 169   process_index_++;
 170
 171   if (i < simix_global->process_to_run.size()) {
 172     /* execute the next process */
 173     XBT_DEBUG("Run next process");
 174     next_context = static_cast<SerialBoostContext*>(simix_global->process_to_run[i]->context);
 175   } else {
 176     /* all processes were run, return to maestro */
 177     XBT_DEBUG("No more process to run");
 178     next_context = static_cast<SerialBoostContext*>(BoostContext::getMaestro());
 179   }
 180   SIMIX_context_set_current(next_context);
 181   BoostContext::swap(this, next_context);
 182 }
 183
 184 void SerialBoostContext::resume()
 185 {
 186   SIMIX_context_set_current(this);
 187   BoostContext::swap(BoostContext::getMaestro(), this);
 188 }
 189
 190 void SerialBoostContext::run_all()
 191 {
 192   if (simix_global->process_to_run.empty())
 193     return;
 194   smx_actor_t first_process = simix_global->process_to_run.front();
 195   process_index_            = 1;
 196   /* execute the first process */
 197   static_cast<SerialBoostContext*>(first_process->context)->resume();
 198 }
 199
 200 // ParallelBoostContext
 201
 202 #if HAVE_THREAD_CONTEXTS
 203
 204 simgrid::xbt::Parmap<smx_actor_t>* ParallelBoostContext::parmap_;
 205 uintptr_t ParallelBoostContext::threads_working_;
 206 xbt_os_thread_key_t ParallelBoostContext::worker_id_key_;
 207 std::vector<ParallelBoostContext*> ParallelBoostContext::workers_context_;
 208
 209 void ParallelBoostContext::initialize()
 210 {
 211   parmap_ = nullptr;
 212   workers_context_.clear();
 213   workers_context_.resize(SIMIX_context_get_nthreads(), nullptr);
 214   xbt_os_thread_key_create(&worker_id_key_);
 215 }
 216
 217 void ParallelBoostContext::finalize()
 218 {
 219   delete parmap_;
 220   parmap_ = nullptr;
 221   workers_context_.clear();
 222   xbt_os_thread_key_destroy(worker_id_key_);
 223 }
 224
 225 void ParallelBoostContext::run_all()
 226 {
 227   threads_working_ = 0;
 228   if (parmap_ == nullptr)
 229     parmap_ = new simgrid::xbt::Parmap<smx_actor_t>(SIMIX_context_get_nthreads(), SIMIX_context_get_parallel_mode());
 230   parmap_->apply(
 231       [](smx_actor_t process) {
 232         ParallelBoostContext* context = static_cast<ParallelBoostContext*>(process->context);
 233         context->resume();
 234       },
 235       simix_global->process_to_run);
 236 }
 237
 238 void ParallelBoostContext::suspend()
 239 {
 240   boost::optional<smx_actor_t> next_work = parmap_->next();
 241   ParallelBoostContext* next_context;
 242   if (next_work) {
 243     XBT_DEBUG("Run next process");
 244     next_context = static_cast<ParallelBoostContext*>(next_work.get()->context);
 245   } else {
 246     XBT_DEBUG("No more processes to run");
 247     uintptr_t worker_id = reinterpret_cast<uintptr_t>(xbt_os_thread_get_specific(worker_id_key_));
 248     next_context        = workers_context_[worker_id];
 249   }
 250
 251   SIMIX_context_set_current(next_context);
 252   BoostContext::swap(this, next_context);
 253 }
 254
 255 void ParallelBoostContext::resume()
 256 {
 257   uintptr_t worker_id = __sync_fetch_and_add(&threads_working_, 1);
 258   xbt_os_thread_set_specific(worker_id_key_, reinterpret_cast<void*>(worker_id));
 259
 260   ParallelBoostContext* worker_context = static_cast<ParallelBoostContext*>(SIMIX_context_self());
 261   workers_context_[worker_id]          = worker_context;
 262
 263   SIMIX_context_set_current(this);
 264   BoostContext::swap(worker_context, this);
 265 }
 266
 267 #endif
 268
 269 XBT_PRIVATE ContextFactory* boost_factory()
 270 {
 271   XBT_VERB("Using Boost contexts. Welcome to the 21th century.");
 272   return new BoostContextFactory();
 273 }
 274 }}} // namespace