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