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