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")
  33 {
  34   BoostContext::parallel_ = SIMIX_context_is_parallel();
  35   if (BoostContext::parallel_) {
  36 #if HAVE_THREAD_CONTEXTS
  37     BoostContext::parmap_ = nullptr;
  38     BoostContext::workers_context_.clear();
  39     BoostContext::workers_context_.resize(SIMIX_context_get_nthreads(), nullptr);
  40     BoostContext::maestro_context_ = nullptr;
  41     xbt_os_thread_key_create(&BoostContext::worker_id_key_);
  42 #else
  43     xbt_die("No thread support for parallel context execution");
  44 #endif
  45   }
  46 }
  47
  48 BoostContextFactory::~BoostContextFactory()
  49 {
  50 #if HAVE_THREAD_CONTEXTS
  51   delete BoostContext::parmap_;
  52   BoostContext::parmap_ = nullptr;
  53   BoostContext::workers_context_.clear();
  54 #endif
  55 }
  56
  57 smx_context_t BoostContextFactory::create_context(std::function<void()> code, void_pfn_smxprocess_t cleanup_func,
  58                                                   smx_actor_t process)
  59 {
  60 #if HAVE_THREAD_CONTEXTS
  61   if (BoostContext::parallel_)
  62     return this->new_context<ParallelBoostContext>(std::move(code), cleanup_func, process);
  63 #endif
  64
  65   return this->new_context<SerialBoostContext>(std::move(code), cleanup_func, process);
  66 }
  67
  68 void BoostContextFactory::run_all()
  69 {
  70 #if HAVE_THREAD_CONTEXTS
  71   if (BoostContext::parallel_) {
  72     BoostContext::threads_working_ = 0;
  73     if (not BoostContext::parmap_)
  74       BoostContext::parmap_ =
  75           new simgrid::xbt::Parmap<smx_actor_t>(SIMIX_context_get_nthreads(), SIMIX_context_get_parallel_mode());
  76     BoostContext::parmap_->apply(
  77         [](smx_actor_t process) {
  78           BoostContext* context = static_cast<BoostContext*>(process->context);
  79           return context->resume();
  80         },
  81         simix_global->process_to_run);
  82     return;
  83   }
  84 #endif
  85
  86   if (simix_global->process_to_run.empty())
  87     return;
  88   smx_actor_t first_process    = simix_global->process_to_run.front();
  89   BoostContext::process_index_ = 1;
  90   /* execute the first process */
  91   static_cast<BoostContext*>(first_process->context)->resume();
  92 }
  93
  94
  95 // BoostContext
  96
  97 bool BoostContext::parallel_                             = false;
  98 simgrid::xbt::Parmap<smx_actor_t>* BoostContext::parmap_ = nullptr;
  99 uintptr_t BoostContext::threads_working_                 = 0;
 100 xbt_os_thread_key_t BoostContext::worker_id_key_;
 101 unsigned long BoostContext::process_index_   = 0;
 102 BoostContext* BoostContext::maestro_context_ = nullptr;
 103 std::vector<BoostContext*> BoostContext::workers_context_;
 104
 105 BoostContext::BoostContext(std::function<void()> code, void_pfn_smxprocess_t cleanup_func, smx_actor_t process)
 106     : Context(std::move(code), cleanup_func, process)
 107 {
 108
 109   /* if the user provided a function for the process then use it, otherwise it is the context for maestro */
 110   if (has_code()) {
 111     this->stack_ = SIMIX_context_stack_new();
 112     /* We need to pass the bottom of the stack to make_fcontext,
 113        depending on the stack direction it may be the lower or higher address: */
 114 #if PTH_STACKGROWTH == -1
 115     void* stack = static_cast<char*>(this->stack_) + smx_context_usable_stack_size;
 116 #else
 117     void* stack = this->stack_;
 118 #endif
 119     ASAN_EVAL(this->asan_stack_ = stack);
 120 #if BOOST_VERSION < 106100
 121     this->fc_ = boost::context::make_fcontext(stack, smx_context_usable_stack_size, BoostContext::wrapper);
 122 #else
 123     this->fc_ = boost::context::detail::make_fcontext(stack, smx_context_usable_stack_size, BoostContext::wrapper);
 124 #endif
 125   } else {
 126 #if BOOST_VERSION < 105600
 127     this->fc_ = new boost::context::fcontext_t();
 128 #endif
 129     if (BoostContext::maestro_context_ == nullptr)
 130       BoostContext::maestro_context_ = this;
 131   }
 132 }
 133
 134 BoostContext::~BoostContext()
 135 {
 136 #if BOOST_VERSION < 105600
 137   if (not this->stack_)
 138     delete this->fc_;
 139 #endif
 140   if (this == maestro_context_)
 141     maestro_context_ = nullptr;
 142   SIMIX_context_stack_delete(this->stack_);
 143 }
 144
 145 void BoostContext::wrapper(BoostContext::arg_type arg)
 146 {
 147 #if BOOST_VERSION < 106100
 148   BoostContext* context = reinterpret_cast<BoostContext*>(arg);
 149 #else
 150   ASAN_FINISH_SWITCH(nullptr, &static_cast<BoostContext**>(arg.data)[0]->asan_stack_,
 151                      &static_cast<BoostContext**>(arg.data)[0]->asan_stack_size_);
 152   static_cast<BoostContext**>(arg.data)[0]->fc_ = arg.fctx;
 153   BoostContext* context                         = static_cast<BoostContext**>(arg.data)[1];
 154 #endif
 155   try {
 156     (*context)();
 157     context->Context::stop();
 158   } catch (StopRequest const&) {
 159     XBT_DEBUG("Caught a StopRequest");
 160   }
 161   ASAN_EVAL(context->asan_stop_ = true);
 162   context->suspend();
 163 }
 164
 165 inline void BoostContext::swap(BoostContext* from, BoostContext* to)
 166 {
 167 #if BOOST_VERSION < 105600
 168   boost::context::jump_fcontext(from->fc_, to->fc_, reinterpret_cast<intptr_t>(to));
 169 #elif BOOST_VERSION < 106100
 170   boost::context::jump_fcontext(&from->fc_, to->fc_, reinterpret_cast<intptr_t>(to));
 171 #else
 172   BoostContext* ctx[2] = {from, to};
 173   void* fake_stack;
 174   ASAN_START_SWITCH(from->asan_stop_ ? nullptr : &fake_stack, to->asan_stack_, to->asan_stack_size_);
 175   boost::context::detail::transfer_t arg = boost::context::detail::jump_fcontext(to->fc_, ctx);
 176   ASAN_FINISH_SWITCH(fake_stack, &static_cast<BoostContext**>(arg.data)[0]->asan_stack_,
 177                      &static_cast<BoostContext**>(arg.data)[0]->asan_stack_size_);
 178   static_cast<BoostContext**>(arg.data)[0]->fc_ = arg.fctx;
 179 #endif
 180 }
 181
 182 void BoostContext::stop()
 183 {
 184   Context::stop();
 185   throw StopRequest();
 186 }
 187
 188 // SerialBoostContext
 189
 190 void SerialBoostContext::suspend()
 191 {
 192   /* determine the next context */
 193   SerialBoostContext* next_context;
 194   unsigned long int i = process_index_;
 195   process_index_++;
 196
 197   if (i < simix_global->process_to_run.size()) {
 198     /* execute the next process */
 199     XBT_DEBUG("Run next process");
 200     next_context = static_cast<SerialBoostContext*>(simix_global->process_to_run[i]->context);
 201   } else {
 202     /* all processes were run, return to maestro */
 203     XBT_DEBUG("No more process to run");
 204     next_context = static_cast<SerialBoostContext*>(maestro_context_);
 205   }
 206   SIMIX_context_set_current(static_cast<smx_context_t>(next_context));
 207   BoostContext::swap(this, next_context);
 208 }
 209
 210 void SerialBoostContext::resume()
 211 {
 212   SIMIX_context_set_current(this);
 213   BoostContext::swap(maestro_context_, this);
 214 }
 215
 216 // ParallelBoostContext
 217
 218 #if HAVE_THREAD_CONTEXTS
 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