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