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 <cstdint>
   7
   8 #include <functional>
   9 #include <utility>
  10 #include <vector>
  11
  12 #include <boost/context/all.hpp>
  13
  14 #include <xbt/log.h>
  15 #include <xbt/xbt_os_thread.h>
  16
  17 #include "src/simix/smx_private.h"
  18 #include "src/internal_config.h"
  19 #include "src/kernel/context/ContextBoost.hpp"
  20
  21 XBT_LOG_EXTERNAL_DEFAULT_CATEGORY(simix_context);
  22
  23 namespace simgrid {
  24 namespace kernel {
  25 namespace context {
  26
  27 class BoostSerialContext : public BoostContext {
  28 public:
  29   BoostSerialContext(std::function<void()> code,
  30       void_pfn_smxprocess_t cleanup_func,
  31       smx_actor_t process)
  32     : BoostContext(std::move(code), cleanup_func, process) {}
  33   void suspend() override;
  34 };
  35
  36 #if HAVE_THREAD_CONTEXTS
  37 class BoostParallelContext : public BoostContext {
  38 public:
  39   BoostParallelContext(std::function<void()> code,
  40       void_pfn_smxprocess_t cleanup_func,
  41       smx_actor_t process)
  42     : BoostContext(std::move(code), cleanup_func, process) {}
  43   void suspend() override;
  44   void resume() override;
  45 };
  46 #endif
  47
  48 // BoostContextFactory
  49
  50 bool BoostContext::parallel_                             = false;
  51 simgrid::xbt::Parmap<smx_actor_t>* BoostContext::parmap_ = nullptr;
  52 uintptr_t BoostContext::threads_working_                 = 0;
  53 xbt_os_thread_key_t BoostContext::worker_id_key_;
  54 unsigned long BoostContext::process_index_   = 0;
  55 BoostContext* BoostContext::maestro_context_ = nullptr;
  56 std::vector<BoostContext*> BoostContext::workers_context_;
  57
  58 BoostContextFactory::BoostContextFactory()
  59   : ContextFactory("BoostContextFactory")
  60 {
  61   BoostContext::parallel_ = SIMIX_context_is_parallel();
  62   if (BoostContext::parallel_) {
  63 #if HAVE_THREAD_CONTEXTS
  64     BoostContext::parmap_ = nullptr;
  65     BoostContext::workers_context_.clear();
  66     BoostContext::workers_context_.resize(SIMIX_context_get_nthreads(), nullptr);
  67     BoostContext::maestro_context_ = nullptr;
  68     xbt_os_thread_key_create(&BoostContext::worker_id_key_);
  69 #else
  70     xbt_die("No thread support for parallel context execution");
  71 #endif
  72   }
  73 }
  74
  75 BoostContextFactory::~BoostContextFactory()
  76 {
  77 #if HAVE_THREAD_CONTEXTS
  78   delete BoostContext::parmap_;
  79   BoostContext::parmap_ = nullptr;
  80   BoostContext::workers_context_.clear();
  81 #endif
  82 }
  83
  84 smx_context_t BoostContextFactory::create_context(std::function<void()> code, void_pfn_smxprocess_t cleanup_func,
  85                                                   smx_actor_t process)
  86 {
  87   BoostContext* context = nullptr;
  88   if (BoostContext::parallel_)
  89 #if HAVE_THREAD_CONTEXTS
  90     context = this->new_context<BoostParallelContext>(std::move(code), cleanup_func, process);
  91 #else
  92     xbt_die("No support for parallel execution");
  93 #endif
  94   else
  95     context = this->new_context<BoostSerialContext>(std::move(code), cleanup_func, process);
  96   return context;
  97 }
  98
  99 void BoostContextFactory::run_all()
 100 {
 101 #if HAVE_THREAD_CONTEXTS
 102   if (BoostContext::parallel_) {
 103     BoostContext::threads_working_ = 0;
 104     if (not BoostContext::parmap_)
 105       BoostContext::parmap_ =
 106           new simgrid::xbt::Parmap<smx_actor_t>(SIMIX_context_get_nthreads(), SIMIX_context_get_parallel_mode());
 107     BoostContext::parmap_->apply(
 108         [](smx_actor_t process) {
 109           BoostContext* context = static_cast<BoostContext*>(process->context);
 110           return context->resume();
 111         },
 112         simix_global->process_to_run);
 113   } else
 114 #endif
 115   {
 116     if (simix_global->process_to_run.empty())
 117       return;
 118     smx_actor_t first_process    = simix_global->process_to_run.front();
 119     BoostContext::process_index_ = 1;
 120     /* execute the first process */
 121     static_cast<BoostContext*>(first_process->context)->resume();
 122   }
 123 }
 124
 125
 126 // BoostContext
 127
 128 void BoostContext::smx_ctx_boost_wrapper(BoostContext::ctx_arg_type arg)
 129 {
 130 #if BOOST_VERSION < 106100
 131   BoostContext* context = reinterpret_cast<BoostContext*>(arg);
 132 #else
 133   static_cast<BoostContext**>(arg.data)[0]->fc_ = arg.fctx;
 134   BoostContext* context                         = static_cast<BoostContext**>(arg.data)[1];
 135 #endif
 136   try {
 137     (*context)();
 138     context->Context::stop();
 139   } catch (StopRequest const&) {
 140     XBT_DEBUG("Caught a StopRequest");
 141   }
 142   context->suspend();
 143 }
 144
 145 inline void BoostContext::smx_ctx_boost_jump_fcontext(BoostContext* from, BoostContext* to)
 146 {
 147 #if BOOST_VERSION < 105600
 148   boost::context::jump_fcontext(from->fc_, to->fc_, reinterpret_cast<intptr_t>(to));
 149 #elif BOOST_VERSION < 106100
 150   boost::context::jump_fcontext(&from->fc_, to->fc_, reinterpret_cast<intptr_t>(to));
 151 #else
 152   BoostContext* ctx[2]                          = {from, to};
 153   boost::context::detail::transfer_t arg        = boost::context::detail::jump_fcontext(to->fc_, ctx);
 154   static_cast<BoostContext**>(arg.data)[0]->fc_ = arg.fctx;
 155 #endif
 156 }
 157
 158 BoostContext::BoostContext(std::function<void()> code,
 159     void_pfn_smxprocess_t cleanup_func, smx_actor_t process)
 160   : Context(std::move(code), cleanup_func, process)
 161 {
 162
 163   /* if the user provided a function for the process then use it, otherwise it is the context for maestro */
 164   if (has_code()) {
 165     this->stack_ = SIMIX_context_stack_new();
 166 // We need to pass the bottom of the stack to make_fcontext, depending on the stack direction it may be the lower
 167 // or higher address:
 168 #if PTH_STACKGROWTH == -1
 169     void* stack = static_cast<char*>(this->stack_) + smx_context_usable_stack_size;
 170 #else
 171     void* stack = this->stack_;
 172 #endif
 173 #if BOOST_VERSION < 106100
 174     this->fc_ = boost::context::make_fcontext(stack, smx_context_usable_stack_size, smx_ctx_boost_wrapper);
 175 #else
 176     this->fc_ = boost::context::detail::make_fcontext(stack, smx_context_usable_stack_size, smx_ctx_boost_wrapper);
 177 #endif
 178   } else {
 179 #if BOOST_VERSION < 105600
 180     this->fc_ = new boost::context::fcontext_t();
 181 #endif
 182     if (BoostContext::maestro_context_ == nullptr)
 183       BoostContext::maestro_context_ = this;
 184   }
 185 }
 186
 187 BoostContext::~BoostContext()
 188 {
 189 #if BOOST_VERSION < 105600
 190   if (not this->stack_)
 191     delete this->fc_;
 192 #endif
 193   if (this == maestro_context_)
 194     maestro_context_ = nullptr;
 195   SIMIX_context_stack_delete(this->stack_);
 196 }
 197
 198 // BoostSerialContext
 199
 200 void BoostContext::stop()
 201 {
 202   Context::stop();
 203   throw StopRequest();
 204 }
 205
 206 void BoostContext::resume()
 207 {
 208   SIMIX_context_set_current(this);
 209   smx_ctx_boost_jump_fcontext(maestro_context_, this);
 210 }
 211
 212 void BoostSerialContext::suspend()
 213 {
 214   /* determine the next context */
 215   BoostSerialContext* next_context;
 216   unsigned long int i = process_index_;
 217   process_index_++;
 218
 219   if (i < simix_global->process_to_run.size()) {
 220     /* execute the next process */
 221     XBT_DEBUG("Run next process");
 222     next_context = static_cast<BoostSerialContext*>(simix_global->process_to_run[i]->context);
 223   } else {
 224     /* all processes were run, return to maestro */
 225     XBT_DEBUG("No more process to run");
 226     next_context = static_cast<BoostSerialContext*>(maestro_context_);
 227   }
 228   SIMIX_context_set_current(static_cast<smx_context_t>(next_context));
 229   smx_ctx_boost_jump_fcontext(this, next_context);
 230 }
 231
 232 // BoostParallelContext
 233
 234 #if HAVE_THREAD_CONTEXTS
 235
 236 void BoostParallelContext::suspend()
 237 {
 238   boost::optional<smx_actor_t> next_work = parmap_->next();
 239   BoostParallelContext* next_context;
 240   if (next_work) {
 241     XBT_DEBUG("Run next process");
 242     next_context = static_cast<BoostParallelContext*>(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 = static_cast<BoostParallelContext*>(workers_context_[worker_id]);
 247   }
 248
 249   SIMIX_context_set_current(static_cast<smx_context_t>(next_context));
 250   smx_ctx_boost_jump_fcontext(this, next_context);
 251 }
 252
 253 void BoostParallelContext::resume()
 254 {
 255   uintptr_t worker_id = __sync_fetch_and_add(&threads_working_, 1);
 256   xbt_os_thread_set_specific(worker_id_key_, reinterpret_cast<void*>(worker_id));
 257
 258   BoostParallelContext* worker_context = static_cast<BoostParallelContext*>(SIMIX_context_self());
 259   workers_context_[worker_id] = worker_context;
 260
 261   SIMIX_context_set_current(this);
 262   smx_ctx_boost_jump_fcontext(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
 273 }}} // namespace