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