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ContextBoost: move parallel_ from BoostContext to BoostContextFactory.
[simgrid.git] / 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