1 /* Copyright (c) 2015-2023. The SimGrid Team. All rights reserved. */
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. */
6 #include "src/mc/remote/AppSide.hpp"
7 #include "simgrid/s4u/Host.hpp"
8 #include "src/internal_config.h"
9 #include "src/kernel/EngineImpl.hpp"
10 #include "src/kernel/actor/ActorImpl.hpp"
11 #include "src/kernel/actor/SimcallObserver.hpp"
12 #include "src/mc/mc_base.hpp"
13 #include "src/mc/mc_config.hpp"
14 #include "src/mc/sosp/RemoteProcessMemory.hpp"
16 #include "src/smpi/include/private.hpp"
18 #include "src/sthread/sthread.h"
19 #include "src/xbt/coverage.h"
21 #include <simgrid/modelchecker.h>
24 #include <cstdio> // setvbuf
28 #include <sys/ptrace.h>
29 #include <sys/socket.h>
30 #include <sys/types.h>
32 XBT_LOG_NEW_DEFAULT_SUBCATEGORY(mc_client, mc, "MC client logic");
33 XBT_LOG_EXTERNAL_CATEGORY(mc_global);
35 namespace simgrid::mc {
37 std::unique_ptr<AppSide> AppSide::instance_;
39 AppSide* AppSide::initialize()
41 if (not std::getenv(MC_ENV_SOCKET_FD)) // We are not in MC mode: don't initialize the MC world
44 // Do not break if we are called multiple times:
46 return instance_.get();
48 simgrid::mc::cfg_do_model_check = true;
50 setvbuf(stdout, nullptr, _IOLBF, 0);
52 // Fetch socket from MC_ENV_SOCKET_FD:
53 const char* fd_env = std::getenv(MC_ENV_SOCKET_FD);
54 int fd = xbt_str_parse_int(fd_env, "Not a number in variable '" MC_ENV_SOCKET_FD "'");
55 XBT_DEBUG("Model-checked application found socket FD %i", fd);
57 // Check the socket type/validity:
59 socklen_t socklen = sizeof(type);
60 xbt_assert(getsockopt(fd, SOL_SOCKET, SO_TYPE, &type, &socklen) == 0, "Could not check socket type");
61 xbt_assert(type == SOCK_SEQPACKET, "Unexpected socket type %i", type);
62 XBT_DEBUG("Model-checked application found expected socket type");
64 instance_ = std::make_unique<simgrid::mc::AppSide>(fd);
66 // Wait for the model-checker:
69 ptrace(PTRACE_TRACEME, 0, nullptr, nullptr);
71 ptrace(PT_TRACE_ME, 0, nullptr, 0);
73 #error "no ptrace equivalent coded for this platform"
75 xbt_assert(errno == 0 && raise(SIGSTOP) == 0, "Could not wait for the model-checker (errno = %d: %s)", errno,
78 s_mc_message_initial_addresses_t message = {};
79 message.type = MessageType::INITIAL_ADDRESSES;
80 message.mmalloc_default_mdp = mmalloc_get_current_heap();
81 xbt_assert(instance_->channel_.send(message) == 0, "Could not send the initial message with addresses.");
83 instance_->handle_messages();
84 return instance_.get();
87 void AppSide::handle_deadlock_check(const s_mc_message_t*) const
89 const auto* engine = kernel::EngineImpl::get_instance();
90 const auto& actor_list = engine->get_actor_list();
91 bool deadlock = not actor_list.empty() && std::none_of(begin(actor_list), end(actor_list), [](const auto& kv) {
92 return mc::actor_is_enabled(kv.second);
96 XBT_CINFO(mc_global, "**************************");
97 XBT_CINFO(mc_global, "*** DEADLOCK DETECTED ***");
98 XBT_CINFO(mc_global, "**************************");
99 engine->display_all_actor_status();
102 s_mc_message_int_t answer = {};
103 answer.type = MessageType::DEADLOCK_CHECK_REPLY;
104 answer.value = deadlock;
105 xbt_assert(channel_.send(answer) == 0, "Could not send response");
107 void AppSide::handle_simcall_execute(const s_mc_message_simcall_execute_t* message) const
109 kernel::actor::ActorImpl* actor = kernel::EngineImpl::get_instance()->get_actor_by_pid(message->aid_);
110 xbt_assert(actor != nullptr, "Invalid pid %ld", message->aid_);
112 // The client may send some messages to the server while processing the transition
113 actor->simcall_handle(message->times_considered_);
114 // Say the server that the transition is over and that it should proceed
115 xbt_assert(channel_.send(MessageType::WAITING) == 0, "Could not send MESSAGE_WAITING to model-checker");
117 // Finish the RPC from the server: return a serialized observer, to build a Transition on Checker side
118 s_mc_message_simcall_execute_answer_t answer = {};
119 answer.type = MessageType::SIMCALL_EXECUTE_ANSWER;
120 std::stringstream stream;
121 if (actor->simcall_.observer_ != nullptr) {
122 actor->simcall_.observer_->serialize(stream);
124 stream << (short)mc::Transition::Type::UNKNOWN;
126 std::string str = stream.str();
127 xbt_assert(str.size() + 1 <= answer.buffer.size(),
128 "The serialized simcall is too large for the buffer. Please fix the code.");
129 strncpy(answer.buffer.data(), str.c_str(), answer.buffer.size() - 1);
130 answer.buffer.back() = '\0';
132 XBT_DEBUG("send SIMCALL_EXECUTE_ANSWER(%s) ~> '%s'", actor->get_cname(), str.c_str());
133 xbt_assert(channel_.send(answer) == 0, "Could not send response");
136 void AppSide::handle_finalize(const s_mc_message_int_t* msg) const
138 bool terminate_asap = msg->value;
139 XBT_DEBUG("Finalize (terminate = %d)", (int)terminate_asap);
140 if (not terminate_asap) {
141 if (XBT_LOG_ISENABLED(mc_client, xbt_log_priority_debug))
142 kernel::EngineImpl::get_instance()->display_all_actor_status();
144 XBT_DEBUG("Smpi_enabled: %d", SMPI_is_inited());
145 if (SMPI_is_inited())
149 coverage_checkpoint();
150 xbt_assert(channel_.send(MessageType::FINALIZE_REPLY) == 0, "Could not answer to FINALIZE");
155 void AppSide::handle_actors_status() const
157 auto const& actor_list = kernel::EngineImpl::get_instance()->get_actor_list();
158 const int num_actors = actor_list.size();
159 XBT_DEBUG("Serialize the actors to answer ACTORS_STATUS from the checker. %d actors to go.", num_actors);
161 std::vector<s_mc_message_actors_status_one_t> status(num_actors);
163 int total_transitions = 0;
165 for (auto const& [aid, actor] : actor_list) {
167 status[i].enabled = mc::actor_is_enabled(actor);
168 status[i].max_considered = actor->simcall_.observer_->get_max_consider();
169 status[i].n_transitions = mc::actor_is_enabled(actor) ? status[i].max_considered : 0;
170 total_transitions += status[i].n_transitions;
174 struct s_mc_message_actors_status_answer_t answer = {};
175 answer.type = MessageType::ACTORS_STATUS_REPLY;
176 answer.count = num_actors;
177 answer.transition_count = total_transitions;
179 xbt_assert(channel_.send(answer) == 0, "Could not send ACTORS_STATUS_REPLY msg");
180 if (answer.count > 0) {
181 size_t size = status.size() * sizeof(s_mc_message_actors_status_one_t);
182 xbt_assert(channel_.send(status.data(), size) == 0, "Could not send ACTORS_STATUS_REPLY data");
185 // Serialize each transition to describe what each actor is doing
186 if (total_transitions > 0) {
187 std::vector<s_mc_message_simcall_probe_one_t> probes(total_transitions);
188 auto probes_iter = probes.begin();
190 for (const auto& actor_status : status) {
191 if (not actor_status.enabled)
194 const auto& actor = actor_list.at(actor_status.aid);
195 const int max_considered = actor_status.max_considered;
197 for (int times_considered = 0; times_considered < max_considered; times_considered++, probes_iter++) {
198 std::stringstream stream;
199 s_mc_message_simcall_probe_one_t& probe = *probes_iter;
201 if (actor->simcall_.observer_ != nullptr) {
202 actor->simcall_.observer_->prepare(times_considered);
203 actor->simcall_.observer_->serialize(stream);
205 stream << (short)mc::Transition::Type::UNKNOWN;
208 std::string str = stream.str();
209 xbt_assert(str.size() + 1 <= probe.buffer.size(),
210 "The serialized transition is too large for the buffer. Please fix the code.");
211 strncpy(probe.buffer.data(), str.c_str(), probe.buffer.size() - 1);
212 probe.buffer.back() = '\0';
214 // NOTE: We do NOT need to reset `times_considered` for each actor's
215 // simcall observer here to the "original" value (i.e. the value BEFORE
216 // multiple prepare() calls were made for serialization purposes) since
217 // each SIMCALL_EXECUTE provides a `times_considered` to be used to prepare
218 // the transition before execution.
220 XBT_DEBUG("Deliver ACTOR_TRANSITION_PROBE payload");
222 for (const auto& probe : probes)
223 xbt_assert(channel_.send(probe) == 0, "Could not send ACTOR_TRANSITION_PROBE payload");
226 void AppSide::handle_actors_maxpid() const
228 s_mc_message_int_t answer = {};
229 answer.type = MessageType::ACTORS_MAXPID_REPLY;
230 answer.value = kernel::actor::ActorImpl::get_maxpid();
231 xbt_assert(channel_.send(answer) == 0, "Could not send response");
234 #define assert_msg_size(_name_, _type_) \
235 xbt_assert(received_size == sizeof(_type_), "Unexpected size for " _name_ " (%zd != %zu)", received_size, \
238 void AppSide::handle_messages() const
240 while (true) { // Until we get a CONTINUE message
241 XBT_DEBUG("Waiting messages from model-checker");
243 std::array<char, MC_MESSAGE_LENGTH> message_buffer;
244 ssize_t received_size = channel_.receive(message_buffer.data(), message_buffer.size());
246 xbt_assert(received_size >= 0, "Could not receive commands from the model-checker");
247 xbt_assert(static_cast<size_t>(received_size) >= sizeof(s_mc_message_t), "Cannot handle short message (size=%zd)",
250 const s_mc_message_t* message = (s_mc_message_t*)message_buffer.data();
251 switch (message->type) {
252 case MessageType::DEADLOCK_CHECK:
253 assert_msg_size("DEADLOCK_CHECK", s_mc_message_t);
254 handle_deadlock_check(message);
257 case MessageType::CONTINUE:
258 assert_msg_size("MESSAGE_CONTINUE", s_mc_message_t);
261 case MessageType::SIMCALL_EXECUTE:
262 assert_msg_size("SIMCALL_EXECUTE", s_mc_message_simcall_execute_t);
263 handle_simcall_execute((s_mc_message_simcall_execute_t*)message_buffer.data());
266 case MessageType::FINALIZE:
267 assert_msg_size("FINALIZE", s_mc_message_int_t);
268 handle_finalize((s_mc_message_int_t*)message_buffer.data());
271 case MessageType::ACTORS_STATUS:
272 assert_msg_size("ACTORS_STATUS", s_mc_message_t);
273 handle_actors_status();
276 case MessageType::ACTORS_MAXPID:
277 assert_msg_size("ACTORS_MAXPID", s_mc_message_t);
278 handle_actors_maxpid();
282 xbt_die("Received unexpected message %s (%i)", to_c_str(message->type), static_cast<int>(message->type));
288 void AppSide::main_loop() const
290 simgrid::mc::processes_time.resize(simgrid::kernel::actor::ActorImpl::get_maxpid());
291 MC_ignore_heap(simgrid::mc::processes_time.data(),
292 simgrid::mc::processes_time.size() * sizeof(simgrid::mc::processes_time[0]));
295 coverage_checkpoint();
298 simgrid::mc::execute_actors();
299 xbt_assert(channel_.send(MessageType::WAITING) == 0, "Could not send WAITING message to model-checker");
300 this->handle_messages();
304 void AppSide::report_assertion_failure() const
306 xbt_assert(channel_.send(MessageType::ASSERTION_FAILED) == 0, "Could not send assertion to model-checker");
307 this->handle_messages();
310 void AppSide::ignore_memory(void* addr, std::size_t size) const
312 if (not MC_is_active())
315 s_mc_message_ignore_memory_t message = {};
316 message.type = MessageType::IGNORE_MEMORY;
317 message.addr = (std::uintptr_t)addr;
319 xbt_assert(channel_.send(message) == 0, "Could not send IGNORE_MEMORY message to model-checker");
322 void AppSide::ignore_heap(void* address, std::size_t size) const
324 if (not MC_is_active())
327 const s_xbt_mheap_t* heap = mmalloc_get_current_heap();
329 s_mc_message_ignore_heap_t message = {};
330 message.type = MessageType::IGNORE_HEAP;
331 message.address = address;
333 message.block = ((char*)address - (char*)heap->heapbase) / BLOCKSIZE + 1;
334 if (heap->heapinfo[message.block].type == 0) {
335 message.fragment = -1;
336 heap->heapinfo[message.block].busy_block.ignore++;
338 message.fragment = (ADDR2UINT(address) % BLOCKSIZE) >> heap->heapinfo[message.block].type;
339 heap->heapinfo[message.block].busy_frag.ignore[message.fragment]++;
342 xbt_assert(channel_.send(message) == 0, "Could not send ignored region to MCer");
345 void AppSide::unignore_heap(void* address, std::size_t size) const
347 if (not MC_is_active())
350 s_mc_message_ignore_memory_t message = {};
351 message.type = MessageType::UNIGNORE_HEAP;
352 message.addr = (std::uintptr_t)address;
354 xbt_assert(channel_.send(message) == 0, "Could not send IGNORE_HEAP message to model-checker");
357 void AppSide::declare_symbol(const char* name, int* value) const
359 if (not MC_is_active())
362 s_mc_message_register_symbol_t message = {};
363 message.type = MessageType::REGISTER_SYMBOL;
364 xbt_assert(strlen(name) + 1 <= message.name.size(), "Symbol is too long");
365 strncpy(message.name.data(), name, message.name.size() - 1);
366 message.callback = nullptr;
367 message.data = value;
368 xbt_assert(channel_.send(message) == 0, "Could send REGISTER_SYMBOL message to model-checker");
371 /** Register a stack in the model checker
373 * The stacks are allocated in the heap. The MC handle them specifically
374 * when we analyze/compare the content of the heap so it must be told where
375 * they are with this function.
377 void AppSide::declare_stack(void* stack, size_t size, ucontext_t* context) const
379 if (not MC_is_active())
382 const s_xbt_mheap_t* heap = mmalloc_get_current_heap();
384 s_stack_region_t region = {};
385 region.address = stack;
386 region.context = context;
388 region.block = ((char*)stack - (char*)heap->heapbase) / BLOCKSIZE + 1;
390 s_mc_message_stack_region_t message = {};
391 message.type = MessageType::STACK_REGION;
392 message.stack_region = region;
393 xbt_assert(channel_.send(message) == 0, "Could not send STACK_REGION to model-checker");
395 } // namespace simgrid::mc