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::model_checking_mode = ModelCheckingMode::APP_SIDE;
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:
67 if (getenv("MC_NEED_PTRACE") != nullptr) {
70 ptrace(PTRACE_TRACEME, 0, nullptr, nullptr);
72 ptrace(PT_TRACE_ME, 0, nullptr, 0);
74 xbt_die("no ptrace equivalent coded for this platform, please don't use the liveness checker here.");
77 xbt_assert(errno == 0 && raise(SIGSTOP) == 0, "Could not wait for the model-checker (errno = %d: %s)", errno,
81 instance_->handle_messages();
82 return instance_.get();
85 void AppSide::handle_deadlock_check(const s_mc_message_t*) const
87 const auto* engine = kernel::EngineImpl::get_instance();
88 const auto& actor_list = engine->get_actor_list();
89 bool deadlock = not actor_list.empty() && std::none_of(begin(actor_list), end(actor_list), [](const auto& kv) {
90 return mc::actor_is_enabled(kv.second);
94 XBT_CINFO(mc_global, "**************************");
95 XBT_CINFO(mc_global, "*** DEADLOCK DETECTED ***");
96 XBT_CINFO(mc_global, "**************************");
97 engine->display_all_actor_status();
100 s_mc_message_int_t answer = {};
101 answer.type = MessageType::DEADLOCK_CHECK_REPLY;
102 answer.value = deadlock;
103 xbt_assert(channel_.send(answer) == 0, "Could not send response");
105 void AppSide::handle_simcall_execute(const s_mc_message_simcall_execute_t* message) const
107 kernel::actor::ActorImpl* actor = kernel::EngineImpl::get_instance()->get_actor_by_pid(message->aid_);
108 xbt_assert(actor != nullptr, "Invalid pid %ld", message->aid_);
110 // The client may send some messages to the server while processing the transition
111 actor->simcall_handle(message->times_considered_);
112 // Say the server that the transition is over and that it should proceed
113 xbt_assert(channel_.send(MessageType::WAITING) == 0, "Could not send MESSAGE_WAITING to model-checker");
115 // Finish the RPC from the server: return a serialized observer, to build a Transition on Checker side
116 s_mc_message_simcall_execute_answer_t answer = {};
117 answer.type = MessageType::SIMCALL_EXECUTE_ANSWER;
118 std::stringstream stream;
119 if (actor->simcall_.observer_ != nullptr) {
120 actor->simcall_.observer_->serialize(stream);
122 stream << (short)mc::Transition::Type::UNKNOWN;
124 std::string str = stream.str();
125 xbt_assert(str.size() + 1 <= answer.buffer.size(),
126 "The serialized simcall is too large for the buffer. Please fix the code.");
127 strncpy(answer.buffer.data(), str.c_str(), answer.buffer.size() - 1);
128 answer.buffer.back() = '\0';
130 XBT_DEBUG("send SIMCALL_EXECUTE_ANSWER(%s) ~> '%s'", actor->get_cname(), str.c_str());
131 xbt_assert(channel_.send(answer) == 0, "Could not send response");
134 void AppSide::handle_finalize(const s_mc_message_int_t* msg) const
136 bool terminate_asap = msg->value;
137 XBT_DEBUG("Finalize (terminate = %d)", (int)terminate_asap);
138 if (not terminate_asap) {
139 if (XBT_LOG_ISENABLED(mc_client, xbt_log_priority_debug))
140 kernel::EngineImpl::get_instance()->display_all_actor_status();
142 XBT_DEBUG("Smpi_enabled: %d", SMPI_is_inited());
143 if (SMPI_is_inited())
147 coverage_checkpoint();
148 xbt_assert(channel_.send(MessageType::FINALIZE_REPLY) == 0, "Could not answer to FINALIZE");
153 void AppSide::handle_need_meminfo()
155 this->need_memory_info_ = true;
156 s_mc_message_need_meminfo_reply_t answer = {};
157 answer.type = MessageType::NEED_MEMINFO_REPLY;
158 answer.mmalloc_default_mdp = mmalloc_get_current_heap();
159 xbt_assert(channel_.send(answer) == 0, "Could not send response to the request for meminfo.");
161 void AppSide::handle_actors_status() const
163 auto const& actor_list = kernel::EngineImpl::get_instance()->get_actor_list();
164 XBT_DEBUG("Serialize the actors to answer ACTORS_STATUS from the checker. %zu actors to go.", actor_list.size());
166 std::vector<s_mc_message_actors_status_one_t> status;
167 for (auto const& [aid, actor] : actor_list)
168 status.emplace_back(s_mc_message_actors_status_one_t{aid, mc::actor_is_enabled(actor),
169 actor->simcall_.observer_->get_max_consider()});
171 struct s_mc_message_actors_status_answer_t answer = {};
172 answer.type = MessageType::ACTORS_STATUS_REPLY;
173 answer.count = static_cast<int>(status.size());
175 xbt_assert(channel_.send(answer) == 0, "Could not send ACTORS_STATUS_REPLY msg");
176 if (answer.count > 0) {
177 size_t size = status.size() * sizeof(s_mc_message_actors_status_one_t);
178 xbt_assert(channel_.send(status.data(), size) == 0, "Could not send ACTORS_STATUS_REPLY data");
181 // Serialize each transition to describe what each actor is doing
182 XBT_DEBUG("Deliver ACTOR_TRANSITION_PROBE payload");
183 for (const auto& actor_status : status) {
184 if (not actor_status.enabled)
187 const auto& actor = actor_list.at(actor_status.aid);
188 const int max_considered = actor_status.max_considered;
190 for (int times_considered = 0; times_considered < max_considered; times_considered++) {
191 std::stringstream stream;
192 s_mc_message_simcall_probe_one_t probe;
194 if (actor->simcall_.observer_ != nullptr) {
195 actor->simcall_.observer_->prepare(times_considered);
196 actor->simcall_.observer_->serialize(stream);
198 stream << (short)mc::Transition::Type::UNKNOWN;
201 std::string str = stream.str();
202 xbt_assert(str.size() + 1 <= probe.buffer.size(),
203 "The serialized transition is too large for the buffer. Please fix the code.");
204 strncpy(probe.buffer.data(), str.c_str(), probe.buffer.size() - 1);
205 probe.buffer.back() = '\0';
207 xbt_assert(channel_.send(probe) == 0, "Could not send ACTOR_TRANSITION_PROBE payload");
209 // NOTE: We do NOT need to reset `times_considered` for each actor's
210 // simcall observer here to the "original" value (i.e. the value BEFORE
211 // multiple prepare() calls were made for serialization purposes) since
212 // each SIMCALL_EXECUTE provides a `times_considered` to be used to prepare
213 // the transition before execution.
216 void AppSide::handle_actors_maxpid() const
218 s_mc_message_int_t answer = {};
219 answer.type = MessageType::ACTORS_MAXPID_REPLY;
220 answer.value = kernel::actor::ActorImpl::get_maxpid();
221 xbt_assert(channel_.send(answer) == 0, "Could not send response");
224 #define assert_msg_size(_name_, _type_) \
225 xbt_assert(received_size == sizeof(_type_), "Unexpected size for " _name_ " (%zd != %zu)", received_size, \
228 void AppSide::handle_messages()
230 while (true) { // Until we get a CONTINUE message
231 XBT_DEBUG("Waiting messages from model-checker");
233 std::array<char, MC_MESSAGE_LENGTH> message_buffer;
234 ssize_t received_size = channel_.receive(message_buffer.data(), message_buffer.size());
236 if (received_size == 0) {
237 XBT_DEBUG("Socket closed on the Checker side, bailing out.");
238 ::_Exit(0); // Nobody's listening to that process anymore => exit as quickly as possible.
240 xbt_assert(received_size >= 0, "Could not receive commands from the model-checker");
241 xbt_assert(static_cast<size_t>(received_size) >= sizeof(s_mc_message_t), "Cannot handle short message (size=%zd)",
244 const s_mc_message_t* message = (s_mc_message_t*)message_buffer.data();
245 switch (message->type) {
246 case MessageType::DEADLOCK_CHECK:
247 assert_msg_size("DEADLOCK_CHECK", s_mc_message_t);
248 handle_deadlock_check(message);
251 case MessageType::CONTINUE:
252 assert_msg_size("MESSAGE_CONTINUE", s_mc_message_t);
255 case MessageType::SIMCALL_EXECUTE:
256 assert_msg_size("SIMCALL_EXECUTE", s_mc_message_simcall_execute_t);
257 handle_simcall_execute((s_mc_message_simcall_execute_t*)message_buffer.data());
260 case MessageType::FINALIZE:
261 assert_msg_size("FINALIZE", s_mc_message_int_t);
262 handle_finalize((s_mc_message_int_t*)message_buffer.data());
265 case MessageType::NEED_MEMINFO:
266 assert_msg_size("NEED_MEMINFO", s_mc_message_t);
267 handle_need_meminfo();
270 case MessageType::ACTORS_STATUS:
271 assert_msg_size("ACTORS_STATUS", s_mc_message_t);
272 handle_actors_status();
275 case MessageType::ACTORS_MAXPID:
276 assert_msg_size("ACTORS_MAXPID", s_mc_message_t);
277 handle_actors_maxpid();
281 xbt_die("Received unexpected message %s (%i)", to_c_str(message->type), static_cast<int>(message->type));
287 void AppSide::main_loop()
289 simgrid::mc::processes_time.resize(simgrid::kernel::actor::ActorImpl::get_maxpid());
290 MC_ignore_heap(simgrid::mc::processes_time.data(),
291 simgrid::mc::processes_time.size() * sizeof(simgrid::mc::processes_time[0]));
294 coverage_checkpoint();
297 simgrid::mc::execute_actors();
298 xbt_assert(channel_.send(MessageType::WAITING) == 0, "Could not send WAITING message to model-checker");
299 this->handle_messages();
303 void AppSide::report_assertion_failure()
305 xbt_assert(channel_.send(MessageType::ASSERTION_FAILED) == 0, "Could not send assertion to model-checker");
306 this->handle_messages();
309 void AppSide::ignore_memory(void* addr, std::size_t size) const
311 if (not MC_is_active() || not need_memory_info_)
314 s_mc_message_ignore_memory_t message = {};
315 message.type = MessageType::IGNORE_MEMORY;
316 message.addr = (std::uintptr_t)addr;
318 xbt_assert(channel_.send(message) == 0, "Could not send IGNORE_MEMORY message to model-checker");
321 void AppSide::ignore_heap(void* address, std::size_t size) const
323 if (not MC_is_active() || not need_memory_info_)
326 const s_xbt_mheap_t* heap = mmalloc_get_current_heap();
328 s_mc_message_ignore_heap_t message = {};
329 message.type = MessageType::IGNORE_HEAP;
330 message.address = address;
332 message.block = ((char*)address - (char*)heap->heapbase) / BLOCKSIZE + 1;
333 if (heap->heapinfo[message.block].type == 0) {
334 message.fragment = -1;
335 heap->heapinfo[message.block].busy_block.ignore++;
337 message.fragment = (ADDR2UINT(address) % BLOCKSIZE) >> heap->heapinfo[message.block].type;
338 heap->heapinfo[message.block].busy_frag.ignore[message.fragment]++;
341 xbt_assert(channel_.send(message) == 0, "Could not send ignored region to MCer");
344 void AppSide::unignore_heap(void* address, std::size_t size) const
346 if (not MC_is_active() || not need_memory_info_)
349 s_mc_message_ignore_memory_t message = {};
350 message.type = MessageType::UNIGNORE_HEAP;
351 message.addr = (std::uintptr_t)address;
353 xbt_assert(channel_.send(message) == 0, "Could not send IGNORE_HEAP message to model-checker");
356 void AppSide::declare_symbol(const char* name, int* value) const
358 if (not MC_is_active() || not need_memory_info_) {
359 XBT_CRITICAL("Ignore AppSide::declare_symbol(%s)", name);
363 s_mc_message_register_symbol_t message = {};
364 message.type = MessageType::REGISTER_SYMBOL;
365 xbt_assert(strlen(name) + 1 <= message.name.size(), "Symbol is too long");
366 strncpy(message.name.data(), name, message.name.size() - 1);
367 message.callback = nullptr;
368 message.data = value;
369 xbt_assert(channel_.send(message) == 0, "Could send REGISTER_SYMBOL message to model-checker");
372 /** Register a stack in the model checker
374 * The stacks are allocated in the heap. The MC handle them specifically
375 * when we analyze/compare the content of the heap so it must be told where
376 * they are with this function.
378 void AppSide::declare_stack(void* stack, size_t size, ucontext_t* context) const
380 if (not MC_is_active() || not need_memory_info_)
383 const s_xbt_mheap_t* heap = mmalloc_get_current_heap();
385 s_stack_region_t region = {};
386 region.address = stack;
387 region.context = context;
389 region.block = ((char*)stack - (char*)heap->heapbase) / BLOCKSIZE + 1;
391 s_mc_message_stack_region_t message = {};
392 message.type = MessageType::STACK_REGION;
393 message.stack_region = region;
394 xbt_assert(channel_.send(message) == 0, "Could not send STACK_REGION to model-checker");
396 } // namespace simgrid::mc