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:
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 instance_->handle_messages();
79 return instance_.get();
82 void AppSide::handle_deadlock_check(const s_mc_message_t*) const
84 const auto* engine = kernel::EngineImpl::get_instance();
85 const auto& actor_list = engine->get_actor_list();
86 bool deadlock = not actor_list.empty() && std::none_of(begin(actor_list), end(actor_list), [](const auto& kv) {
87 return mc::actor_is_enabled(kv.second);
91 XBT_CINFO(mc_global, "**************************");
92 XBT_CINFO(mc_global, "*** DEADLOCK DETECTED ***");
93 XBT_CINFO(mc_global, "**************************");
94 engine->display_all_actor_status();
97 s_mc_message_int_t answer = {};
98 answer.type = MessageType::DEADLOCK_CHECK_REPLY;
99 answer.value = deadlock;
100 xbt_assert(channel_.send(answer) == 0, "Could not send response");
102 void AppSide::handle_simcall_execute(const s_mc_message_simcall_execute_t* message) const
104 kernel::actor::ActorImpl* actor = kernel::EngineImpl::get_instance()->get_actor_by_pid(message->aid_);
105 xbt_assert(actor != nullptr, "Invalid pid %ld", message->aid_);
107 // The client may send some messages to the server while processing the transition
108 actor->simcall_handle(message->times_considered_);
109 // Say the server that the transition is over and that it should proceed
110 xbt_assert(channel_.send(MessageType::WAITING) == 0, "Could not send MESSAGE_WAITING to model-checker");
112 // Finish the RPC from the server: return a serialized observer, to build a Transition on Checker side
113 s_mc_message_simcall_execute_answer_t answer = {};
114 answer.type = MessageType::SIMCALL_EXECUTE_ANSWER;
115 std::stringstream stream;
116 if (actor->simcall_.observer_ != nullptr) {
117 actor->simcall_.observer_->serialize(stream);
119 stream << (short)mc::Transition::Type::UNKNOWN;
121 std::string str = stream.str();
122 xbt_assert(str.size() + 1 <= answer.buffer.size(),
123 "The serialized simcall is too large for the buffer. Please fix the code.");
124 strncpy(answer.buffer.data(), str.c_str(), answer.buffer.size() - 1);
125 answer.buffer.back() = '\0';
127 XBT_DEBUG("send SIMCALL_EXECUTE_ANSWER(%s) ~> '%s'", actor->get_cname(), str.c_str());
128 xbt_assert(channel_.send(answer) == 0, "Could not send response");
131 void AppSide::handle_finalize(const s_mc_message_int_t* msg) const
133 bool terminate_asap = msg->value;
134 XBT_DEBUG("Finalize (terminate = %d)", (int)terminate_asap);
135 if (not terminate_asap) {
136 if (XBT_LOG_ISENABLED(mc_client, xbt_log_priority_debug))
137 kernel::EngineImpl::get_instance()->display_all_actor_status();
139 XBT_DEBUG("Smpi_enabled: %d", SMPI_is_inited());
140 if (SMPI_is_inited())
144 coverage_checkpoint();
145 xbt_assert(channel_.send(MessageType::FINALIZE_REPLY) == 0, "Could not answer to FINALIZE");
150 void AppSide::handle_initial_addresses()
152 this->need_memory_info_ = true;
153 s_mc_message_initial_addresses_reply_t answer = {};
154 answer.type = MessageType::INITIAL_ADDRESSES_REPLY;
155 answer.mmalloc_default_mdp = mmalloc_get_current_heap();
156 xbt_assert(channel_.send(answer) == 0, "Could not send response with initial addresses.");
158 void AppSide::handle_actors_status() const
160 auto const& actor_list = kernel::EngineImpl::get_instance()->get_actor_list();
161 const int num_actors = actor_list.size();
162 XBT_DEBUG("Serialize the actors to answer ACTORS_STATUS from the checker. %d actors to go.", num_actors);
164 std::vector<s_mc_message_actors_status_one_t> status(num_actors);
166 int total_transitions = 0;
168 for (auto const& [aid, actor] : actor_list) {
170 status[i].enabled = mc::actor_is_enabled(actor);
171 status[i].max_considered = actor->simcall_.observer_->get_max_consider();
172 status[i].n_transitions = mc::actor_is_enabled(actor) ? status[i].max_considered : 0;
173 total_transitions += status[i].n_transitions;
177 struct s_mc_message_actors_status_answer_t answer = {};
178 answer.type = MessageType::ACTORS_STATUS_REPLY;
179 answer.count = num_actors;
180 answer.transition_count = total_transitions;
182 xbt_assert(channel_.send(answer) == 0, "Could not send ACTORS_STATUS_REPLY msg");
183 if (answer.count > 0) {
184 size_t size = status.size() * sizeof(s_mc_message_actors_status_one_t);
185 xbt_assert(channel_.send(status.data(), size) == 0, "Could not send ACTORS_STATUS_REPLY data");
188 // Serialize each transition to describe what each actor is doing
189 if (total_transitions > 0) {
190 std::vector<s_mc_message_simcall_probe_one_t> probes(total_transitions);
191 auto probes_iter = probes.begin();
193 for (const auto& actor_status : status) {
194 if (not actor_status.enabled)
197 const auto& actor = actor_list.at(actor_status.aid);
198 const int max_considered = actor_status.max_considered;
200 for (int times_considered = 0; times_considered < max_considered; times_considered++, probes_iter++) {
201 std::stringstream stream;
202 s_mc_message_simcall_probe_one_t& probe = *probes_iter;
204 if (actor->simcall_.observer_ != nullptr) {
205 actor->simcall_.observer_->prepare(times_considered);
206 actor->simcall_.observer_->serialize(stream);
208 stream << (short)mc::Transition::Type::UNKNOWN;
211 std::string str = stream.str();
212 xbt_assert(str.size() + 1 <= probe.buffer.size(),
213 "The serialized transition is too large for the buffer. Please fix the code.");
214 strncpy(probe.buffer.data(), str.c_str(), probe.buffer.size() - 1);
215 probe.buffer.back() = '\0';
217 // NOTE: We do NOT need to reset `times_considered` for each actor's
218 // simcall observer here to the "original" value (i.e. the value BEFORE
219 // multiple prepare() calls were made for serialization purposes) since
220 // each SIMCALL_EXECUTE provides a `times_considered` to be used to prepare
221 // the transition before execution.
223 XBT_DEBUG("Deliver ACTOR_TRANSITION_PROBE payload");
225 for (const auto& probe : probes)
226 xbt_assert(channel_.send(probe) == 0, "Could not send ACTOR_TRANSITION_PROBE payload");
229 void AppSide::handle_actors_maxpid() const
231 s_mc_message_int_t answer = {};
232 answer.type = MessageType::ACTORS_MAXPID_REPLY;
233 answer.value = kernel::actor::ActorImpl::get_maxpid();
234 xbt_assert(channel_.send(answer) == 0, "Could not send response");
237 #define assert_msg_size(_name_, _type_) \
238 xbt_assert(received_size == sizeof(_type_), "Unexpected size for " _name_ " (%zd != %zu)", received_size, \
241 void AppSide::handle_messages()
243 while (true) { // Until we get a CONTINUE message
244 XBT_DEBUG("Waiting messages from model-checker");
246 std::array<char, MC_MESSAGE_LENGTH> message_buffer;
247 ssize_t received_size = channel_.receive(message_buffer.data(), message_buffer.size());
249 xbt_assert(received_size >= 0, "Could not receive commands from the model-checker");
250 xbt_assert(static_cast<size_t>(received_size) >= sizeof(s_mc_message_t), "Cannot handle short message (size=%zd)",
253 const s_mc_message_t* message = (s_mc_message_t*)message_buffer.data();
254 switch (message->type) {
255 case MessageType::DEADLOCK_CHECK:
256 assert_msg_size("DEADLOCK_CHECK", s_mc_message_t);
257 handle_deadlock_check(message);
260 case MessageType::CONTINUE:
261 assert_msg_size("MESSAGE_CONTINUE", s_mc_message_t);
264 case MessageType::SIMCALL_EXECUTE:
265 assert_msg_size("SIMCALL_EXECUTE", s_mc_message_simcall_execute_t);
266 handle_simcall_execute((s_mc_message_simcall_execute_t*)message_buffer.data());
269 case MessageType::FINALIZE:
270 assert_msg_size("FINALIZE", s_mc_message_int_t);
271 handle_finalize((s_mc_message_int_t*)message_buffer.data());
274 case MessageType::INITIAL_ADDRESSES:
275 assert_msg_size("INITIAL_ADDRESSES", s_mc_message_t);
276 handle_initial_addresses();
279 case MessageType::ACTORS_STATUS:
280 assert_msg_size("ACTORS_STATUS", s_mc_message_t);
281 handle_actors_status();
284 case MessageType::ACTORS_MAXPID:
285 assert_msg_size("ACTORS_MAXPID", s_mc_message_t);
286 handle_actors_maxpid();
290 xbt_die("Received unexpected message %s (%i)", to_c_str(message->type), static_cast<int>(message->type));
296 void AppSide::main_loop()
298 simgrid::mc::processes_time.resize(simgrid::kernel::actor::ActorImpl::get_maxpid());
299 MC_ignore_heap(simgrid::mc::processes_time.data(),
300 simgrid::mc::processes_time.size() * sizeof(simgrid::mc::processes_time[0]));
303 coverage_checkpoint();
306 simgrid::mc::execute_actors();
307 xbt_assert(channel_.send(MessageType::WAITING) == 0, "Could not send WAITING message to model-checker");
308 this->handle_messages();
312 void AppSide::report_assertion_failure()
314 xbt_assert(channel_.send(MessageType::ASSERTION_FAILED) == 0, "Could not send assertion to model-checker");
315 this->handle_messages();
318 void AppSide::ignore_memory(void* addr, std::size_t size) const
320 if (not MC_is_active() || not need_memory_info_)
323 s_mc_message_ignore_memory_t message = {};
324 message.type = MessageType::IGNORE_MEMORY;
325 message.addr = (std::uintptr_t)addr;
327 xbt_assert(channel_.send(message) == 0, "Could not send IGNORE_MEMORY message to model-checker");
330 void AppSide::ignore_heap(void* address, std::size_t size) const
332 if (not MC_is_active() || not need_memory_info_)
335 const s_xbt_mheap_t* heap = mmalloc_get_current_heap();
337 s_mc_message_ignore_heap_t message = {};
338 message.type = MessageType::IGNORE_HEAP;
339 message.address = address;
341 message.block = ((char*)address - (char*)heap->heapbase) / BLOCKSIZE + 1;
342 if (heap->heapinfo[message.block].type == 0) {
343 message.fragment = -1;
344 heap->heapinfo[message.block].busy_block.ignore++;
346 message.fragment = (ADDR2UINT(address) % BLOCKSIZE) >> heap->heapinfo[message.block].type;
347 heap->heapinfo[message.block].busy_frag.ignore[message.fragment]++;
350 xbt_assert(channel_.send(message) == 0, "Could not send ignored region to MCer");
353 void AppSide::unignore_heap(void* address, std::size_t size) const
355 if (not MC_is_active() || not need_memory_info_)
358 s_mc_message_ignore_memory_t message = {};
359 message.type = MessageType::UNIGNORE_HEAP;
360 message.addr = (std::uintptr_t)address;
362 xbt_assert(channel_.send(message) == 0, "Could not send IGNORE_HEAP message to model-checker");
365 void AppSide::declare_symbol(const char* name, int* value) const
367 if (not MC_is_active() || not need_memory_info_) {
368 XBT_CRITICAL("Ignore AppSide::declare_symbol(%s)", name);
372 s_mc_message_register_symbol_t message = {};
373 message.type = MessageType::REGISTER_SYMBOL;
374 xbt_assert(strlen(name) + 1 <= message.name.size(), "Symbol is too long");
375 strncpy(message.name.data(), name, message.name.size() - 1);
376 message.callback = nullptr;
377 message.data = value;
378 xbt_assert(channel_.send(message) == 0, "Could send REGISTER_SYMBOL message to model-checker");
381 /** Register a stack in the model checker
383 * The stacks are allocated in the heap. The MC handle them specifically
384 * when we analyze/compare the content of the heap so it must be told where
385 * they are with this function.
387 void AppSide::declare_stack(void* stack, size_t size, ucontext_t* context) const
389 if (not MC_is_active() || not need_memory_info_)
392 const s_xbt_mheap_t* heap = mmalloc_get_current_heap();
394 s_stack_region_t region = {};
395 region.address = stack;
396 region.context = context;
398 region.block = ((char*)stack - (char*)heap->heapbase) / BLOCKSIZE + 1;
400 s_mc_message_stack_region_t message = {};
401 message.type = MessageType::STACK_REGION;
402 message.stack_region = region;
403 xbt_assert(channel_.send(message) == 0, "Could not send STACK_REGION to model-checker");
405 } // namespace simgrid::mc