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Better responsabilities splitup between CheckerSide and RemoteProcessMemory
[simgrid.git] / src / mc / api / RemoteApp.cpp
index ad68366..df0c81f 100644 (file)
@@ -4,21 +4,16 @@
  * under the terms of the license (GNU LGPL) which comes with this package. */
 
 #include "src/mc/api/RemoteApp.hpp"
-#include "src/internal_config.h" // HAVE_SMPI
 #include "src/mc/explo/Exploration.hpp"
 #include "src/mc/mc_config.hpp"
 #include "xbt/asserts.h"
-#if HAVE_SMPI
-#include "smpi/smpi.h"
-#include "src/smpi/include/private.hpp"
-#endif
-#include "signal.h"
 #include "src/mc/api/State.hpp"
 #include "src/mc/mc_config.hpp"
 #include "src/mc/mc_exit.hpp"
 #include "src/mc/mc_private.hpp"
 #include "xbt/log.h"
 #include "xbt/system_error.hpp"
+#include <signal.h>
 
 #include <algorithm>
 #include <array>
 #ifdef __linux__
 #include <sys/prctl.h>
 #endif
+#include <sys/ptrace.h>
+#include <sys/wait.h>
+
+#ifdef __linux__
+#define WAITPID_CHECKED_FLAGS __WALL
+#else
+#define WAITPID_CHECKED_FLAGS 0
+#endif
 
 XBT_LOG_NEW_DEFAULT_SUBCATEGORY(mc_Session, mc, "Model-checker session");
 XBT_LOG_EXTERNAL_CATEGORY(mc_global);
@@ -102,12 +105,6 @@ XBT_ATTRIB_NORETURN static void run_child_process(int socket, const std::vector<
 
 RemoteApp::RemoteApp(const std::vector<char*>& args)
 {
-#if HAVE_SMPI
-  smpi_init_options(); // only performed once
-  xbt_assert(smpi_cfg_privatization() != SmpiPrivStrategies::MMAP,
-             "Please use the dlopen privatization schema when model-checking SMPI code");
-#endif
-
   // Create an AF_LOCAL socketpair used for exchanging messages
   // between the model-checker process (ourselves) and the model-checked
   // process:
@@ -126,37 +123,66 @@ RemoteApp::RemoteApp(const std::vector<char*>& args)
   // Parent (model-checker):
   ::close(sockets[0]);
 
-  xbt_assert(mc_model_checker == nullptr, "Did you manage to start the MC twice in this process?");
-
-  auto process   = std::make_unique<simgrid::mc::RemoteProcess>(pid);
-  model_checker_ = std::make_unique<simgrid::mc::ModelChecker>(std::move(process), sockets[1]);
+  checker_side_ = std::make_unique<simgrid::mc::CheckerSide>(sockets[1], pid);
 
-  mc_model_checker = model_checker_.get();
-  model_checker_->start();
+  start();
 
   /* Take the initial snapshot */
-  model_checker_->wait_for_requests();
-  initial_snapshot_ = std::make_shared<simgrid::mc::Snapshot>(0);
+  wait_for_requests();
+  initial_snapshot_ = std::make_shared<simgrid::mc::Snapshot>(0, page_store_, checker_side_->get_remote_memory());
 }
 
 RemoteApp::~RemoteApp()
 {
   initial_snapshot_ = nullptr;
-  if (model_checker_) {
-    model_checker_->shutdown();
-    model_checker_   = nullptr;
-    mc_model_checker = nullptr;
-  }
+  shutdown();
 }
+void RemoteApp::start()
+{
+  XBT_DEBUG("Waiting for the model-checked process");
+  int status;
 
+  // The model-checked process SIGSTOP itself to signal it's ready:
+  const pid_t pid = checker_side_->get_pid();
+
+  xbt_assert(waitpid(pid, &status, WAITPID_CHECKED_FLAGS) == pid && WIFSTOPPED(status) && WSTOPSIG(status) == SIGSTOP,
+             "Could not wait model-checked process");
+
+  errno = 0;
+#ifdef __linux__
+  ptrace(PTRACE_SETOPTIONS, pid, nullptr, PTRACE_O_TRACEEXIT);
+  ptrace(PTRACE_CONT, pid, 0, 0);
+#elif defined BSD
+  ptrace(PT_CONTINUE, pid, (caddr_t)1, 0);
+#else
+#error "no ptrace equivalent coded for this platform"
+#endif
+  xbt_assert(errno == 0,
+             "Ptrace does not seem to be usable in your setup (errno: %d). "
+             "If you run from within a docker, adding `--cap-add SYS_PTRACE` to the docker line may help. "
+             "If it does not help, please report this bug.",
+             errno);
+}
 void RemoteApp::restore_initial_state() const
 {
-  this->initial_snapshot_->restore(&model_checker_->get_remote_process());
+  this->initial_snapshot_->restore(checker_side_->get_remote_memory());
 }
 
 unsigned long RemoteApp::get_maxpid() const
 {
-  return model_checker_->get_remote_process().get_maxpid();
+  // note: we could maybe cache it and count the actor creation on checker side too.
+  // But counting correctly accross state checkpoint/restore would be annoying.
+
+  checker_side_->get_channel().send(MessageType::ACTORS_MAXPID);
+  s_mc_message_int_t answer;
+  ssize_t answer_size = checker_side_->get_channel().receive(answer);
+  xbt_assert(answer_size != -1, "Could not receive message");
+  xbt_assert(answer_size == sizeof answer, "Broken message (size=%zd; expected %zu)", answer_size, sizeof answer);
+  xbt_assert(answer.type == MessageType::ACTORS_MAXPID_REPLY,
+             "Received unexpected message %s (%i); expected MessageType::ACTORS_MAXPID_REPLY (%i)",
+             to_c_str(answer.type), (int)answer.type, (int)MessageType::ACTORS_MAXPID_REPLY);
+
+  return answer.value;
 }
 
 void RemoteApp::get_actors_status(std::map<aid_t, ActorState>& whereto) const
@@ -168,16 +194,15 @@ void RemoteApp::get_actors_status(std::map<aid_t, ActorState>& whereto) const
   //                    <----- send ACTORS_STATUS_REPLY
   //                    <----- send `N` `s_mc_message_actors_status_one_t` structs
   //                    <----- send `M` `s_mc_message_simcall_probe_one_t` structs
-  model_checker_->channel().send(MessageType::ACTORS_STATUS);
+  checker_side_->get_channel().send(MessageType::ACTORS_STATUS);
 
   s_mc_message_actors_status_answer_t answer;
-  ssize_t received = model_checker_->channel().receive(answer);
-  xbt_assert(received != -1, "Could not receive message");
-  xbt_assert(received == sizeof(answer) && answer.type == MessageType::ACTORS_STATUS_REPLY,
-             "Received unexpected message %s (%i, size=%i) "
-             "expected MessageType::ACTORS_STATUS_REPLY (%i, size=%i)",
-             to_c_str(answer.type), (int)answer.type, (int)received, (int)MessageType::ACTORS_STATUS_REPLY,
-             (int)sizeof(answer));
+  ssize_t answer_size = checker_side_->get_channel().receive(answer);
+  xbt_assert(answer_size != -1, "Could not receive message");
+  xbt_assert(answer_size == sizeof answer, "Broken message (size=%zd; expected %zu)", answer_size, sizeof answer);
+  xbt_assert(answer.type == MessageType::ACTORS_STATUS_REPLY,
+             "Received unexpected message %s (%i); expected MessageType::ACTORS_STATUS_REPLY (%i)",
+             to_c_str(answer.type), (int)answer.type, (int)MessageType::ACTORS_STATUS_REPLY);
 
   // Message sanity checks
   xbt_assert(answer.count >= 0, "Received an ACTOR_STATUS_REPLY message with an actor count of '%d' < 0", answer.count);
@@ -190,7 +215,7 @@ void RemoteApp::get_actors_status(std::map<aid_t, ActorState>& whereto) const
   std::vector<s_mc_message_actors_status_one_t> status(answer.count);
   if (answer.count > 0) {
     size_t size      = status.size() * sizeof(s_mc_message_actors_status_one_t);
-    ssize_t received = model_checker_->channel().receive(status.data(), size);
+    ssize_t received = checker_side_->get_channel().receive(status.data(), size);
     xbt_assert(static_cast<size_t>(received) == size);
   }
 
@@ -206,17 +231,16 @@ void RemoteApp::get_actors_status(std::map<aid_t, ActorState>& whereto) const
   std::vector<s_mc_message_simcall_probe_one_t> probes(answer.transition_count);
   if (answer.transition_count > 0) {
     for (auto& probe : probes) {
-      size_t size      = sizeof(s_mc_message_simcall_probe_one_t);
-      ssize_t received = model_checker_->channel().receive(&probe, size);
+      ssize_t received = checker_side_->get_channel().receive(probe);
       xbt_assert(received >= 0, "Could not receive response to ACTORS_PROBE message (%s)", strerror(errno));
-      xbt_assert(static_cast<size_t>(received) == size,
+      xbt_assert(static_cast<size_t>(received) == sizeof probe,
                  "Could not receive response to ACTORS_PROBE message (%zd bytes received != %zu bytes expected",
-                 received, size);
+                 received, sizeof probe);
     }
   }
 
   whereto.clear();
-  auto probes_iter = std::move_iterator(probes.begin());
+  std::move_iterator probes_iter(probes.begin());
 
   for (const auto& actor : status) {
     xbt_assert(actor.n_transitions == 0 || actor.n_transitions == actor.max_considered,
@@ -225,39 +249,105 @@ void RemoteApp::get_actors_status(std::map<aid_t, ActorState>& whereto) const
                "(currently %d), but only %d transition(s) was/were said to be encoded",
                actor.max_considered, actor.n_transitions);
 
-    auto actor_transitions = std::vector<std::unique_ptr<Transition>>(actor.n_transitions);
+    std::vector<std::shared_ptr<Transition>> actor_transitions;
     for (int times_considered = 0; times_considered < actor.n_transitions; times_considered++, probes_iter++) {
       std::stringstream stream((*probes_iter).buffer.data());
-      auto transition = std::unique_ptr<Transition>(deserialize_transition(actor.aid, times_considered, stream));
-      actor_transitions[times_considered] = std::move(transition);
+      actor_transitions.emplace_back(deserialize_transition(actor.aid, times_considered, stream));
     }
 
-    XBT_DEBUG("Received %d transitions for actor %ld", actor.n_transitions, actor.aid);
+    XBT_DEBUG("Received %zu transitions for actor %ld", actor_transitions.size(), actor.aid);
     whereto.try_emplace(actor.aid, actor.aid, actor.enabled, actor.max_considered, std::move(actor_transitions));
   }
 }
 
 void RemoteApp::check_deadlock() const
 {
-  xbt_assert(model_checker_->channel().send(MessageType::DEADLOCK_CHECK) == 0, "Could not check deadlock state");
+  xbt_assert(checker_side_->get_channel().send(MessageType::DEADLOCK_CHECK) == 0, "Could not check deadlock state");
   s_mc_message_int_t message;
-  ssize_t s = model_checker_->channel().receive(message);
-  xbt_assert(s != -1, "Could not receive message");
-  xbt_assert(s == sizeof(message) && message.type == MessageType::DEADLOCK_CHECK_REPLY,
-             "Received unexpected message %s (%i, size=%i) "
-             "expected MessageType::DEADLOCK_CHECK_REPLY (%i, size=%i)",
-             to_c_str(message.type), (int)message.type, (int)s, (int)MessageType::DEADLOCK_CHECK_REPLY,
-             (int)sizeof(message));
+  ssize_t received = checker_side_->get_channel().receive(message);
+  xbt_assert(received != -1, "Could not receive message");
+  xbt_assert(received == sizeof message, "Broken message (size=%zd; expected %zu)", received, sizeof message);
+  xbt_assert(message.type == MessageType::DEADLOCK_CHECK_REPLY,
+             "Received unexpected message %s (%i); expected MessageType::DEADLOCK_CHECK_REPLY (%i)",
+             to_c_str(message.type), (int)message.type, (int)MessageType::DEADLOCK_CHECK_REPLY);
 
   if (message.value != 0) {
+    auto* explo = Exploration::get_instance();
     XBT_CINFO(mc_global, "Counter-example execution trace:");
-    for (auto const& frame : model_checker_->get_exploration()->get_textual_trace())
+    for (auto const& frame : explo->get_textual_trace())
       XBT_CINFO(mc_global, "  %s", frame.c_str());
     XBT_INFO("You can debug the problem (and see the whole details) by rerunning out of simgrid-mc with "
              "--cfg=model-check/replay:'%s'",
-             model_checker_->get_exploration()->get_record_trace().to_string().c_str());
-    model_checker_->get_exploration()->log_state();
+             explo->get_record_trace().to_string().c_str());
+    explo->log_state();
     throw DeadlockError();
   }
 }
+
+void RemoteApp::wait_for_requests()
+{
+  /* Resume the application */
+  if (checker_side_->get_channel().send(MessageType::CONTINUE) != 0)
+    throw xbt::errno_error();
+  get_remote_process_memory().clear_cache();
+
+  if (checker_side_->running())
+    checker_side_->dispatch_events();
+}
+
+void RemoteApp::shutdown()
+{
+  XBT_DEBUG("Shutting down model-checker");
+
+  if (checker_side_->running()) {
+    XBT_DEBUG("Killing process");
+    finalize_app(true);
+    kill(checker_side_->get_pid(), SIGKILL);
+    checker_side_->terminate();
+  }
+}
+
+Transition* RemoteApp::handle_simcall(aid_t aid, int times_considered, bool new_transition)
+{
+  s_mc_message_simcall_execute_t m = {};
+  m.type                           = MessageType::SIMCALL_EXECUTE;
+  m.aid_                           = aid;
+  m.times_considered_              = times_considered;
+  checker_side_->get_channel().send(m);
+
+  get_remote_process_memory().clear_cache();
+  if (checker_side_->running())
+    checker_side_->dispatch_events(); // The app may send messages while processing the transition
+
+  s_mc_message_simcall_execute_answer_t answer;
+  ssize_t s = checker_side_->get_channel().receive(answer);
+  xbt_assert(s != -1, "Could not receive message");
+  xbt_assert(s == sizeof answer, "Broken message (size=%zd; expected %zu)", s, sizeof answer);
+  xbt_assert(answer.type == MessageType::SIMCALL_EXECUTE_ANSWER,
+             "Received unexpected message %s (%i); expected MessageType::SIMCALL_EXECUTE_ANSWER (%i)",
+             to_c_str(answer.type), (int)answer.type, (int)MessageType::SIMCALL_EXECUTE_ANSWER);
+
+  if (new_transition) {
+    std::stringstream stream(answer.buffer.data());
+    return deserialize_transition(aid, times_considered, stream);
+  } else
+    return nullptr;
+}
+
+void RemoteApp::finalize_app(bool terminate_asap)
+{
+  s_mc_message_int_t m = {};
+  m.type               = MessageType::FINALIZE;
+  m.value              = terminate_asap;
+  xbt_assert(checker_side_->get_channel().send(m) == 0, "Could not ask the app to finalize on need");
+
+  s_mc_message_t answer;
+  ssize_t s = checker_side_->get_channel().receive(answer);
+  xbt_assert(s != -1, "Could not receive answer to FINALIZE");
+  xbt_assert(s == sizeof answer, "Broken message (size=%zd; expected %zu)", s, sizeof answer);
+  xbt_assert(answer.type == MessageType::FINALIZE_REPLY,
+             "Received unexpected message %s (%i); expected MessageType::FINALIZE_REPLY (%i)", to_c_str(answer.type),
+             (int)answer.type, (int)MessageType::FINALIZE_REPLY);
+}
+
 } // namespace simgrid::mc