-/* Copyright (c) 2015-2022. The SimGrid Team. All rights reserved. */
+/* Copyright (c) 2015-2023. The SimGrid Team. All rights reserved. */
/* This program is free software; you can redistribute it and/or modify it
* under the terms of the license (GNU LGPL) which comes with this package. */
#include "src/kernel/actor/SimcallObserver.hpp"
#include "src/mc/mc_base.hpp"
#include "src/mc/mc_config.hpp"
-#include "src/mc/remote/RemoteProcess.hpp"
+#include "src/mc/mc_environ.h"
#if HAVE_SMPI
#include "src/smpi/include/private.hpp"
#endif
-#include "xbt/coverage.h"
+#include "src/sthread/sthread.h"
+#include "src/xbt/coverage.h"
#include "xbt/str.h"
-#include "xbt/xbt_modinter.h" /* mmalloc_preinit to get the default mmalloc arena address */
#include <simgrid/modelchecker.h>
#include <cerrno>
+#include <cinttypes>
#include <cstdio> // setvbuf
#include <cstdlib>
-#include <cstring>
#include <memory>
+#include <numeric>
#include <sys/ptrace.h>
#include <sys/socket.h>
#include <sys/types.h>
+#include <sys/un.h>
+#include <sys/wait.h>
XBT_LOG_NEW_DEFAULT_SUBCATEGORY(mc_client, mc, "MC client logic");
XBT_LOG_EXTERNAL_CATEGORY(mc_global);
std::unique_ptr<AppSide> AppSide::instance_;
-AppSide* AppSide::initialize()
+AppSide* AppSide::get()
{
- if (not std::getenv(MC_ENV_SOCKET_FD)) // We are not in MC mode: don't initialize the MC world
+ // Only initialize the MC world once
+ if (instance_ != nullptr)
+ return instance_.get();
+
+ if (std::getenv(MC_ENV_SOCKET_FD) == nullptr) // We are not in MC mode: don't initialize the MC world
return nullptr;
- // Do not break if we are called multiple times:
- if (instance_)
- return instance_.get();
+ XBT_DEBUG("Initialize the MC world.");
- simgrid::mc::cfg_do_model_check = true;
+ simgrid::mc::set_model_checking_mode(ModelCheckingMode::APP_SIDE);
setvbuf(stdout, nullptr, _IOLBF, 0);
int fd = xbt_str_parse_int(fd_env, "Not a number in variable '" MC_ENV_SOCKET_FD "'");
XBT_DEBUG("Model-checked application found socket FD %i", fd);
- // Check the socket type/validity:
- int type;
- socklen_t socklen = sizeof(type);
- xbt_assert(getsockopt(fd, SOL_SOCKET, SO_TYPE, &type, &socklen) == 0, "Could not check socket type");
- xbt_assert(type == SOCK_SEQPACKET, "Unexpected socket type %i", type);
- XBT_DEBUG("Model-checked application found expected socket type");
-
instance_ = std::make_unique<simgrid::mc::AppSide>(fd);
- // Wait for the model-checker:
- errno = 0;
-#if defined __linux__
- ptrace(PTRACE_TRACEME, 0, nullptr, nullptr);
-#elif defined BSD
- ptrace(PT_TRACE_ME, 0, nullptr, 0);
-#else
-#error "no ptrace equivalent coded for this platform"
-#endif
- xbt_assert(errno == 0 && raise(SIGSTOP) == 0, "Could not wait for the model-checker (errno = %d: %s)", errno,
- strerror(errno));
-
- s_mc_message_initial_addresses_t message{MessageType::INITIAL_ADDRESSES, mmalloc_get_current_heap(),
- kernel::actor::ActorImpl::get_maxpid_addr()};
- xbt_assert(instance_->channel_.send(message) == 0, "Could not send the initial message with addresses.");
-
instance_->handle_messages();
return instance_.get();
}
void AppSide::handle_deadlock_check(const s_mc_message_t*) const
{
- auto* engine = kernel::EngineImpl::get_instance();
+ const auto* engine = kernel::EngineImpl::get_instance();
const auto& actor_list = engine->get_actor_list();
bool deadlock = not actor_list.empty() && std::none_of(begin(actor_list), end(actor_list), [](const auto& kv) {
return mc::actor_is_enabled(kv.second);
engine->display_all_actor_status();
}
// Send result:
- s_mc_message_int_t answer{MessageType::DEADLOCK_CHECK_REPLY, deadlock};
- xbt_assert(channel_.send(answer) == 0, "Could not send response");
+ s_mc_message_int_t answer = {};
+ answer.type = MessageType::DEADLOCK_CHECK_REPLY;
+ answer.value = deadlock;
+ xbt_assert(channel_.send(answer) == 0, "Could not send response: %s", strerror(errno));
}
void AppSide::handle_simcall_execute(const s_mc_message_simcall_execute_t* message) const
{
kernel::actor::ActorImpl* actor = kernel::EngineImpl::get_instance()->get_actor_by_pid(message->aid_);
xbt_assert(actor != nullptr, "Invalid pid %ld", message->aid_);
+ xbt_assert(actor->simcall_.observer_ == nullptr || actor->simcall_.observer_->is_enabled(),
+ "Please, model-checker, don't execute disabled transitions.");
// The client may send some messages to the server while processing the transition
actor->simcall_handle(message->times_considered_);
// Say the server that the transition is over and that it should proceed
- xbt_assert(channel_.send(MessageType::WAITING) == 0, "Could not send MESSAGE_WAITING to model-checker");
+ xbt_assert(channel_.send(MessageType::WAITING) == 0, "Could not send MESSAGE_WAITING to model-checker: %s",
+ strerror(errno));
// Finish the RPC from the server: return a serialized observer, to build a Transition on Checker side
- s_mc_message_simcall_execute_answer_t answer;
- memset(&answer, 0, sizeof(answer));
- answer.type = MessageType::SIMCALL_EXECUTE_ANSWER;
+ s_mc_message_simcall_execute_answer_t answer = {};
+ answer.type = MessageType::SIMCALL_EXECUTE_REPLY;
std::stringstream stream;
if (actor->simcall_.observer_ != nullptr) {
actor->simcall_.observer_->serialize(stream);
answer.buffer.back() = '\0';
XBT_DEBUG("send SIMCALL_EXECUTE_ANSWER(%s) ~> '%s'", actor->get_cname(), str.c_str());
- xbt_assert(channel_.send(answer) == 0, "Could not send response");
+ xbt_assert(channel_.send(answer) == 0, "Could not send response: %s", strerror(errno));
}
void AppSide::handle_finalize(const s_mc_message_int_t* msg) const
#endif
}
coverage_checkpoint();
- xbt_assert(channel_.send(MessageType::FINALIZE_REPLY) == 0, "Could not answer to FINALIZE");
+ xbt_assert(channel_.send(MessageType::FINALIZE_REPLY) == 0, "Could not answer to FINALIZE: %s", strerror(errno));
std::fflush(stdout);
if (terminate_asap)
::_Exit(0);
}
+void AppSide::handle_fork(const s_mc_message_fork_t* msg)
+{
+ int status;
+ int pid;
+ /* Reap any zombie child, saving its status for later use in AppSide::handle_wait_child() */
+ while ((pid = waitpid(-1, &status, WNOHANG)) > 0)
+ child_statuses_[pid] = status;
+
+ pid = fork();
+ xbt_assert(pid >= 0, "Could not fork application sub-process: %s.", strerror(errno));
+
+ if (pid == 0) { // Child
+ int sock = socket(AF_UNIX,
+#ifdef __APPLE__
+ SOCK_STREAM, /* Mac OSX does not have AF_UNIX + SOCK_SEQPACKET, even if that's faster*/
+#else
+ SOCK_SEQPACKET,
+#endif
+ 0);
+
+ struct sockaddr_un addr = {};
+ addr.sun_family = AF_UNIX;
+ std::copy_n(begin(msg->socket_name), MC_SOCKET_NAME_LEN, addr.sun_path);
+
+ xbt_assert(connect(sock, (struct sockaddr*)&addr, sizeof addr) >= 0, "Cannot connect to Checker on %c%s: %s.",
+ (addr.sun_path[0] ? addr.sun_path[0] : '@'), addr.sun_path + 1, strerror(errno));
+
+ channel_.reset_socket(sock);
+
+ s_mc_message_int_t answer = {};
+ answer.type = MessageType::FORK_REPLY;
+ answer.value = getpid();
+ xbt_assert(channel_.send(answer) == 0, "Could not send response to WAIT_CHILD_REPLY: %s", strerror(errno));
+ } else {
+ XBT_VERB("App %d forks subprocess %d.", getpid(), pid);
+ }
+}
+void AppSide::handle_wait_child(const s_mc_message_int_t* msg)
+{
+ int status;
+ errno = 0;
+ if (auto search = child_statuses_.find(msg->value); search != child_statuses_.end()) {
+ status = search->second;
+ child_statuses_.erase(search); // We only need this info once
+ } else {
+ waitpid(msg->value, &status, 0);
+ }
+ xbt_assert(errno == 0, "Cannot wait on behalf of the checker: %s.", strerror(errno));
+
+ s_mc_message_int_t answer = {};
+ answer.type = MessageType::WAIT_CHILD_REPLY;
+ answer.value = status;
+ xbt_assert(channel_.send(answer) == 0, "Could not send response to WAIT_CHILD: %s", strerror(errno));
+}
void AppSide::handle_actors_status() const
{
auto const& actor_list = kernel::EngineImpl::get_instance()->get_actor_list();
- int count = actor_list.size();
- XBT_DEBUG("Serialize the actors to answer ACTORS_STATUS from the checker. %d actors to go.", count);
-
- struct s_mc_message_actors_status_answer_t answer {
- MessageType::ACTORS_STATUS_REPLY, count
- };
- std::vector<s_mc_message_actors_status_one_t> status(count);
- int i = 0;
+ XBT_DEBUG("Serialize the actors to answer ACTORS_STATUS from the checker. %zu actors to go.", actor_list.size());
+
+ std::vector<s_mc_message_actors_status_one_t> status;
for (auto const& [aid, actor] : actor_list) {
- status[i].aid = aid;
- status[i].enabled = mc::actor_is_enabled(actor);
- status[i].max_considered = actor->simcall_.observer_->get_max_consider();
- i++;
+ xbt_assert(actor);
+ xbt_assert(actor->simcall_.observer_, "simcall %s in actor %s has no observer.", actor->simcall_.get_cname(),
+ actor->get_cname());
+ s_mc_message_actors_status_one_t one = {};
+ one.type = MessageType::ACTORS_STATUS_REPLY_TRANSITION;
+ one.aid = aid;
+ one.enabled = mc::actor_is_enabled(actor);
+ one.max_considered = actor->simcall_.observer_->get_max_consider();
+ status.push_back(one);
}
- xbt_assert(channel_.send(answer) == 0, "Could not send ACTORS_STATUS_REPLY msg");
+
+ struct s_mc_message_actors_status_answer_t answer = {};
+ answer.type = MessageType::ACTORS_STATUS_REPLY_COUNT;
+ answer.count = static_cast<int>(status.size());
+
+ xbt_assert(channel_.send(answer) == 0, "Could not send ACTORS_STATUS_REPLY msg: %s", strerror(errno));
if (answer.count > 0) {
size_t size = status.size() * sizeof(s_mc_message_actors_status_one_t);
- xbt_assert(channel_.send(status.data(), size) == 0, "Could not send ACTORS_STATUS_REPLY data");
+ xbt_assert(channel_.send(status.data(), size) == 0, "Could not send ACTORS_STATUS_REPLY data: %s", strerror(errno));
}
+
+ // Serialize each transition to describe what each actor is doing
+ XBT_DEBUG("Deliver ACTOR_TRANSITION_PROBE payload");
+ for (const auto& actor_status : status) {
+ const auto& actor = actor_list.at(actor_status.aid);
+ const int max_considered = actor_status.max_considered;
+
+ for (int times_considered = 0; times_considered < max_considered; times_considered++) {
+ std::stringstream stream;
+ s_mc_message_simcall_probe_one_t probe;
+ probe.type = MessageType::ACTORS_STATUS_REPLY_SIMCALL;
+
+ if (actor->simcall_.observer_ != nullptr) {
+ actor->simcall_.observer_->prepare(times_considered);
+ actor->simcall_.observer_->serialize(stream);
+ } else {
+ stream << (short)mc::Transition::Type::UNKNOWN;
+ }
+
+ std::string str = stream.str();
+ xbt_assert(str.size() + 1 <= probe.buffer.size(),
+ "The serialized transition is too large for the buffer. Please fix the code.");
+ strncpy(probe.buffer.data(), str.c_str(), probe.buffer.size() - 1);
+ probe.buffer.back() = '\0';
+
+ XBT_DEBUG("send ACTOR_TRANSITION_PROBE(%s) ~> '%s'", actor->get_cname(), str.c_str());
+ xbt_assert(channel_.send(probe) == 0, "Could not send ACTOR_TRANSITION_PROBE payload: %s", strerror(errno));
+ }
+ // NOTE: We do NOT need to reset `times_considered` for each actor's
+ // simcall observer here to the "original" value (i.e. the value BEFORE
+ // multiple prepare() calls were made for serialization purposes) since
+ // each SIMCALL_EXECUTE provides a `times_considered` to be used to prepare
+ // the transition before execution.
+ }
+}
+void AppSide::handle_actors_maxpid() const
+{
+ s_mc_message_int_t answer = {};
+ answer.type = MessageType::ACTORS_MAXPID_REPLY;
+ answer.value = kernel::actor::ActorImpl::get_maxpid();
+ xbt_assert(channel_.send(answer) == 0, "Could not send response: %s", strerror(errno));
}
#define assert_msg_size(_name_, _type_) \
xbt_assert(received_size == sizeof(_type_), "Unexpected size for " _name_ " (%zd != %zu)", received_size, \
sizeof(_type_))
-void AppSide::handle_messages() const
+void AppSide::handle_messages()
{
while (true) { // Until we get a CONTINUE message
- XBT_DEBUG("Waiting messages from model-checker");
+ XBT_DEBUG("Waiting messages from the model-checker");
std::array<char, MC_MESSAGE_LENGTH> message_buffer;
ssize_t received_size = channel_.receive(message_buffer.data(), message_buffer.size());
- xbt_assert(received_size >= 0, "Could not receive commands from the model-checker");
+ if (received_size == 0) {
+ XBT_DEBUG("Socket closed on the Checker side, bailing out.");
+ ::_Exit(0); // Nobody's listening to that process anymore => exit as quickly as possible.
+ }
+ xbt_assert(received_size >= 0, "Could not receive commands from the model-checker: %s", strerror(errno));
+ xbt_assert(static_cast<size_t>(received_size) >= sizeof(s_mc_message_t), "Cannot handle short message (size=%zd)",
+ received_size);
const s_mc_message_t* message = (s_mc_message_t*)message_buffer.data();
switch (message->type) {
+ case MessageType::CONTINUE:
+ assert_msg_size("MESSAGE_CONTINUE", s_mc_message_t);
+ return;
+
case MessageType::DEADLOCK_CHECK:
assert_msg_size("DEADLOCK_CHECK", s_mc_message_t);
handle_deadlock_check(message);
break;
- case MessageType::CONTINUE:
- assert_msg_size("MESSAGE_CONTINUE", s_mc_message_t);
- return;
-
case MessageType::SIMCALL_EXECUTE:
assert_msg_size("SIMCALL_EXECUTE", s_mc_message_simcall_execute_t);
handle_simcall_execute((s_mc_message_simcall_execute_t*)message_buffer.data());
handle_finalize((s_mc_message_int_t*)message_buffer.data());
break;
+ case MessageType::FORK:
+ assert_msg_size("FORK", s_mc_message_fork_t);
+ handle_fork((s_mc_message_fork_t*)message_buffer.data());
+ break;
+
+ case MessageType::WAIT_CHILD:
+ assert_msg_size("WAIT_CHILD", s_mc_message_int_t);
+ handle_wait_child((s_mc_message_int_t*)message_buffer.data());
+ break;
+
case MessageType::ACTORS_STATUS:
assert_msg_size("ACTORS_STATUS", s_mc_message_t);
handle_actors_status();
break;
+ case MessageType::ACTORS_MAXPID:
+ assert_msg_size("ACTORS_MAXPID", s_mc_message_t);
+ handle_actors_maxpid();
+ break;
+
default:
xbt_die("Received unexpected message %s (%i)", to_c_str(message->type), static_cast<int>(message->type));
break;
}
}
-void AppSide::main_loop() const
+void AppSide::main_loop()
{
simgrid::mc::processes_time.resize(simgrid::kernel::actor::ActorImpl::get_maxpid());
- MC_ignore_heap(simgrid::mc::processes_time.data(),
- simgrid::mc::processes_time.size() * sizeof(simgrid::mc::processes_time[0]));
+ sthread_disable();
coverage_checkpoint();
+ sthread_enable();
while (true) {
simgrid::mc::execute_actors();
- xbt_assert(channel_.send(MessageType::WAITING) == 0, "Could not send WAITING message to model-checker");
+ xbt_assert(channel_.send(MessageType::WAITING) == 0, "Could not send WAITING message to model-checker: %s",
+ strerror(errno));
this->handle_messages();
}
}
-void AppSide::report_assertion_failure() const
+void AppSide::report_assertion_failure()
{
- xbt_assert(channel_.send(MessageType::ASSERTION_FAILED) == 0, "Could not send assertion to model-checker");
+ xbt_assert(channel_.send(MessageType::ASSERTION_FAILED) == 0, "Could not send assertion to model-checker: %s",
+ strerror(errno));
this->handle_messages();
}
-void AppSide::ignore_memory(void* addr, std::size_t size) const
-{
- if (not MC_is_active())
- return;
-
- s_mc_message_ignore_memory_t message;
- message.type = MessageType::IGNORE_MEMORY;
- message.addr = (std::uintptr_t)addr;
- message.size = size;
- xbt_assert(channel_.send(message) == 0, "Could not send IGNORE_MEMORY message to model-checker");
-}
-
-void AppSide::ignore_heap(void* address, std::size_t size) const
-{
- if (not MC_is_active())
- return;
-
- const s_xbt_mheap_t* heap = mmalloc_get_current_heap();
-
- s_mc_message_ignore_heap_t message;
- message.type = MessageType::IGNORE_HEAP;
- message.address = address;
- message.size = size;
- message.block = ((char*)address - (char*)heap->heapbase) / BLOCKSIZE + 1;
- if (heap->heapinfo[message.block].type == 0) {
- message.fragment = -1;
- heap->heapinfo[message.block].busy_block.ignore++;
- } else {
- message.fragment = (ADDR2UINT(address) % BLOCKSIZE) >> heap->heapinfo[message.block].type;
- heap->heapinfo[message.block].busy_frag.ignore[message.fragment]++;
- }
-
- xbt_assert(channel_.send(message) == 0, "Could not send ignored region to MCer");
-}
-
-void AppSide::unignore_heap(void* address, std::size_t size) const
-{
- if (not MC_is_active())
- return;
-
- s_mc_message_ignore_memory_t message;
- message.type = MessageType::UNIGNORE_HEAP;
- message.addr = (std::uintptr_t)address;
- message.size = size;
- xbt_assert(channel_.send(message) == 0, "Could not send IGNORE_HEAP message to model-checker");
-}
-
-void AppSide::declare_symbol(const char* name, int* value) const
-{
- if (not MC_is_active())
- return;
-
- s_mc_message_register_symbol_t message;
- memset(&message, 0, sizeof(message));
- message.type = MessageType::REGISTER_SYMBOL;
- xbt_assert(strlen(name) + 1 <= message.name.size(), "Symbol is too long");
- strncpy(message.name.data(), name, message.name.size() - 1);
- message.callback = nullptr;
- message.data = value;
- xbt_assert(channel_.send(message) == 0, "Could send REGISTER_SYMBOL message to model-checker");
-}
-
-/** Register a stack in the model checker
- *
- * The stacks are allocated in the heap. The MC handle them specifically
- * when we analyze/compare the content of the heap so it must be told where
- * they are with this function.
- */
-void AppSide::declare_stack(void* stack, size_t size, ucontext_t* context) const
-{
- if (not MC_is_active())
- return;
-
- const s_xbt_mheap_t* heap = mmalloc_get_current_heap();
-
- s_stack_region_t region;
- memset(®ion, 0, sizeof(region));
- region.address = stack;
- region.context = context;
- region.size = size;
- region.block = ((char*)stack - (char*)heap->heapbase) / BLOCKSIZE + 1;
-
- s_mc_message_stack_region_t message;
- message.type = MessageType::STACK_REGION;
- message.stack_region = region;
- xbt_assert(channel_.send(message) == 0, "Could not send STACK_REGION to model-checker");
-}
} // namespace simgrid::mc