#include "src/kernel/actor/SimcallObserver.hpp"
#include "src/mc/mc_base.hpp"
#include "src/mc/mc_config.hpp"
+#include "src/mc/mc_environ.h"
+#if SIMGRID_HAVE_STATEFUL_MC
#include "src/mc/sosp/RemoteProcessMemory.hpp"
+#endif
#if HAVE_SMPI
#include "src/smpi/include/private.hpp"
#endif
#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. %s=%s", MC_ENV_NEED_PTRACE, std::getenv(MC_ENV_NEED_PTRACE));
- simgrid::mc::model_checking_mode = ModelCheckingMode::APP_SIDE;
+ 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 (getenv(MC_ENV_NEED_PTRACE) != nullptr) {
+ errno = 0;
#if defined __linux__
- ptrace(PTRACE_TRACEME, 0, nullptr, nullptr);
+ ptrace(PTRACE_TRACEME, 0, nullptr, nullptr);
#elif defined BSD
- ptrace(PT_TRACE_ME, 0, nullptr, 0);
+ ptrace(PT_TRACE_ME, 0, nullptr, 0);
#else
-#error "no ptrace equivalent coded for this platform"
+ xbt_die("no ptrace equivalent coded for this platform, please don't use the liveness checker here.");
#endif
- xbt_assert(errno == 0 && raise(SIGSTOP) == 0, "Could not wait for the model-checker (errno = %d: %s)", errno,
- strerror(errno));
+
+ xbt_assert(errno == 0 && raise(SIGSTOP) == 0, "Could not wait for the model-checker (errno = %d: %s)", errno,
+ strerror(errno));
+ }
instance_->handle_messages();
return instance_.get();
// 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 = {};
- answer.type = MessageType::SIMCALL_EXECUTE_ANSWER;
+ answer.type = MessageType::SIMCALL_EXECUTE_REPLY;
std::stringstream stream;
if (actor->simcall_.observer_ != nullptr) {
actor->simcall_.observer_->serialize(stream);
if (terminate_asap)
::_Exit(0);
}
-void AppSide::handle_initial_addresses()
+void AppSide::handle_fork(const s_mc_message_int_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;
+ snprintf(addr.sun_path, 64, "/tmp/simgrid-mc-%lu", static_cast<unsigned long>(msg->value));
+ auto addr_size = offsetof(struct sockaddr_un, sun_path) + strlen(addr.sun_path);
+
+ xbt_assert(connect(sock, (struct sockaddr*)&addr, addr_size) >= 0,
+ "Cannot connect to Checker on %s: %s.", addr.sun_path, 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)
{
- this->need_memory_info_ = true;
- s_mc_message_initial_addresses_reply_t answer = {};
- answer.type = MessageType::INITIAL_ADDRESSES_REPLY;
- answer.mmalloc_default_mdp = mmalloc_get_current_heap();
- xbt_assert(channel_.send(answer) == 0, "Could not send response with initial addresses.");
+ 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_need_meminfo()
+{
+#if SIMGRID_HAVE_STATEFUL_MC
+ this->need_memory_info_ = true;
+ s_mc_message_need_meminfo_reply_t answer = {};
+ answer.type = MessageType::NEED_MEMINFO_REPLY;
+ answer.mmalloc_default_mdp = mmalloc_get_current_heap();
+ xbt_assert(channel_.send(answer) == 0, "Could not send response to the request for meminfo.");
+#else
+ xbt_die("SimGrid was compiled without MC suppport, so liveness and similar features are not available.");
+#endif
}
void AppSide::handle_actors_status() const
{
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.emplace_back(s_mc_message_actors_status_one_t{aid, mc::actor_is_enabled(actor),
- actor->simcall_.observer_->get_max_consider()});
+ for (auto const& [aid, actor] : actor_list) {
+ 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);
+ }
struct s_mc_message_actors_status_answer_t answer = {};
- answer.type = MessageType::ACTORS_STATUS_REPLY;
- answer.count = static_cast<int>(status.size());
+ 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");
if (answer.count > 0) {
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);
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());
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::INITIAL_ADDRESSES:
- assert_msg_size("INITIAL_ADDRESSES", s_mc_message_t);
- handle_initial_addresses();
+ case MessageType::FORK:
+ assert_msg_size("FORK", s_mc_message_int_t);
+ handle_fork((s_mc_message_int_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::NEED_MEMINFO:
+ assert_msg_size("NEED_MEMINFO", s_mc_message_t);
+ handle_need_meminfo();
break;
case MessageType::ACTORS_STATUS:
if (not MC_is_active() || not need_memory_info_)
return;
+#if SIMGRID_HAVE_STATEFUL_MC
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");
+#else
+ xbt_die("Cannot really call ignore_heap() in non-SIMGRID_MC mode.");
+#endif
}
void AppSide::ignore_heap(void* address, std::size_t size) const
if (not MC_is_active() || not need_memory_info_)
return;
+#if SIMGRID_HAVE_STATEFUL_MC
const s_xbt_mheap_t* heap = mmalloc_get_current_heap();
s_mc_message_ignore_heap_t message = {};
}
xbt_assert(channel_.send(message) == 0, "Could not send ignored region to MCer");
+#else
+ xbt_die("Cannot really call ignore_heap() in non-SIMGRID_MC mode.");
+#endif
}
void AppSide::unignore_heap(void* address, std::size_t size) const
if (not MC_is_active() || not need_memory_info_)
return;
+#if SIMGRID_HAVE_STATEFUL_MC
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");
+#else
+ xbt_die("Cannot really call unignore_heap() in non-SIMGRID_MC mode.");
+#endif
}
void AppSide::declare_symbol(const char* name, int* value) const
return;
}
+#if SIMGRID_HAVE_STATEFUL_MC
s_mc_message_register_symbol_t message = {};
message.type = MessageType::REGISTER_SYMBOL;
xbt_assert(strlen(name) + 1 <= message.name.size(), "Symbol is too long");
message.callback = nullptr;
message.data = value;
xbt_assert(channel_.send(message) == 0, "Could send REGISTER_SYMBOL message to model-checker");
+#else
+ xbt_die("Cannot really call declare_symbol() in non-SIMGRID_MC mode.");
+#endif
}
/** Register a stack in the model checker
* when we analyze/compare the content of the heap so it must be told where
* they are with this function.
*/
+#if HAVE_UCONTEXT_H /* Apple don't want us to use ucontexts */
void AppSide::declare_stack(void* stack, size_t size, ucontext_t* context) const
{
if (not MC_is_active() || not need_memory_info_)
return;
+#if SIMGRID_HAVE_STATEFUL_MC
const s_xbt_mheap_t* heap = mmalloc_get_current_heap();
s_stack_region_t region = {};
message.type = MessageType::STACK_REGION;
message.stack_region = region;
xbt_assert(channel_.send(message) == 0, "Could not send STACK_REGION to model-checker");
+#else
+ xbt_die("Cannot really call declare_stack() in non-SIMGRID_MC mode.");
+#endif
}
+#endif
+
} // namespace simgrid::mc
