inline const char *add_to_process_id_name(const char *name)
{
static std::string str;
get_process_id_name(str);
str += name;
return str.c_str();
}
int robust_mutex_test(int argc, char *argv[])
{
try {
if(argc == 1) { //Parent process
//First usual mutex tests
{
// test_all_lock<RobustMutex>();
// test_all_mutex<true, RobustMutex>();
}
std::cout << "robust mutex recovery test" << std::endl;
//Remove shared memory on construction and destruction
class shm_remove
{
public:
shm_remove() {
shared_memory_object::remove
(::boost::interprocess::test::get_process_id_name());
}
~shm_remove() {
shared_memory_object::remove
(::boost::interprocess::test::get_process_id_name());
}
} remover;
//Construct managed shared memory
managed_shared_memory segment(create_only, get_process_id_name(), 65536);
//Create two robust mutexes
RobustMutex *instance = segment.construct<RobustMutex>
("robust mutex")[2]();
//Create a flag to notify that both mutexes are
//locked and the owner is going to die soon.
bool *go_ahead = segment.construct<bool> ("go ahead")(false);
//Launch child process
std::string s(argv[0]);
s += " child ";
s += get_process_id_name();
std::cout << "... launching child" << std::endl;
if(0 != std::system(s.c_str()))
return 1;
//Wait until child locks the mutexes and dies
while(!*go_ahead) {
detail::thread_yield();
}
std::cout << "... recovering mutex[0]" << std::endl;
//First try to recover lock[0], put into consistent
//state and relock it again
{
//Done, now try to lock it to see if robust
//mutex recovery works
instance[0].lock();
if(!instance[0].previous_owner_dead())
return 1;
instance[0].consistent();
instance[0].unlock();
//Since it's consistent, locking is possible again
instance[0].lock();
instance[0].unlock();
}
//Now with lock[1], but dont' put it in consistent state
//so the mutex is no longer usable
std::cout << "... recovering mutex[1]" << std::endl;
{
//Done, now try to lock it to see if robust
//mutex recovery works
instance[1].lock();
if(!instance[1].previous_owner_dead())
return 1;
//Unlock a recovered mutex without putting it into
//into consistent state marks mutex as unusable.
instance[1].unlock();
//Since it's NOT consistent, locking is NOT possible again
bool exception_thrown = false;
try {
instance[1].lock();
}
catch(interprocess_exception &) {
exception_thrown = true;
}
if(!exception_thrown) {
return 1;
}
}
//Now with lock[2], this was locked by child but not
//unlocked
std::cout << "... recovering mutex[2]" << std::endl;
{
//Done, now try to lock it to see if robust
//mutex recovery works
instance[2].lock();
if(!instance[2].previous_owner_dead())
return 1;
//Unlock a recovered mutex without putting it into
//into consistent state marks mutex as unusable.
instance[2].unlock();
//Since it's NOT consistent, locking is NOT possible again
bool exception_thrown = false;
try {
instance[2].lock();
}
catch(interprocess_exception &) {
exception_thrown = true;
}
if(!exception_thrown) {
return 1;
}
}
}
else {
//Open managed shared memory
managed_shared_memory segment(open_only, argv[2]);
//Find mutexes
RobustMutex *instance = segment.find<RobustMutex>("robust mutex").first;
assert(instance);
if(std::string(argv[1]) == std::string("child")) {
std::cout << "launched child" << std::endl;
//Find flag
bool *go_ahead = segment.find<bool>("go ahead").first;
assert(go_ahead);
//Lock, flag and die
bool try_lock_res = instance[0].try_lock() && instance[1].try_lock();
assert(try_lock_res);
if(!try_lock_res)
return 1;
bool *go_ahead2 = segment.construct<bool>("go ahead2")(false);
assert(go_ahead2);
//Launch grandchild
std::string s(argv[0]);
s += " grandchild ";
s += argv[2];
std::cout << "... launching grandchild" << std::endl;
if(0 != std::system(s.c_str())) {
std::cout << "launched terminated with error" << std::endl;
return 1;
}
//Wait until child locks the 2nd mutex and dies
while(!*go_ahead2) {
detail::thread_yield();
}
//Done, now try to lock number 3 to see if robust
//mutex recovery works
instance[2].lock();
if(!instance[2].previous_owner_dead()) {
return 1;
}
*go_ahead = true;
}
else {
std::cout << "launched grandchild" << std::endl;
//grandchild locks the lock and dies
bool *go_ahead2 = segment.find<bool>("go ahead2").first;
assert(go_ahead2);
//Lock, flag and die
bool try_lock_res = instance[2].try_lock();
assert(try_lock_res);
if(!try_lock_res) {
return 1;
}
*go_ahead2 = true;
}
}
} catch(...) {
std::cout << "Exception thrown error!" << std::endl;
throw;
}
return 0;
}
inline const char *get_process_id_name()
{
static std::string str;
get_process_id_name(str);
return str.c_str();
}