void Booster::sendDataToParent()
{
// Number of data items to be sent to
// the parent (launcher) process
const unsigned int NUM_DATA_ITEMS = 3;
struct iovec iov[NUM_DATA_ITEMS];
struct msghdr msg;
struct cmsghdr *cmsg;
char buf[CMSG_SPACE(sizeof(int))];
// Signal the parent process that it can create a new
// waiting booster process and close write end
const char booster = boosterType();
iov[0].iov_base = const_cast<char *>(&booster);
iov[0].iov_len = sizeof(char);
// Send to the parent process pid of invoker for tracking
pid_t pid = invokersPid();
iov[1].iov_base = &pid;
iov[1].iov_len = sizeof(pid_t);
// Send to the parent process booster respawn delay value
int delay = m_appData->delay();
iov[2].iov_base = &delay;
iov[2].iov_len = sizeof(int);
msg.msg_iov = iov;
msg.msg_iovlen = NUM_DATA_ITEMS;
msg.msg_name = NULL;
msg.msg_namelen = 0;
// Set special control fields if exit status of the launched
// application is needed. In this case we want to give the fd of the
// invoker <-> booster socket connection to the parent process (launcher)
// so that it can send the exit status back to invoker. It'd be impossible
// from the booster process if exec() was used.
if (m_connection->isReportAppExitStatusNeeded())
{
// Send socket file descriptor to parent
int fd = m_connection->getFd();
msg.msg_control = buf;
msg.msg_controllen = sizeof(buf);
cmsg = CMSG_FIRSTHDR(&msg);
cmsg->cmsg_level = SOL_SOCKET;
cmsg->cmsg_type = SCM_RIGHTS;
cmsg->cmsg_len = CMSG_LEN(sizeof(int));
memcpy(CMSG_DATA(cmsg), &fd, sizeof(int));
}
else
{
msg.msg_control = NULL;
msg.msg_controllen = 0;
}
if (sendmsg(boosterLauncherSocket(), &msg, 0) < 0)
{
Logger::logError("Booster: Couldn't send data to launcher process\n");
}
}
void Booster::initialize(int initialArgc, char ** initialArgv, int newBoosterLauncherSocket,
int socketFd, SingleInstance * singleInstance,
bool newBootMode)
{
m_bootMode = newBootMode;
setBoosterLauncherSocket(newBoosterLauncherSocket);
// Drop priority (nice = 10)
pushPriority(10);
// Preload stuff
if (!m_bootMode)
preload();
// Rename process to temporary booster process name
std::string temporaryProcessName = "booster [";
temporaryProcessName += boosterType();
temporaryProcessName += "]";
const char * tempArgv[] = {temporaryProcessName.c_str()};
renameProcess(initialArgc, initialArgv, 1, tempArgv);
// Restore priority
popPriority();
while (true)
{
// Wait and read commands from the invoker
Logger::logDebug("Booster: Wait for message from invoker");
if (!receiveDataFromInvoker(socketFd))
throw std::runtime_error("Booster: Couldn't read command\n");
// Run process as single instance if requested
if (m_appData->singleInstance())
{
// Check if instance is already running
SingleInstancePluginEntry * pluginEntry = singleInstance->pluginEntry();
if (pluginEntry)
{
if (!pluginEntry->lockFunc(m_appData->appName().c_str()))
{
// Try to activate the window of the existing instance
if (!pluginEntry->activateExistingInstanceFunc(m_appData->appName().c_str()))
{
Logger::logWarning("Booster: Can't activate existing instance of the application!");
m_connection->sendExitValue(EXIT_FAILURE);
}
else
{
m_connection->sendExitValue(EXIT_SUCCESS);
}
m_connection->close();
// invoker requested to start an application that is already running
// booster is not needed this time, let's wait for the next connection from invoker
continue;
}
// Close the single-instance plugin
singleInstance->closePlugin();
}
else
{
Logger::logWarning("Booster: Single-instance launch wanted, but single-instance plugin not loaded!");
}
}
//this instance of booster will be used to start application, exit from the loop
break;
}
// Send parent process a message that it can create a new booster,
// send pid of invoker, booster respawn value and invoker socket connection.
sendDataToParent();
// Give the process the real application name now that it
// has been read from invoker in receiveDataFromInvoker().
renameProcess(initialArgc, initialArgv, m_appData->argc(), m_appData->argv());
close(boosterLauncherSocket());
// close invoker socket connection
m_connection->close();
// Don't care about fate of parent applauncherd process any more
prctl(PR_SET_PDEATHSIG, 0);
}
