threads)
*/
-// Here a basic concept of how to add signal support to the scheduler:
-//
-// ... no, I had overlooked one race condition. So back to the signal-pipe approach ...
-
#include "Scheduler.hh"
//#include "Scheduler.ih"
// Custom includes
-#include "../Utils/senfassert.hh"
-#include <errno.h>
-#include <sys/epoll.h>
-#include <unistd.h>
-#include <fcntl.h>
-#include "../Utils/Exception.hh"
-#include "../Utils/Backtrace.hh"
-
-static const int EPollInitialSize = 16;
#define prefix_
///////////////////////////////cc.p////////////////////////////////////////
-prefix_ senf::Scheduler::Scheduler()
- : files_(0), timerIdCounter_(0), epollFd_ (epoll_create(EPollInitialSize)), terminate_(false),
- eventTime_(0), eventEarly_(ClockService::milliseconds(11)), eventAdjust_(0)
-{
- if (epollFd_<0)
- SENF_THROW_SYSTEM_EXCEPTION("::epoll_create()");
-
- if (::pipe(sigpipe_) < 0)
- SENF_THROW_SYSTEM_EXCEPTION("::pipe()");
-
- int flags (::fcntl(sigpipe_[1],F_GETFL));
- if (flags < 0)
- SENF_THROW_SYSTEM_EXCEPTION("::fcntl(F_GETFL)");
- flags |= O_NONBLOCK;
- if (::fcntl(sigpipe_[1], F_SETFL, flags) < 0)
- SENF_THROW_SYSTEM_EXCEPTION("::fcntl(F_SETFL)");
-
- ::epoll_event ev;
- ::memset(&ev, 0, sizeof(ev));
- ev.events = EV_READ;
- ev.data.fd = sigpipe_[0];
- if (::epoll_ctl(epollFd_, EPOLL_CTL_ADD, sigpipe_[0], &ev) < 0)
- SENF_THROW_SYSTEM_EXCEPTION("::epoll_ctl(EPOLL_CTL_ADD)");
-}
-
-prefix_ void senf::Scheduler::registerSignal(unsigned signal, SimpleCallback const & cb)
-{
- ::sigset_t sig;
- ::sigemptyset(&sig);
- if (::sigaddset(&sig, signal) < 0)
- throw InvalidSignalNumberException();
- ::sigprocmask(SIG_BLOCK, &sig, 0);
- ::sigaddset(&sigset_, signal);
- if (sigHandlers_.size() <= signal)
- sigHandlers_.resize(signal+1);
- sigHandlers_[signal] = cb;
-
- registerSigHandlers();
-}
-
-prefix_ void senf::Scheduler::unregisterSignal(unsigned signal)
-{
- if (::sigdelset(&sigset_, signal) < 0)
- throw InvalidSignalNumberException();
- sigHandlers_[signal] = 0;
- ::signal(signal, SIG_DFL);
- registerSigHandlers();
-}
-
-prefix_ void senf::Scheduler::do_add(int fd, FdCallback const & cb, int eventMask)
-{
- if (eventMask == 0)
- return;
-
- FdTable::iterator i (fdTable_.find(fd));
- int action (EPOLL_CTL_MOD);
- if (i == fdTable_.end()) {
- action = EPOLL_CTL_ADD;
- i = fdTable_.insert(std::make_pair(fd, EventSpec())).first;
- }
- else if (i->second.epollMask() == 0) {
- action = EPOLL_CTL_ADD;
- fdErase_.erase( std::remove(fdErase_.begin(), fdErase_.end(), unsigned(fd)),
- fdErase_.end() );
- }
-
- if (eventMask & EV_READ) i->second.cb_read = cb;
- if (eventMask & EV_PRIO) i->second.cb_prio = cb;
- if (eventMask & EV_WRITE) i->second.cb_write = cb;
-
- epoll_event ev;
- memset(&ev,0,sizeof(ev));
- ev.events = i->second.epollMask();
- ev.data.fd = fd;
-
- for (;;) {
- if ( (!i->second.file) && (epoll_ctl(epollFd_, action, fd, &ev) < 0) ) {
- switch (errno) {
- case EPERM :
- // Argh ... epoll does not support ordinary files :-( :-(
- i->second.file = true;
- ++ files_;
- return;
- case ENOENT :
- action = EPOLL_CTL_ADD;
- break;
- default:
- SENF_THROW_SYSTEM_EXCEPTION("::epoll_ctl()");
- }
- }
- else
- return;
- }
-}
-
-prefix_ void senf::Scheduler::do_remove(int fd, int eventMask)
-{
- if (eventMask == 0)
- return;
-
- FdTable::iterator i (fdTable_.find(fd));
- if (i == fdTable_.end())
- return;
-
- if (eventMask & EV_READ) i->second.cb_read = 0;
- if (eventMask & EV_PRIO) i->second.cb_prio = 0;
- if (eventMask & EV_WRITE) i->second.cb_write = 0;
-
- epoll_event ev;
- memset(&ev,0,sizeof(ev));
- ev.events = i->second.epollMask();
- ev.data.fd = fd;
-
- int action (EPOLL_CTL_MOD);
- bool file (i->second.file);
- if (ev.events==0) {
- action = EPOLL_CTL_DEL;
- fdErase_.push_back(fd);
- }
-
- if (! file && epoll_ctl(epollFd_, action, fd, &ev) < 0 && errno != ENOENT)
- SENF_THROW_SYSTEM_EXCEPTION("::epoll_ctl()");
- if (file)
- -- files_;
-}
-
-prefix_ void senf::Scheduler::registerSigHandlers()
-{
- for (unsigned signal (1); signal < sigHandlers_.size(); ++signal) {
- if (sigHandlers_[signal]) {
- struct ::sigaction sa;
- sa.sa_sigaction = & Scheduler::sigHandler;
- sa.sa_mask = sigset_;
- sa.sa_flags = SA_SIGINFO;
- if (signal == SIGCHLD)
- sa.sa_flags |= SA_NOCLDSTOP;
- if (::sigaction(signal, &sa, 0) < 0)
- SENF_THROW_SYSTEM_EXCEPTION("::sigaction()");
- }
- }
-}
-
-prefix_ void senf::Scheduler::sigHandler(int signal, ::siginfo_t * siginfo, void *)
-{
- // This is a bit unsafe. Better write single bytes and place the siginfo into an explicit
- // queue. Since signals are only unblocked during epoll_wait, we even wouldn't need to
- // synchronize access to that queue any further.
-
- ::write(instance().sigpipe_[1], siginfo, sizeof(*siginfo));
-
- // We ignore errors. The file handle is set to non-blocking IO. If any failure occurs (pipe
- // full), the signal will be dropped. That's like kernel signal handling which may also drop
- // signals.
-}
-
-prefix_ int senf::Scheduler::EventSpec::epollMask()
- const
-{
- int mask (0);
- if (cb_read) mask |= EPOLLIN;
- if (cb_prio) mask |= EPOLLPRI;
- if (cb_write) mask |= EPOLLOUT;
- return mask;
-}
-
prefix_ void senf::Scheduler::process()
{
terminate_ = false;
- eventTime_ = ClockService::now();
- while (! terminate_) {
-
- // Since a callback may have disabled further timers, we need to check for canceled timeouts
- // again.
-
- while (! timerQueue_.empty()) {
- TimerMap::iterator i (timerQueue_.top());
- if (! i->second.canceled)
- break;
- timerMap_.erase(i);
- timerQueue_.pop();
- }
-
- for (FdEraseList::iterator i (fdErase_.begin()); i != fdErase_.end(); ++i)
- fdTable_.erase(*i);
- fdErase_.clear();
-
- int timeout (-1);
- if (files_ > 0)
- timeout = 0;
- else {
- if (timerQueue_.empty()) {
- if (fdTable_.empty())
- break;
- }
- else {
- ClockService::clock_type delta (
- (timerQueue_.top()->second.timeout - eventTime_ + eventAdjust_)/1000000UL);
- timeout = delta < 0 ? 0 : delta;
- }
- }
-
- ///\todo Handle more than one epoll_event per call
- struct epoll_event ev;
-
- if (::sigprocmask(SIG_UNBLOCK, &sigset_, 0) < 0)
- SENF_THROW_SYSTEM_EXCEPTION("::sigprocmask(SIG_UNBLOCK)");
- int events (::epoll_wait(epollFd_, &ev, 1, timeout));
- if (::sigprocmask(SIG_BLOCK, &sigset_, 0) < 0)
- SENF_THROW_SYSTEM_EXCEPTION("::sigprocmask(SIG_BLOCK)");
-
- if (events<0)
- if (errno != EINTR)
- SENF_THROW_SYSTEM_EXCEPTION("::epoll_wait()");
-
- eventTime_ = ClockService::now();
-
- // We always run timeout handlers. This is important, even if a file-descriptor is signaled
- // since some descriptors (e.g. real files) will *always* be ready and we still may want to
- // handle timers. Time handlers are run before file events to not delay them unnecessarily.
-
- while (! timerQueue_.empty()) {
- TimerMap::iterator i (timerQueue_.top());
- if (i->second.canceled)
- ;
- else if (i->second.timeout <= eventTime_ + eventEarly_)
- i->second.cb();
- else
- break;
- timerQueue_.pop();
- timerMap_.erase(i);
- }
-
- // Check the signal queue
- if (events > 0 && ev.data.fd == sigpipe_[0]) {
- ::siginfo_t siginfo;
- if (::read(sigpipe_[0], &siginfo, sizeof(siginfo)) < int(sizeof(siginfo))) {
- // We ignore truncated records which may only occur if the signal
- // queue became filled up
- SENF_LOG((senf::log::IMPORTANT)("Truncated signal record!"));
- continue;
- }
- if (siginfo.si_signo < int(sigHandlers_.size()) && sigHandlers_[siginfo.si_signo])
- sigHandlers_[siginfo.si_signo]();
- continue;
- }
-
- for (FdTable::iterator i = fdTable_.begin(); i != fdTable_.end(); ++i) {
- EventSpec & spec (i->second);
-
- if (! (spec.file || (events > 0 && i->first == ev.data.fd)))
- continue;
-
- unsigned extraFlags (0);
- unsigned mask (spec.file ? spec.epollMask() : ev.events);
-
- if (mask & EPOLLHUP) extraFlags |= EV_HUP;
- if (mask & EPOLLERR) extraFlags |= EV_ERR;
-
- if (mask & EPOLLIN) {
- SENF_ASSERT(spec.cb_read);
- spec.cb_read(EventId(EV_READ | extraFlags));
- }
- else if (mask & EPOLLPRI) {
- SENF_ASSERT(spec.cb_prio);
- spec.cb_prio(EventId(EV_PRIO | extraFlags));
- }
- else if (mask & EPOLLOUT) {
- SENF_ASSERT(spec.cb_write);
- spec.cb_write(EventId(EV_WRITE | extraFlags));
- }
- else {
- // This branch is only taken, if HUP or ERR is signaled but none of IN/OUT/PRI.
- // In this case we will signal all registered callbacks. The callbacks must be
- // prepared to be called multiple times if they are registered to more than
- // one event.
- if (spec.cb_write)
- spec.cb_write(EventId(extraFlags));
- if (spec.cb_prio)
- spec.cb_prio(EventId(extraFlags));
- if (spec.cb_read)
- spec.cb_read(EventId(extraFlags));
- }
- }
+ while(! terminate_ && ! (fdDispatcher_.empty() &&
+ timerDispatcher_.empty() &&
+ fileDispatcher_.empty())) {
+ signalDispatcher_.unblockSignals();
+ timerDispatcher_.unblockSignals();
+ manager_.processOnce();
+ timerDispatcher_.blockSignals();
+ signalDispatcher_.blockSignals();
+ fileDispatcher_.prepareRun();
+ runner_.run();
}
}
projects / senf.git / blobdiff